" Just convert to AC and be done with it! " That's a good point, since there are
a lot of devices that really like 120vac..
I'm using 48v in my little backup unit and just going to 120vac, using a cheapo MSW inverter.
I do have a sinewave inverter for our 'fine' electronics, but it's a low power unit.
Anyhow, the connected 500w PV array drives a plain old PWM charge controller,
since my original goal was
only to keep the batteries charged up.
Wasn't worried about using PV power in real-time, but being able to have power
for my sump pumps at 3AM when a storm took out the grid.
My Backup system has worked out fine (& we have not had any major gird fails).
But, hindsight being 20:20, I should have gone with different hardware.
Hardware that would be
more compatible to any change in
goals.
The initial cost would have been a lot more, but I would have purchased:
A. higher wattage PV (using a fixed array w/ elevation),
B. a power-point-tracking controller,
C. a high KW sinewave inverter (off grid type),
D. and a larger, long life battery pack (48v).
That hardware would cost a lot more, but would have been a better investment,
in the event of changing goals or power requirements.
~~~
Lately, I've been testing the capability of my little back-up system using
the new A7 AirTap hotwater heater as a load.
Since the A7 only uses about 1 kWh per day, it just might work out.
Provided we don't get too many days like this weekend.
