Economy 7 top up

[cold comfort farm]

I am slowly putting together a Lister generator, battery and inverter. My question is this: if I switched my supply back to economy 7. would it be economical to boost the batteries via a battery charger on economy 7 then discharge them thorough the day. Assuming that the Lister has not charged the batteries to full capacity. Would this work out more economical or am I missing something such as conversion factors. 
The kw tariff ratings are:
Day units 8.81p
Night units 3.83p 12pm till 8am

I intend to run the lister for several hours each evening. switch off at bed time then around silly oclock in the morning automatically switch over from battery to mains (assuming there is not enough life left in the bank). and top up the batteries with cheap electric. switch back before 8am therefore i dont use any day units as i am using the energy stored in the battery.

This is too simple, so what have i missed.
Many Thanks.


Stephen

[rmchambers]

This is doable if you have enough battery capacity for it.

There was some talk on one of the solar web sites about buying loads of off-peak power to charge up your batteries at night and then in the day time sell the power back to the power company (net metering) which will sort of let you play the futures game.  Selling cheap electricity at the higher tier's price.

Now I don't know how feasible this would be in the long run and I'd imagine the power company would look a bit strange at a customer that used oodles of night-time KWH and produced oodles of daytime KWH.

So - if you had enough battery capacity and the lister couldn't charge the whole bank then buying up off-peak KWH to charge the bank and use them during the day (offset your prime-time kwh usage) that would work.  Is it efficient enough to be worth doing it?  hard to say.  Depends on what it costs you to get everything set up, the price differentials between peak/off peak, and how long it would take to amortize the costs of the equipment at the rate of return (or price offset) over the life of the project.

Robert

[Andre Blanchard]

This is doable if you have enough battery capacity for it.

There was some talk on one of the solar web sites about buying loads of off-peak power to charge up your batteries at night and then in the day time sell the power back to the power company (net metering) which will sort of let you play the futures game.  Selling cheap electricity at the higher tier's price.

Now I don't know how feasible this would be in the long run and I'd imagine the power company would look a bit strange at a customer that used oodles of night-time KWH and produced oodles of daytime KWH.

I have to think that if money could be made doing that then the power company would be doing it themselves, and they could buy batteries in volumes that would get them a price per KWH that you or I never will in a home sized system.