How to Measure Global Warming Cures

Note that a Watt is the SI unit of power, being a rate of one Joule per second.
Your electric energy consumption is reported to you in kilowatthours (kWh) which is a thousand Watts for 3600 seconds, and therefore 3.6 million Joules. That's 3.6 MegaJoules (3.6 MJ).

I have also elected to use the concept Gigawatt-year, which I hope is obvious, although some years have more hours than others.

First of all, if a website mentions that a project will supply "N thousand homes" then that part is pure humbug. An ordinary household's peak demand may easily be twenty times its average kilowatt demand. An ordinary laser printer uses very little power on standby, but its startup demand for printing a sheet is enough to blow the fuse on a 15 Amp circuit that it is sharing with a modest electric heater. That's an instantaneous load of about 1.6 kilowatts.
In fact, every 20A circuit breaker in your home represents a provision for not more than 20 amps times 110 volts of power, which is 2.2 kilowatts. You've probably got ten of them. Even if your average hourly consumption is well under 2 Kilowatt-hours (kwh).

Hydroelectricity is the easiest way to meet electrical demand peaks. A turbine already turning with just enough water flow that it is idling, can almost instantaneously deliver many megawatts of power.
A power source that has to wait for a sufficient breeze is useless for this!
Failure to meet peak loads is so catastrophic that the California distributors of electrical power were desperate enough to pay exorbitant prices for it in the debacle of 2000, following the light winter snowfall that cut into hydroelectric water reserves.

Power is the rate of energy production, measured electrically by the Watt, which is a rate of one Joule per second, the Joule (J) being the basic international scientific unit of energy. The effective electrical unit of energy, familiar enough to household bill payers, is the kilowatt-hour, or kWh, which costs about ten cents today.
A kilowatt (kW) being a thousand Watts, and an hour being 3600 seconds, it follows, if you care, that:
One kWh = 3,600,000 J (Joules)
= 3.6 MJ (megaJoules).

You may have deduced that the Joule is quite a small measure of energy. There are 24x365 = 8760 hours in a non-leap year.

The total annual production of electrical energy in the USA is better measured in terms of the product of a gigawatt and a year, the gigawatt-year. The Department of Energy's Energy Information Administration has a great deal of good information about energy, as it certainly ought. It is not particularly easy to navigate.
Several of its tables measure energy in quadrillions of Btu's, a measure that ought to be obsolete. Electric Power Annual report for 2007 has links to reports from which I learned the following:

Generation in thousands of megawatthours

Generation in gigawattyears