I am wondering if my electricity bill is exactly 00 a month
how much would this 175 watt solar panel save me (on a monthly basis)
http://www.solarpanelstore.com/solar-power.large-solar-panels.sharp.175.info.1.html
I am wondering if my electricity bill is exactly 00 a month
how much would this 175 watt solar panel save me (on a monthly basis)
http://www.solarpanelstore.com/solar-power.large-solar-panels.sharp.175.info.1.html
Prices for electricity usage in the US are currently running close to 10 cents per kwh.
If you are paying $1000/month, you are using approximately 10000 kwh per month. This is really high, BTW. It implies that you are using about 14 kw 24/7.
Anyway, of those 14 kw, you want to offset some of it with a 175 watt (0.175 kw) panel (which costs $890), so you would be saving 0.175/14, or about 1.25% of your total load. Your savings (not allowing for depreciation on the price of the panel) would be about $12.50 per month. And that’s assuming that your panel is functioning 24 hrs/day, which it can’t. Assuming 12 hours of darkness cuts that savings in half to about $6.25 savings per month.
Another way to look at it would be to say that the 175 watts from the panel are guaranteed to be used by the house. Again, let’s assume that the panel can actually provide that level of power for 12 hours a day and that the price of electricity is $0.10/kwh. You have 0.175 kw for 12 hrs = 2.1 kwh or 21 cents per day of savings. Assuming an average of 30 days per month gives you $6.30 savings per month, a figure that agrees well with the analysis above.
$6.30 savings/month times 12 months = $75.60 savings/year
$890/75.60 = 11.7 or about a 12 year payout on the panel (by which time it may very well need to be replaced).
Also remember that the panel’s 175 watt rating is based on optimum operating conditions. Cloudy days, morning/evening sun, dirt accumulation and other conditions will reduce its output.
I think you may begin to see why photovoltaic power generation is still in its infancy.
Are you sure that $1000 a month is right? That’s more than we spent in a year on electricity, even before solar panels.
The savings from a panel really vary by location and electricity price, but for our house, each watt of panel saves 7.2 cents a year, or 0.6 cents a month. So the 175-watt panel would save $1.05 a month, every month, for 25 years or more.