All wholesale electricity charts and indicators

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Chart

Source: ICIS data & Ofgem calculations.

Information correct as of: July 2019

This chart shows the monthly average of volatility for GB gas, electricity baseload and electricity peakload prices based on Day-ahead contracts.

Policy Areas:

  • Electricity - wholesale markets
  • Gas - wholesale markets

Data Table

Price volatility of gas and electricity by month: Day-ahead contracts (GB)
Month beginningElectricity (baseload)Electricity (peakload)Gas
01/01/200399%643%332%
01/02/2003102%635%313%
01/03/200356%232%158%
01/04/200338%135%128%
01/05/200340%177%141%
01/06/200347%216%192%
01/07/2003116%531%111%
01/08/2003159%687%141%
01/09/200384%424%210%
01/10/200356%323%194%
01/11/200360%334%135%
01/12/200377%484%125%
01/01/200490%407%256%
01/02/200494%452%444%
01/03/200439%127%113%
01/04/200428%118%105%
01/05/200430%162%115%
01/06/200442%228%67%
01/07/200435%169%58%
01/08/200418%105%70%
01/09/200418%125%100%
01/10/200443%144%126%
01/11/200456%238%133%
01/12/200442%211%119%
01/01/200546%231%131%
01/02/200537%167%126%
01/03/200581%319%416%
01/04/200532%153%160%
01/05/200517%72%93%
01/06/200526%124%135%
01/07/200546%279%126%
01/08/200517%106%92%
01/09/200529%146%89%
01/10/200533%176%103%
01/11/200550%194%226%
01/12/200579%338%294%
01/01/200670%282%209%
01/02/200659%205%205%
01/03/2006114%436%389%
01/04/200681%331%291%
01/05/200623%94%121%
01/06/200629%145%219%
01/07/200665%302%182%
01/08/200690%444%90%
01/09/200638%190%105%
01/10/200648%227%567%
01/11/200672%297%217%
01/12/200687%328%183%
01/01/200763%294%154%
01/02/200741%194%120%
01/03/200730%154%140%
01/04/200733%167%86%
01/05/200742%219%106%
01/06/200753%290%84%
01/07/200740%181%107%
01/08/200733%129%95%
01/09/200744%172%127%
01/10/200775%248%122%
01/11/200792%413%113%
01/12/200777%363%91%
01/01/200861%266%92%
01/02/200820%102%50%
01/03/200815%70%49%
01/04/200831%156%41%
01/05/200824%111%78%
01/06/200843%234%48%
01/07/200843%203%75%
01/08/200833%160%212%
01/09/200834%149%146%
01/10/200841%156%105%
01/11/200848%212%144%
01/12/200860%277%98%
01/01/200960%275%110%
01/02/200935%151%100%
01/03/200923%98%87%
01/04/200916%66%96%
01/05/200928%102%71%
01/06/200931%109%82%
01/07/200931%112%68%
01/08/200918%65%81%
01/09/200928%111%203%
01/10/200921%92%266%
01/11/200918%93%106%
01/12/200922%89%66%
01/01/201031%127%141%
01/02/201020%50%99%
01/03/201010%42%60%
01/04/201013%51%75%
01/05/201020%77%113%
01/06/201016%60%73%
01/07/201014%59%55%
01/08/201011%52%49%
01/09/20108%34%72%
01/10/201013%47%83%
01/11/201014%56%42%
01/12/201051%239%49%
01/01/201123%112%40%
01/02/20118%30%38%
01/03/201112%37%31%
01/04/201113%40%53%
01/05/20116%26%55%
01/06/20116%26%22%
01/07/20116%31%22%
01/08/20118%32%24%
01/09/201112%48%66%
01/10/201113%65%86%
01/11/201114%51%48%
01/12/20119%44%34%
01/01/201212%43%36%
01/02/201225%108%144%
01/03/201215%70%70%
01/04/201214%50%49%
01/05/201211%42%29%
01/06/201211%54%29%
01/07/201210%39%28%
01/08/20128%34%29%
01/09/201210%34%30%
01/10/201212%43%25%
01/11/201221%87%24%
01/12/201220%70%20%
01/01/201320%80%32%
01/02/201320%79%32%
01/03/201337%125%87%
01/04/201333%119%105%
01/05/201314%42%25%
01/06/201313%44%35%
01/07/201313%45%46%
01/08/201311%29%18%
01/09/201313%35%15%
01/10/201314%51%21%
01/11/201320%75%33%
01/12/201321%73%20%
01/01/201421%77%17%
01/02/201416%60%19%
01/03/201419%53%35%
01/04/201415%47%33%
01/05/201412%41%30%
01/06/201410%35%42%
01/07/201412%53%43%
01/08/201412%53%47%
01/09/201418%74%51%
01/10/201423%89%41%
01/11/201442%187%50%
01/12/201426%108%26%
01/01/201528%90%36%
01/02/201524%97%39%
01/03/201518%74%38%
01/04/201517%51%27%
01/05/201517%48%28%
01/06/201517%50%28%
01/07/201514%47%22%
01/08/201512%37%31%
01/09/201511%41%28%
01/10/201511%43%24%
01/11/201517%64%36%
01/12/201523%71%34%
01/01/201629%115%39%
01/02/201630%149%39%
01/03/201633%170%25%
01/04/201628%121%27%
01/05/201624%117%58%
01/06/201621%96%39%
01/07/201624%104%32%
01/08/201626%126%43%
01/09/2016151%495%131%
01/10/2016182%663%87%
01/11/2016141%638%43%
01/12/201685%425%41%
01/01/201730%167%54%
01/02/201718%89%52%
01/03/201717%79%30%
01/04/201717%69%25%
01/05/201723%126%35%
01/06/201742%189%79%
01/07/201782%371%77%
01/08/201732%130%42%
01/09/201722%100%30%
01/10/201726%94%64%
01/11/201719%94%28%
01/12/201721%82%52%
01/01/201821%81%42%
01/02/201816%76%47%
01/03/201867%248%478%
01/04/201829%128%83%
01/05/201818%95%33%
01/06/201817%66%44%
01/07/201817%71%36%
01/08/201810%54%24%
01/09/201813%63%33%
01/10/201818%58%50%
01/11/201819%81%49%
01/12/201829%134%43%
01/01/201923%104%54%
01/02/201927%115%34%
01/03/201913%54%29%

More information

Price volatility of gas and electricity (Day-ahead contracts): At-a-glance summary

The volatility of day-ahead gas and power prices has been generally decreasing in recent years. Volatility for both gas and power remained low over the course of 2015 and the first half of 2016, but increased during winter 2016/17.

A sharp increase in the average of volatility for GB gas occured in March 2018, with record high gas prices due to both high demand and supply issues: gas demand reached the highest level in seven years and there was a series of unplanned outages across GB supply infrastructure that increased the gas price further. Since May 2018 volatility for both gas and electricity has remained low and stable, hovering between 24% to 50% for gas, and 10% and 29% for electricity.

Relevance and further information

Price volatility is an important market indicator for a range of reasons. For example:

  • Companies with capacity that can flexibly increase or decrease their supply of gas or electricity can profit from high volatility by increasing output when prices are high and decreasing output when prices are low. Such companies include gas storage facilities or conventional coal and gas-fired power stations.
  • High levels of volatility can challenge smaller companies where they are less able to access credit and collateral.

