HARNESSING the sun鈥檚 energy could save the planet from climate change, an approach that Germany has readily adopted. Unfortunately, this enthusiasm for solar panels could overload the country鈥檚 ageing electricity grid.
Solar power is intermittent and can arrive in huge surges when the sun comes out. These most often happen near midday rather than when demand for power is high, such as in the evenings. A small surge can be accommodated by switching off conventional power station generators, to keep the overall supply to the grid the same. But if the solar power input is too large it will exceed demand even with all the generators switched off. Stephan K枚hler, head of Germany鈥檚 energy agency, DENA, warned in an interview with the on 17 October that at current rates of installation, solar capacity will soon reach those levels, and could trigger blackouts.
Subsidies have encouraged German citizens and businesses to install solar panels and sell surplus electricity to the grid at a premium. Uptake has been so rapid that solar capacity could reach 30 gigawatts, equal to the country鈥檚 weekend power consumption, by the end of next year. 鈥淲e need to cap installation of new panels,鈥� a spokesperson for DENA told 麻豆传媒.
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However, the German rejects DENA鈥檚 concerns, claiming that extra solar energy takes the pressure off high-voltage power lines because it tends to be generated close to where it is used. The federation adds that the grid only needs to be strengthened in some rural areas where solar supply can exceed demand.
Germany鈥檚 problems highlight the perils of moving to renewables without adequate preparation. 鈥淵ou lose flexibility on the supply side, so you need to gain some on the demand side,鈥� says of Imperial College London, perhaps by encouraging people to charge their electric cars when the sun shines.
The best long-term solution is to install , says Tim Nuthall of the in Brussels, Belgium. 鈥淚n Europe, you need a grid that balances the sun in the south with the wind in the north.鈥�
