This is the maximum potential amount of electricity that the company can produce using all its generators, or its Owned Generation Capacity in Watts plus its Long Term Contract Generation Capacity in Watts .
Generation capacity of often measured in Megawatts, or MWs, which refers to Millions of Watts. A Watt is a unit of power, referring to one joule per second (J/s) - the amount of energy generated in a second. A 100 MW power plant generates 100 million joules of electricity per second.
Generation capacity is also measured in Kilowatt-hours (kWh) which refers to the amount of energy used. A kWh is exactly 3.6 Megajoules - 3.6 million joules. One watt-second is one joule. When an electric utility refers to electricity usage of X kWh per year, it means that the company's customers used X times 3.6 million joules of energy TOTAL for the year.