But not only can renewables supply baseload power, they can do something far more valuable: supply power flexibly according to demand. Now nuclear power really is redundant.
Grid Integration
Experience with measures and innovations for grid integration in all these categories is given, from several jurisdictions like Germany, Denmark, and California, where renewables already provide 20-40% shares of electricity and plans to reach 50% exist.
This year, it will have closer to a third renewable power, close the new target for 2020, which now stands at 35 percent. Moreover, the level of 20 percent – once thought hard to reach by 2020 – has become hard to fall below in 2015.
The company responsible for more than one-third of Germany’s electricity grid says there is no issue absorbing high levels of variable renewable energy such as wind and solar, and grids could absorb up to 70 per cent penetration without the need for storage.
The UK press has been full of stories implying that wind power is to blame for the National Grid having to call in expensive demand shedding measures recently to keep the lights on. What they will not tell you is how often wind power saves the UK consumer large amounts of money because the National Grid does not have to buy in expensive reserves of power. Also they do not tell you that wind power in fact has quite a substantial contribution to effective firm power station capacity.
“Up to a renewable electricity share of 60%, the addition of power storage devices is not a condition for the addition of solar PV and wind power plants… Even at high degrees of penetration (90% in Germany), the required balancing can largely be achieved without additional power storage”
Fluctuating wind and solar power are expected to increase the need for dispatchable generators to ramp up and down quickly. So why has the operating reserve shrunk in Germany?
Nuclear power covered a whopping 87.2 percent of power demand in France and 73.3 percent of power generation in 2013 (the difference stems from power trading). But because France’s nuclear fleet is so large, nuclear production led to a negative residual load about 10 percent of the time in 2013 (see slide 19) – three times the level of Denmark.
In line with previous investigations, such as the one by Fraunhofer ISE, the AEE finds that storage across weeks at a time will “not become relevant until renewables make up at least 60 to 80 percent of power consumption.” In contrast, short-term storage (for hours or a day or two) will be needed sooner, but it will partly also pertain to stabilizing the grid.
