questions about fuel and generators (incl. a legal one)

[Andy Dingley]

Diesel has better lubricating properties than kerosene / paraffin. If you use raw paraffin or heating oil to run a Diesel engine, you'll kill the injector pump. If you want to make a habit of this, find a Diesel (such as an ex-Army multi-fuel engine) that uses a separate lubricating oil supply for the pump, rather than relying on the fuel to do it.

"Diesel" can be either tax-free (unheard of in practice), agric diesel (red, cheap tax), boat diesel (blue, slightly cheap tax) or DERV (Diesel Engine Road Vehicle, clear, full tax).

I can't see any combustion engine self-generation scheme being cost- effective, compared to Grid. Even if you went for CHP (Combined Heat & Power) you need to have simultaneous demand for both heat and power to make it work out.

[dom]

It wouldn't be. And even if it was, the tariffs would be fixed so it wouldn't be.

[Cynic]

You don't have a hope of generating electricity as cheaply as a large power station, so you'll be losing money, but it *might* reduce the overhead of an underloaded genny running 24/7. IIUC the cost of the equipment needed before you will be permitted to connect your genny to the grid is pretty high.

A better way is to have a large battery bank that powers the house, with the generator cutting in automatically when the charge gets below a set amount and runs just long enough to recharge the batteries. An invertor with sufficient output to power a house is very expensive, so are large capacity batteries. Maybe best to do it the old-fashioned way and use the batteries to power a brushless DC motor that drives an AC generator rather than using an electronic invertor. The diesel or paraffin generator would be DC and connected to the batteries via a charging circuit and battery charge monitor.

For standing batteries you might go for a bank of open lead-acid cells in a small outbuilding. The plates can be removed from the container of each cell and replaced separately when needed (the old plates sold for recycling), and the acid can be filtered and the container cleaned periodically. The plates would probably last 3 to 5 years between replacements.

You'll not get the cost down below what you pay for on-grid electricity though, and using home-generated power should only be contemplated if you don't have access to a grid supply.

DIY electricity only becomes cost-effective in factories that need

*huge* amounts of power.

[Phil]

Most of the potential problems in doing this, as highlighted on this thread, are to do with needing 240VAC.

If you can get by with 12vdc you reduce the cost & complexity manifold. Genset / Photovoltaics would recharge your battery bank.

Think about it - LCD televisions that use an external 'brick' PSU are often 12vdc, as are a lot of consumer appliances. Lighting would be a doddle with LEDs.

What will catch you out are fridge/freezers, washing machines & the like.

[Mike Ross]

uk.rec.engines.stationary

Mike

--

'As I walk along these shores I am the history within'

[Cynic]

Lighting is no problem with 12V (though you'll probably have to DIY if you want LED lighting), but if you look at the output voltage of all the "bricks" you have, ITYF that the voltages vary greatly from 5V to

24V or even higher. A 12V "brick" is one of the most common, but I'd be surprised if as many as half of the ones you have are at that voltage. OTOH low power 12V invertors are cheap enough that you could buy one for each item that uses a "brick" PSU.

Yup, and they need a very sizable invertor. Don't go by their rated power consumption - with many appliances it is the switch-on surge current required that limits them to needing a *big* invertor. Vacuum cleaners are also big-power items.

You can buy 12V fridges, freezers and microwave ovens for boats and caravans, but they are a heck of a price! Small 12V kettles are also available. You can buy PC PSUs that run from 12V - again many times the price of the equivalent mains units.

You can also get gas and paraffin fridges and freezers, which would probably be better than running from 12V.

The battery for a house would probably have to be very sizable if to want to keep the charge cycle down to an hour or two per day. Batteries on continuous cycles do not last all that long. Just the cost of replacing the battery bank every 3 to 5 years is quite likely more than your electricity bills over the same period!

[terry]

Not the least of concerns is fuel storage and leakage from same. Leaks from tanks and fuel lines have here (Canada) cost householders in some cases thousands! In many instances not being covered by homeowners liability insurance. When 'oil' is used, household insurance premiums can often be higher if liquid fuel is used because of the potential for leaks. By certain mandated dates; storage tanks, in most provinces of Canada, must now have a 'sump' and/or be constructed in such a way that there is a weir or catchment around them, capable of holding 100% of the full contents. The catchment device often being integral with the tank. As a result tanks now cost much more than in the past, are bigger and more unwieldy etc. Oil that leaks into the ground can travel long distances and pollute the property of others. In several instances the excavation s have been huge and have extended onto other properties at great cost for restoration! In one case in St. John's Newfoundland, the hole was so large that the owners built a complete sub-ground basement and addition to their home in an area that had been an oil soaked parking lo ! It is understood that in some cases leakage only became apparent when increasing costs for fuel oil caused homeowners to check the 'quantities' of oil being bought! Thus oil leakage had been going on for some time! Electricity produced by water power would seem the 'safest' from an environmental viewpoint. But then there is usually flooding and water back up! Sometimes with dire consequences. The next safest being, and perhaps less polluting, being nuclear? But then there was Chernobyl, and 3 Mile island etc. etc. Must go and throw on another bit of wood scrap and plug in the electric kettle for a cuppa! Maybe the somw will be gone in another few weeks; maybe by early-mid May!

