[nathanbedford]

What is the diff?

[expatpat]

Energy is the amount of power accumulated, or, vice versa, power is the rate at which energy is used up or accumulated. The writer probably meant power, since the energy develooped by the Hoover dam in 24 hours woould be awful hard to store.

[Physicist]

Energy (measured, for example, in joules, BTU's or Watt-hours) is a conserved quantity, like gallons of water. Power (measured, for example, in Watts) is the rate at which energy is delivered.

Watts are equal to joules per second. If I say that an energy source is delivering 60 Watts, you have no idea how much energy it has produced unless I tell you how long it has been on. If I say it's been on for 100 hours, you know that six kiloWatthours of energy has been used.

The Hoover Dam delivers 2 GigaWatts of power. In a day's time, that's 48 GigaWatthours of energy. An HPM (according to this article) also delivers 2 GigaWatts of power, but it won't operate for 24 hours straight. It will operate for a tiny fraction of a second. In that time, it will deliver the same amount of energy that the Hoover Dam produces in, well, a tiny fraction of a second.

Doesn't sound as impressive, does it?