The challenge of storing excess renewable energy is perhaps the biggest hurdle to a complete makeover of the global energy economy in which renewables take over. How to plan for the times when the sun doesn’t shine and the wind doesn’t blow is a big headache and the current solutions, like expensive grid battery storage, won’t catalyze the type of changes to our energy supply that will make a dent in climate change.
Ironically it’s the opposite problem–what to do when you’ve got more wind or solar power flowing than the grid needs–that may hold a key to the solution. The Pacific Northwest is flush with hydroelectric and wind power. The problem is that these power sources peak in the early summer and spring when the ice packs are melting and the wind kicks up.
National Geographic takes a look at one often cited solution–compressed air energy storage (CAES). The concept has been around for decades, the idea being that energy from renewables can be captured and used to compress air, which is then released and converted back to electrons when needed. What’s interesting about the Pacific Northwest is that it contains a lot of porous rock underground, which can be ideal for CAES because it allows air to move in and out easily, creating even short term storage scenarios where energy is stored overnight for mid-day release.
Energy storage remains the key to unlocking a renewable energy economy and CAES is probably worth a few more test projects.