how many panels would i need to run my tv 85.watts dvd,12
watts ,vcr 12 watts, webtv,12 watts 1 hrs, or 2 hrs. a day
lets say 5 days a week sometimes 7 i am from alabama
so we get a lot of sun and also how much would it cost
Well, as others have said, you might need to get a bit more
specific to get accurate estimates. That said, I think there
is enough to give you an idea.
First you need to know how much electricity you need.
Add up the wattage's and multiply by the hours you want
to use them to get watt-hours (or kwh). Yours add up
to 85+12+12+12= 121 watts x 2 hours = 242 watt-hours.
Now, you'll need more than this amount of electricity
a day because you lose some at all stages. Batteries
only put out, say, 80% of the energy you put into them,
inverters only 80% to 90%. In your case you can figure
242wh/.80/.80 = 378 watt-hours.
Then you need to know how much sunlight you get there.
NREL can help a little there.
http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/
http://rredc.nrel.gov/solar/calculators/PVWATTS/
Most places in the United States get at least 3 to 4
kwh/m^2/day (just think of it as 'sun hours'). If you
want to know many much PV panel to buy then divide
the total watt-hours required by the 'sun hours'.
This would be, say, 378/3 = 126 watts.
Panels come in all different sizes and they are sold
by their STC rated wattages. You should only figure
on 80% of this in the real world. That is, a 100W
panel only should be expected to produce 80W. It may
produce more for a decade or two but they do degrade.
You can figure anywhere from $3.50 to $5.00 an STC
watt when buying the panels themselves and then
perhaps another dollar or two for batteries and
everything else.
This means you'll need (126W/.80) 158 watts of PV
costing some (158w x $7) $1106.
Now, you could probably reduce that somewhat in any
number of ways but this gives you an idea of the
kind of ballpark you'll be playing in.
Anthony