NikiandAlex said:
I want to get a solar power system going in my RV. I'm absolutly clueless and didn't know where to turn, so I thought someone with knowledge of electricity on this message board could help.
I have a 28 ft RV, the manual says an outside power source is 115 Volts, the breaker box says 30 amps and at .11 cents/thing (?) we paid $50.00 over a months time when we camped at a campground. The RV packages are measured in watts and I don't know what to look for. Any advice??
OK. If you paid $50 for a month of power and you were charged 11 cents per kilowatt-hour, you used 454 kilowatt-hours (KWh). That is 50 divided by 0.11.
Now there are 24 hours x 30 days in a month. That's 720 hours. Now we divide 454 kilowatt hours by 720 hours, and you get .631 kilowatts, average. That's 631 watts on average. Take six 100-watt bulbs and screw them in sockets, and turn them on. Leave them burning for an entire month, and you would use the same amount of electricity.
If you consider one day's worth of use, take the 631 watts and multiply by 24 hours. you use 15,144 watt-hours in one day. Now assume you have 6 hours of usable sunlight in a day. To generate 15,144 watt-hours in 6 hours of daylight, you would need an array of solar panels rated at AT LEAST 2,524 watts. And a large bank of batteries to store up enough charge to last through the night, until the sun shines again. You would need to produce 2524 watts for 6 hours, to provide for your average use of 631 watts for 24 hours.
Oh, what's that you say? The sun doesn't shine every day where you live? Well then you would need to double or triple that battery bank to tide you over until the next sunny day, or run a generator for a few hours to charge up your battery bank.
First thing to do would be to shut off the air conditioner and open the windows. Park under trees for the shade. A figure I seem to recall from the website at
www.homepower.com is that for every $1 you spend on buying more energy-effecient items, you can save $4 on an alternative energy system. Put another way, you will need to make some serious changes to your energy usage to make solar worthwhile.
What appliances do you have on this RV? A/C? Fridge? Water heater (gas or electric?) Microwave? Laundry?
I think Rambler's '3 things' hit it on the head for most of us. His math is right too
John