Energy usage question?

Question

i want to calculate our energy usage in watts, so that i can show my family how much it costs to leave electricity things on. our last bill was 393.45 and used 2,245 kWh. i want to see how much one kWh cost and how to imply it to see how much energy a TV uses. the tv says it uses 134 watts

Answer 1

A KWh (Kilowatt hour) is kilowatts * hours.  Kilo is 1000 so this is 1000 watts* hours.

The general idea here is, if you operate a 1000 watt light for 1 hour, you have used 1 KWh.  Also, if you operate ten 100 watt bulbs for 1 hour, you have used 1 KWh.  Likewise, if you operate a 500 watt bulb for two hours, you have used 1 KWh.   You get the idea.

So, if the TV draws 134 watts, that will be 0.134kWh for every hour it's operating.  

Your electric cost is $393.45 / 2245KWh = $0.17526 per KWh.

So, it costs 0.134 KWh * $0.175/KWh = $0.0234 per hour to operate the TV.  However, you probably ought to include the life of the TV, too.  Say, you have a new $1500 LCD TV, it's average life would be around 14 years at 8 hours a day.  That's another $0.037 per hour.  

So, tell your kids it's costing the family $0.06 per hour to operate the TV.  That's about $175.52 a year for the average family.

Answer 2

CHECK WITH THE POWER COMPANY.== MY 56 INCH HD. T.V. IS ON 24 HOURS A DAY, COMPUTER IS ON ABOUT 15 HOURS A DAY ALL APPLIANCES VARIES. MY BILL $60.00 PER MONTH.

Answer 3

Well just by simple division, if your bill was $393.45 for 2,245 kWh, your electricity costs 17.5 cents per kilawatt-hour.  However, that's pretty high, so your bill probably included natural gas costs as well.

Generally speaking, electricity costs around 10-12 cents per kWh.  If your TV uses 134 watts, and you leave it on for an hour, it's using 134 Watt-hours.  This is 0.134 kWh, which comes out to 1.6 cents per hour of TV if your electricity costs 12 cents per kWh.  So watching TV for 6 hours comes out to about 10 cents of electricity.

Each individual appliance just adds a little, but when you're using a bunch of appliances for long periods each day (TVs, computers, leaving cell phone chargers plugged in, lights, etc.) it adds up.  If you add up a bunch of these things you can impress your family, but 1.6 cents per hour doesn't sound very impressive.

Answer 4

Look on your electric bill.  At least if you are in California, there are at least three levels of prices.  Most homes have trouble staying within the first two price levels.  You should figure how much EACH ADDITIONAL kwh will cost, because those are the ones you will be reducing.  In Los Angeles, the incremental kwh charge is over 30 cents per kwh.  BTW, how on earth are you using 2245 kwh????  Do you have an ice-skating rink?  Alternatively, call your electric company or e-mail them and ask what the incremental rate is for your service.