Methodology

  • The monthly calculation takes the logarithmical differences of daily average prices across two consecutive trading days. These are used to calculate the relative standard deviation on a rolling monthly basis (21 trading days).
  • To show the data in annual terms, the value obtained is multiplied by the square root of the total number of trading days in a year (252 trading days).
  • Volatility values are usually expressed as a percentage, so the annual value is finally multiplied by 100.
  • All volatility values for a given month are then averaged together to get a single monthly data point.
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Chart

Javascript is required to render chart Spark and dark spreads (GB).

Source: Ofgem analysis of data from ICIS and Bloomberg.

Information correct as of: July 2019

The chart shows clean spark and dark spreads in GB. These indicate the average revenue a power station can expect from generating a unit of electricity during ‘baseload’ operation, after fuel and carbon costs. 

Clean spark spreads refer to gas generation and clean dark spreads refer to coal generation. 

Policy Areas:

  • Electricity - wholesale markets

Data Table

Spark and dark spreads (GB)
DateSpark (low eff)SparkSpark (high eff)DarkPower price (baseload)
01/10/20076.049.2315.481.9143.82
01/11/200713.7517.4424.6512.7157.35
01/12/20075.759.617.125.351.24
01/01/200810.3514.3622.1910.2157.73
01/02/20088.0611.8719.312.7453.08
01/03/20086.4610.5618.574.554.92
01/04/200814.0618.6927.7616.7768.85
01/05/200819.624.0532.7414.9572.18
01/06/200831.8336.5945.8821.488.01
01/07/200834.3338.9247.8818.5588.53
01/08/200834.1238.2546.3115.8282.86
01/09/200844.4949.6659.7640.47105.58
01/10/200836.3940.6849.0637.0587.06
01/11/200821.1525.2433.2525.7669.56
01/12/200812.5216.724.8922.2162.01
01/01/200910.3914.7423.2423.7761.79
01/02/20095.618.9915.5911.9745.52
01/03/20096.699.1313.915.2735.58
01/04/20098.6210.9115.383.4335.67
01/05/20099.812.0116.333.5635.93
01/06/200910.1612.2616.373.8734.98
01/07/200911.7313.6117.292.6433.97
01/08/200911.9613.817.41.0533.72
01/09/200912.4414.1517.50.2532.68
01/10/200911.3613.4217.451.3835.72
01/11/20098.2410.3914.6-0.5333.68
01/12/20096.799.2313.990.6135.57
01/01/20105.017.9513.723.339.85
01/02/20104.196.8712.121.8335.92
01/03/20105.638.0912.91-0.0134.75
01/04/20106.929.4514.41-0.2236.88
01/05/20106.059.0314.87-0.5641.33
01/06/20104.978.1114.26-0.6942.12
01/07/20103.837.1913.752.7743.53
01/08/20102.725.8712.03-0.0739.95
01/09/20104.94813.980.1341.12
01/10/20103.286.6813.330.4143.5
01/11/20103.587.214.282.1146.4
01/12/20105.9810.3818.999.358.03
01/01/20110.974.9912.840.248.43
01/02/20110.634.5112.09-0.3946.47
01/03/2011-0.174.212.730.7451.41
01/04/20111.485.6613.82-1.0650.86
01/05/20111.135.2913.420.2350.27
01/06/20111.175.3713.581.4750.82
01/07/20111.665.5813.240.5347.96
01/08/20112.025.8613.360.4247.36
01/09/20113.487.2714.690.8848.32
01/10/20110.674.5712.212.4246.83
01/11/2011-1.182.8310.653.8546.15
01/12/2011-1.512.39.753.3343.54
01/01/2012-1.442.259.463.8442.17
01/02/2012-3.41.059.7311.6649.1
01/03/2012-1.272.6910.459.5145.64
01/04/2012-1.882.1610.0711.1545.91
01/05/2012-1.632.229.7311.8543.79
01/06/2012-1.961.789.099.6242.24
01/07/2012-1.851.929.299.3142.71
01/08/2012-2.571.148.386.7641.21
01/09/2012-4.98-0.897.1110.5943.39
01/10/2012-3.780.579.0615.4647.6
01/11/2012-3.211.29.8415.8949
01/12/2012-2.511.9110.5617.4249.76
01/01/2013-2.481.9610.6319.549.96
01/02/2013-2.412.1411.0520.0351.44
01/03/2013-4.191.4912.5832.8662.9
01/04/2013-5.13-0.358.9817.1651.3
01/05/2013-4.50.028.8515.5148.89
01/06/2013-2.052.1310.2915.2447.31
01/07/2013-4.250.238.9916.148.73
01/08/2013-5.3-0.857.8515.4747.31
01/09/2013-4.020.529.3916.5949.63
01/10/2013-4.86-0.378.4114.8248.22
01/11/2013-2.312.3711.532053.05
01/12/2013-5.46-0.78.6117.9250.81
01/01/2014-5.43-0.937.8514.9747.67
01/02/2014-3.740.48.4812.9845.15
01/03/2014-2.581.399.1712.8144.41
01/04/2014-1.741.949.136.6741.77
01/05/2014-0.3839.624.7639.62
01/06/20140.963.989.892.2736.67
01/07/20141.174.079.740.6435.46
01/08/20141.274.3710.441.7137.97
01/09/20140.684.2811.337.4843.28
01/10/20140.74.4311.739.344.81
01/11/20140.724.7612.6511.748.43
01/12/2014-2.871.098.847.8343.96
01/01/2015-1.212.269.067.1439.86
01/02/2015-1.891.889.258.6242.68
01/03/2015-0.912.629.527.6140.8
01/04/2015-1.042.7810.232.7144.03
01/05/2015-1.71.939.010.4841.13
01/06/2015-0.573.0210.031.0841.84
01/07/2015-0.353.2510.291.4542.2
01/08/20151.124.4911.080.8140.99
01/09/20151.264.7311.52.3442.23
01/10/20150.473.8410.430.8840.3
01/11/20151.244.3710.48-1.3238.2
01/12/2015-0.622.48.29-3.1735
01/01/20163.035.8911.47-0.836.8
01/02/20162.154.8110.01-2.533.59
01/03/20163.546.1911.38-1.5434.92
01/04/20162.515.1810.38-3.1333.99
01/05/20162.285.0210.37-3.2734.64
01/06/20162.255.2211.03-2.337.37
01/07/20163.456.4112.18-4.4838.37
01/08/20164.527.2312.51-7.0536.47
01/09/201623.0725.6330.638.7853.32
01/10/201619.4322.9629.858.3661.12
01/11/201623.7527.6335.2114.6869.6
01/12/20166.8410.6117.98-1.2251.42
01/01/20173.667.8516.05-0.9353.23
01/02/20171.625.6713.6-2.4549.56
01/03/20171.965.3712.04-7.542.26
01/04/20172.956.2712.74-7.5642.1
01/05/20172.445.7312.14-7.5341.24
01/06/20174.127.1313.01-11.3639.68
01/07/20176.329.4315.5-9.2243.05
01/08/20171.615.1412.06-10.7643.4
01/09/20172.436.2213.62-8.9247.17
01/10/20172.366.1313.48-10.2846.82
01/11/20171.185.4313.75-5.9151.45
01/12/20171.856.4615.47-1.4856.35
01/01/20182.217.0714.37-6.4250.84
01/02/2018-1.833.7212.05-1.1253.68
01/03/2018-3.542.511.544.0856.79
01/04/2018-0.035.0412.66-6.4350.74
01/05/2018-0.584.913.13-8.3754.25
01/06/2018-0.54.9513.13-11.0954
01/07/20180.376.114.68-10.0357.61
01/08/2018-0.026.1815.47-8.4661.94
01/09/2018-3.423.714.36-5.867.69
01/10/2018-0.116.3716.1-6.2864.76
01/11/2018-0.915.414.86-4.1562.19
01/12/20180.196.616.22-6.8564.32
01/01/20192.788.7517.70-5.4962.44
01/02/2019-0.334.7312.32-12.5050.27
01/03/20190.054.5411.28-16.2544.96

More information

Spark and dark spreads: At-a-glance summary

Spark spreads have improved over the last three years and gas generation has been more profitable than coal since mid-2015, with higher clean spark spreads relative to clean dark spreads. This has led to more gas plants producing electricity. With the power price remaining broadly flat, the improvement has come from relative falling gas prices.

