Virtual Power Plants

Virtual Power Plants

PG&E and Tesla recently announce the launch of their pilot program to create virtual power plant. The Tesla battery being the worlds most widely distributed battery, the program expected to save customers money and increase grid reliability, which in California I think we can all agree is a top priority.

This type of announced program is helpful in stimulating discussion, but anything more than a casual read may prompt more questions than answers. For example, assuming the batteries are charged from the local power grid in the first place, and given that no system is 100% efficient, won’t the charge then discharge of batteries from/back to the grid result in energy lost from the system?

This appears to be a simple financial play on time-of-day rates, akin to pumped storage. That is, use electricity when the price is low then give it back during times when the price is high. Won’t a simple demand side management program between the utility and consumers accomplish the same thing? Why would Tesla be needed to aggregate the program’s enrollment? Surely an energy-challenged locale would already have something similar in place for this? And if Tesla is aggregating the program, do they share in the money?

Must admit to feeling ignorant on this subject, though can offer the excuse of not being a Tesla car or battery owner. Am aware the Tesla batter can utilize both wind and solar to charge the battery, but ONLY if the homeowner already has a PV in place. In the absence of the PV, the charge is simply a pull on the grid.

What am I missing?