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The local authorities where I live told us in February/March timeframe that blackouts are coming in the fall, so I planned ahead and got some battery backed sol

The local authorities where I live told us in February/March timeframe that blackouts are coming in the fall, so I planned ahead and got some battery backed solar. It's damn expensive. My house is mostly in the shade, and most of my roof faces north and is steeply sloped, so all I could do is a small solar array of about 2.5kW, which now, at the end of october, is producing about 7kWh per day. This solar array cost about $8000. This feeds into a Tesla PowerWall, which is the cheapest such system available. It can store 13kWh with 89% round trip efficiency. This cost $19,000 installed. Tesla advertises $7,000, but you need a whole lot more ancillary equipment and a lot of wiring complexity. So, we're at $27,000 for something that can produce 260W continuously 24/7 if the grid is out. This isn't very much. It's enough to run the fridge and a LED light or two. I realize I'm limited by my solar panels, and if I had the roof space, I could double my available power for roughly another $3,000. (these prices are pre-30% tax incentive). A tri-fuel (natural gas, propane, gasoline) hardwired generator would have been a better way to go. I wasn't expecting multi-day outages.

mistrial9 7y ago
your total capacity "watts" number doesnt match your description (?)
- oppositelock 7y ago
  What do you mean? A 2.5kW array will produce 2500W of power when the sun is at 90 degrees to it. This never happens to me, so I get less, 1,200-2,000W output depending on season and time of day. Now, in october, the array at best produces 1,400W, but the graph itself is sinusoidal, so the net power produced is 7kWh. Different units here - kW (which is specific power) verus kWh, which is power used.
ghaff 7y ago
Or have a propane refrigerator/freezer. That doesn't replace having a big electric fridge but you can keep a subset of things in there that will spoil easily and/or are expensive. So long as you're in a climate where furnace/air conditioning isn't critical, not having electricity for a few days isn't really that big a deal modulo having young kids, elderly, medical issues, etc.
dmckeon 7y ago
We replaced a failed generator with a 7500 watt gas-powered model for about US$950, including tax. Noisy, but handles most of a house (with careful load management). The fun part was finding a container for gasoline - Home Depot & about 10 other stores had sold out. Ended up buying a 2 gallon container of kitty litter, dumping out the litter, & rinsing out the container. Also saw a queue of about 10 Tesla owners waiting on (Super)charging spots - fun times.

mistrial9 7y ago

your total capacity "watts" number doesnt match your description (?)

oppositelock 7y ago
What do you mean? A 2.5kW array will produce 2500W of power when the sun is at 90 degrees to it. This never happens to me, so I get less, 1,200-2,000W output depending on season and time of day. Now, in october, the array at best produces 1,400W, but the graph itself is sinusoidal, so the net power produced is 7kWh. Different units here - kW (which is specific power) verus kWh, which is power used.

ghaff 7y ago

Or have a propane refrigerator/freezer. That doesn't replace having a big electric fridge but you can keep a subset of things in there that will spoil easily and/or are expensive. So long as you're in a climate where furnace/air conditioning isn't critical, not having electricity for a few days isn't really that big a deal modulo having young kids, elderly, medical issues, etc.

dmckeon 7y ago

We replaced a failed generator with a 7500 watt gas-powered model for about US$950, including tax. Noisy, but handles most of a house (with careful load management). The fun part was finding a container for gasoline - Home Depot & about 10 other stores had sold out. Ended up buying a 2 gallon container of kitty litter, dumping out the litter, & rinsing out the container. Also saw a queue of about 10 Tesla owners waiting on (Super)charging spots - fun times.