True.........but varies widely on the price paid, power companies got regulators to approve as much as a 70-80 % discount on the pay back. That makes personal selling back a real screw in some areas. Example you buy at .10 KW they buy back at .03kw. Some power companies buy back at par but that is also rare.
Pardon the hijack. I'll try to shed some light on how this works. The problem is doing so without writing a long-winded dissertation on the subject.
Power is really priced by the hour. The load on the electrical grid varies hour to hour. As the load varies, power companies must adjust generation to meet that load. The combination of generation that is operating in any given hour is what dictates the price for that hour.
All generators have a sweet spot. The sweet spot is the load at which they are most fuel efficient. Power companies (and customers) want those generators running at the sweet spot to make the most economical power. But the variation of the load from hour to hour means that it is difficult at best to achieve running each generator at optimum load.
Some generators are designed to be cycled on and off while others cannot be. It is now becoming common in many power markets that power costs can go negative during minimum load conditions. That's right, some power producers will pay someone to take power during off peak conditions because it keeps generators online and nearer to running at the sweet spot.
Some generators only operate during peak load conditions. These units are often called "peakers". They generally are the least efficient units and cost the most to operate.
During peak load conditions, all generation including the peakers are online and operating. During these times power costs can be $1.00/kWh or more.
Wind and solar can be problematic for power companies because enough backup generation must still be online to take the place of the wind and solar should conditions warrant. Wind speed can be highly variable over the course of an hour and a dark cloud can cut solar output drastically so other generation is required to be running in standby (or at lower load than optimum) to pick up the load immediately as needed.
Power companies frequently have take or pay wholesale contracts which require them to buy power even when they don't need it. Or they might schedule a power delivery of X amount for hour #17 of the day and then heavy cloud cover causes the load to be less than expected but they have to pay for the scheduled amount anyway.
All of these complexities is what led regulators to come up with something known as the "avoided cost" method for paying customers who sell power back to the utility company. This requires power companies to calculate the cost they avoided by buying power instead from a customer and that becomes the rate paid to customers who sell power back.
That avoided cost can be negative at times of low load and astronomical at times of peak load so utilities usually calculate an average avoided cost.
Regulators looked at other ways of having power companies buy back power but most involve other customers subsidizing the buy back and that's why it's not an apples to apples buy back.
It's pretty complicated and I could have expounded for more pages than anyone would care to read but I hope this helps a bit.
DC
So geothermal isn't all it's touted to be depending on the configuration, and it's capital cost is high. 
until you get caught.........