[IslandCrow]

As with the last few autumns with the storms and the days drawing in my mind goes back to thinking of the possibility of buying a pv and/or wind setup for an electrical back-up system.

It is clear that even using the system for some of my current electrical needs, such a savings in the electricity that I would have otherwise bought will come no where near the cost of the system.

Since I work from home I guess I could add into the calculation the value of the time that I would be working if a power cut came during my working hours. But this still comes to 225 hours of working time during power cuts (which would be about 1 ½ months continuous). Even on this calculation the costs seem high for the benefits.

The question I have for you is how do you cost/value benefits for facilities that normally are cheap, but might not be always available? [eg for water would you use the cost of town supplies, or the cost of bottled water, or.....] And do you calculate in a factor for the possiblity of high inflation (not necessarily hyper-inflation)? Or do we work on the principle of "as I can afford this toy lets buy it"?

{I guess the electric backup might wait a bit longer, but in the summer I did add a hand-pump to the old well in our yard. If the electricity goes the wood burning stove is used instead of the more convient electric one, and the same stove is used for heat as the heat-pump stops working. The water supply also gets cut during power cuts to the hand pump covers this area of concern, although we will probably need to boil the water first}

[Newfie]

Perhaps you want to look at a small gas generator that can produce a limited amount of power. The Honda EU 2000 units come to mind as highly recommended.

How much power do you really need? Pump your water? Run your heater? Run your computer?

Do a needs analysis first. Buy Nigel Calder's cruisers guide. For about $25 it gives you a good way to do the analysis and a comparative discussion. It centers around boats, but is relevant to small homesteads.

[Pops]

It's always about storage, isn't it?

When you have wind/sun you can pump water to a holding tank for later use and you can freeze it to keep the milk cool but to run the old computer/lights/TV/whatever you need batteries and those buggers are expensive and they wear out. We have fairly reliable coal-fired power, the longest we've been out is about 2 weeks after an ice storm. I paid $300 for a cheap ($1,200 new?) 8kw gas generator that takes very little maintenance and starts every time (gotta use Stabil!)

So I'm with Newfie, unless or until they've come out with a battery that doesn't wear out in 10 or 15 years, I'd rather bet I could buy a small amount of diesel than replace a bank of dead batteries.

I'd bet you could set up a bullet-proof diesel genset with a huge storage tank - and fill it up - for the cost of a small battery bank. Here is the first page I found - 8kw Perkins for $5k. This pagesays at 1/4 load a 20kw generator uses half a gallon an hour so say 100 gallons a year, maybe a 2-300 gal tank?

$7-$8k all set up and it'll last just about as long as you can afford to buy peanut oil!

[IslandCrow]

Thanks for the responses...a generator does seem the cheapest option, even if it is using fossil fuel . The local firm that sells/installs solar and wind, when supplying off-grid houses seems to prefer a wind + generator set up (we are in an island area so wind power is good, but very far north so solar is best for summer cottages not for winter heating).

The basic power would be to run the computer setup. Laptop and printer, with the last being the real power drain. Right now I am not feeling too happy with batteries, as the one in my 2 year old laptop is totally dead. Also I would want to add some lights (our lighting backup now consists of candles plus a hand wind-up led-lantern).

If I went up in power useage I would then want to run the heat pump. Last January it ran 67% of the time using 1435 kWh of electricity, and in February the figures were 63% and 1244 kWh. I would not try to run the cooker. The fridge would be off-line, but we have a cold pantry. The freezer going off would be more of a problem unless in mid winter.

[Pops]

What about a wind setup that instead of batteries uses surplus power for heating water for drinking and space heating? That way you get a benefit from it full time and when the grid goes down you can use it to charge the lap batteries?

Then you could get by with a smaller bi-fuel generator (propane/gasoline) for backup backup and the printer/freezer/whatever bigger need arises.