Energy Network Indicators

Each year, network companies must report on their performance and outputs under Ofgem’s RIIO (Revenue = Incentives + Innovation + Outputs) network price controls. To ensure value for money for consumers, the price controls limit the amount by which network costs can rise and stipulate levels of performance. These network indicators give a snapshot of our monitoring.

Our network indicators

Select a sector from the below to view our network indicators in detail and for an overview of our monitoring themes.

If you have feedback on the indicators, please contact us

    Network highlights at December 2017

    The 2016/2017 annual reports for network company performance under RIIO show that they are performing well for customers. The companies are meeting or on track to meet most of their targets.

    • In 2016/17 the number of power cuts across GB reduced by 3% compared with 2015/16, however the duration of power cuts increased by 1%. Overall the number and length of power cuts has almost halved since 2002.
    • Customer service continues to improve with the majority of network companies meeting or beating customer service targets in 2016/17. Scores in both electricity distribution and gas distribution currently stand at 8.8 out of 10.
    • In 2016/2017 electricity distribution and electricity transmission network companies reduced the carbon footprint of their networks compared with 2015/2016.
    • By 2016/2017 gas distribution networks had connected over 52,000 fuel poor homes to the gas grids since the start of the price control in 2013.
    • Most of the companies are underspending their allowances. Traditionally their spending increases further into the price control when they deliver large, capital-intensive projects. Ofgem requires the companies to share savings from underspending with customers.

    So far, since the start of RIIO in 2013 Ofgem has secured additional savings of over £5 billion for consumers by a combination of reduced revenues or voluntary contributions from companies. 

    What do the network companies report on?

    The RIIO price controls are designed to encourage network companies to play a full role in delivering a sustainable energy sector, and to do so in a way that brings consumers value for money. Under RIIO, each company has to deliver and report on a range of outputs:

    • Reliability: We expect companies to improve network reliability and reduce the number and duration of power interruptions.
    • Connections: Companies will provide a better service for customers wanting to connect to the network.
    • Customer Service: We incentivise companies to deliver good customer service and listen to stakeholders.
    • Social Obligations: Companies will do more to help vulnerable customers, particularly during power interruptions.
    • Environmental: Companies must reduce their carbon emissions and other environmental impacts.
    • Safety: Companies are funded to ensure the network remains safe and meets Health and Safety Executive standards.

    You can find out more at: The energy network: how it works for you

    All electricity transmission charts and data (RIIO-T1)

    There are three electricity transmission network ownersopen key term pop-up. They operate the high voltage network carrying electricity across GB. 

    The RIIO-T1 price control runs from 1 April 2013 to 31 March 2021. The data presented here gives a snapshot of the network owners’ financial performance and their performance against key RIIO-T1 outputs for consumers.

    Chart

    Source: RIIO electricity transmission annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of customer satisfaction with electricity transmission owners under the RIIO-T1 price control. It shows three scores comprising customer satisfaction over the four completed years of the price control.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Electricity - transmission

    Data Table

    Customer satisfaction with network owners: Electricity transmission (RIIO-T1)

    Network ownersYear 1 stakeholder engagement incentive reward scoreYear 2 stakeholder engagement incentive reward scoreYear 3 stakeholder engagement incentive reward scoreYear 4 stakeholder engagement incentive reward scoreYear 1 stakeholder survey scoreYear 2 stakeholder survey scoreYear 3 stakeholder survey scoreYear 4 stakeholder survey scoreYear 1 customer survey score (NGET only)Year 2 customer survey score (NGET only)Year 3 customer survey score (NGET only)Year 4 customer survey score (NGET only)
    National Grid Electricity Transmission5.7566.2577.537.747.537.77.417.47.547.4
    Scottish Power Transmission4.95.56.256.257.47.16.97.9
    Scottish Hydro Electricity Transmission5.4665.46.57.78.28.7

    More information

    Customer satisfaction with network owners: At-a-glance summary

    • The stakeholder survey score for all companies was up from the value reported last year. 
    • National Grid Electricity Transmission reported a strong customer survey score in 2016/17, but at a slightly lower score than 2015/16 level.

    Relevance and further information

    • We want electricity transmission network owners to understand consumers’ needs and proactively engage with them to make sure these are met.
    • Network owners receive an annual financial reward or penalty based on their survey scores. Rewards can be up to 0.5% of annual revenues per company.
    • There is also a stakeholder engagement incentive discretionary reward, which is an annual panel assessment of stakeholder engagement. 

    Methodology

    For the customer and stakeholder satisfaction surveys incentive, companies may be rewarded or penalised depending on their performance against the targets set. The methodology for this incentive is outlined in the network owner’s licence conditions.

    Ofgem and an independent panel of experts conduct the assessment for the stakeholder engagement incentive.

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    Chart

    Source: RIIO electricity transmission annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of company performance on network connections delivered on time under the four completed years of the RIIO-T1 price control. 

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Electricity - transmission

    Data Table

    Network connections by transmission owners: Electricity transmission (RIIO-T1)

    Year 1 not on timeYear 1 on timeYear 2 not on timeYear 2 on timeYear 3 not on timeYear 3 on timeYear 4 not on timeYear 4 on time
    National Grid Electricity Transmission0139023502800187
    Scottish Power Transmission2502860116063
    Scottish Hydro Electricity Transmission047098088059

    More information

    Network connections by transmission owners: At-a-glance summary

    In 2016/17 a total of 309 applications were submitted from parties seeking to connect to the electricity transmission network, all of which were delivered on time.

    Relevance and further information

    Electricity transmission owners are required to deliver timely and effective connections to the network.

    Under the price control, we expect companies to provide a good service for customers wanting to connect to the network.

    Methodology

    Each year, network companies must report on their performance under the RIIO-T1 price control. Our review of their submissions and supporting information informs our annual publications on network company performance.

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    Chart

    Source: RIIO electricity transmission annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of company performance on reliability and availability of energy. It shows the volume of electricity not supplied by electricity transmission owners. ‘Energy not supplied’ means the volume of energy to customers that is lost as a result of faults or failures on the network.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Electricity - transmission

    Data Table

    Volume of energy not supplied: Electricity transmission (RIIO-T1)

    Year 1 actualYear 1 targetYear 2 actualYear 2 targetYear 3 actualYear 3 targetYear 4 actualYear 4 target
    National Grid Electricity Transmission1353168.73164.53166.8316
    Scottish Power Transmission42.22252.822513.922510.3225
    Scottish Hydro Electricity Transmission35.6120106.112001204.4120

    More information

    Volume of energy not supplied: At-a-glance summary

    • All three transmission operators have significantly outperformed their targets in year four (2016-17) of the RIIO-T1 price control.

    Relevance and further information

    • Ofgem sets targets for each transmission owners’ level of energy not supplied.
    • Under the price control, we expect companies to maintain network reliability and reduce the number and duration of power cuts.

    Methodology

    Each year, network companies must report on their performance under the RIIO-T1 price control. Our review of their submissions and supporting information informs our annual publications on network company performance.

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    Chart

    Source: RIIO electricity transmission annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of environmental impact. It shows company performance against an emissions reduction target electricity transmission owners must deliver for consumers under RIIO-T1.

