UK generated more electricity from solar than coal over last six months

Solar has bested coal in the electricity production stakes over the past six months, finds a new report by Carbon Brief.

In what is a first for the country, the amount of gigawatt hours generated by the sun between April and September reached 6,964 (GWh), which amounted to 5.4% of the U.K.’s electricity demand and, significantly, represented greater output than coal.

The report by Carbon Brief serves to highlight the starkly different directions in which the two respective sources are moving, and while solar’s share of the overall energy mix is still small, its impact has been profoundly positive.

The writing has been on the wall for some time. In April solar eclipsed coal for a single day, then throughout May, PV’s output outshone that of coal, while the recent data puts solar at 6.9 GWh between April and September, with coal at a relatively anemic 6.4 GWh.

“This is a valuable milestone on the road to renewables overtaking fossil fuels,” said a spokeswoman for the Solar Trade Association (STA), which this week issued a report (examined below) revealing the low cost of integrating solar into the U.K.’s power system. “It is a testament to just how effective the British solar industry has been at installing clean and reliable power and at bringing down costs.”

However, solar’s shine is set to be short-lived. The months April to September are traditionally the strongest for solar output in the U.K., and coincided with a widespread phasedown of coal plants nationwide. Allied to further regressive cuts to solar support, and it is unlikely that the technology will enjoy such a prominent role in the U.K.’s electricity output for a while yet.

The U.K.’s aging coal fleet is being gradually phased out, with just 10 coal power plants remaining in operation in the U.K. today.

Solar overcoming integration problems

Although solar’s influence is likely to be stunted over the next few years, the nation’s most popular form of energy technology is also likely to be its cheapest by the next decade, finds a new report by the Solar Trade Association (STA).

The STA analysis, conducted in collaboration with Aurora energy Research, finds that incorporating solar into the U.K.’s power system – complete with requisite ‘back-up’ – is just £1.30/MWh, or less than 2% of the costs of solar today.

Because of solar’s variability, there have been concerns that its true costs were masked because all calculations should include the necessary back-up costs associated with solar. The STA has duly done the cost analysis, and the results would appear to ease fears that solar+back-up is still too expensive.

“The tremendous growth in local, clean generation has challenged the old power supply model,” said STA chief executive Paul Barwell. “Yet ministers can be reassured that the rapid expansion in solar power over recent years has been absorbed efficiently and affordably by the system.”

The STA report shows that if solar power reached 10% of the U.K.’s electricity output – approximately 40 GW – then there would be only a modest increase in the cost of managing variability, rising to a maximum of £6-£7/MWh.

With solar costs projected to continue to fall, allied to this much-called for clarity on integration costs, solar can become the country’s cheapest form of energy generation in the 2020s.

The report also shows how solar’s decentralized nature will bring a greater flexibility to an increasingly smarter power system. As more batteries are added to the grid, the cost of variability falls to £10.50/MWh, whch is actually a net benefit of £3.70/MWh, the report shows. This is due to solar+storage being able to closely match demand requirements, requiring very little in the way of back-up.

“Our analysis shows that such integration is possible and surprisingly affordable: the U.K. could more than triple the amount of solar power on the system by 2030, with associated costs of integration and back-up so low as to be dwarfed by the enormous cost savings anticipated from falling solar prices over the same period,” said Aurora Energy Research director and lead author of the report, Benjamin Irons.

A further interesting point concerns the controversial Hinkley C nuclear plant. According to the STA, solar’s variability costs would fall a further 55% to £3.10/MWh if Hinkley C is not replaced because nuclear power is an inflexible source of power that constrains the economics of flexible generation.

The report is to be presented today by the STA at its Smart Power event being held at the Conservative Party Conference.

Welcoming the report, Angus MacNeil MP, Chair of the Common’s Energy and Climate Change Committee said: “This welcome research puts numbers and maths behind the variability of solar power. It gives a concrete understanding of what solar has to offer compared to other technologies. Combined with reducing capital costs solar is going to be as cheap as source of power as you’ll find anywhere."