Specification of Energy units

Joule

1 Joule is the SI unit of work or energy, equal to the work done by a force of one newton when its point of application moves one metre in the direction of action of the force.

Calorie

A unit of energy equivalent to the heat energy needed to raise the temperature of 1 gram of water by 1 °C (now often defined as equal to 4.1868 joules)

Watt

1 watt is equal to 1 joule/sec

Horse Power HP

1 HP equal to the work done by a force of 75 kg when it is lifted 1 meter vertical up from the surface of the earth in 1 sec.
Equals 75 kg * 9.81 m/s2 x 1 m/s = 736,5 N/sec = 735,75 watt

Watt Hour

1 Watt hour (Wh) = 1 Watt in 3600 sec = 3600 Joules

kWh

1 kWh = 1000 Wh

NOTE energy and power

Wh or kWh is ENERGY, while W, kW or HP is power, which is defined as energy transferred per second.

MWh

1 MWh = 1000000 Wh or 1000 kWh

kW and MW

1 kW = 1000 Watts and 1 MW = 1000000 Watts

How many Windturbines to replace a Nuclear plant

How many 11 MW Windturbines does it take to replace a 1600 MW (1.6 GW) nuclear power plant?
Nuclear plant production pr year in GWh = 1.6 x 365 x 3600 x 0.95 = 1997280 GWh
Windturbine = 11/1000 x 365 x 3600 x 0.35 = 5059 GWh
Number of turbines: 1997280 / 5059 = 395 Windturbines.
The 0.95 and the 0.35 is the availability number. Since the wind is not constant, it is much lower for the windturbine, than for the nuclear plant, that only needs maintenance once a year to replace fuel rods, etc., but can run at full power the rest of the year, regardless of the weather.