# winter charging

Registered Users Posts: 5
Ok please help my new idea is to use a static engine 5/ 10 hp running on domestic natural house gas which I calculate to cost about ¼ of the cost of red diesel to turn a high output 48 volt alternator with an output of 2.800 watts to charge
My 1200amph battery bank would it work out cheaper than E7 electric in winter

• Banned Posts: 17,615 ✭✭
Re: winter charging

Since most of us are not in the UK, could you explain what "E7 electric" is?

Otherwise it's a matter of calculating how much NG would be consumed to run the engine for a given time to produce the necessary Watt hours and comparing the cost of that to the electric.

This does not include initial investment in building the generator or ongoing maintenance.
• Registered Users Posts: 5
Re: winter charging
Since most of us are not in the UK, could you explain what "E7 electric" is?

Otherwise it's a matter of calculating how much NG would be consumed to run the engine for a given time to produce the necessary Watt hours and comparing the cost of that to the electric.

This does not include initial investment in building the generator or ongoing maintenance.

in the uk at we have a night economy rate which is 1/3 of day rate so we do our charging at night so when the sun don,t shine we use a bit of E7
now building a unit is no problem that is just a hobby but there is no point if it not cheeper
• Banned Posts: 17,615 ✭✭
Re: winter charging

In that case "cheaper" would be a matter of actual cost per kW hour on your cheap rate vs. the actual cost of generating a kW hour from the NG.

There you get into the quite complicated mathematics of converting a quantity of NG @ "so much" into an amount of Watt hours of electricity, including the efficiency of the engine on NG (low compared to other fuels) and the losses in conversion to electricity.

Over here it wouldn't be worth it because electric is so cheap (think sixpence per kW hour).
• Solar Expert Posts: 3,009 ✭✭✭✭
Re: winter charging

And the cost of batteries, their maintenance and replacement as necessary.
Off hand, you may be much further ahead initiating conservation measures, replacing older appliances with new high efficiency models and eliminating the waste of energy.
• Solar Expert Posts: 1,571 ✭✭
Re: winter charging

Hi Robbymax, I recommend you try the navitron forums which is UK specific: www.navitron.org.uk/forum there are a few people on their who are using recycled veg oil based generators. Don't know anyone using natural gas because it's too expensive.