Spark and dark spreads (GB)

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 %.
Date correct
July 2019
Policy area