D
danny burstein
- Jan 1, 1970
- 0
I've got a neighbor, kind of.., who has a car garage with an
overhead door. No electric lines to it, so the door has to
be lifted manually.
Even with decent springs and counterweighting it's a big pain.
Running electricity to it would be a big pain and expense, so I
was thinking of a solar solution.
I've measured my own garage which does have an electric opener.
There's a steady background draw of 3 watts for the controls
and the safety "electric eye" at the door bottom. When the motor
is running it pulls about 600 watts for the 10 second cycle.
So I figure... if we take a reasonable worst case scenario
it'll get run through 5 cycles/day.
Power usage:
a: 3 watts times 24 hours => 0.072 kw-hr/day
b: 600 watts times (10*2*5) = 60 kw-sec /day
-> => 0.041 kw-hr/day
total: 0.11 kw-hr/day (110 watt-hr)
So far so good. If my math is right... then a 35 watt panel,
which back of envelope would get me 140 watt-hr/day (based
on getting the equiv. of 4 hours of direct sunlight), so I'd
have a bit to spare for inefficiencies and to keep the battery
charged on cloudy days or if the door gets used more.
(And if I can kill off the standby draw, even better).
The big problem is that overhead motor pulls that 600 watts,
with probably two or three times that at start up. Which
means using a big inverter...
But given the cost of running an electric line, this still
looks like a decent alternative.
Before I pull my hair out on this, has anyone had experience
and could offer a suggestion or two?
The biggest question, I guess, would be finding a DC motor
that would be usable in a garage lift assembly... The big
advantage is it would eliminate the need for the inverter.
Thanks.
overhead door. No electric lines to it, so the door has to
be lifted manually.
Even with decent springs and counterweighting it's a big pain.
Running electricity to it would be a big pain and expense, so I
was thinking of a solar solution.
I've measured my own garage which does have an electric opener.
There's a steady background draw of 3 watts for the controls
and the safety "electric eye" at the door bottom. When the motor
is running it pulls about 600 watts for the 10 second cycle.
So I figure... if we take a reasonable worst case scenario
it'll get run through 5 cycles/day.
Power usage:
a: 3 watts times 24 hours => 0.072 kw-hr/day
b: 600 watts times (10*2*5) = 60 kw-sec /day
-> => 0.041 kw-hr/day
total: 0.11 kw-hr/day (110 watt-hr)
So far so good. If my math is right... then a 35 watt panel,
which back of envelope would get me 140 watt-hr/day (based
on getting the equiv. of 4 hours of direct sunlight), so I'd
have a bit to spare for inefficiencies and to keep the battery
charged on cloudy days or if the door gets used more.
(And if I can kill off the standby draw, even better).
The big problem is that overhead motor pulls that 600 watts,
with probably two or three times that at start up. Which
means using a big inverter...
But given the cost of running an electric line, this still
looks like a decent alternative.
Before I pull my hair out on this, has anyone had experience
and could offer a suggestion or two?
The biggest question, I guess, would be finding a DC motor
that would be usable in a garage lift assembly... The big
advantage is it would eliminate the need for the inverter.
Thanks.
