Peter Scott wrote:


Mikeyboy wrote:
I posted a week ago to inquire what capacity generator I might need to
power things like central heating, freezer, large american fridge
freezer. The consensus seems to be, go for a 2 kw one, Honda if
possible.

I also note that things like inverters can do some of the jobs that a
generator can. Would one be relevant in my case?

Thanks for your help in advance.

Mike

Almost certainly not. The cost of inverters powerful enough, with a
suitable overhead, to run even modest devices will be great. I have
found that switch on surges mean that at least 50% additional power
handling is needed, depending on the sort of load. And of course you
will need to spend a lot on batteries to store the necessary energy if
the idea is to have more than a few minutes running time, and then find
somewhere to put them. 1kWh = 3.6 MJ. 1amp hour at 12V is 1 x 3600 x 12,
which is 43 kJ (remember ItV from physics?). Thus if my calcs are
correct you need 83 Ah, which might need to be doubled to allow for
inverter inefficiency. That's two meaty batteries for just one
electricity unit.

Peter Scott

Well,. it all depends..

Here is a data point..3500Watts, 5KVA, around £1500...

http://www.morecomputers.com/extra.asp?pn=SUA5000RMI5U

Now I am not sure about this particular model, but many others will take
external batteries..

I would think around £6000 might easily get you a 24hr+ electricity
supply, at normal sorts of loads.

With off peak being about 8 times cheaper than on peak, its an
interesting calculation..

If your quarterly bill is more than around £150, its probably worthwhile..


THEN use a genny set to charge the batteries.. ;-)