The UK’s solar panels generated more electricity than coal across the past six months combined, Carbon Brief analysis shows, rounding off a historic half-year of firsts.
Saturday 9 April 2016 was the first-ever day where more electricity was generated in the UK by solar than by coal. May 2016 was the first-ever month. The three months from June through to September was the first-ever quarter. And now the six months to September is the first half year.
These firsts reflect the changing face of UK electricity supplies, with solar capacity having nearly doubled during 2015. They also reflect historic lows for coal-fired generation, driven by changes in wholesale energy markets and the carbon price floor. Carbon Brief runs through the numbers.
Solar six months
The UK’s solar panels generated an estimated 6,964 gigawatt hours (GWh) of electricity during quarter two (Q2) and three (Q3) of 2016, from April through to September. (See note below regarding data sources and methodology).
The solar output was equivalent to 5.2% of UK electricity demand for the half-year period. It was nearly 10% higher than the 6,342 GWh generated by coal, which covered 4.7% of demand.
Starting on 1 July, there were 10 straight weeks when solar output exceeded that from coal.
Solar output is strongly affected by the UK’s seasonal cycle. Roughly three-quarters of annual UK solar power is generated during the sunnier half-year from April to September. In contrast, coal generation tends to increase in winter when electricity demand peaks.
The chart below shows these contrasting seasonal cycles. It also shows two contrasting broader trends.
First, UK solar capacity has to date reached around 12 gigawatts (GW), according to research by Solar Intelligence, up from around 6GW at the start of 2015. Solar generation is increasing as a result, up 26% in 2016 to date, compared to the same period in 2015.
(Note that solar capacity additions have fallen this year, following subsidy cuts. Note also that while government figures for new capacity have been consistently too low, independent estimates also show the drop.)
Total electricity generation from UK solar and coal during calendar months in 2015 and 2016 to date, gigawatt hours (GWh). Sources: Sheffield Solar and Gridwatch. Chart by Carbon Brief using Highcharts.
Second, the chart shows how coal generation has fallen rapidly, at a rate that is far beyond its usual annual cycle. Output in 2016 to date was 65% below that in 2015. It was down 76% in Q2 and 82% in Q3 compared to a year earlier.
This year also saw UK coal generation fall to zero on 9 April, for the first time since 1882, when a coal-fired power station started supplying electricity to the public for the first time. Since then, there have been 199 hours when coal was generating no power in the UK.
The drop in coal output has come about because of wholesale energy market price shifts being more favourable to gas-fired generators than to coal. In addition, the UK’s carbon floor price doubled in April 2015, again shifting the economics of electricity generation in favour of gas over coal.
The key role of the carbon floor price in driving coal off the system is underlined in recent analysis from consultancy Cornwall Energy. This shows that removing the UK’s top-up carbon tax would mean coal plants once again being cheaper to run than gas.
Tom Edwards, Cornwall Energy senior consultant writes:
“This would return the market to the position seen in 2014 when coal-fired generators were running baseload [all the time] and gas-fired stations were pushed to the margin.”
It’s worth noting that while gas-fired power stations have replaced most of the reduction in coal output, the total supplied by the two fossil fuels is also falling. This is because of increases in electricity supplied by renewables and imports, along with falling demand.
Methods: The figures for shares of total UK electricity generation are estimates. They only include solar generation and other forms of generation that are connected to the transmission grid network. Embedded generation from wind or other sources is not centrally metered and data is not available. However, this missing data will not alter the relative positions of solar and coal generation.
Figures for solar output in the UK are estimates produced by Sheffield Solar. The project recently updated its estimates of installed UK solar capacity. Its estimates scale real live data obtained from 324 solar sites around the UK.
Carbon Brief analysis shows the Sheffield Solar estimates to have a very small average error of 4%, compared to official government figures for solar generation since the start of 2015.