The chart shows an inversion in this trend for March 2018. This was due to both a decrease in coal prices and a marked surge in gas prices due to temperatures below seasonal normal and a number of outages in this period. As a result, coal-fired generation ran close to maximum capacity.

Relevance and further information

Clean spark and dark spreads give some insight into the profitability of coal and gas-fired generation. As such this is a good indication of which kinds of plants are likely to operate or whether investment in new plants is likely.

Methodology

  • Dark and spark spreads are calculated using the following fuel efficiency assumptions. 
  • The efficiencies used are: Dark = 35 %, Spark = 50 %, Spark (high efficiency) = 60 %, Spark (low efficiency) = 45 %.
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Chart

Source: BEIS, ICE, ICIS, N2EX & EPEX SPOT.

Information correct as of: July 2019

The chart shows total monthly volumes of electricity traded in GB across different trading platforms. The churn ratio is also shown. ‘Churn’ is the number of times one unit of electricity is traded.

Policy Areas:

  • Electricity - wholesale markets

Data Table

Electricity trading volumes and churn ratio by month and platform (GB)
DateChurnN2EXEPEX SPOTICEOTC
01/01/20103.50.351.162.98114.5
01/02/20103.90.51.420.76113.46
01/03/201040.51.840.43118.9
01/04/20104.90.181.190.56126.67
01/05/20104.31.731.370.48109.05
01/06/20103.81.661.760.6689.44
01/07/20103.41.581.372.5180.92
01/08/20102.51.641.380.1458.95
01/09/20102.62.41.880.9459.19
01/10/20102.52.71.430.2965.37
01/11/20102.73.191.760.4174.34
01/12/20101.83.072.380.2257.24
01/01/20112.42.81.770.6373.72
01/02/20113.62.591.641.1998.62
01/03/20114.42.542.081.51128.35
01/04/20112.82.581.830.2164.68
01/05/20112.12.871.820.0548.82
01/06/20113.53.622.170.6979.88
01/07/20113.43.081.670.5678.67
01/08/20113.72.471.711.286.89
01/09/20113.53.392.061.2781.8
01/10/201134.921.90.5973.12
01/11/20113.56.432.062.9386.51
01/12/201128.342.651.2548.31
01/01/20123.27.891.681.9988.61
01/02/20123.59.191.511.0393.33
01/03/2012310.861.791.3170.23
01/04/20122.17.241.240.8147.74
01/05/20123.37.371.252.177.04
01/06/20123.311.561.610.2666.01
01/07/20123.211.71.30.9164.2
01/08/20122.912.421.431.1456.57
01/09/20122.816.611.732.0149.5
01/10/20122.711.871.390.6259.66
01/11/20122.611.291.50.2862.18
01/12/2012214.72.070.8443.73
01/01/20133.111.691.780.9883.68
01/02/20133.611.781.580.5889.65
01/03/20132.414.5321.1755.62
01/04/20132.510.962.050.2653.81
01/05/20132.910.232.050.1761.17
01/06/20133.112.382.030.8656.48
01/07/20132.910.131.870.2658.21
01/08/20133.19.951.750.2762.02
01/09/20133.213.181.850.6662.1
01/10/20133.511.011.910.5179.34
01/11/20132.611.561.90.5560.32
01/12/20132.215.031.880.6545.88
01/01/20143.411.431.730.7389.98
01/02/20143.511.281.620.8882.6
01/03/20143.613.612.030.3986.67
01/04/20144.511.831.970.1899.72
01/05/20143.411.52.140.2471.51
01/06/20143.710.661.810.1570.21
01/07/20143.610.661.970.2272.53
01/08/20143.69.52.270.1471.84
01/09/20143.610.112.10.173.68
01/10/20143.111.32.760.2668.6
01/11/20142.911.762.730.4465.37
01/12/20142.412.423.020.6253.51
01/01/20153.312.513.190.9987.8
01/02/20154.110.135.071.3796.59
01/03/20153.69.44.741.4788.79
01/04/20152.88.65.070.2853.44
01/05/20152.68.895.410.5946.98
01/06/201538.015.180.5455.62
01/07/20153.98.035.31.0478.31
01/08/20153.18.395.020.7857.81
01/09/20153.68.285.390.772.31
01/10/20153.89.195.420.883.46
01/11/20153.49.395.770.9278.29
01/12/20152.99.226.05171.23
01/01/20164.79.836.691.28122.35
01/02/2016511.946.81.21117.91
01/03/2016413.527.640.3789.79
01/04/20164.38.243.931.1997.36
01/05/20164.88.254.11.3898.38
01/06/20164.37.913.870.7782.87
01/07/20163.68.174.10.9267.05
01/08/20163.58.073.942.1664.78
01/09/20166.38.133.774.3127.37
01/10/20166.28.973.912.57139.45
01/11/20165.89.654.135.29141.76
01/12/20163.89.354.263.2589.34
01/01/20174.210.625.592.17107.06
01/02/20173.48.965.061.378.15
01/03/20172.99.455.251.0565.19
01/04/20172.58.894.950.2343.27
01/05/20175.28.544.770.72108.54
01/06/20173.88.424.850.3870.81
01/07/201749.525.110.0776.83
01/08/20173.89.445.440.1370.25
01/09/201759.365.50.6896.68
01/10/20173.99.556.480.5579.14
01/11/20172.910.46.370.660.85
01/12/20172.711.016.310.0659.57
01/01/20182.911.286.090.1167.64
01/02/20182.910.595.820.1960.93
01/03/20183.610.486.490.0476.84
01/04/20183.29.55.670.264.67
01/05/20184.79.425.360.0892.41
01/06/20183.98.634.950.1472.6
01/07/20183.29.065.020.1259.1
01/08/20184.39.035.250.0481.71
01/09/20184.99.055.590.1394.69
01/10/20184.310.476.070.1289.14
01/11/20183.811.156.210.1583.8
01/12/20182.611.586.280.0653.14
01/01/20193.410.856.370.1683.26
01/02/20193.510.095.680.0470.91
01/03/20193.410.206.500.1969.90

More information

Electricity trading volumes and churn ratio: At-a-glance summary

There is a diverse range of products and platforms available for those looking to trade power in GB. However, the majority of electricity trades are still done over-the-counter (OTC). Baseload products persistently dominate; accounting for the vast majority of OTC traded volumes. Since the implementation of our Secure and Promote Licence Condition there has been an increase in the number of times units of power are traded before delivery (churn), indicating a slight improvement in churn. 

