Is Solar Worth it? Anyone in Austin Area get it installed?

[karpo1]

Originally Posted by Need4Camaro

I'm no electrical engineer but those batteries appear only to output approximately 51 volts and store 5.12kWh per battery.. ..A Tesla Powerwall can output up to 240 volts and stores about 13.5kWh of energy..

If its possible to connect those batteries in series to increase voltage to atleast 120V (which most household appliances, including your fridge require - Washer/Dryer/HVAC = 240V) then it would theoretically take about 3 batteries to match 1 Tesla Powerwall in terms of power availability.. which alone isn't enough to backup a home for several days. I could also be wrong about the power availability as hooking up in series doesn't seem to increase capacity, but only voltage.. If that is the case then energy storage would be less than half of a Powerwall.

Either way though I would be surprised if they were capable of keeping a HVAC system running for any meaningful length of time.

Luckily I did study electrical engineering a bit. Yes, batteries are 48V but setup needs inverter to convert electricity to 120V/240V, not setting batteries on series. Same applies to Tesla powerwall, it has internal inverter and similar batteries as server rack batteries.

20kW with 3000W solar would make one room livable in TX. 9000BTU Heat pump on cooling takes ~750W, bigger fridge/freezer takes 100-400W but its not running constantly. Could estimate total consumption being 1000W. Solar input from 3000W panels would be ~2500W on sunny day, so while everything is running 1500W would be going to charge the batteries. Night time cooling need is less as heatpump running maybe 50% of the time so ~5000-8000Wh needed per night, that can be charged back during the day time.

Youtube channel for building such setups:

https://www.youtube.com/watch?v=mzZR6SWonrY

[Need4Camaro]

Originally Posted by karpo1

Luckily I did study electrical engineering a bit. Yes, batteries are 48V but setup needs inverter to convert electricity to 120V/240V, not setting batteries on series. Same applies to Tesla powerwall, it has internal inverter and similar batteries as server rack batteries.

20kW with 3000W solar would make one room livable in TX. 9000BTU Heat pump on cooling takes ~750W, bigger fridge/freezer takes 100-400W but its not running constantly. Could estimate total consumption being 1000W. Solar input from 3000W panels would be ~2500W on sunny day, so while everything is running 1500W would be going to charge the batteries. Night time cooling need is less as heatpump running maybe 50% of the time so ~5000-8000Wh needed per night, that can be charged back during the day time.

Youtube channel for building such setups:

https://www.youtube.com/watch?v=mzZR6SWonrY

After seeing that I have to admit that looks like a very feasible option. Seems as though you would have to do your own installation though.