Photo credit: By Glyn Drury, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=13931265
Paneli za jua za Uingereza zilitoa umeme zaidi kuliko makaa ya mawe katika miezi sita iliyopita pamoja, Uchambuzi wa Carbon Brief unaonyesha, kukamilisha nusu ya mwaka wa kihistoria wa kwanza. Siku ya Jumamosi, Aprili 9, 2016, ilikuwa siku ya kwanza kabisa ambapo umeme zaidi ulitokezwa nchini Uingereza na jua kuliko makaa ya mawe. Mei 2016 ilikuwa mwezi wa kwanza kabisa. Miezi mitatu kutoka Juni hadi Septemba ilikuwa robo ya kwanza kabisa. Sasa miezi sita hadi Septemba ni nusu ya kwanza ya mwaka. "Hii ni mara ya kwanza kuonyesha ""mabadiliko"" ya uso wa usambazaji wa umeme wa Uingereza, na uwezo wa jua umekuwa karibu mara mbili wakati wa 2015." Pia zinaonyesha viwango vya chini vya kihistoria vya uzalishaji wa makaa ya mawe, vinavyoongozwa na mabadiliko katika masoko ya nishati ya jumla na kiwango cha chini cha bei ya kaboni. Carbon Brief inaendesha kupitia namba. Kwa mujibu wa ripoti ya UK Solar Panel, paneli za jua nchini Uingereza zilitoa umeme wa karibu saa 6,964 za gigawatt (GWh) katika robo ya pili na tatu ya mwaka 2016 kuanzia Aprili hadi Septemba. (Tazama maelezo hapa chini kuhusu vyanzo vya data na mbinu). Uzalishaji wa jua ulikuwa sawa na 5.2% ya mahitaji ya umeme wa Uingereza kwa kipindi cha nusu mwaka. Kwa mujibu wa ripoti hiyo, kiwango cha umeme kilichotengenezwa kwa makaa ya mawe kilikuwa karibu na GWh 6,342 (gWh 4.7% ya mahitaji). Kuanzia Julai 1, kulikuwa na wiki kumi mfululizo wakati uzalishaji wa jua ulipozidi ule wa makaa ya mawe. Uzalishaji wa jua unaathiriwa sana na mzunguko wa msimu wa Uingereza. Karibu robo tatu ya nishati ya jua ya kila mwaka nchini Uingereza hutengenezwa wakati wa nusu ya mwaka wa jua kutoka Aprili hadi Septemba. Kinyume chake, uzalishaji wa makaa ya mawe huelekea kuongezeka wakati wa majira ya baridi kali wakati mahitaji ya umeme yanapofikia kilele. Chati iliyo hapa chini inaonyesha mizunguko hiyo ya majira yenye kutofautisha. Pia inaonyesha mwenendo mbili tofauti za jumla. Kwa mujibu wa utafiti uliofanywa na Solar Intelligence, uwezo wa jua nchini Uingereza umefikia karibu gigawatt 12 (GW) tangu mwanzo wa mwaka 2015. Kwa mujibu wa ripoti hiyo, nishati ya jua imepanda kwa asilimia 26 katika mwaka 2016 ikilinganishwa na mwaka 2015. (Kumbuka kwamba nyongeza ya uwezo wa jua imepungua mwaka huu, kufuatia kupunguzwa kwa ruzuku. Kumbuka pia kwamba wakati takwimu za serikali kwa ajili ya uwezo mpya wamekuwa mfululizo chini sana, makadirio huru pia kuonyesha kushuka.) Utoaji wa umeme kutoka kwa jua na makaa ya mawe nchini Uingereza katika miezi ya kalenda ya 2015 na 2016 hadi sasa, Gigawathours (GWh). Vyanzo: Sheffield Solar na Gridwatch. Chati na Carbon Brief kutumia Highcharts. Kwa upande mwingine, chati inaonyesha jinsi uzalishaji wa makaa ya mawe umepungua