Relevance and further information

Churn is one metric used to assess market liquidity. It shows how often a unit of electricity is traded before it is delivered to end consumers. Liquidity is an important feature of mature markets, often reflecting a large number of buyers and sellers.

Liquid markets also facilitate new entry by making it easier to buy and sell electricity at a good price. For example, in a liquid market a new supplier can more easily enter the market and buy the electricity they need to cover their consumers’ demand whilst also having confidence in the price they are paying for that electricity.

Volumes on the respective platforms tend to reflect the time horizon of the contracts traded and are not reflective of the total contribution to market liquidity. 

Methodology

Churn ratios are calculated by dividing total traded electricity volumes by the total amount of electricity demanded.

Trading data are based on total volumes from over-the-counter trading (sourced from ICIS) and the major electricity exchanges (ICE, EPEX SPOT and N2EX)

Physical demand data is sourced from BEIS Energy trends.

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Chart

Javascript is required to render chart Electricity bid-offer spreads by contract type (GB).

Source: Ofgem calculations using data from ICIS .

Information correct as of: July 2019

This chart shows bid-offer spreads across a range of contracts for electricity delivered in GB for different periods of time in the future. Figures are presented as monthly averages of daily spreads.

Policy Areas:

  • Electricity - wholesale markets

Data Table

Electricity bid-offer spreads by contract type (GB)
Month beginningDay-aheadFront MonthFront QuarterFront SeasonSecond SeasonThird SeasonFourth Season
01/01/20060.63%0.60%0.87%0.68%0.70%1.10%0.90%
01/02/20060.71%0.64%0.91%0.86%0.57%0.91%0.60%
01/03/20061.16%0.60%1.03%1.01%0.58%1.15%0.75%
01/04/20060.70%0.60%0.97%0.56%0.91%0.71%0.97%
01/05/20060.97%0.75%0.75%0.54%0.83%0.53%0.79%
01/06/20061.29%0.59%1.00%0.57%0.76%0.59%0.81%
01/07/20060.74%0.68%0.73%0.51%0.65%0.60%0.82%
01/08/20060.86%0.46%0.72%0.52%0.62%0.61%0.87%
01/09/20061.19%0.64%0.97%0.66%0.66%0.80%0.96%
01/10/20061.66%0.55%0.71%0.86%0.77%1.03%1.00%
01/11/20061.29%0.59%0.72%0.74%0.70%0.95%0.87%
01/12/20061.44%0.88%1.19%1.22%0.99%1.37%1.10%
01/01/20071.68%1.00%2.23%1.08%0.84%1.10%1.03%
01/02/20071.99%1.17%1.85%1.16%0.83%1.20%1.33%
01/03/20072.38%1.08%1.74%1.36%0.83%1.23%1.04%
01/04/20072.75%0.86%0.95%0.78%0.99%0.99%1.48%
01/05/20072.23%0.94%1.46%0.76%0.73%1.01%1.26%
01/06/20072.35%0.74%0.92%0.66%0.73%0.94%1.15%
01/07/20072.93%0.76%1.27%0.61%0.82%0.77%1.25%
01/08/20071.82%0.83%1.14%0.62%0.67%0.76%1.08%
01/09/20071.73%0.67%0.92%0.63%0.86%0.64%0.79%
01/10/20071.37%0.74%0.76%0.74%0.78%1.02%0.83%
01/11/20070.89%0.65%0.81%0.71%0.85%1.04%1.00%
01/12/20071.15%0.63%0.94%0.83%0.74%1.30%1.24%
01/01/20080.73%0.63%1.19%0.82%0.75%1.02%0.97%
01/02/20081.12%0.58%1.21%0.84%0.68%1.16%0.90%
01/03/20080.88%0.40%0.94%0.62%0.51%1.01%0.70%
01/04/20080.83%0.38%0.74%0.62%0.74%0.70%0.91%
01/05/20080.85%0.40%0.63%0.56%0.55%0.69%0.94%
01/06/20080.74%0.41%0.68%0.49%0.57%0.68%0.90%
01/07/20080.78%0.29%0.96%0.52%0.67%0.72%0.78%
01/08/20080.82%0.40%0.77%0.60%0.76%0.68%1.09%
01/09/20080.71%0.33%0.69%0.67%0.66%0.67%0.95%
01/10/20080.95%0.62%0.87%0.69%0.74%1.17%1.11%
01/11/20080.70%0.57%1.08%0.80%0.88%1.19%1.21%
01/12/20081.34%0.83%1.22%0.96%0.89%1.30%1.12%
01/01/20091.35%0.84%2.03%1.03%0.92%1.55%1.26%
01/02/20091.92%0.93%1.96%1.05%0.86%1.49%1.26%
01/03/20091.88%0.85%1.48%1.09%0.79%1.28%1.14%
01/04/20092.13%0.80%0.99%0.57%0.75%0.73%1.17%
01/05/20091.43%0.47%1.19%0.61%0.80%0.81%1.19%
01/06/20091.52%0.61%1.11%0.62%0.88%0.74%0.92%
01/07/20092.02%0.74%0.97%0.69%0.82%1.03%1.23%
01/08/20092.30%0.65%1.21%0.69%0.61%0.72%0.70%
01/09/20091.10%0.47%1.38%0.83%0.79%0.88%0.99%
01/10/20090.70%0.47%0.55%0.72%0.55%0.82%0.73%
01/11/20090.68%0.42%0.51%0.48%0.61%0.94%0.90%
01/12/20090.72%0.89%1.19%1.09%1.01%1.38%1.24%
01/01/20100.64%0.60%1.50%0.81%0.81%1.16%1.13%
01/02/20100.61%0.49%1.19%0.67%0.69%1.05%1.07%
01/03/20100.80%0.60%1.72%1.11%0.66%1.09%1.08%
01/04/20100.73%0.79%0.93%0.80%0.98%1.13%1.42%
01/05/20100.63%0.60%0.77%0.60%0.90%0.95%1.39%
01/06/20100.67%0.63%1.15%0.75%1.09%1.13%1.39%
01/07/20100.56%0.64%1.83%0.67%0.99%1.00%1.22%
01/08/20100.55%0.67%1.58%0.69%1.02%1.10%1.38%
01/09/20100.66%0.50%1.58%0.64%0.73%0.77%1.16%
01/10/20100.56%0.57%0.83%0.55%0.64%0.85%1.00%
01/11/20100.53%0.52%0.56%0.49%0.49%0.71%0.87%
01/12/20100.49%0.53%0.98%0.70%0.65%1.13%0.91%
01/01/20110.45%1.91%1.72%0.43%0.49%0.81%0.98%
01/02/20110.48%1.40%1.66%0.46%0.44%0.78%0.75%
01/03/20110.48%0.63%1.36%0.52%0.39%0.63%0.64%
01/04/20110.39%0.42%0.52%0.50%0.49%0.62%0.76%
01/05/20110.43%0.41%0.48%0.39%0.55%0.77%0.87%
01/06/20110.39%0.43%0.67%0.44%0.68%0.63%0.71%