[terry]

Not the least of concerns is fuel storage and leakage from same. Leaks from tanks and fuel lines have here (Canada) cost householders in some cases thousands! In many instances not being covered by homeowners liability insurance. When 'oil' is used, household insurance premiums can often be higher if liquid fuel is used because of the potential for leaks. By certain mandated dates; storage tanks, in most provinces of Canada, must now have a 'sump' and/or be constructed in such a way that there is a weir or catchment around them, capable of holding

100% of the full contents. The catchment device often being integral with the tank. As a result tanks now cost much more than in the past, are bigger and more unwieldy etc. Oil that leaks into the ground can travel long distances and pollute the property of others. In several instances the excavation s have been huge and have extended onto other properties at great cost for restoration! In one case in St. John's Newfoundland, the hole was so large that the owners built a complete sub-ground basement and addition to their home in an area that had been an oil soaked parking lot! It is understood that in some cases leakage only became apparent when increasing costs for fuel oil caused homeowners to check the 'quantities' of oil being bought! Thus oil leakage had been going on for some time! Electricity produced by water power would seem the 'safest' from an environmental viewpoint. But then there is usually flooding and water back up! Sometimes with dire consequences. The next safest being, and perhaps less polluting, being nuclear? But then there was Chernobyl, and 3 Mile island etc. etc. Must go and throw on another bit of wood scrap on the wood stove and plug in the electric kettle for a cuppa! Maybe the snow will be gone in another few weeks; maybe by early-mid May!

[JohnW]

... and be careful that the device can run off a 12v battery source, which ranges from some 11v to over 14v from discharged to charging. "12V" is actually getting quite flat (25-30%) for lead-acid...

[Phil]

Putting the cart before the horse ! If you wanted to go off-grid, what I am saying is that you should consider designing your house & appliances from the outset to use only

12vdc.

Phil.

[Alasdair]

You could run a diesel engine on paraffin mixed with lubricating oil but I would be concerned about damage to the engine.

Not really practical as it would involve getting a steam engine to drive the genny

This is the best, if noisiest idea. Get hold of a Lister Start-o-matic which automatically switches on when a light or power switch is put on in the house. Contact R. A. Lister & Co of Dursley, Gloucestershire and find out if they are still available.

It is both feasable and legal but is a lot of hassle. Diesel oil for stationary engines has no duty on it and you buy it from a distributor in bulk. I don't know whether it has VAT or not. It is called Gas Oil although it is ordinary diesel but dyed red.

This is quite normal but unless you use wind power or hydro-electricity, it is likely to be more expensive than mains. From a legal point of view, you can generate your electricity from any fuel you like except, possibly, nuclear energy which is tightly regulated.

I have answered your specific questions above.

[John Nagelson]

Sold at the pump in some agricultural areas in the UK.

That's not my aim though! :-)

John

[Andy Dingley]

Why only 12V? Go DC by all means, but 48V is easy and even "mains voltage" DC systems with battery backup are practical, so long as you know what you're doing ("mains" switches don't like breaking a DC load). Distributing any sort of useful power at low voltages gets difficult from the high current, extra losses and extra cabling costs.

If you really are going for Hobbit-technology and building the lot from recycled car batteries, but a separate battery and automatic charger into each light fitting and keep the premises wiring at 240V AC from the genset. You'd be using a bunch of batteries anyway, the wiring costs make it sensible to distribute them close to the loads.

[Max Demian]

So what, pray is your aim; or rather your purpose?

We are all dying to know ;-)

[Rod]

Couldn't agree more. I suspect half (or more) of the "answers" so far supplied are of little or no use - but we don't currently know which half.... :-)

[The Natural Philosopher]

Its virtually the same as red diesel, so a diesel genny is a good thing to try.

In the power cuts of the 70's the place I worked aty had one..we tried a ford 2 liter petrol but it couldn't take running at decent power continuously, and it was swapped for a truck motor. I think about 3-4 litres. Perkins probably.

You probably don't need more than about 10KVAwhich is about 15bhp, so a small economical diesel around 1 lites and a tad is probably not a bad choice.

Cut one out of a scrapper car, along with mounts, and hook up to a generator..you will need to run it at 3000 RPM, which is not a bad rev range for a diesel.

Almost impossible: you need blown boiler steam type plant. Mind you if you DO put a steam turbine in teh back yard, you can burn all sorts of stuff on it, but beware. Boilers need stringent sfatey ceks and a lot of 'chimney sweeping'. The main reaoson they vanished from railways was the super high maintenance.

Buy heating oil.

Dunno about legal, but those sorts of oils do bad things to diesel injectors.

Anorther possibility is a crap small gas turbine out of a small aircarft. I dont know of anything between 'model jets' and 'fukls size airfract jets' but there maty in fact be something. If you can use teh waste heat these aren't a bad bet. In any case whatever you use, pump any coolant or exhaust stuff into a heat exchanger for hot water and CH usage.

[The Natural Philosopher]

Gravity feed.

Any good range type system - aga or rayburn - adapted for oil will do space heating very very well with no need for elelctricity, though our aga does modulate the oil flow between 'high' and 'low' with an electric themostat.

It also solves most of your cooking needs.

If you use a large bore gravity feed to a hot water tank, that does hot water as well.

Heating other bits of the house? Well if you have chimneys or put in steel flues, the solid fuel wood burner stoves are fabulous if you have access to your own wood supply.

That takes electricity out of the heating/cooking systems completely.

Leaving a lower amount needed for mostly lights, and electronics stuff.

[The Natural Philosopher]

A certain person I know adds 50% of '28 second' to every 1/2 tank of diesel he buys.

It runs..smokes a bit.

[Anthony R. Gold]

I guess that is for fiscal rather that cold climate reasons.

At least it doesn't have any red dye :-)

Tony

[Andy Champ]

Surely the PC is the easy part - there are car adaptors for most laptops.

Andy