At first glance, there’s nothing atypical about the small gray house located on a quiet residential street in Richmond, Calif. But look further and you’ll see that it’s the first piece of a revolutionary new type of power plant. Unlike traditional plants, you won’t find any massive cooling towers or transmission lines. That’s because this electrified home is part of a virtual power plant, or VPP.   VPPs are flexible energy sources that can be used to reduce load or provide power to the electric grid, just like typical power plants. But instead of the energy coming from one central source, it comes from a bunch of smaller, distributed energy resources (DERs), such as home solar panels, residential battery packs, and electric vehicles.