01/07/20110.45%0.58%0.70%0.39%0.67%0.66%0.78%
01/08/20110.65%0.46%0.77%0.43%0.57%0.69%0.97%
01/09/20110.56%0.54%0.74%0.54%0.64%0.71%0.88%
01/10/20110.48%0.46%0.63%0.64%0.69%0.87%0.96%
01/11/20110.59%0.44%0.56%0.52%0.54%0.99%0.94%
01/12/20110.49%0.55%1.00%0.68%0.75%1.23%1.16%
01/01/20120.54%0.53%1.78%0.70%0.73%0.86%0.94%
01/02/20120.44%0.60%1.75%0.64%0.55%0.83%0.98%
01/03/20120.47%0.55%1.37%0.70%0.54%0.82%0.85%
01/04/20120.48%0.70%0.90%0.62%0.68%0.77%1.11%
01/05/20120.46%0.52%0.89%0.48%0.70%0.75%1.08%
01/06/20120.49%0.58%1.04%0.46%0.69%0.85%1.18%
01/07/20120.49%0.58%1.14%0.47%0.83%0.81%0.98%
01/08/20120.55%0.52%1.13%0.42%0.79%0.85%0.97%
01/09/20120.48%0.49%0.96%0.49%0.74%0.75%0.90%
01/10/20120.48%0.47%0.77%0.42%0.62%0.89%0.89%
01/11/20120.47%0.44%0.58%0.43%0.47%0.89%0.89%
01/12/20120.51%0.42%0.84%0.52%0.67%0.83%0.98%
01/01/20130.40%0.42%0.96%0.44%0.44%0.79%0.80%
01/02/20130.49%0.44%1.06%0.63%0.57%0.76%0.79%
01/03/20130.42%0.48%1.05%0.49%0.55%0.60%0.68%
01/04/20130.39%0.48%0.71%0.41%0.57%0.57%0.77%
01/05/20130.41%0.50%0.59%0.40%0.50%0.51%0.76%
01/06/20130.45%0.44%0.55%0.38%0.53%0.46%0.70%
01/07/20130.43%0.40%0.64%0.36%0.47%0.37%0.51%
01/08/20130.42%0.44%0.53%0.37%0.47%0.36%0.47%
01/09/20130.40%0.41%0.67%0.39%0.49%0.47%0.53%
01/10/20130.42%0.33%0.45%0.33%0.30%0.45%0.43%
01/11/20130.34%0.41%0.33%0.25%0.24%0.48%0.42%
01/12/20130.37%0.39%0.57%0.38%0.42%0.44%0.56%
01/01/20140.37%0.44%0.78%0.32%0.28%0.29%0.36%
01/02/20140.40%0.54%0.94%0.59%0.53%0.46%0.41%
01/03/20140.43%0.50%1.11%0.66%0.51%0.56%0.37%
01/04/20140.48%0.34%0.46%0.37%0.33%0.32%0.44%
01/05/20140.44%0.39%0.41%0.32%0.28%0.30%0.36%
01/06/20140.22%0.40%0.56%0.28%0.31%0.27%0.41%
01/07/20140.33%0.35%0.48%0.27%0.26%0.28%0.41%
01/08/20140.33%0.31%0.40%0.25%0.21%0.30%0.31%
01/09/20140.25%0.28%0.33%0.27%0.30%0.25%0.26%
01/10/20140.25%0.24%0.33%0.22%0.25%0.37%0.24%
01/11/20140.21%0.23%0.24%0.32%0.25%0.26%0.30%
01/12/20140.25%0.33%0.27%0.26%0.26%0.33%0.35%
01/01/20150.29%0.22%0.30%0.25%0.26%0.33%0.28%
01/02/20150.26%0.29%0.35%0.24%0.32%0.36%0.39%
01/03/20150.25%0.21%0.28%0.27%0.24%0.32%0.31%
01/04/20150.24%0.21%0.24%0.24%0.24%0.26%0.33%
01/05/20150.24%0.17%0.28%0.27%0.20%0.24%0.33%
01/06/20150.28%0.23%0.23%0.24%0.21%0.28%0.34%
01/07/20150.26%0.22%0.30%0.23%0.23%0.31%0.30%
01/08/20150.24%0.19%0.29%0.25%0.20%0.28%0.32%
01/09/20150.27%0.26%0.34%0.29%0.26%0.30%0.28%
01/10/20150.27%0.19%0.33%0.25%0.26%0.30%0.35%
01/11/20150.31%0.27%0.27%0.28%0.22%0.31%0.35%
01/12/20150.27%0.27%0.26%0.29%0.32%0.36%0.35%
01/01/20160.27%0.23%0.33%0.25%0.27%0.32%0.31%
01/02/20160.32%0.24%0.34%0.34%0.28%0.32%0.33%
01/03/20160.36%0.23%0.31%0.29%0.24%0.25%0.33%
01/04/20160.29%0.23%0.31%0.25%0.28%0.33%0.39%
01/05/20160.29%0.34%0.28%0.28%0.32%0.40%0.42%
01/06/20160.27%0.30%0.33%0.30%0.32%0.34%0.41%
01/07/20160.31%0.29%0.45%0.35%0.32%0.33%0.43%
01/08/20160.29%0.27%0.35%0.27%0.28%0.34%0.35%
01/09/20160.25%0.28%0.33%0.35%0.29%0.34%0.37%
01/10/20160.23%0.35%0.31%0.31%0.33%0.31%0.30%
01/11/20160.23%0.32%0.38%0.36%0.30%0.32%0.34%
01/12/20160.27%0.38%0.41%0.30%0.35%0.34%0.30%
01/01/20170.30%0.32%0.44%0.35%0.30%0.30%0.35%
01/02/20170.38%0.28%0.35%0.28%0.28%0.26%0.32%
01/03/20170.47%0.36%0.34%0.32%0.25%0.33%0.33%
01/04/20170.47%0.25%0.32%0.35%0.31%0.33%0.38%
01/05/20170.49%0.31%0.27%0.24%0.29%0.39%0.38%
01/06/20170.51%0.30%0.29%0.28%0.34%0.32%0.38%
01/07/20170.47%0.22%0.32%0.23%0.30%0.29%0.37%
01/08/20170.50%0.23%0.33%0.22%0.25%0.44%0.38%
01/09/20170.42%0.41%0.41%0.31%0.25%0.35%0.40%
01/10/20170.25%0.16%0.18%0.15%0.16%0.21%0.25%
01/11/20170.21%0.13%0.15%0.13%0.15%0.19%0.19%
01/12/20170.22%0.14%0.17%0.14%0.16%0.21%0.24%
01/01/20180.42%0.29%0.46%0.33%0.34%0.41%0.42%
01/02/20180.44%0.30%0.39%0.35%0.31%0.43%0.46%
01/03/20180.49%0.36%0.40%0.30%0.26%0.30%0.41%
01/04/20180.55%0.33%0.37%0.30%0.32%0.35%0.41%
01/05/20180.39%0.29%0.37%0.24%0.30%0.33%0.43%
01/06/20180.45%0.31%0.44%0.34%0.38%0.42%0.45%
01/07/20180.37%0.34%0.36%0.29%0.29%0.39%0.41%
01/08/20180.36%0.34%0.35%0.25%0.29%0.32%0.37%
01/09/20180.34%0.29%0.36%0.27%0.32%0.44%0.45%
01/10/20180.31%0.29%0.36%0.33%0.32%0.42%0.46%
01/11/20180.43%0.25%0.31%0.28%0.27%0.35%0.44%
01/12/20180.38%0.33%0.37%0.26%0.34%0.49%0.45%
01/01/20190.32%0.26%0.40%0.31%0.33%0.44%0.51%
01/02/20190.40%0.33%0.28%0.35%0.34%0.33%0.40%
01/03/20190.44%0.32%0.36%0.38%0.22%0.35%0.39%

More information

Electricity bid-offer spreads: At-a-glance summary

Bid-offer spreads have consistently narrowed over the course of the last four years, indicating that the ability of firms to trade has improved over the period. This follows the Secure and Promote reforms that Ofgem put in place which place obligations on large generators to post bids and offers. Spreads are typically wider for peak products than for baseload, reflecting the higher volume of trading that occurs in baseload products.

