alt Hacker NewsWe're off grid and have 7kw of panels, and 40kwh of 48v lithium batteries, with a generator for backup, which is rarely used since we are frugal with electricity and switch everything off when not in use.
I set it all up myself, and while it is not trivial, it's not difficult either.
Learning to put connectors on properly, size cables and put lugs on properly, learn about earthing and breakers...just one bit at a time.
I'm about to set up another system on the roof of an outbuilding to supply power for a water pump and irrigation where we grow food. This will be much easier and simpler since it will have only one 48V lithium battery, but I'll still use Victron stuff and connect it to a Cerbo so it can be monitored.
If I sold this place and bought somewhere on the grid, the first thing I'd do is cut the cord and set up my own system again.
Replies
do you have a blog or some links of walking through the process of getting everything setup?
Curious, how did you deal with inspections and building codes? Or is it in a county with no building codes?
»We're off grid and have 7kw of panels, and 40kwh of 48v lithium batteries, with a generator for backup, which is rarely used since we are frugal with electricity and switch everything off when not in use.«
Good for you, but this is neither a concept for large cities nor for the industry.
What inverter hardware did you use?
I have an el cheapo 120 VAC 3600W import inverter with just two 100AH AGM batteries in series as it's a 24 VDC unit. Right now its all temporary and more experiment than practical.
Inverter mounted to a portable frame I built from bolted slotted angle with two battery shelves for a total of 4 batteries (only 2 now.) The batteries have a 200A terminal fuse and run through a 200A disconnect to the inverter using #2 AWG cable. The inverter, AC input, AC output are all grounded to a single ground bar that is bonded to the metal frame. AC Input is fed from a 12 AWG cord with 15A plug. AC output runs two 15A MCCB's, each terminated to a single socket hanging off a short whip cord. A cheap two wire digital DC volt meter is wired in series with a push button so I can see the battery voltage at a glance when I have the inverter powered down.
I temporarily setup the panels in my yard as an experiment but since I am in the city, I don't get good sun in my yard with all the obstructions. Honestly I ran it for two days, took the panels down before it rained, and didn't get a chance to measure anything. The panels really need to go on the roof and I have no intention of doing that any time soon.
The system did come in handy as a backup for my boiler when a wind storm knocked the power out for an hour and a half this past winter. I have thought about setting it up as a UPS for my little IT setup at home but 3600W is super overkill.