     We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Electricity - transmission

    Data Table

    Sulphur Hexafluoride (SF6) emissions: Electricity transmission (RIIO-T1)

    Year 1 actual emissionsYear 1 target emissionsYear 2 actual emissionsYear 2 target emissionsYear 3 actual emissionsYear 3 target emissionsYear 4 actual emissionsYear 4 target emissions
    National Grid Electricity Transmission1011011,933954412,035950212,0971079512242
    Scottish Power Transmission729.5573.3494.6591.8441618.9388707
    Scottish Hydro Electricity Transmission335.27150.7339.2173.1272.26223.6253253

    More information

    Sulphur Hexafluoride (SF6) emissions: At-a-glance summary

    • In 2016/17, both National Grid Electricity Transmission and Scottish Power Transmission outperformed against their target emissions levels for SF6.
    • Scottish Hydro Electricity  Transmission's leakage rate is, again above the target figure and will therefore be penalised under the incentive mechanism, although the level is marginal. 
    • Scottish Hydro Electricity  Transmission and Scottish Power Transmission reported a reduction in SF6 leakage from the previous year. 

    Relevance and further information

    • SF6 is an extremely effective electrical insulator and so is used in high-voltage switchgear and other electrical equipment. It is also a potent greenhouse gas.
    • Electricity transmission owners are incentivised to limit their emissions of SF6. Ofgem target levels of emissions that we expect companies to beat. 

    Methodology

    Each year, network companies must report on their performance under the RIIO-T1 price control. Our review of their submissions and supporting information informs our annual publications on network company performance.

    close

    Chart

    Source: RIIO electricity transmission annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of financial performance. It shows our estimates of electricity transmission owners’ return on regulatory equity (RoRE). It is our current view of an eight-year average RoRE over RIIO-T1.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Electricity - transmission

    Data Table

    Return on regulatory equity: Electricity transmission (RIIO-T1)

    Network companiesCurrent eight-year view
    National Grid Electricity Transmission9.28%
    National Grid Electricity Transmission (excl. System Operator)8.63%
    Scottish Hydro Electricity Transmission10.07%
    Scottish Power Transmission9.87%

    More information

    Return on regulatory equity (RoRE): At-a-glance summary

    • RoRE across the sector is 9.49%
    • It ranges from 9.28% for National Grid Electricity Transmission to 10.07% for Scottish Hydro Electricity Transmission.
    • The baseline is 7.0%.

    Relevance and further info

    • RoRE helps us monitor the financial performance of network companies under the price control.
    • RoRE should be compared to the cost of equity allowed at the start of the price control. For all electricity transmission owners, this was 7.0%
    • No electricity transmission owners are forecast to earn returns below their cost of equity.
    • The numbers include the impact of the Mid-Period Review and National Grid’s voluntary deferral.

    Methodology

    • Our RoRE calculation is based on a mix of the first four years' performance, company forecasts and simple averages.
    • There are a number of factors not reflected in our RoRE calculations which may impact the return realised by shareholders. The largest is potential clawbacks for non-delivery of outputs.
    • Our calculation assumes all outputs will be delivered.
    • Returns may not equal the actual returns seen by shareholders.
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    Chart

    Javascript is required to render chart Expenditure vs allowance: Electricity transmission (RIIO-T1).

    Source: RIIO electricity transmission annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of financial performance. It compares electricity transmission owners’ realised total expenditure for their regulated business activities against their allowance for each year of the RIIO-T1 network price control.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Electricity - transmission

    Data Table

    Expenditure vs allowance: Electricity transmission (RIIO-T1)

    Network companiesYear 1 expenditureYear 1 allowanceYear 2 expenditureYear 2 allowanceYear 3 expenditureYear 3 allowanceYear 4 expenditureYear 4 allowance
    National Grid Electricity Transmission (TO only)1.51.91.11.71.21.41.11.3
    Scottish Power Transmission0.30.40.30.50.40.40.30.2
    Scottish Hydro Electricity Transmission0.20.20.30.40.50.80.50.7

    More information

    Expenditure vs allowance: At-a-glance summary

    • National Grid Electricity Transmission (TO only) and Scottish Hydro Electricity Transmission both report total expenditure below the annual revenue allowance in 2016-17. National Grid Electricity Transmission reported an underspend of £0.2 billion (14%) and Scottish Hydro Electricity Transmission reported an underspend of £0.2 billion (34%).
    • Scottish Power Transmission reported a total expenditure of £0.1 billion above their annual revenue allowance in 2016-17.  Scottish Power Transmission explains that this largely reflects the MPR decision, changes in project delivery profiles and also the changes to the timing of windfarm connections.

    Relevance and further information

    • This chart is an indicator of company financial performance against cost allowances for the first four years of RIIO-T1.
    • We set the total amount each company can spend ahead of the price control (company ‘allowances’) and monitor their actual spend (‘total expenditure’) against these amounts annually.
    • Network companies are allowed to retain a part of any savings achieved, with the rest being passed on to consumers.

    Methodology

    Each year, network companies must report on their performance under the RIIO-T1 price control. Our review of their submissions and supporting information informs our annual publications on network company performance.

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    Chart

    Javascript is required to render chart Estimated network costs per domestic customer (GB average).

    Source: Ofgem analysis of network companies’ cost information .

    Information correct as of: December 2017

    This chart shows our estimate of trends in the annual cost of the different components of network charges for a domestic customer with a fixed amount of consumption. Balancing Services Use of System charges are not included in the chart.

    Click the ‘more information’ tab above for a summary of the latest trends, an explanation of network costs and for further detail on how we calculate the costs.

    Policy Areas:

    • Electricity - distribution
    • Electricity - transmission
    • Gas - distribution
    • Gas - transmission

    Data Table

    Estimated network costs per domestic customer (GB average)

    Annualised network costsElectricity (transmission)Electricity (distribution)Gas (transmission)Gas (distribution)
    Apr-14279410110
    May-14279410110
    Jun-14279410110
    Jul-14279410110
    Aug-14279410110
    Sep-14279410110
    Oct-14279410110
    Nov-14279410110
    Dec-14279410110
    Jan-15279410110
    Feb-15279410110
    Mar-15279410110
    Apr-1532879114
    May-1532879114
    Jun-1532879114
    Jul-1532879114
    Aug-1532879114
    Sep-1532879114
    Oct-1532879114
    Nov-1532879114
    Dec-1532879114
    Jan-1632879114
    Feb-1632879114
    Mar-1632879114
    Apr-1638939116
    May-1638939116
    Jun-1638939116
    Jul-1638939116
    Aug-1638939116
    Sep-1638939116
    Oct-1638939116
    Nov-1638939116
    Dec-1638939116
    Jan-1738939116
    Feb-1738939116
    Mar-1738939116
    Apr-1738869113
    May-1738869113
    Jun-1738869113
    Jul-1738869113
    Aug-1738869113
    Sep-1738869113
    Oct-1738869113
    Nov-1738869113
    Dec-1738869113
    Jan-1838869113
    Feb-1838869113
    Mar-1838869113
    Apr-1837839118
    May-1837839118
    Jun-1837839118
    Jul-1837839118
    Aug-1837839118
    Sep-1837839118
    Oct-1837839118
    Nov-1837839118
    Dec-1837839118
    Jan-1937839118
    Feb-1937839118
    Mar-1937839118

    More information

    Estimated network costs per domestic customer: At-a-glance summary

    • The majority of network costs for a domestic customer are for the use of the gas and electricity distribution networks.
    • For a household whose consumption does not change, on average across GB we expect network costs in 2018/19 to increase for gas distribution, decrease for electricity distribution, and stay broadly static for transmission costs compared to the previous charging year.
    • Actual costs will vary depending on where a customer lives, how much energy they use, and what type of meter they have.

    What are network costs?

    Suppliers are charged for the costs to build, maintain, improve and operate the energy networks. Most of the networks are owned by monopoly businesses. Therefore through regulation, we limit the revenue that these companies can recover from customer charges to run the networks.

    The network charges paid by suppliers vary depending on where their customers live, what type of meter they have, when energy is used and how much energy they use. In total, these charges accounted for approximately a quarter of a dual fuel bill in 2016.