Relevance and further information

The bid-offer spread is one indicator of market liquidity. It is the difference between the best bid to buy and the best offer to sell. It measures the premium an urgent buyer must pay if it wants to buy and the discount an urgent seller must make if it wants to sell. Tighter spreads suggest a more liquid market and robust pricing. 

Liquidity is an important feature of mature markets, often reflecting a large number of buyers and sellers. Liquid markets also facilitate new entry by making it easier to buy and sell electricity at a good price. For example, in a liquid market a new supplier can more easily enter the market and buy the power they need to cover their consumers’ demand whilst also having confidence in the price they are paying.

Methodology

The bid-offer spread is calculated by subtracting the bid price from the offer price and dividing it by the offer price. It is then multiplied by 100 to give a percentage. 

Spreads are based on over-the-counter trading and are assessed by ICIS at 4.30pm each business day.

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Chart

Javascript is required to render chart Electricity generation mix by quarter and fuel source (GB).

Source: BEIS Energy trends section 5: Electricity (ET 5.1) .

Information correct as of: July 2019

This chart shows quarterly totals of electricity generation by technology type for the GB National Electricity Transmission System, as well as net imports.

Policy Areas:

  • Electricity - wholesale markets

Data Table

Electricity generation mix by quarter and fuel source (GB)
DateCoalOilGasNuclearHydro (natural flow) Wind (onshore and offshore) and SolarBioenergyPumped storage (net supply)Other fuelsNet imports (Interconnectors)
Q1 200647.562.0629.9820.521.111.092.37-0.340.871.4
Q2 200628.55133.6918.210.960.792.13-0.250.782.86
Q3 200626.861.0735.3617.240.671.012.11-0.310.81.62
Q4 200638.521.2938.7313.261.821.352.49-0.30.81.63
Q1 200737.021.2242.8214.121.941.652.26-0.280.761.12
Q2 200724.11.0343.4713.730.840.931.96-0.280.860.89
Q3 200725.620.8136.5515.730.941.191.98-0.330.92.66
Q4 200742.291.439.5513.661.311.512.34-0.340.780.54
Q1 200833.421.0347.6113.141.972.222.18-0.290.812.42
Q2 200826.291.2141.9311.080.841.272.05-0.30.83.56
Q3 200822.011.5243.2810.960.731.312.07-0.350.683.72
Q4 200836.332.1340.1712.491.572.352.32-0.350.741.33
Q1 200937.811.8837.2715.41.562.62.53-0.330.780.57
Q2 200919.11.0338.1116.450.911.982.28-0.260.712.78
Q3 200915.571.0342.0716.11.132.122.23-0.290.80.81
Q4 200925.321.4246.0114.811.62.62.57-0.290.74-1.3
Q1 201030.971.2947.3316.520.842.432.7-0.290.6-1.69
Q2 201018.550.8344.6812.610.651.672.66-0.270.631.42
Q3 201018.811.0340.1111.820.852.772.84-0.230.612.76
Q4 201033.861.1640.3415.491.233.452.94-0.280.560.18
Q1 201133.360.8137.5917.671.293.412.99-0.260.71.06
Q2 201118.090.5136.2517.41.133.692.8-0.220.71.53
Q3 201118.150.737.9214.311.223.122.98-0.230.732.36
Q4 201133.410.7932.0513.2825.993.07-0.240.531.27
Q1 201239.910.7726.7115.621.825.253.45-0.260.731.99
Q2 201229.630.6124.7716.830.794.332.63-0.240.813.12
Q3 201227.310.522.5416.381.054.913.11-0.250.824.06
Q4 201238.670.724.2515.121.636.713.75-0.270.822.7
Q1 201339.30.4726.7116.611.246.923.58-0.270.792.81
Q2 201327.360.4223.714.050.967.194.4-0.260.833.56
Q3 201325.190.5420.9516.970.745.593.86-0.260.784.65
Q4 201331.730.4422.6616.51.7310.713.83-0.250.783.4
Q1 201432.770.4921.3115.012.2211.523.91-0.260.924.89
Q2 201420.960.4723.3315.91.16.64.7-0.250.885.08
Q3 201415.080.4128.6214.220.776.695.12-0.240.95.43
Q4 201426.270.3825.7412.771.7411.25.8-0.260.935.12
Q1 201528.040.4723.1916.51212.786.05-0.251.114.96
Q2 201515.190.3823.0215.371.4111.446.1-0.231.075.6
Q3 201512.170.4926.0615.041.029.926.11-0.251.095.92
Q4 201516.580.525.7316.981.8213.687.14-0.251.034.62
Q1 201613.940.333.4515.752.1612.997.45-0.271.36.04
Q2 20164.340.5133.8215.130.9711.126.72-0.261.25.36
Q3 20162.570.4132.0417.131.1911.935.38-0.231.254.74
Q4 20168.250.4941.317.141.2511.636.62-0.31.431.61
Q1 20179.90.3437.2516.031.8814.57.64-0.291.182.61
Q2 20171.460.3331.2216.20.914.86.67-0.251.195.25
Q3 20172.050.4229.6216.511.313.596.61-0.211.195.3
Q4 20177.970.3936.1515.161.7918.646.21-0.251.221.6
Q1 20188.260.4636.2315.121.5719.186.43-0.270.945.38
Q2 20181.150.2831.5215.1115.137.52-0.240.955.15
Q3 20181.760.3128.5215.670.8915.167.68-0.20.934.93
Q4 20184.80.4732.813.211.9520.578.7-0.190.993.65
Q1 20192.890.2735.7612.631.7220.527.38-0.191.426.05

More information

Electricity generation mix: At-a-glance summary

The GB electricity system is undergoing a period of significant change as we transition from a large-scale conventional fossil fuel dominated generation mix to intermittent renewable generation. Over the past few years, we have seen a marked increase in output from wind and solar farms. Since 2015, the share of electricity generated from gas increased, while the share generated from coal decreased. This was partly due to improved economics for gas-fired generators.

Relevance and further information

The electricity generation mix is a useful indicator of trends in the diversity and origin of electricity in GB.

Methodology

Positive values represent supplies to the GB system. This includes electricity produced by GB power stations and imports via interconnectors. 

Negative values represent supplies from the GB system (excluding end consumer demand). This includes power demanded by GB power stations and exports via interconnectors. 

Data marked as ‘(net)’ is underpinned by both positive (generation) and negative (demand) values. For instance, interconnectors can both import and export electricity. Similarly, pumped storage can both demand electricity to pump and generate electricity when releasing water through its turbines. As data is summarised as quarterly values, the net calculation for certain generation sources underestimates the full extent of generation and demand.

