What is TWh per year?

1 terawatt-hour per year = 114 megawatts

1 TWh/year = 114 MW

or

1.14 X 108 Watt

The unit "terawatt-hour per year" is a convoluted method of saying (what calculates to) 114 megawatts.

1 megawatt =106 watts

The year and the hour are different units of time. They are related to each other:

1 year = 8 765.81277 hours

terawatt = 1012 watts

Therefore

(1012 watts X 1/8765.8 year)/year = 1.14 X 108 Watt = 114 X 106 watts = 114 Megawatts