    Different charges apply for the high voltage/pressure transmission networks (which take electricity and gas around Great Britain) and the lower voltage/pressure distribution networks, which connect customers to the overall networks.

    As well as the charges to suppliers that are considered here, electricity generators and gas producers are also charged for their use of the networks. It is important to note that trends in network costs will therefore also affect supplier costs indirectly through wholesale prices.

    Methodology

    • Network costs are calculated by combining charging information published by the network companies with assumptions about consumption and losses for domestic customers.
    • All costs are calculated for medium annual typical domestic consumption values of 12,000kWh for gas and 3,100kWh of electricity, which is held fixed across the charging years. The actual network costs a supplier incurs to serve a customer will depend on how much energy is used, the timing of its use as well as the charges that apply from one year to the next.
    • The costs shown are GB averages, calculated by taking a customer number weighted average of the tariffs that apply in different regions of the country.
    • The costs are expressed in nominal money (i.e. the amount of money a customer ‘pays over the counter’), rather than in real terms (i.e. after adjusting for inflation). For electricity, the costs reported are for a standard unrestricted meter.
    • Balancing Services Use of System charges are not included on the chart. These charges cover the cost of services used to balance the electricity system and internal system operator operating costs.

    The methodology we use to calculate these charges is consistent with our methodology for the Supplier Cost Index, and that used to set the value of the prepayment meter price cap. Further details on the calculations are available in our Supplier Cost Index methodology.

    Further information

    You can find further information on the different components making up an energy bill at Understand your gas and electricity bill.

    To see how the network fits together, visit The energy network: How it works for you.

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    All electricity distribution charts and data (RIIO-ED1)

    There are 14 electricity distribution network operatorsopen key term pop-up, owned by six ownership groups. They operate the low voltage electricity network, taking energy from the transmission system to homes and businesses.

    The RIIO-ED1 price control runs from 1 April 2015 to 31 March 2023. The data presented here gives a snapshot of the network owners' financial performance and their performance against key outputs for consumers.

    Chart

    Source: RIIO electricity distribution annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of customer satisfaction with electricity distribution operators under the RIIO-ED1 price control. Distribution network operators are scored against three broad measures of customer service: customer satisfaction (the 'customer survey score'), stakeholder engagement and complaints handling. This chart shows performance against two of those scores for the second year of the price control. Performance against the complaints handling metric is detailed in the RIIO-ED1 annual report.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

     

    Policy Areas:

    • Electricity - distribution

    Data Table

    Customer satisfaction with network operators: Electricity distribution (RIIO-ED1)

    Distribution network operatorStakeholder engagement incentive reward scoreCustomer survey score
    Electricity North West6.388.32
    Northern Powergrid6.58.64
    Western Power Distribution8.538.91
    UK Power Networks7.538.64
    SP Energy Networks6.288.73
    Scottish & Southern Electricity Networks5.238.6

    More information

    Customer satisfaction with network operators: At-a-glance summary

    • The performance of each distribution network operator group varies across the three broad measures of customer service elements, but overall performance has improved since the DPCR5 price control.
    • Western Power Distribution performs best across all three measures, while Scottish and Southern Electricity Networks and Electricity Northwest Ltd have most room for improvement.

    Relevance and further information

    We want distribution network operators to understand consumers’ needs and proactively engage with them to make sure these are met.

    There is a financial incentive that encourages distribution network operators to deliver good customer service.  It consists of three elements:

    • customer satisfaction
    • complaints handling
    • stakeholder engagement.

    Methodology

    We set targets, with associated penalties and rewards, for customer satisfaction and complaints.

    Ofgem and an independent panel of experts conduct the assessment for the stakeholder engagement incentive.

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    Chart

    Source: RIIO electricity distribution annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of the reliability and availability of the electricity distribution network. It shows the number of interruptions experienced by customers and the average length of interruptions.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Electricity - distribution

    Data Table

    Customer interruptions and minutes lost: Electricity distribution (RIIO-ED1)

    Target for customers interruptedActual number of customers interrupted Target average minutes lost per customer per year Actual average minutes lost per customer per year
    Electricity North West 48.03 32.90 45.83 33.71
    Northern Powergrid 65.13 50.91 62.86 41.50
    Western Power Distribution 62.95 49.30 42.48 29.84
    UK Power Networks 53.68 37.95 47.44 31.37
    SP Energy Networks 44.98 40.53 44.96 33.33
    Scottish and Southern Electricity Networks 66.38 57.96 57.58 51.59

    More information

    Customer interruptions and minutes lost: At-a-glance summary

    • Some network operators missed individual parts of the targets but for all network operator groups the overall score exceeded their overall targets in 2016-17 despite more challenging weather conditions. 
    • Customer interruptions were lowest for Electricity Northwest Ltd and highest for Scottish and Southern Electricity Networks.
    • Customer minutes lost were lowest for Western Power Distribution and highest for Scottish and Southern Electricity Networks.

    Relevance and further information

    • Distribution network operators invest in their network to increase reliability and resilience against severe weather and to protect the network from the effects of climate change.
    • We incentivise distribution network operators to improve the reliability on their network, penalising underperformance and rewarding those who beat their targets.

    Methodology

    We set annual targets for customer interruptions and customer minutes lost.  Each year distribution network operators must report on their performance under the RIIO-ED1 price control. This allows us to assess if targets have been met and to reward or penalise network operators appropriately. 

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    Chart

    Source: RIIO electricity distribution annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of network operator performance on connections to the electricity distribution network. It shows the average time to connect (TTC) for single service low voltage (LVSSA) connections and small project demand (LVSSB) connections. It compares these to the targets set in 2013.

    We update this chart on an annual basis. Click the ‘more information’ tab above for details of how to interpret the figures and for information on methodology 

    Policy Areas:

    • Electricity - distribution

    Data Table

    Average time to connect to the network: Electricity distribution (RIIO-ED1)

    Distribution network operatorsLVSSA targetLVSSA (2016/17)LVSSB targetLVSSB (2016/17)
    Electricity North West42.0831.9152.731.67
    Northern Powergrid42.0848.9752.756.77
    Western Power Distribution42.0835.4752.744.8
    UK Power Networks42.0855.5752.763.88
    SP Energy Networks42.0848.1852.761.86
    Scottish & Southern Electricity Networks42.0837.1452.752.06

    More information

     Average time to connect to the distribution network: At-a-glance summary

    • All distribution network groups reduced their time to connect (TTC) since the targets were set, but in 2016-17 eight of the fourteen DNOs did not meet the TTC targets we set.
    • Average TTC across both connection types was lowest for Electricity North West Ltd and highest for UK Power Networks.

    Relevance and further info

    Under RIIO, each company has to deliver a range of outputs, which they are required to report on each year. This chart provides us with an indicator of network performance against connections.

    Methodology

    Each year, network companies must report on their performance under the RIIO-ED1 price control. Our review of their submissions and supporting information informs our annual publications on network company performance.

    close

    Chart

    Source: RIIO electricity distribution annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of environmental impact. It shows the length of overhead lines removed in National Parks, Areas of Outstanding Natural Beauty and National Scenic Areas. In RIIO-ED1, each distribution network operator is able to recover a defined amount of funding to pay for undergrounding of network cables in these designated areas.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Electricity - distribution

    Data Table

    Undergrounding of overhead lines: Electricity distribution (RIIO-ED1)

    Distribution network operatorsLength of installations (km)Total expenditure (GBP £ million)
    Electricity North West12.210.94
    Northern Powergrid12.522.84
    Western Power Distribution8.590.59
    UK Power Networks3.650.53
    SP Energy Networks1.620.35
    Scottish & Southern Electricity Networks6.970.69

    More information

    Undergrounding of overhead lines: At-a-glance summary

    In 2016-17 approximately 46km of overhead lines were removed by the distribution network operators at a cost of £6 million.