The data is updated quarterly using BEIS’ Energy Trends publication. Some historical figures may differ because of rounding.

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Javascript is required to render chart Prepayment price cap and prices since January 2016 (GB).

Source: Energylinx (Until May 2017) & Energyhelpline (June 2017 onwards).

Information correct as of: July 2019

This chart compares trends in prices since 2016 for a dual fuel customer paying prepayment. It shows both the market cheapest tariffs and average standard variable tariffs (SVT) for this payment method. The values are calculated for a customer with typical energy use.

From February 2017 the prices shown in the chart, including the level of the prepayment price cap, are calculated using the latest TDCV values that entered into effect from 1st of October 2017 (see the methodology section for more details).

In practical terms, this means that the tariffs offered after February 2017 are likely to appear slightly lower than those before February 2017.  

Policy Areas:

  • Electricity - retail markets
  • Electricity - wholesale markets
  • Gas - retail markets
  • Gas - wholesale markets

Data Table

Prepayment price cap and prices since January 2016 (GB)
DateSVT - prepayment (market average)Cheapest tariff - prepayment (all suppliers)Prepayment price cap
28/12/2015 1,163.44 1,055.61
28/01/2016 1,163.18 1,055.61
28/02/2016 1,158.61 1,054.20
28/03/2016 1,138.39 1,051.22
28/04/2016 1,131.32 1,030.27
28/05/2016 1,131.32 1,017.61
28/06/2016 1,131.32 985.97
28/07/2016 1,130.22 985.97
28/08/2016 1,130.22 985.97
28/09/2016 1,130.22 985.97
28/10/2016 1,130.22 985.97
28/11/2016 1,122.72 985.97
28/12/2016 1,122.72 985.97
28/01/2017 1,115.77 985.97
28/02/2017 1,061.14 970.67
28/03/2017 1,059.99 970.67
28/04/2017 1,032.30 970.67 1,050.35
28/05/2017 1,032.30 979.27 1,050.35
28/06/2017 1,032.30 979.27 1,050.35
28/07/2017 1,032.69 979.27 1,050.35
28/08/2017 1,031.31 979.27 1,050.35
28/09/2017 1,034.46 979.27 1,050.35
28/10/2017 1,030.60 978.04 1,031.27
28/11/2017 1,030.60 978.04 1,031.27
28/12/2017 1,030.60 957.12 1,031.27
28/01/2018 1,030.72 960.06 1,031.27
28/02/2018 1,030.72 945.76 1,031.27
28/03/2018 1,030.85 945.76 1,031.27
28/04/2018 1,079.09 946.63 1,088.55
28/05/2018 1,086.20 946.63 1,088.55
28/06/2018 1,086.19 946.63 1,088.55
28/07/2018 1,086.08 946.63 1,088.55
28/08/2018 1,086.06 946.54 1,088.55
28/09/2018 1,086.06 983.86 1,088.55
28/10/2018 1,135.42 983.86 1,135.99
28/11/2018 1,135.42 983.86 1,135.99
28/12/2018 1,135.42 983.86 1,135.99
28/01/2019 1,135.23 1,016.48 1,135.99
28/02/2019 1,135.23 1,023.39 1,135.99
28/03/2019 1,135.23 1,023.39 1,135.99
28/04/2019 1,241.44 1,023.39 1,242.07
28/05/2019 1,241.44 1,052.46 1,242.07
28/06/2019 1,241.44 1,052.46 1,242.07
28/07/2019 1,242.07

More information

At-a-glance summary

In April 2017, the prepayment price cap came into force, limiting the amount that suppliers can charge their prepayment customers. These customers tend to be unable to access the cheapest deals and are also more likely to be in vulnerable circumstances.

The cheapest prepayment tariffs available in the market have remained below the average SVT for a prepayment customer following the introduction of the prepayment price cap. This differential between the average SVT and the cheapest prepayment tariff has remained at £189 between May and June 2019.

On 1 April 2019, the level of the prepayment price cap increased from £1,136 to £1,242 for a dual fuel customer who uses a typical amount of energy. This increase was mainly due to higher wholesale energy costs and network costs.. For more information on the latest updates, see our chart Breakdown of the prepayment price cap.

Relevance and further information

This chart helps us track the differential between the average prepayment SVT and the market cheapest PPM tariff price a customer will pay if they use prepayment to pay their energy bills. Both prices are compared with the prepayment price cap that currently apply to all prepayment customers, excluding those on ‘interoperable’ smart meters.

Customers who get the Government’s Warm Home Discount (WHD) and are on a standard variable or default tariff were protected by a ‘safeguard tariff’ set at the level of the prepayment price cap until the end of 2018, after which they were transferred to the default tariff price cap. The default tariff price cap came into effect on 1 January 2019, limiting the amount that suppliers can charge customers on default tariffs.

The default tariff cap has different levels set to reflect how customers pay, where they live and the type of energy meter they have. When transferred, WHD customers will be placed on the cheaper default cap level set for direct debit payment methods – it won’t matter how they pay.

You can find further information on energy price caps here.

Methodology

  • We calculate the bill values associated with the different tariff types using a ‘typical medium domestic consumer’. As of October 2017, typical consumption values for a medium consumer are 12,000kWh/year for gas and 3,100kWh/year for electricity (profile class 1).  
  • All prices shown are for a dual fuel customer (i.e. where a customer takes gas and electricity from the same supplier).  
  • The market average SVTs are based on the prices of the 12 largest suppliers in the prepayment segment. We have weighted the SVT of each supplier using an estimate of their total share of all prepayment accounts (for prepayment). We update the weightings every six months in January and July to reflect customer numbers four months prior to publication. The time lag is due to data availability. For example, the average given for 28 January 2017 uses weights based on customer numbers at 31 October 2016, while the average for 28 December 2016 uses weights at 31 March 2016.  
  • An SVT refers to a supply contract which is for a period of an indefinite length, and which does not have a fixed-term period applying to any of the terms and conditions. It’s an energy supplier’s basic offer. If a customer does not choose a specific energy plan, for example after their fixed tariff ends, they will be moved onto an SVT until they have chosen a new one. A customer can also make an active choice to select an SVT. 
  • We exclude tariffs with limited availability – such as tariffs only available to new customers (also known as ‘acquisition’ tariffs) or tariffs restricted to certain regions - when calculating the market cheapest tariff. This is so we give a representative picture of tariffs generally available to all customers across GB. 
  • We include tariffs available with ‘white label’ suppliers in our calculation of the cheapest tariffs. White label suppliers are organisations without supply licences that partner with an active licensed supplier to offer gas and electricity using their own brand. 
  • The cheapest tariff shown on the chart includes any collective switching tariffs after the first quarter of 2016. 
  • In all cases, the prices shown are based on suppliers’ tariffs averaged across GB regions. The level of the prepayment price cap is based on the values published on our website, adjusted to reflect current typical domestic consumption values, and to include VAT.

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Chart

Source: ICIS.

Information correct as of: August 2019

This chart shows the price of electricity on the wholesale market in GB for delivery the next working day at a constant ‘baseload’ rate. The data is averaged by month rather than by day and covers around an eight year time period. Further information on wholesale prices can be found in our State of the Energy Market 2018 report

The data comes from ICIS’s price assessment of over-the-counter trading through brokers. A full explanation of ICIS’s methodology is available on ICIS's website.