haraka, kwa kiwango ambacho ni mbali zaidi ya mzunguko wake wa kawaida wa kila mwaka. Kwa mujibu wa ripoti hiyo, uzalishaji wa mwaka 2016 ulikuwa chini ya asilimia 65 ya uzalishaji wa mwaka 2015. Ilikuwa chini ya asilimia 76 katika robo ya pili na asilimia 82 katika robo ya tatu ikilinganishwa na mwaka uliopita. Mwaka huu pia uliona uzalishaji wa makaa ya mawe wa Uingereza ukianguka hadi sifuri tarehe 9 Aprili, kwa mara ya kwanza tangu 1882, wakati kituo cha umeme cha makaa ya mawe kilianza kutoa umeme kwa umma kwa mara ya kwanza. Tangu wakati huo, kwa muda wa saa 199, makaa ya mawe hayakuweza kuzalisha umeme nchini Uingereza. Kupungua kwa uzalishaji wa makaa ya mawe kumetokea kwa sababu ya mabadiliko ya bei ya soko la nishati ya jumla kuwa mazuri zaidi kwa jenereta za gesi kuliko makaa ya mawe. Kwa kuongezea, bei ya chini ya kaboni ya Uingereza iliongezeka mara mbili mnamo Aprili 2015, tena ikibadilisha uchumi wa uzalishaji wa umeme kwa niaba ya gesi badala ya makaa ya mawe. "Hatua ya ""bodi ya chini ya kaboni"" ni muhimu kwa kuondoa makaa ya mawe kutoka kwa mfumo wa umeme wa dunia, kulingana na utafiti wa hivi karibuni kutoka kwa kampuni ya ushauri ya Cornwall Energy." Hii inaonyesha kwamba kuondoa ushuru wa juu wa kaboni wa Uingereza ingemaanisha kuwa mitambo ya makaa ya mawe tena ni ya bei nafuu kuendesha kuliko gesi. "Tom Edwards, mshauri mwandamizi wa Cornwall Energy, aliandika: ""Hii itarudisha soko kwenye nafasi ya 2014 wakati jenereta za makaa ya mawe zilikuwa zikifanya kazi kwa mzigo wa msingi na vituo vya gesi vilipelekwa kwenye pembe. "" Inastahili kutajwa kwamba wakati vituo vya umeme vya gesi vimechukua nafasi ya kupunguzwa kwa uzalishaji wa makaa ya mawe, jumla ya mafuta mawili ya mafuta pia inashuka." Hii ni kwa sababu ya ongezeko la umeme uliotolewa na vyanzo vya nishati mbadala na uagizaji, pamoja na kupungua kwa mahitaji. Njia: Takwimu kwa ajili ya hisa ya jumla ya uzalishaji wa umeme Uingereza ni makadirio. Wao tu ni pamoja na uzalishaji wa jua na aina nyingine ya uzalishaji kwamba ni kushikamana na mtandao wa usafirishaji wa mtandao. Uzalishaji ulioingizwa kutoka kwa upepo au vyanzo vingine haupimwa kwa njia ya kati na data haipatikani. Hata hivyo, data hii inayokosekana haitabadilisha nafasi za jamaa za uzalishaji wa jua na makaa ya mawe. Takwimu za uzalishaji wa jua nchini Uingereza ni makadirio yaliyotolewa na Sheffield Solar. Mfumo huo umesasisha hivi karibuni makadirio yake ya uwezo wa jua uliowekwa nchini Uingereza. Kwa mujibu wa ripoti hiyo, data za kihistoria za jua zinapatikana katika maeneo 324 nchini Uingereza. Uchambuzi wa Carbon Brief unaonyesha makadirio ya Sheffield Solar kuwa na makosa madogo sana ya wastani ya 4%, ikilinganishwa na takwimu rasmi za serikali kwa uzalishaji wa jua tangu mwanzo wa 2015. Picha: Gwen Gwen, CC BY-SA 2.0 (Kichapo cha kwanza)