    Relevance and further information

    Undergrounding reduces the visual impact of overhead lines on the environment. This contributes towards the environment output the distribution network operators must deliver for customers.  

    Methodology

    Allowances are calculated to reflect stakeholder interest in visual amenity and each network operator’s funding is based on the amount of its network in Areas of Outstanding Natural Beauty and National Parks.

    Each year, distribution network operators must report on expenditure and activity related to undergrounding. This allows us to determine if they are meeting stakeholder requirements.

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    Chart

    Source: RIIO electricity distribution annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of financial performance. It shows our estimates of electricity distribution network operators’ return on regulatory equity (RoRE). It is our current view of an eight-year average RoRE over RIIO-ED1.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Electricity - distribution

    Data Table

    Return on regulatory equity: Electricity distribution (RIIO-ED1)

    Distribution OperatorsCurrent eight year view
    ENWL9.27%
    NPg8.22%
    WPD9.90%
    UKPN11.37%
    SPEN7.14%
    SSEN8.85%

    More information

    Return on regulatory equity (RoRE): At-a-glance summary

    • RoRE across the sector is 9.45%,
    • It ranges from 7.14% for Scottish Power Energy Networks to 11.37% for UK Power Networks.

    Relevance and further information

    • RoRE helps us monitor the financial performance of distribution network operators under the price control.
    • RoRE should be compared to the cost of equity allowed at the start of the price control. The Western Power Distribution group was allowed 6.4% and the remaining five groups 6.0%.
    • No distribution network operators are forecast to earn returns below their cost of equity.

    Methodology

    • Our RoRE calculation is based on a mix of first year performance, company forecasts and simple averages.
    • There are a number of factors not reflected in our RoRE calculations which may impact the return realised by shareholders. The largest being potential clawbacks for non-delivery of outputs.
    • Our calculation assumes all outputs will be delivered.
    • Returns may not equal the actual returns seen by shareholders.
    close

    Chart

    Source: RIIO electricity distribution annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of financial performance. It compares electricity distribution operators’ realised total expenditure for their regulated business activities against their allowance for the first year of the RIIO-ED1 network price control.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Electricity - distribution

    Data Table

    Expenditure vs allowance: Electricity distribution (RIIO-ED1)

    Distribution network operatorsYear 1 expenditureYear 1 allowanceYear 2 expenditureYear 2 allowance
    Electricity North West249256211244
    Northern Powergrid447459408441
    Western Power Distribution10069821046979
    UK Power Networks657870722899
    SP Energy Networks440477469486
    Scottish & Southern Electricity Networks441505483513

    More information

    Expenditure vs allowance: At-a-glance summary

    • Five of the six distribution network operator groups underspent their allowances in 2016/17.
    • Underspend was greatest for UK Power Networks.
    • Only Western Power Distribution overspent on its allowances.

    Relevance and further information

    • This chart is an indicator of company financial performance against cost allowances for the first and second years of the RIIO-ED1 price control period.
    • We set the total amount each company can spend ahead of the price control (company ‘allowances’) and monitor their actual spend (‘total expenditure’) against these amounts annually.
    • Network companies are allowed to retain a part of any savings achieved, with the rest being passed on to consumers.

    Methodology

    Each year, distribution network operators must report on their performance under the RIIO-ED1 price control. Our review of their submissions and supporting information informs our annual publications on distribution network operator financial performance. 

    close

    Chart

    Javascript is required to render chart Estimated network costs per domestic customer (GB average).

    Source: Ofgem analysis of network companies’ cost information .

    Information correct as of: December 2017

    This chart shows our estimate of trends in the annual cost of the different components of network charges for a domestic customer with a fixed amount of consumption. Balancing Services Use of System charges are not included in the chart.

    Click the ‘more information’ tab above for a summary of the latest trends, an explanation of network costs and for further detail on how we calculate the costs.

    Policy Areas:

    • Electricity - distribution
    • Electricity - transmission
    • Gas - distribution
    • Gas - transmission

    Data Table

    Estimated network costs per domestic customer (GB average)

    Annualised network costsElectricity (transmission)Electricity (distribution)Gas (transmission)Gas (distribution)
    Apr-14279410110
    May-14279410110
    Jun-14279410110
    Jul-14279410110
    Aug-14279410110
    Sep-14279410110
    Oct-14279410110
    Nov-14279410110
    Dec-14279410110
    Jan-15279410110
    Feb-15279410110
    Mar-15279410110
    Apr-1532879114
    May-1532879114
    Jun-1532879114
    Jul-1532879114
    Aug-1532879114
    Sep-1532879114
    Oct-1532879114
    Nov-1532879114
    Dec-1532879114
    Jan-1632879114
    Feb-1632879114
    Mar-1632879114
    Apr-1638939116
    May-1638939116
    Jun-1638939116
    Jul-1638939116
    Aug-1638939116
    Sep-1638939116
    Oct-1638939116
    Nov-1638939116
    Dec-1638939116
    Jan-1738939116
    Feb-1738939116
    Mar-1738939116
    Apr-1738869113
    May-1738869113
    Jun-1738869113
    Jul-1738869113
    Aug-1738869113
    Sep-1738869113
    Oct-1738869113
    Nov-1738869113
    Dec-1738869113
    Jan-1838869113
    Feb-1838869113
    Mar-1838869113
    Apr-1837839118
    May-1837839118
    Jun-1837839118
    Jul-1837839118
    Aug-1837839118
    Sep-1837839118
    Oct-1837839118
    Nov-1837839118
    Dec-1837839118
    Jan-1937839118
    Feb-1937839118
    Mar-1937839118

    More information

    Estimated network costs per domestic customer: At-a-glance summary

    • The majority of network costs for a domestic customer are for the use of the gas and electricity distribution networks.
    • For a household whose consumption does not change, on average across GB we expect network costs in 2018/19 to increase for gas distribution, decrease for electricity distribution, and stay broadly static for transmission costs compared to the previous charging year.
    • Actual costs will vary depending on where a customer lives, how much energy they use, and what type of meter they have.

    What are network costs?

    Suppliers are charged for the costs to build, maintain, improve and operate the energy networks. Most of the networks are owned by monopoly businesses. Therefore through regulation, we limit the revenue that these companies can recover from customer charges to run the networks.

    The network charges paid by suppliers vary depending on where their customers live, what type of meter they have, when energy is used and how much energy they use. In total, these charges accounted for approximately a quarter of a dual fuel bill in 2016.

    Different charges apply for the high voltage/pressure transmission networks (which take electricity and gas around Great Britain) and the lower voltage/pressure distribution networks, which connect customers to the overall networks.

    As well as the charges to suppliers that are considered here, electricity generators and gas producers are also charged for their use of the networks. It is important to note that trends in network costs will therefore also affect supplier costs indirectly through wholesale prices.

    Methodology

    • Network costs are calculated by combining charging information published by the network companies with assumptions about consumption and losses for domestic customers.
    • All costs are calculated for medium annual typical domestic consumption values of 12,000kWh for gas and 3,100kWh of electricity, which is held fixed across the charging years. The actual network costs a supplier incurs to serve a customer will depend on how much energy is used, the timing of its use as well as the charges that apply from one year to the next.
    • The costs shown are GB averages, calculated by taking a customer number weighted average of the tariffs that apply in different regions of the country.
    • The costs are expressed in nominal money (i.e. the amount of money a customer ‘pays over the counter’), rather than in real terms (i.e. after adjusting for inflation). For electricity, the costs reported are for a standard unrestricted meter.
    • Balancing Services Use of System charges are not included on the chart. These charges cover the cost of services used to balance the electricity system and internal system operator operating costs.

