How many watts does a normal 4 person family use

Question

i need to know an average or a little higher than average cause im buying solor panels

Answer 1

We have 4 people at home right now and we use on average 100 kwh.  The cost for solar panels for a regular rambler house is between $26,000 and $30,000 depending on your usage. These $$ amonts calculated using 100 kwh of electricity and 177 kwh of wood.

Just look at your electric bill. It is measured in kwh (1000 watts per hour) if you use 500 watts per day, you will consume 1 kwh in 2 days. If you use 2000 watts per day you will consume 1 kwh in 12 hours.

Ovens and microwaves generally consume the most energy, converting that energy into heat. Microwaves usually run between 500 and a kw but you rarely run them for more than an hour. Conventional ovens can consume around a kw in 10 minutes depending on how hot you need it, so most of our energy is dissipating into thin air! A 1 kw appliance running for 30 mins per day will take 2 days to consume 1 kw, however on your bill it is different.

There are on average 30 days in a month or billing cycle, thus 720 total billable hours. If you use 100 kw (100,000 watts) during the month, that's 100,000/720, or 138 kwh billed (at 7.5 cents per kwh, that's a bill of $9.66) OR your bill may simply already be in kwh, and you don't have to do any converting, hopefully this is the case. For the example, I've used 100 kwh in one month.  Next you need to convert the amount of energy in the wood to watts.

According to the second link, you can expect 6050 Btu/pound of wood. Following the first link we see that 1 BTU = 0.0002929 kwh, thus 6050 BTUs = 1.772045 kwh per pound of wood.

Take your monthly poundage of wood and multiply that by 1.77 and that will give you your monthly wattage in wood.

Example:  Electric bill: 100 kwh used. Wood burned: 100 pounds = 177 kwh. That means you use on average 277 kwh.  (277,000 watts in one hour = 384.72 watts per actual hour.  As per your request, you need a little above average, so round this up to 400 watts. You will need solar panels that total at least 400 watts. If those panels collect at 400 watts for one hour, you've just harvested 400 wh or 0.4 kwh. Most solar panels collect at 12 to 48 volts. House mains run at 120 volts. So 400 watt panels collecting at 12 volts that charge a battery to full in 10 hours, will be completely drained at 120 volts in one hour. Since the 400 watts used per day is at 120 volts, you will need at least 4000 watts of solar panels to run everything at the 120 volts of regular usage.  (12 volts of panel * 10 = 120 effective volts)

http://cgi.ebay.com/Suntech-SU170-Monocr...

This is a currently running eBay auction, the panel is $1080 with shipping and runs at 170 watts, no volts given so I'm guessing it's 12 volts. 4000 watts / 170 = 24 total panels needed. That's $25,500 in just panels. You will also need cables, batteries, blocking diodes, inverters for 120 volt current, etc so let's round that up to between $26k and $30k.

If you consume less power than you use, most electric companies will pay you for the electricity you send them. Expect about 5 cents per kwh.

So if you are planning on REPLACING your electric meter and wood stove(s), you will be looking at about $30,000 of equipment.  I would recommend SUPPLEMENTING your electric usage with solar panels at whatever rate you can afford, one panel every other month, every 2nd month, etc unless you can afford the $30k all at once.

For those readers who DO use gas, the gas bill uses decatherms, 1 decatherm = 10 therms. 1 therm = 29.291 kwh, thus 1 decatherm (100 therms) = 2929.1 kwh or about 3 megawatt hours.  

Answer 2

You can find this on your electric bill. It varies widely but generally about 800 to 1500 KWH per month.

1 KWH = 1000 watts for 1 hour or 100 wats for 10 hrs ect.

1 kwh costs about $.08 to $.15 depanding on the utility rates where you live.

Answer 3

To find out what your family uses call your utility company, they should be able to give you your usage history. Mine gave me my history for 2 years.

I live in a 2000sf 2 story home with a pool. For the summer months last year I was averaging about 60kwh per day. I made a few changes and this summer I was averaging about 40kwh per day. I put in a 3.74 kwdc system and I'm now averaging 5kwh per day. It will vary by season.

I decided not to zero out my electric bill, I got a system that maximized my rebates, I may add to the system in a few years and will be able to take another rebate.

Answer 4

It all depends. Are you using gas heat, do you have central air conditioning etc.? Without an electric water heater or heat pump, without an electric stove, without electric air conditioning, most homes probably pull 3000 watts.