Little power storage or coal power needed for 40% green power supply
A study conducted this summer by German engineering association VDE finds that there will be little need for power storage if Germany increases its share of renewable electricity by around 50%. And perhaps even more importantly, the engineers show that baseload power – coal and nuclear – will have to go as the country switches to renewables.
Internationally, there are great doubts about whether Germany will be able to switch from nuclear to renewables without ramping up coal power – a concerned not common within Germany, however, as a recent study (PDF in German) published by Germany's VDE Association for Electrical, Electronic & Information Technologies shows.
The VDE is not primarily a green organization, so the findings are all the more interesting – both in terms of what was investigated and in terms of what was assumed. The main question in this study is how intermittent wind and solar power will affect the grid and how much electricity will have to be stored. In five scenarios, the VDE finds that dispatchable power generators will mainly have to be flexible, but also that this requirement can be met in all of the scenarios. And up to a 40% share of renewables, the cost of power storage (or otherwise lost excess power production) remains moderate, only raising the cost of power by 10% in the worst case.
The findings do not come as much of a surprise. Renewables International has already calculated based on current statistics that Germany will not need to make major changes to the grid or require a lot of power storage if it reaches its current targets for wind and solar, at which point the country will roughly have 40% of its power from renewables. In the first half of 2012, Germany had around 25% renewable power, and the main effect has been offset power from natural gas turbines up to now, but increasingly renewables are cutting into the baseload. Neighboring Denmark, however, already has 40% renewable power and has managed to make do without major power storage up to now.
To move beyond 40% to 80% renewable power (the target for around 2050), Germany could need as much as 14 GW of short-term and 18 GW of seasonal power storage to meet its peak power demand of around 80 GW in the moderate scenario. At that point, power prices would be roughly 10% greater than in 2011, but reaching 100% renewable power will be quite expensive indeed. The German engineers estimate that the final 20% will triple the need for power storage, raising prices once again by around 19%.
For international readers, one of the assumptions is perhaps even more interesting than all of these findings. One of the charts (see above) shows not only that nuclear will disappear (the nuclear phaseout is national policy), but also that coal power will be ramped down considerably, practically disappearing by the time the country reaches 80% renewable power. Here, we see why the international community misunderstands what Germany plans to do with coal. The country's phaseout of coal power is based not on an official policy, but rather on a general understanding among experts in the power sector that the switch to renewables will gradually obliterate the need for baseload power. So if Germany is currently failing to communicate its plans to phase out coal power over the next few decades, it's because there is a consensus within Germany that this will happen, not a discussion about whether it should. In other words, Germans see no need to talk about these plans with each other, so they do not recognize the need to tell the outside world. (Craig Morris)