40% renewables wouldn’t need much coal, storage: study

There isn’t much of a need for power storage in Germany even if it increases the share of its electricity that is generated by renewable sources by around 50%, according to a new study by the German engineering association VDE.

Importantly, the study has shown that “baseload power – coal and nuclear – will have to go as the country switches to renewables.”

German engineering association VDE finds that the need for storage will be modest [up] to a 40% share of renewable power, at which point the need will increase. But the chart [above] also shows that German engineers believe that nuclear (red), brown coal (brown), and hard coal (black) are incompatible with renewable power. German engineers expect their country to mainly switch to cogeneration (fired with both biomass and fossil fuels) along with gas turbines running on natural gas and power-to-gas, a way of storing excess power seasonally.

There have been doubts expressed in the international media that Germany may not be able to switch over directly from nuclear to renewables without first relying on ramped-up coal use during the transition. But that concern isn’t a common one within Germany. As the new study shows, renewables completely ‘obliterate’ the need for baseload power.

The study’s main question was: How will intermittent wind and solar power affect the grid? And how much electricity will need 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,” Craig Morris of Renewables International writes.

The study’s findings aren’t really a surprise. Renewables International had already found based on its calculations that Germany won’t need to make any real changes to its grid and won’t need very much power storage if it meets the targets that it currently has set for wind and solar. And we’ve reported on the lack of need for storage up to a high renewables penetration rate several times, as well.

If the targets are met, Germany will get around 40% of its electricity from renewables. As a comparison, it got around 25% of their electricity from renewable sources during the first half of 2012. So far, the effect has mostly been to offset power from natural gas, but it’s been increasingly “cutting into the baseload.” Denmark, which is already sourcing over 40% of its power from renewable sources, hasn’t had to create any major power storage infrastructure so far.

“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%.”

As the chart above shows, not only will nuclear disappear (as national policy is to phase it out), but coal power use will fall off, nearly disappearing by the time the country sources 80% of its electricity from renewable sources.

“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.”
Clean Technica (https://s.tt/1pywf) – Reproduced with permission.