Policy Areas:

  • Electricity - wholesale markets

Data Table

Electricity prices: Day-ahead baseload contracts – monthly average (GB)
Month beginningPrice
01/06/201042.18
01/07/201043.53
01/08/201039.95
01/09/201041.12
01/10/201043.5
01/11/201046.4
01/12/201058.03
01/01/201148.43
01/02/201146.47
01/03/201151.41
01/04/201150.88
01/05/201150.27
01/06/201150.82
01/07/201147.96
01/08/201147.36
01/09/201148.32
01/10/201146.83
01/11/201146.15
01/12/201143.54
01/01/201242.17
01/02/201249.1
01/03/201245.64
01/04/201245.91
01/05/201243.79
01/06/201242.24
01/07/201242.71
01/08/201241.21
01/09/201243.39
01/10/201247.6
01/11/201249
01/12/201249.76
01/01/201349.96
01/02/201351.44
01/03/201362.9
01/04/201351.3
01/05/201348.89
01/06/201347.31
01/07/201348.73
01/08/201347.31
01/09/201349.63
01/10/201348.22
01/11/201353.05
01/12/201350.81
01/01/201447.67
01/02/201445.15
01/03/201444.41
01/04/201441.77
01/05/201439.62
01/06/201436.67
01/07/201435.46
01/08/201437.95
01/09/201443.28
01/10/201444.81
01/11/201448.43
01/12/201443.96
01/01/201539.86
01/02/201542.86
01/03/201540.91
01/04/201543.97
01/05/201541.21
01/06/201541.66
01/07/201542.2
01/08/201540.86
01/09/201542.04
01/10/201540.29
01/11/201538.01
01/12/201535.07
01/01/201636.95
01/02/201633.85
01/03/201634.76
01/04/201634.37
01/05/201634.61
01/06/201637.51
01/07/201638.4
01/08/201636.51
01/09/201651.13
01/10/201656.03
01/11/201667.54
01/12/201649.87
01/01/201753.37
01/02/201749.49
01/03/201741.99
01/04/201742.10
01/05/201741.24
01/06/201739.68
01/07/201743.05
01/08/201743.34
01/09/201747.17
01/10/201746.68
01/11/201751.45
01/12/201756.18
01/01/201850.84
01/02/201853.68
01/03/201856.79
01/04/201850.74
01/05/201854.25
01/06/201854.00
01/07/201857.61
01/08/201861.94
01/09/201867.69
01/10/201864.76
01/11/201862.19
01/12/201864.32
01/01/201962.55
01/02/201950.27
01/03/201944.96
01/04/201943.87
01/05/201941.35

More information

Electricity prices (Day-ahead, baseload contracts): At-a-glance summary

Electricity wholesale prices in GB over the past decade have largely been driven by changes in the gas price. This is because gas-fired generation is often the marginal source of supply and hence sets the electricity price. Changes in carbon prices have also influenced electricity prices in recent years.

Relevance and further information

Day-ahead prices are a good indicator of the short-term price of electricity in GB. However, Day-ahead prices are just one measure of the price of electricity. Suppliers will often buy most of their electricity months or even years in advance of when it will be delivered, so Day-ahead prices may not necessarily reflect the price that suppliers will have paid for their electricity.

The ‘baseload’ rate refers to a contract for electricity that is produced continually throughout the day and is distinct from ‘peak rates’ when electricity is bought/sold for consumption at peak times (7am to 7pm).  

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Source: Ofgem calculations using data from Elexon and NETA reports.

Information correct as of: April 2019

This chart shows the market shares of companies who supply electricity to the GB National Transmission System by year. 

The companies with the largest 8 market shares are identified largest to smallest, with all other companies shown as ‘Other’.

Policy Areas:

  • Electricity - wholesale markets

Data Table

Wholesale electricity generation market shares by company in 2018 (GB)
CompanyShare
EDF27%
RWE13%
SSE9%
Drax7%
Uniper6%
EEX5%
ScottishPower3%
Orsted3%
Other28%

More information

Wholesale electricity supply market shares: At-a-glance summary

This chart shows the market shares of companies who supply electricity to the GB National Transmission System by year. 

The companies with the largest 8 market shares are identified largest to smallest, with all other companies shown as ‘Other’.

Our analysis of market concentration suggests that the GB wholesale electricity market appears to have relatively low levels of concentration. 

In 2018, EDF Energy had the largest share, accounting for over a quarter of total generation. However, EDF Energy’s generation portfolio is mostly nuclear plant. Nuclear plants have very low marginal costs and are not designed to frequently increase or decrease output. This means they generally run as a flat baseload source of power at high-load factors.

Relevance and further information

Market shares are an important indicator of trends in market concentration and competition. High market shares for a small number of firms suggest low levels of competition, and vice versa.  

Methodology

We calculate market shares from metered volumes associated with individual power stations and interconnectors (called Balancing Mechanism Units or BM units). 

Volumes are split based on equity stakes.

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Source: Ofgem analysis of companies’ Consolidated Segmental Statements.

Information correct as of: August 2018

This chart shows the Earnings Before Interest and Tax (EBIT) margins for the generation activities of the six large energy suppliers in the GB market. 

A company’s EBIT margin is their revenue minus their costs, before accounting for taxes and interest. These margins have been divided to highlight variations in profitability for different types of power generation technology.

Policy Areas:

  • Electricity - wholesale markets

Data Table

Large suppliers: Electricity generation profitability by technology type in 2017 (GB)
CompanyNuclearConventionalRenewable
Centrica8.9%1.2%0%
E.ON0%*39.4%
EDF5.3%-21.4%37.3%
RWE0%-2.9%41.1%
ScottishPower0%-1.8%46.2%
SSE0%5.79%53.83%

More information

Electricity generation profitability by technology type: At-a-glance summary

Profitability of electricity generation for the six large suppliers active in the electricity wholesale market can be shown through analysis of their Consolidated Segmental Statements (CSS). There has been a marked reduction in conventional generator profitability in recent years. On the flip side there has been an increase in renewable generation profitability.  

Relevance and further information

The Earnings Before Interest and Tax (EBIT) margin is a useful indicator of trends in energy company profits. The level of profit in a market is a good measure of how competitive that market is. Here we have shown profitability by power generation technology type to indicate which forms of technology generation are most profitable for generators. 

Methodology

EBIT is calculated by subtracting the total direct costs, total indirect costs (such as operating costs) and depreciation and amortisation for supplying energy from a supplier’s total revenue.

The EBIT margin is calculated by dividing a supplier’s total revenue by the EBIT value. It is expressed as a percentage, so the figure is multiplied by 100.

We have split margins into conventional generation (eg coal, gas, oil), renewables (eg wind, hydro) and nuclear.

The data in this chart may differ from the data that can be found in the supplier’s externally published Consolidated Segmental Statements. This is because we have made some adjustments to improve comparability. These mostly relate to removing certain impairment and restructuring costs. Detail on these adjustments can be found in Ofgem's review of 2017 CSS.

Note: Following E.ON’s separation of its fossil fuel generation assets to Uniper in 2016, and subsequent sale of Uniper, the activities of Uniper UK Limited are not included in E.ON’s UK CSS for 2017. As a result, E.ON’s revenues from conventional generation have significantly decreased from 2016 and so have not been included in the chart as they are not directly comparable with the margins for the other Big 6.   

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