Wait wait Wait, can you give me more on this kWh thing? I thought I understood this already.
A single kW is a unit of power, literally 1000 watts.
A kWh is a unit of energy, as in stored or delivered.
Draw 500 watts for 2 hours? That’s a kWh.
Or have a battery that can hold 1 kWh, then assuming 100% efficiency you could draw 1000 watts from it for an hour before it was empty.
All of this is kW times hour, I would say?
But in my mind I would interchangeably say per hour as well, they feel the same.
If you use exactly 20 kW for an hour, it will translate to 20 kWh. But if your power usage varies over time, you can’t keep track of it so simple. It’s just how it is.
The unit is really watt [W] and the Greek prefix kilo (k) for 1000. This way it’s fast and easy to convert to different scales (like Mega, Giga etc) for comparing numbers
A watt is a derived unit for a rate of change, an amount of energy used in a unit of time, so P = E / t. A kW per hour would be a rate divided by time, or E / t^2, resulting in another rate.
More colloquially, think of watts/power by analogy to another rate, that of speed. Moving at a speed of 100kph for 3 hours results in 300 speed-hours of distance. Saying 100 kilometers per hour per 3 hours sounds awkward, but is actually a weird way to say acceleration, a rate of change of speed. (And probably a hint to get your car serviced.)
Anyway, the key is to think of a kilowatt as a rate, not a quantity.
Wait wait Wait, can you give me more on this kWh thing? I thought I understood this already.
A single kW is a unit of power, literally 1000 watts.
A kWh is a unit of energy, as in stored or delivered. Draw 500 watts for 2 hours? That’s a kWh. Or have a battery that can hold 1 kWh, then assuming 100% efficiency you could draw 1000 watts from it for an hour before it was empty.
All of this is kW times hour, I would say? But in my mind I would interchangeably say per hour as well, they feel the same.
Obviously I’m wrong, but I’d like to know why lol
If you use exactly 20 kW for an hour, it will translate to 20 kWh. But if your power usage varies over time, you can’t keep track of it so simple. It’s just how it is.
The unit is really watt [W] and the Greek prefix kilo (k) for 1000. This way it’s fast and easy to convert to different scales (like Mega, Giga etc) for comparing numbers
A watt is a derived unit for a rate of change, an amount of energy used in a unit of time, so P = E / t. A kW per hour would be a rate divided by time, or E / t^2, resulting in another rate.
More colloquially, think of watts/power by analogy to another rate, that of speed. Moving at a speed of 100kph for 3 hours results in 300 speed-hours of distance. Saying 100 kilometers per hour per 3 hours sounds awkward, but is actually a weird way to say acceleration, a rate of change of speed. (And probably a hint to get your car serviced.)
Anyway, the key is to think of a kilowatt as a rate, not a quantity.