B
Bruce Harvey
Crappy said:Hi All,
I am planning on putting up some PV panels on my house to, initially,
run lights and some of the plug circuits but ultimately, run
everything (barring the stove) (Heating is gas)
The panels will be on the first story roof, all the electronics etc,
directly below on the ground floor. Cable run would be about 10m (33
foot).
My question is, all things considered, which is best. To combat the
losses on the low voltage cable, obviously 48V would be better. Or
would 24v system still be ok?
I want to start with 2 or 4 panels. Two would force the 24v option
but if need be, can do 4. I plan to expand it in the near future to
have more panels as well as a wind turbine.
Thinking out loud here, expanding a 12v system means the possibility
to buy one panel at a time. 24 or 48v means 2 or 4 at a time.
Likewise, the turbine will be more expensive.
Is the effort worth going higher source voltages or not really.
Inverters (UK is 230V) are cheap for 24v and have a high enough
rating. I would use two or 3 to run different circuits in the house.
12V inverters are higher cost for high powered ones.
Advantages of 24 and 48 would be less current on the DC side of things
as well. Fewer losses there.
So, after rambling and thinking out loud, 12V is not a good idea (or
is it), 24V is better but 48 would be best provided I can get the
inverters etc.
Is 48 really much better than 24? Can I stick with 24?
Thanks,
Crispin
The length of run you are talking about would be ok for 24v assuming you
have sized your cables correctly for the job. Also because you are using 24V
the cables can be smaller diameter (read cheaper) but to avoid the problem
of needing to upgrade 2 panels at a time you can get 24V (nominal) panels.
So, 24V would be a good option for you to upgrade slowly over time. Would
need more info about loads to help you more but you get the idea. BTW I use
48V system in Australia but is attached to 2.8kW solar PV and MPPT charge
controller. Runs my entire house.