Why generators are terrified of solar

By Giles Parkinson on 26 March 2012

The first graph illustrates what a typical day on the electricity market in Germany looked like in March four years ago; the second illustrates what is happening now, with 25GW of solar PV installed across the country. Essentially, it means that solar PV is not just licking the cream off the profits of the fossil fuel generators – as happens in Australia with a more modest rollout of PV – it is in fact eating their entire cake.Here is a pair of graphs that demonstrate most vividly the merit order effect and the impact that solar is having on electricity prices in Germany; and why utilities there and elsewhere are desperate to try to reign in the growth of solar PV in Europe. It may also explain why Australian generators are fighting so hard against the extension of feed-in tariffs in this country.

Both graphs were published last week on the website Renewables International, and were sourced from EPEX, the European power price exchange. The first graph, from 2008, shows peaking power prices rising to around €60/MWh and staying there for most of the day, with some visible peaks around noon and the early evening – the size of which would depend on the temperature and the usage.

The second graph shows a brief leap to €65/MWh around 9am, before the impact of solar PV takes hold – erasing the midday peak entirely and leaving only a smaller one in the evening. The huge bite out of day-prices is also a bite out of fossil fuel generators’ earnings and profits. Note that the average peak price in the second graph is barely higher than the baseload price.

Deutsche Bank solar analyst Vishal Shah noted in a report last month that EPEX data was showing solar PV was cutting peak electricity prices by up to 40 per cent, a situation that utilities in Germany and elsewhere in Europe were finding intolerable. “With Germany adopting a drastic cut, we expect major utilities in other European countries to push for similar cuts as well,” Shah noted.

Analysts elsewhere said one quarter of Germany’s gas-fired capacity may be closed, because of the impact of surging solar and wind capacity. Enel, the biggest utility in Italy, which had the most solar PV installed in 2011, highlighted its exposure to reduced peaking prices when it said that a €5/MWh fall in average wholesale prices would translate into a one-third slump in earnings from the generation division.

Imagine how that graph might look in Australia with a similar deployment of solar in a country that actually has some sun. Wind has already helped reduce wholesale prices in South Australia, although it has left daytime peaks more or less untouched. Solar would have an altogether different impact.