One residential solar power company that has managed to stay relevant, SolarCity, is upping its game-plan to make solar power even more appealing, by supplying backup power packs similar to the lithium-ion battery packs being used by Tesla Motors.
Solar power has typically been played down because of the expense of solar panels and control systems, but SolarCity has gotten a lot of people to install solar power systems simply by not making residents pay for the panels. Instead, residents pay for the power the solar panels produce, just like paying the utility company. The difference is, of course, that their own roofs produce clean energy.
Another issue that utility companies and residents have to deal with when it comes to solar power is intermittency, that is, power generation drops off precipitously when a cloud blocks the sun, but bounces right back to full power as soon as the cloud passes. The switching and balancing gear that are in use by utility companies cannot handle this kind of intermittent load, which is where the lithium-ion battery pack comes in.
Using similar lithium-ion battery pack technology, SolarCity can balance the intermittency problem with their solar panels. When the sun is shining, the battery packs are charged, and when the sun is not shining, the battery backup instantly transfers power back into the system, eliminating the voltage drops and spikes. The battery packs themselves, based off the same technology as in the Tesla Model S, will most likely come in different sizes, depending on the capacity of the solar power system installed, as well as how much backup power the client wants. If grid power goes down, some of these new solar power systems might have a week, or more, of backup power to keep things running until the power comes back on.
Of course, the relationship between SolarCity and Tesla Motors is pretty clear, entrepreneur Elon Musk having a controlling interest in both companies, so why haven’t they thought of this before?