California illustrates the success of solar power in some areas of the world where sunshine and technology investment meet.
In March, California powered the whole state sustainably for a few hours. This achievement brings some new challenges.
The abundance of renewable power at certain times means grid managers have a new task on their hands—dealing with all the energy.
We don’t yet have batteries capable of storing huge amounts of electricity, and grids can only support so much. There are times, therefore, when really successful renewables have to be “curtailed,” or stopped from feeding the grid, to prevent surges. (Just as there are times when other “baseload” power sources need to step in, for example when the sun’s not out and at night.)
Germany, which has also invested heavily in both solar and wind power, sometimes has so much power it has to pay neighboring countries to use it—a quirk of the transition to high levels of renewables it calls the Energiewende, or energy transformation.
This doesn’t mean, however, that Californians are paying nothing for their power because wholesale prices don’t translate directly into retail prices, which are based on averages, not single days. But it will mean energy companies start to rethink how they deliver and charge for electricity as the mix of renewables increases.