Anyone else had a bill for the recent cold snap?

[Fintray]

I have an ancient generator, but really need to sort out something both more reliable and with a bit more oomph. Trouble is, decent generators tend to be costly, and there's no point in buying something that conks out after a few hours. Pity Biff's not here, as I remember him making a cracking generator from a tough little engine he'd picked up from somewhere. Might try and have a look back through the Wayback machine to try and find it, if only to get some ideas. I'd prefer a diesel, as the fuel doesn't go off so easily and the chances are the engine would be more reliable.

I was lucky as I got my Lister generator for free . If I remember correctly Biff used some Chinese clone engine with either a 24v lorry alternator or a wind turbine permanent magnet generator.
Picking up an engine shouldn't be too expensive, just finding the right generator might be slightly harder. When it comes to coupling them together I saw a simple method when I was in Nigeria, which just used strips of car tyre bolted between plates on the engine and the generator shafts.

[Joeboy]

I have an ancient generator, but really need to sort out something both more reliable and with a bit more oomph. Trouble is, decent generators tend to be costly, and there's no point in buying something that conks out after a few hours. Pity Biff's not here, as I remember him making a cracking generator from a tough little engine he'd picked up from somewhere. Might try and have a look back through the Wayback machine to try and find it, if only to get some ideas. I'd prefer a diesel, as the fuel doesn't go off so easily and the chances are the engine would be more reliable.

I was lucky as I got my Lister generator for free . If I remember correctly Biff used some Chinese clone engine with either a 24v lorry alternator or a wind turbine permanent magnet generator.
Picking up an engine shouldn't be too expensive, just finding the right generator might be slightly harder. When it comes to coupling them together I saw a simple method when I was in Nigeria, which just used strips of car tyre bolted between plates on the engine and the generator shafts.

Like a flexible spider coupling?

[Fintray]

With the amount of kit you have it looks logical first to get so the system will run off grid then find the most economical way to run a generator to charge the battery as you know the battery will run everything else for a while.

I wholeheartedly agree just need to find out a bit more about how to charge the battery safely from a generator. I've just found some German made ex-German army radio generators that might do the job. They look to be tough, and put out 50V DC, so might be OK for charging the batteries.

Air cooled generator sitting next to the A2A heat pump inlet may raise the COP a bit.

That ^^^ is an absolutely brilliant idea! Thanks very much indeed. It would make a very useful difference I'm sure, and recovering some of the waste heat from the generator like that would assuage my conscience a bit about needing to burn a bit of fossil fuel!

Might have a look at whether I could make that work a bit better by making an open enclosure that would allow the heat pump to draw air over the generator, to try and recover as much of the waste heat as possible.

Just remember if you allow the exhaust to go through the ashp you will rot it out very quickly, so you may need to consider extending the exhaust system. you could run the exhaust pipework in front of the ashp to recovr some of the "waste" heat, but you may need to deal with the rather acidic condensate.

I too have been looking at a generator for use in power cuts. I have a small petrol one, but make my own biodiesel so a diesel one would make much more sense,

When I worked in a papermill we had problems with some of the aircon units leaking gas, after several replacements it was traced to slightly elevated levels of H2S in the atmosphere coming from the adjacent effluent treatment plant, expensive coated fan coil units cured the problems.

[Fintray]

I have an ancient generator, but really need to sort out something both more reliable and with a bit more oomph. Trouble is, decent generators tend to be costly, and there's no point in buying something that conks out after a few hours. Pity Biff's not here, as I remember him making a cracking generator from a tough little engine he'd picked up from somewhere. Might try and have a look back through the Wayback machine to try and find it, if only to get some ideas. I'd prefer a diesel, as the fuel doesn't go off so easily and the chances are the engine would be more reliable.

I was lucky as I got my Lister generator for free . If I remember correctly Biff used some Chinese clone engine with either a 24v lorry alternator or a wind turbine permanent magnet generator.
Picking up an engine shouldn't be too expensive, just finding the right generator might be slightly harder. When it comes to coupling them together I saw a simple method when I was in Nigeria, which just used strips of car tyre bolted between plates on the engine and the generator shafts.