    The methodology we use to calculate these charges is consistent with our methodology for the Supplier Cost Index, and that used to set the value of the prepayment meter price cap. Further details on the calculations are available in our Supplier Cost Index methodology.

    Further information

    You can find further information on the different components making up an energy bill at Understand your gas and electricity bill.

    To see how the network fits together, visit The energy network: How it works for you.

    close

    All gas transmission charts and data (RIIO-T1)

    National Grid Gas Transmissionopen key term pop-up is responsible for operating the high pressure transmission of gas across GB.

    The RIIO-T1 price control runs from 1 April 2013 to 31 March 2021. The data presented here gives a snapshot of their financial performance and performance against key outputs for consumers.

    Chart

    Javascript is required to render chart Customer satisfaction: Gas transmission (RIIO-T1).

    Source: RIIO gas transmission annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of customer satisfaction with National Grid Gas Transmission.  It shows three scores comprising customer satisfaction over the three completed years of the price control.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Gas - transmission

    Data Table

    Customer satisfaction: Gas transmission (RIIO-T1)

    Network companyYear 1 stakeholder engagement incentive reward scoreYear 2 stakeholder engagement incentive reward scoreYear 3 stakeholder engagement incentive reward scoreYear 4 stakeholder engagement incentive reward scoreYear 1 stakeholder survey scoreYear 2 stakeholder survey scoreYear 3 stakeholder survey scoreYear 4 stakeholder survey scoreYear 1 customer survey scoreYear 2 customer survey scoreYear 3 customer survey scoreYear 4 customer survey score
    National Grid Gas Transmission5.756.256.156.57.797.948.027.9827.157.597.558.027

    More information

    Customer satisfaction: At-a-glance summary

    National Grid Gas Transmission outperformed their targets for both customer and stakeholder satisfaction surveys in 2016-17.

    Relevance and further information

    • We want transmission owners to understand consumers’ needs and proactively engage with them to make sure these are met.
    • National Grid Gas Transmission receive an annual financial reward or penalty based on their customer survey scores. Rewards can be up to 0.5% of their annual revenue.
    • There is also a stakeholder engagement incentive discretionary reward, which is an annual panel assessment of stakeholder engagement.

    Methodology

    For the customer and stakeholder satisfaction surveys incentive, companies may be rewarded or penalised depending on their performance against the targets set.

    Ofgem and an independent panel of experts conduct the assessment for the stakeholder engagement incentive.

    close

    Chart

    Javascript is required to render chart Network reliability: Gas transmission (RIIO-T1).

    Source: National Grid (opens an external website).

    Information correct as of: December 2017

    This chart is an indicator of the reliability and availability of the gas National Transmission System over the three completed years of the RIIO-T1 price control.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Gas - transmission

    Data Table

    Network reliability: Gas transmission (RIIO-T1)

    National Grid Gas TransmissionTargetActual
    Year 1 (2013/14)100%100%
    Year 2 (2014/15)100%100%
    Year 3 (2015/16)100%100%
    Year 4 (2016/17)100%99.975%

    More information

    Network reliability: At-a-glance summary

    National Grid Gas Transmission achieved 99.975% reliability on its network during 2016-17. Due to rounding, the reliability still shows as 100%.

    Relevance and further information

    Network availability is the time that the network is available.

    Methodology

    National Grid reports this information on their website each year.

    close

    Chart

    Javascript is required to render chart Network connections: Gas transmission (RIIO-T1).

    Source: RIIO gas transmission annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of National Grid Gas Transmission’s performance on network connections. It shows applications received and offers made by National Grid Gas Transmission over the three completed years of the RIIO-T1 price control.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Gas - transmission

    Data Table

    Network connections: Gas transmission (RIIO-T1)

    Connection offers receivedOffers made or processing within timescale
    Year 1 (2013/14)66
    Year 2 (2014/15)86
    Year 3 (2015/16)66
    Year 4 (2016/17)88

    More information

    Network connections: At-a-glance summary

    In 2016/17 a total of seven applications were submitted from parties seeking to connect to the National Transmission System with one offer carried over from the previous year.

    Three offers were made within the required timescales, one application was withdrawn by the customer. The remainder have been carried over to 2017/18.

    Relevance and further information

    • National Grid Gas Transmission is required to deliver timely and effective connections for customers applying to connect to the network.
    • We expect companies to provide a good service for customers wanting to connect to the network. 

    Methodology

    Each year, network companies must report on their performance under the RIIO-T1 price control. Our review of their submissions and supporting information informs our annual publications on network company performance.

    close

    Chart

    Javascript is required to render chart Business carbon footprint: Gas transmission (RIIO-T1).

    Source: RIIO gas transmission annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of environmental impact. It shows National Grid Gas Transmission’s business carbon footprint for emissions in tonnes of carbon dioxide equivalent (tCO2e) for the three completed years of the RIIO-T1 price control. Click on Scopes 1 and 2 in the chart legend to view the column data for Scope 3.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Gas - transmission

    Data Table

    Business carbon footprint: Gas transmission (RIIO-T1)

    Scope 1Scope 2Scope 3
    Year 1 (2013-14)321,34628,253627
    Year 2 (2014-15)260,21935,593747
    Year 3 (2015-16)356,24561,325630
    Year 4 (2016-17)557,240118,784942

    More information

    Business carbon footprint: At-a-glance summary

    The increase in Scope 1 emissions figures during 2016-17, compared to the previous year, is due to increased usage of gas-fired compressors. Scope 2 emissions figures are driven by the increased amount of electricity needed to power the electric-driven compressor units. The increase in compressor usage has been driven by the higher gas flows from the St Fergus gas terminal compared to the previous year.

    Relevance and further information

    National Grid Gas Transmission reports annually on their business carbon footprint to allow interested stakeholders to monitor its performance. There are no financial incentives linked to this output.

    The business carbon footprint measure includes:

    • Scope 1 - emissions directly related to the day-to-day business activities of network business.
    • Scope 2 - emissions which arise from operating the network, including the CO2 emissions from losses of electricity or shrinkage of gas that occur as a result of transporting energy on the network.
    • Scope 3 - emissions due to third party contractors carrying out business activities on behalf of the network.

    Emissions from natural gas fuel combustion to run gas-powered compressor units are included in the Scope 1 emissions figures. 

    Methodology

    Each year, network companies must report on their performance under the RIIO-T1 price control. Our review of their submissions and supporting information informs our annual publications on network company performance.

    close

    Chart

    Javascript is required to render chart Return on regulatory equity: Gas transmission (RIIO-T1).

    Source: RIIO gas transmission annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of financial performance. It shows our estimates of National Grid Gas Transmission’s return on regulatory equity (RoRE). It is our current view of an eight-year average RoRE over the RIIO-T1 period.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Gas - transmission

    Data Table

    Return on regulatory equity: Gas transmission (RIIO-T1)

    Current eight-year view
    National Grid Gas Transmission7.46%

    More information

    Return on regulatory equity: At-a-glance summary

    • National Grid Gas Transmission’s RoRE is 7.46%.

    Relevance and further information

    • RoRE helps us monitor the financial performance of network companies under the price control.
    • RoRE should be compared to the cost of equity allowed at the start of the price control. For National Grid Gas Transmission this was 6.8%. 
    • National Grid Gas Transmission’s numbers include the impact of the Mid-Period Review.

