Stan,
I once worked up seminar on electric use for rallies. I had several names for it. One was "Dry Camping With a Hair Dryer". Included was how much it costs. Another was "Can I Use a Toaster and Microwave When on 30 Amp Hookups". As it turned out, I never found a Rally Master that wanted it on their schedule.
A Kwh is the billing unit where you have used 1,000 watts for an hour. Leave ten 100 watt bulbs on for an hour and you pay for one Kwh.
Your heater will have a watts rating listed on it. Most are about 1500 watts on high. Any higher and the circuit breaker will trip.
That is because a typical circuit breaker is 15 amps. 15 amps times 120 volts is 1800 watts. So a 1500 watt heater leaves a 300 watt margin. Many, including me, think that that is not enough margin and will only run a space heater on medium.
How much does it cost? A heater on the 1000 watt setting is the same as the 10 hundred watt bulbs. If you run it for an hour it will use one Kwh. If you have a 1500 watt heater it will use 1.5 Kwh in an hour.
Nowhere in the USA can you get a Kwh for a penny. In my neighborhood where there is relatively cheap hydro power, it is about 8 cents. Your office quoting you 12 cents is reasonable. Many of the parks we stayed at used power as a profit center and would take the meter reading and mark up the price of a Kwh about 50%. In some cases double. But, once you know the price, you can watch your meter and calculate the dollars.
The short version is that if the park is charging you 12 cents for a Kwh and you are using your space heater on a 1000 watt "medium" setting, you are paying 12 cents an hour. In our Beaver, in cool weather, it stayed on most of the day. Depending on park mark up policy, it could end up as high as $2 a day. Running the clothes dryer would add a little too.
FWIW, an air-conditioner uses around the same wattage as a space heater.
Hair dryers are only used for about 5 minutes, so at 12 cents a Kwh, dry hair is worth about a penny unless you are dry camping and have to use the generator.
