Posted by kleary00 on February 17, 2007, 5:27 pm
I am planning to add a PV system to a shed in my backyard. I have
checked out what I want to do (run a window A/C unit - less than 500
watts - if I am correct, about 5 Amps.) If I couple that with a
flourescent light or 2, and possible small future usage expansion, it
seems a 10A system would be well more than enough to create.
My questions comes as this: Should I even look into a system this
small - which, most importantly, will not get much use at all - it
might be used every weekend at best - is it worth all the effort to
set up a PV system? I think it would be cheaper than having an
electrician come out and set up a separate circuit for the shed, but I
could be wrong. It seems I could rig up a small system, but I don't
know how effective a $90 charge controller would be, as well as a $120
inverter.
Any help would be greatly appreciated.
Posted by Steve Spence on February 17, 2007, 8:08 pm
kleary00@gmail.com wrote:
> I am planning to add a PV system to a shed in my backyard. I have
> checked out what I want to do (run a window A/C unit - less than 500
> watts - if I am correct, about 5 Amps.) If I couple that with a
> flourescent light or 2, and possible small future usage expansion, it
> seems a 10A system would be well more than enough to create.
>
> My questions comes as this: Should I even look into a system this
> small - which, most importantly, will not get much use at all - it
> might be used every weekend at best - is it worth all the effort to
> set up a PV system? I think it would be cheaper than having an
> electrician come out and set up a separate circuit for the shed, but I
> could be wrong. It seems I could rig up a small system, but I don't
> know how effective a $90 charge controller would be, as well as a $120
> inverter.
> Any help would be greatly appreciated.
>
Assuming your a/c runs at 500 watts, and you want to run it 8 hours a
day, that's 4kWh's. If you get 4 full sun hours a day, that's 1000 watts
of pv at close to $8000 with the 3kw inverter, 6 deep cycle batteries,
and two 60 amp charge controllers.
--
Steve Spence
Dir., Green Trust
http://www.green-trust.org
Posted by George Ghio on February 17, 2007, 11:45 pm
Steve Spence wrote:
> kleary00@gmail.com wrote:
>> I am planning to add a PV system to a shed in my backyard. I have
>> checked out what I want to do (run a window A/C unit - less than 500
>> watts - if I am correct, about 5 Amps.) If I couple that with a
>> flourescent light or 2, and possible small future usage expansion, it
>> seems a 10A system would be well more than enough to create.
>>
>> My questions comes as this: Should I even look into a system this
>> small - which, most importantly, will not get much use at all - it
>> might be used every weekend at best - is it worth all the effort to
>> set up a PV system? I think it would be cheaper than having an
>> electrician come out and set up a separate circuit for the shed, but I
>> could be wrong. It seems I could rig up a small system, but I don't
>> know how effective a $90 charge controller would be, as well as a $120
>> inverter.
>> Any help would be greatly appreciated.
>>
>
> Assuming your a/c runs at 500 watts, and you want to run it 8 hours a
> day, that's 4kWh's. If you get 4 full sun hours a day, that's 1000 watts
> of pv at close to $8000 with the 3kw inverter, 6 deep cycle batteries,
> and two 60 amp charge controllers.
>
ROTFLMHO
--
Posted via a free Usenet account from http://www.teranews.com
Posted by beemerwacker on February 18, 2007, 3:09 am
Crap, I gotta agree with George.
ROTFLMHO
Let us know how it works out. (snicker)
Posted by Steve Spence on February 18, 2007, 7:55 am
beemerwacker wrote:
> Crap, I gotta agree with George.
>
> ROTFLMHO
>
> Let us know how it works out. (snicker)
>
Would you like to show where my math is bad?
500 watt load * 8 hours = 4 kWh load
1000 watts of PV * 4 sun hours = 4 kWh generation
A A/C unit of that size is going to need a hefty inverter to start it, a
3kw unit at $2400 should work fine. I use one and it starts my 1/2 hp
jet pump beautifully. The 2500 watt inverter struggled. 6 Trojan t-105's
would store 660ah at 12vdc, 330 amp hour useable (3.9kWh). Ok, add two
more batteries then, for a total of 8 instead of six. It's fine if you
want to snicker, but do tell where you think I went wrong.
--
Steve Spence
Dir., Green Trust
http://www.green-trust.org
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> checked out what I want to do (run a window A/C unit - less than 500
> watts - if I am correct, about 5 Amps.) If I couple that with a
> flourescent light or 2, and possible small future usage expansion, it
> seems a 10A system would be well more than enough to create.
>
> My questions comes as this: Should I even look into a system this
> small - which, most importantly, will not get much use at all - it
> might be used every weekend at best - is it worth all the effort to
> set up a PV system? I think it would be cheaper than having an
> electrician come out and set up a separate circuit for the shed, but I
> could be wrong. It seems I could rig up a small system, but I don't
> know how effective a $90 charge controller would be, as well as a $120
> inverter.
> Any help would be greatly appreciated.
>