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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 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

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.

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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 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 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

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

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.
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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 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 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.

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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 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 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. 

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