Like a flexible spider coupling?

Exactly, simple, cheap and reliable.

[Joeboy]

I was lucky as I got my Lister generator for free . If I remember correctly Biff used some Chinese clone engine with either a 24v lorry alternator or a wind turbine permanent magnet generator.
Picking up an engine shouldn't be too expensive, just finding the right generator might be slightly harder. When it comes to coupling them together I saw a simple method when I was in Nigeria, which just used strips of car tyre bolted between plates on the engine and the generator shafts.

Like a flexible spider coupling?

Exactly, simple, cheap and reliable.

Excellent idea, I can see it.

[openspaceman]

Thankfully I've never had to run it for 4 days, I would normally just run it during the day and shut it off at bedtime, mine uses diesel at 1L/hr running the house. I didn't try my inverters during the power cut so I don't know if they would have worked or not though.

We've never had a power cut for more than a few hours as most of the distribution network is underground.

If it ever became commonplace being able to keep the solar PV up and running would be fundamental in controlling fuel costs.

[Fintray]

Like a flexible spider coupling?

Exactly, simple, cheap and reliable.

Excellent idea, I can see it.

Better still, here is a picture of it:

[Fintray]

Thankfully I've never had to run it for 4 days, I would normally just run it during the day and shut it off at bedtime, mine uses diesel at 1L/hr running the house. I didn't try my inverters during the power cut so I don't know if they would have worked or not though.

We've never had a power cut for more than a few hours as most of the distribution network is underground.

If it ever became commonplace being able to keep the solar PV up and running would be fundamental in controlling fuel costs.

Thankfully it is unlikely to become commonplace (I hope) but after a few days without power and heating the fuel cost concern disappears, you just want the power.

[openspaceman]

Ref “A bit of a non problem for the occasional power cut but easy enough to extend the exhaust into a coil and then vent it. “

With Diesel If you extract to much heat from the coil Sulfuric acid will condense in the coil. The temperature at the end must be above 138 Deg C.
For the occasional power cut I would stick with normal Diesel generator
I have converted petrol cars / lawn mowers / generators to propane. First car in 1970
Propane a lot more reliable than petrol. Leave it for years. Then go and start it.

I guess it would be sulfurous acid from the oxidation of hydrogen sulfide. The welder chap that used to do my repairs was often required to plate the silencers of large SI converted diesels at a landfill gas site near Redhill and I had some flue gas recirculating pipes perforate on a woodchip burner at a large store, being used to dispose of flat pack returns, so I recognise the problem of acid condensate even on stainless steel.

I am surprised at the 138C figure as while I know at lower power levels diesel exhaust is cooler than SI exhaust but I would have expected the water vapour partial pressure to stay gaseous in the mixture with CO2, O2 and N2. After all even with methane burning in low excess air in a boiler the flue temperature has to drop below 50C to reach the dew point and go into condensing mode. Wood burners are a bit different as they must exhaust above 100C to prevent any condensation and associated stains.

A couple of potentially contradictory points:

I would go for natural gas or lpg in a SI genset simply for their cleanliness and extended oil change intervals, I too had a V8 LR converted. One of the things I note with the small stationary engine lpg conversions is they don't sense for a spark and cut the gas supply when it disappears. SI engines work at stoichiometric fuel to air mix and their exhaust temperature is constant.

A diesel beats an SI engine for conversion efficiency at lower power settings but if you aim to only charge the battery at bulk charging rate plus any base load then the engine can be set to run constantly at a fixed, optimum load when there is little difference with a naturally aspirated diesel. Once reaching a float voltage the engine is off, thus it does not put many hours on the engine compared with running a synchronous genset all the time, BTDTGTTS.

So hotter exhaust and water cooled makes me favour SI for regular use for low hours.

I have nothing against diesels having spent my working life sitting on various diesel plant, though I doubt they did my lungs much good.

[openspaceman]

Thankfully it is unlikely to become commonplace (I hope) but after a few days without power and heating the fuel cost concern disappears, you just want the power.

Yes a pipe dream maybe to see if I can do without grid electricity at all.

I wonder what the cost of disconnection and re connection would be, potentially saving about £200/year