    Methodology

    • Our RoRE calculation is based on a mix of the first three years’ performance, company forecasts and simple averages.
    • There are a number of factors not reflected in our RoRE calculations which may impact the return realised by shareholders. The largest being potential clawbacks for non-delivery of outputs.
    • The calculation assumes all outputs will be delivered.
    • Returns may not equal the actual returns seen by shareholders.
    close

    Chart

    Javascript is required to render chart Expenditure vs allowance: Gas transmission (RIIO-T1).

    Source: RIIO gas transmission annual report 2016-17.

    Information correct as of: December 2017

    This chart compares National Grid Gas Transmission’s total expenditure for their regulated business activities against their allowance for each year under the RIIO-T1 price control. 

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Gas - transmission

    Data Table

    Expenditure vs allowance: Gas transmission (RIIO-T1)

    Network companyYear 1 expenditureYear 1 allowanceYear 2 expenditureYear 2 allowanceYear 3 expenditureYear 3 allowanceYear 4 expenditureYear 4 allowance
    National Grid Gas Transmission232.0255.6224.2254.4230.0227.5274.6238.6

    More information

    Expenditure vs allowance: At-a-glance summary

    We set a total expenditure allowance of £2.3 billion for the full RIIO-T1 period. This figure excludes forecast allowances for uncertain costs.

    National Grid Gas Transmission is currently underspending against their allowances by 2% for the first four years of RIIO-T1.

    Network companies are allowed to retain a part of any savings achieved, and the rest is passed on to consumers. 

    Relevance and further information

    This chart is an indicator of company RIIO-T1 financial performance against cost allowances so far.

    The allowances reflect NGGT view. They are lower than anticipated at the start of the price control due to the forecast effect of reopener mechanisms.

    Methodology

    Each year, network companies must report on their performance under the RIIO-T1 price control. Our review of their submissions and supporting information informs our annual publications on network company performance.

    close

    Chart

    Javascript is required to render chart Estimated network costs per domestic customer (GB average).

    Source: Ofgem analysis of network companies’ cost information .

    Information correct as of: December 2017

    This chart shows our estimate of trends in the annual cost of the different components of network charges for a domestic customer with a fixed amount of consumption. Balancing Services Use of System charges are not included in the chart.

    Click the ‘more information’ tab above for a summary of the latest trends, an explanation of network costs and for further detail on how we calculate the costs.

    Policy Areas:

    • Electricity - distribution
    • Electricity - transmission
    • Gas - distribution
    • Gas - transmission

    Data Table

    Estimated network costs per domestic customer (GB average)

    Annualised network costsElectricity (transmission)Electricity (distribution)Gas (transmission)Gas (distribution)
    Apr-14279410110
    May-14279410110
    Jun-14279410110
    Jul-14279410110
    Aug-14279410110
    Sep-14279410110
    Oct-14279410110
    Nov-14279410110
    Dec-14279410110
    Jan-15279410110
    Feb-15279410110
    Mar-15279410110
    Apr-1532879114
    May-1532879114
    Jun-1532879114
    Jul-1532879114
    Aug-1532879114
    Sep-1532879114
    Oct-1532879114
    Nov-1532879114
    Dec-1532879114
    Jan-1632879114
    Feb-1632879114
    Mar-1632879114
    Apr-1638939116
    May-1638939116
    Jun-1638939116
    Jul-1638939116
    Aug-1638939116
    Sep-1638939116
    Oct-1638939116
    Nov-1638939116
    Dec-1638939116
    Jan-1738939116
    Feb-1738939116
    Mar-1738939116
    Apr-1738869113
    May-1738869113
    Jun-1738869113
    Jul-1738869113
    Aug-1738869113
    Sep-1738869113
    Oct-1738869113
    Nov-1738869113
    Dec-1738869113
    Jan-1838869113
    Feb-1838869113
    Mar-1838869113
    Apr-1837839118
    May-1837839118
    Jun-1837839118
    Jul-1837839118
    Aug-1837839118
    Sep-1837839118
    Oct-1837839118
    Nov-1837839118
    Dec-1837839118
    Jan-1937839118
    Feb-1937839118
    Mar-1937839118

    More information

    Estimated network costs per domestic customer: At-a-glance summary

    • The majority of network costs for a domestic customer are for the use of the gas and electricity distribution networks.
    • For a household whose consumption does not change, on average across GB we expect network costs in 2018/19 to increase for gas distribution, decrease for electricity distribution, and stay broadly static for transmission costs compared to the previous charging year.
    • Actual costs will vary depending on where a customer lives, how much energy they use, and what type of meter they have.

    What are network costs?

    Suppliers are charged for the costs to build, maintain, improve and operate the energy networks. Most of the networks are owned by monopoly businesses. Therefore through regulation, we limit the revenue that these companies can recover from customer charges to run the networks.

    The network charges paid by suppliers vary depending on where their customers live, what type of meter they have, when energy is used and how much energy they use. In total, these charges accounted for approximately a quarter of a dual fuel bill in 2016.

    Different charges apply for the high voltage/pressure transmission networks (which take electricity and gas around Great Britain) and the lower voltage/pressure distribution networks, which connect customers to the overall networks.

    As well as the charges to suppliers that are considered here, electricity generators and gas producers are also charged for their use of the networks. It is important to note that trends in network costs will therefore also affect supplier costs indirectly through wholesale prices.

    Methodology

    • Network costs are calculated by combining charging information published by the network companies with assumptions about consumption and losses for domestic customers.
    • All costs are calculated for medium annual typical domestic consumption values of 12,000kWh for gas and 3,100kWh of electricity, which is held fixed across the charging years. The actual network costs a supplier incurs to serve a customer will depend on how much energy is used, the timing of its use as well as the charges that apply from one year to the next.
    • The costs shown are GB averages, calculated by taking a customer number weighted average of the tariffs that apply in different regions of the country.
    • The costs are expressed in nominal money (i.e. the amount of money a customer ‘pays over the counter’), rather than in real terms (i.e. after adjusting for inflation). For electricity, the costs reported are for a standard unrestricted meter.
    • Balancing Services Use of System charges are not included on the chart. These charges cover the cost of services used to balance the electricity system and internal system operator operating costs.

    The methodology we use to calculate these charges is consistent with our methodology for the Supplier Cost Index, and that used to set the value of the prepayment meter price cap. Further details on the calculations are available in our Supplier Cost Index methodology.

    Further information

    You can find further information on the different components making up an energy bill at Understand your gas and electricity bill.

    To see how the network fits together, visit The energy network: How it works for you.

    close

    All gas distribution charts and data (RIIO-GD1)

    There are eight gas distribution network operatorsopen key term pop-up, owned by four ownership groups. They operate the local gas networks, taking energy from the gas transmission system to homes and businesses.

    The RIIO-GD1 price control runs from 1 April 2013 to 31 March 2021. The data presented here gives a snapshot of the network owners' financial performance and their performance against key outputs for consumers.

    Chart

    Source: RIIO gas distribution annual report 2016-17.

    Information correct as of: November 2017

    This chart is an indicator of customer satisfaction with gas distribution companies under the RIIO-GD1 price control. It shows three scores comprising customer satisfaction over the four completed years of the price control.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Gas - distribution

    Data Table

    Customer satisfaction with network owners: Gas distribution (RIIO-GD1)

    Stakeholder Engagement Incentive Reward Score 2013/14SEIRS 2014/15SEIRS 2015/16Average customer satisfaction score 2013/14AVCSC 2014/15AVCSC 2015/16AVCSC 2016/17
    Cadent7.155.96.98.158.238.368.39
    NGN6.755.56.88.759.019.179.17
    SGN6.056.45.758.648.728.989.13
    WWU6.37.056.058.699.049.059.11

    More information

    At-a-glance summary

    Average industry performance for customer satisfaction has continued to increase and most gas distribution network owners improved on their average score from last year.

    SGN Scotland has achieved the highest average score in 2016-17 and has the highest average customer satisfaction in RIIO-GD1 so far.

    Cadent has been penalised for failure to meet their targets in two of the three satisfaction scoring categories (planned work and connections). All other companies are meeting targets and earning financial rewards.

    Relevance and further information

    We want gas distribution companies to understand consumers’ needs and proactively engage with them to make sure these are met.

    Customer satisfaction is measured annually across three categories:

    • planned work
    • unplanned work and
    • connections work.

    We set targets[VN1] ,  with associated penalties and rewards, for customer satisfaction based on how well gas distribution owners perform in each category.

    Methodology

    Each year, gas distribution network owners must report on their performance under the RIIO-GD1 price control. Our review of their submissions and supporting information informs our annual publications on network company performance.

     [VN1]Have standardised with other charts. Please check this is correct.

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    Chart

    Javascript is required to render chart Fuel poor connections: Gas distribution (RIIO-GD1).

    Source: RIIO gas distribution annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of gas distribution companies’ performance on fuel poor connections. It shows the number of fuel poor connections made by each gas distribution company over the four completed years of the RIIO-GD1 price control.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology. 

    Policy Areas:

    • Gas - distribution

    Data Table

    Fuel poor connections: Gas distribution (RIIO-GD1)

    Commitment (4 year cumulative)Actual (4 year cumulative)
    EoE54155967
    Lon13801119
    NW67106664
    WM41904282
    NGN68337967
    Sc794314364
    So46764550
    WWU65977448

    More information

    At-a-glance summary

    So far in RIIO-GD1, gas distribution companies have connected 52,361 fuel poor households, just over 57% of their eight-year target of 91,203.

    Cadent’s London network is currently behind schedule compared to the three-year linear forecast, but it still expects to meet the eight-year target.

    Relevance and further information

    The Fuel Poor Network Extension Scheme helps vulnerable and fuel poor households that are off the gas grid to switch to natural gas by offering funding towards the cost of connecting to the gas network.

    We increased Fuel Poor network extension targets by 20%  following a public consultation in 2015.

    Methodology

    Each year, network companies must report on their performance under the RIIO-GD1 price control. Our review of their submissions and supporting information informs our annual publications on network company performance.

    close

    Chart

    Javascript is required to render chart Network availability: Gas distribution (RIIO-GD1).

    Source: RIIO gas distribution annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of network availability. It shows the gas distribution network availability as a percentage over the three completed years of the RIIO-GD1 price control. Availability for 2016/17 has been consistently 99.998 for GB customers. You can see how this breaks down by network owner in the table below.

     

    Year 1

    Year 2

    Year 3

    Year 4

    Cadent

    99.997%

    99.997%

    99.996%

    99.996%

    NGN

    99.998%

    99.998%

    99.998%

    99.998%

    SGN

    99.997%

    99.998%

    99.998%

    99.998%

    WWU

    99.999%

    99.998%

    99.999%

    99.999%

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Gas - distribution

    Data Table

    Network availability: Gas distribution (RIIO-GD1)

    Year 1 (2013-14)Year 2 (2014-15)Year 3 (2015-16)Year 4 (2016-17)
    Cadent99.997%99.997%99.996%99.996%
    NGN99.998%99.998%99.998%99.998%
    SGN99.997%99.998%99.998%99.998%
    WWU99.999%99.998%99.999%99.999%

    More information

    At-a-glance summary

    Network availability (availability of supply) to GB consumers was 99.998% in 2016-17 and has been consistent over the RIIO-GD1 period so far.  

    Relevance and further information

    Network availability is the time (as a % of total time during that period) that the GD network is available to consumers.

    Network availability accounts for both planned and unplanned interruptions.

    Methodology

    Each year, network companies must report on their performance under the RIIO-GD1 price control. Our review of their submissions and supporting information informs our annual publications on network company performance.

    close

    Chart

    Javascript is required to render chart Risk removed from the network: Gas distribution (RIIO-GD1).

    Source: RIIO gas distribution annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of network safety. Due to their nature, gas networks pose a safety risk. We set targets for gas distribution network owners to reduce the safety risk on their networks. The chart shows the level of safety risk network owners have removed by replacing or abandoning iron gas mains over the three completed years of the RIIO-GD1 price control.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Gas - distribution

    Data Table

    Risk removed from the network: Gas distribution (RIIO-GD1)

    Proportionate risk reductionActual Risk reduction
    Cadent290,335400,768
    NGN55,596140,953
    SGN90,782183,768
    WWU49,36478,827

    More information

    At-a-glance summary

    At this stage of the price control, all four gas distribution companies expect to exceed their targets and are currently removing more risk than might be expected.

    Relevance and further information

    All network owners explain that they are targeting higher risk mains first as a way to achieve this output early. As a consequence, since the start of the RIIO-GD1 price control, the iron mains risk across the distribution networks has reduced by 0.80 incidents per year from the original start position of 2.49 incidents per year.

    Methodology

    Each year, network companies must report on their performance under the RIIO-GD1 price control. Our review of their submissions and supporting information informs our annual publications on network company performance.

    close

    Chart

    Javascript is required to render chart Volume of gas lost from the distribution network (RIIO-GD1).

    Source: RIIO gas distribution annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of company performance on environmental impact. It shows the annual volume of gas lost (referred to as ‘shrinkage’)  by gas distribution network owners. Shrinkage is the dominant element of network owners’ business carbon footprint.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Gas - distribution

    Data Table

    Volume of gas lost from the distribution network (RIIO-GD1)

    Target 13/14Actual 13/14Target 14/15Actual 14/15Target 15/16Actual 15/16Target 16/17Actual 16/17
    Cadent16281418149813741460137414221307
    NGN459417445397432382423354
    SGN884825848785826766802733
    WWU440417429414421381413378

    More information

    At-a-glance summary

    All gas distribution network owners are meeting their annual volume of gas lost (‘shrinkage‘) targets and forecast to meet them for the rest of the RIIO-GD1 price control period.

    Relevance and further information

    Under the price control, we expect companies to reduce their environmental impact, including reducing the amount of shrinkage from their networks.

    We incentivise gas distribution companies to minimise shrinkage through two mechanisms:

    • the Environmental Emissions Incentive and
    • the Shrinkage Incentive.

    Shrinkage targets were updated in 2014/15 following an update of the model used. We have therefore revised the 2013/14 figures to make them relative to the new targets.

    Methodology

    Each year, network companies must report on their performance under the RIIO-GD1 price control. Our review of their submissions and supporting information informs our annual publications on network company performance.

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    Chart

    Javascript is required to render chart Return on regulatory equity: Gas distribution (RIIO-GD1).

    Source: RIIO gas distribution annual report 2016-17.

    Information correct as of: December 2017

    This chart is an indicator of financial performance. It shows our estimates of gas distribution network owners’ return on regulatory equity (RoRE). It is our current view of an eight-year average RoRE over RIIO-GD1.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Electricity - distribution
    • Gas - distribution

    Data Table

    Return on regulatory equity: Gas distribution (RIIO-GD1)

    Current eight-year view
    Cadent9.57%
    NGN11.41%
    SGN11.56%
    WWU11.67%

    More information

    At-a-glance summary

    • RoRE across the gas distribution sector is 10.58%
    • It ranges from 9.57% for Cadent to 11.67% for Wales and West Utilities.

    Relevance and further information

    • RoRE helps us monitor the financial performance of network companies under the price control.
    • RoRE should be compared to the cost of equity allowed at the start of the price control. For all gas distribution owners, this was 6.7%
    • No gas distribution owners are forecast to earn returns below their cost of equity.

    Methodology

    • Our RoRE calculation is based on a mix of the first four years’ performance, company forecasts and simple averages.
    • There are a number of factors not reflected in our RoRE calculations which may impact the return realised by shareholders. The largest being potential clawbacks for non-delivery of outputs.
    • Our calculation assumes all outputs will be delivered. Returns may not equal the actual returns seen by shareholders.
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    Chart

    Javascript is required to render chart Expenditure vs allowance: Gas distribution (RIIO-GD1).

    Source: RIIO gas distribution annual report 2016-17.

    Information correct as of: December 2017

    This chart compares gas distribution companies’ realised total expenditure for their regulated business activities against their allowance for the four years of RIIO-GD1 network price control.

    We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

    Policy Areas:

    • Gas - distribution

    Data Table

    Expenditure vs allowance: Gas distribution (RIIO-GD1)

    CompanyY1 ExpenditureY1 AllowanceY2 ExpenditureY2 AllowanceY3 ExpenditureY3 AllowanceY4 ExpenditureY4 Allowance
    Cadent-EoE315.4341309.9327.4306.8323.1305.4326.9
    Cadent-Lon248.6290.1228.8291.2245.3309.1258.1301.3
    Cadent-NW231.9262.4263248.4233.1240.3207.9242.2
    Cadent-WM169.3195.6157.9195.5178.1188.7171.8186.6
    NGN220.2256.2234.6263.6232.2266.9226.8264
    SGN-Sc151.3214.6173.9206.7168.5200.6170.4224
    SGN-So329.3442.4345.3419.6343.6419.4360.2431.3
    WWU227.9268.9217.2263.7213.4260211.4261.8

    More information

    At-a-glance summary

    • Gas distribution network owners forecast that they will outperform their cost allowances over the eight years of RIIO-GD1 by 12.0%.
    • Cost savings are shared with consumers, which help keep down the network costs part of an energy bill.

    Relevance and further information

    • This chart is an indicator of company financial performance against cost allowances for the four completed years of the RIIO-GD1 price control period.
    • We set the total amount each company can spend ahead of the price control (company ‘allowances’) and monitor their actual spend (‘total expenditure’) against these amounts annually.
    • The expenditure shown only accounts for controllable total expenditure.
    • Network companies are allowed to retain a part of any savings they achieve, with the rest being passed on to consumers.

    Methodology

    • Each year, network companies must report on their performance under the RIIO-GD1 price control. Our review of their submissions and supporting information informs our annual publications on network company performance. 
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    Chart

    Javascript is required to render chart Estimated network costs per domestic customer (GB average).

    Source: Ofgem analysis of network companies’ cost information .

    Information correct as of: December 2017

    This chart shows our estimate of trends in the annual cost of the different components of network charges for a domestic customer with a fixed amount of consumption. Balancing Services Use of System charges are not included in the chart.

    Click the ‘more information’ tab above for a summary of the latest trends, an explanation of network costs and for further detail on how we calculate the costs.

    Policy Areas:

    • Electricity - distribution
    • Electricity - transmission
    • Gas - distribution
    • Gas - transmission

    Data Table

    Estimated network costs per domestic customer (GB average)

    Annualised network costsElectricity (transmission)Electricity (distribution)Gas (transmission)Gas (distribution)
    Apr-14279410110
    May-14279410110
    Jun-14279410110
    Jul-14279410110
    Aug-14279410110
    Sep-14279410110
    Oct-14279410110
    Nov-14279410110
    Dec-14279410110
    Jan-15279410110
    Feb-15279410110
    Mar-15279410110
    Apr-1532879114
    May-1532879114
    Jun-1532879114
    Jul-1532879114
    Aug-1532879114
    Sep-1532879114
    Oct-1532879114
    Nov-1532879114
    Dec-1532879114
    Jan-1632879114
    Feb-1632879114
    Mar-1632879114
    Apr-1638939116
    May-1638939116
    Jun-1638939116
    Jul-1638939116
    Aug-1638939116
    Sep-1638939116
    Oct-1638939116
    Nov-1638939116
    Dec-1638939116
    Jan-1738939116
    Feb-1738939116
    Mar-1738939116
    Apr-1738869113
    May-1738869113
    Jun-1738869113
    Jul-1738869113
    Aug-1738869113
    Sep-1738869113
    Oct-1738869113
    Nov-1738869113
    Dec-1738869113
    Jan-1838869113
    Feb-1838869113
    Mar-1838869113
    Apr-1837839118
    May-1837839118
    Jun-1837839118
    Jul-1837839118
    Aug-1837839118
    Sep-1837839118
    Oct-1837839118
    Nov-1837839118
    Dec-1837839118
    Jan-1937839118
    Feb-1937839118
    Mar-1937839118

    More information

    Estimated network costs per domestic customer: At-a-glance summary

    • The majority of network costs for a domestic customer are for the use of the gas and electricity distribution networks.
    • For a household whose consumption does not change, on average across GB we expect network costs in 2018/19 to increase for gas distribution, decrease for electricity distribution, and stay broadly static for transmission costs compared to the previous charging year.
    • Actual costs will vary depending on where a customer lives, how much energy they use, and what type of meter they have.

    What are network costs?

    Suppliers are charged for the costs to build, maintain, improve and operate the energy networks. Most of the networks are owned by monopoly businesses. Therefore through regulation, we limit the revenue that these companies can recover from customer charges to run the networks.

    The network charges paid by suppliers vary depending on where their customers live, what type of meter they have, when energy is used and how much energy they use. In total, these charges accounted for approximately a quarter of a dual fuel bill in 2016.

    Different charges apply for the high voltage/pressure transmission networks (which take electricity and gas around Great Britain) and the lower voltage/pressure distribution networks, which connect customers to the overall networks.

    As well as the charges to suppliers that are considered here, electricity generators and gas producers are also charged for their use of the networks. It is important to note that trends in network costs will therefore also affect supplier costs indirectly through wholesale prices.

    Methodology

    • Network costs are calculated by combining charging information published by the network companies with assumptions about consumption and losses for domestic customers.
    • All costs are calculated for medium annual typical domestic consumption values of 12,000kWh for gas and 3,100kWh of electricity, which is held fixed across the charging years. The actual network costs a supplier incurs to serve a customer will depend on how much energy is used, the timing of its use as well as the charges that apply from one year to the next.
    • The costs shown are GB averages, calculated by taking a customer number weighted average of the tariffs that apply in different regions of the country.
    • The costs are expressed in nominal money (i.e. the amount of money a customer ‘pays over the counter’), rather than in real terms (i.e. after adjusting for inflation). For electricity, the costs reported are for a standard unrestricted meter.
    • Balancing Services Use of System charges are not included on the chart. These charges cover the cost of services used to balance the electricity system and internal system operator operating costs.

    The methodology we use to calculate these charges is consistent with our methodology for the Supplier Cost Index, and that used to set the value of the prepayment meter price cap. Further details on the calculations are available in our Supplier Cost Index methodology.

    Further information

    You can find further information on the different components making up an energy bill at Understand your gas and electricity bill.

    To see how the network fits together, visit The energy network: How it works for you.

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    Related publications

    RIIO electricity transmission annual report 2016-17

    RIIO electricity distribution annual report 2016-17

    RIIO gas transmission annual report 2016-17

    RIIO gas distribution annual report 2016-17

    These market indicators and data are not intended for use or to be relied on for any commercial purposes. View copyright and disclaimer

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    Publications and updates

    • Published: 29th Nov 2018
    • Charts and data
    • 1 Associated documents
    Upcoming release dates for our market indicators and data on the Ofgem Data Portal.