Advice about electrical generators here in the UK.

Hi all,

I'm after a simple explanation about generators that will allow me to function if my electric goes off.

I'm in the UK if that makes a difference. I'm not made of money but could save for a decentish one if need be.

I know nothing about generators, so a real basic guide to them would be much appreciated.

Any recommended ones? How much upkeep, maintainence and working knowledge do they require? How much can you run off one?

Thanks for any advice,

CX.

Get yourself down to your local market, and if there's a tool stall, ask them if they have any. I've come across three in the last couple of months at my local market, one was a battered old 2-stroke that looked about 40yrs old but was assured it ticked over just nicely (was based on the old type of mower engine) and 2 newish building-site standard rigs. All 3 had 240v and 12v outputs though am not sure of what the wattage/amperage output was.

I had to pass on the old genny as I didnt have the ready-cash available, but would have pulled it to bits to clean and also to familiarise with its workings incase of breakdown

reply to post by Taikonaut


Good idea, thanks for that, never thought about the markets.

Theres the classifieds too, will have a look through our local rag.

Cheers.

CX.

reply to post by CX


The smallest practical generator for a residence is about 3.5 KW or 3500 Watts, a 5000 will run a residence and a freezer or maybe washing machine and a 7500 to 10K will do a whole house. The problem with the big ones is they are gas hogs, the smaller the better in terms of longivity (length of run on a tank of gas). Diesel is more economic, noisier and stinkier.

Most of them will have both a 110v and a 220v leg so you can do both in a house. That may be a moot point in Europe. You need only the 220 leg, I suppose.

Generators, generally speaking are a noisy pain to live around. They are for emergencies although you'd be surprised how many people use them full or part time.

I much prefer solar/ batteries/ inverter.

You could try wind turbine and solar kits... Google: homemade solar wind turbine...

Also google: solar backup- I believe they even work fairly well in low sun places like the UK...

Hand-cranked energy works for individual things like lights and radios.

cheap vertical farms are good for food.

Petrol gennys will run up to about 3KvA. A 6KvA is a beast of a machine and takes diesel. They're not bad to have as a back up if you can afford the things but they're well out of my price range, and you have to have a supply of fuel which can be a game-breaker in some scenarios.

Some friends of mine have been considering the solar-tron option and if you look around even some wind-turbine options from ye olde garden shed.

You'll find if you you make the effort of looking.

Thanks for the info everyone

Gives me some food for thought.

CX.

Originally posted by plumranch
reply to post by CX

 

The smallest practical generator for a residence is about 3.5 KW or 3500 Watts, a 5000 will run a residence and a freezer or maybe washing machine and a 7500 to 10K will do a whole house.

Rather than scale-up the size of generator required, you should be looking at scaling-down your power demands. 3kW/h is more than enough to run an entire household, and if you go the solar+battery route you'll find out just how quickly you use your max battery capacity (the higher the voltage+the lower the amperage=minimised resistance losses and a greater efficiency)

As an aside, if you are going the solar/ solar&wind hybrid route, by all means start out building a 12v array to learn how it works, but anything worth supplying an off-grid demsnd will need a 24v setup as minimum, and a 48v setup as preferrable

reply to post by Taikonaut

Rather than scale-up the size of generator required, you should be looking at scaling-down your power demands. 3kW/h is more than enough to run an entire household, and if you go the

What happens if you use too small a generator? When both the freezer and the refrigerator kick in at the same time plus maybe the well pump, the generator quickly is overloaded, heats up the circuit breaker and you are back in the dark. Then you unplug a few appliances and start over.

Appliances that use less energy like a high efficiency freezer or frig are also very expensive compared to the garden varieties.

Green is good, cool and expensive.

Being in a flat in the UK ( or an apartment for you Americans) I too have wondered about power outages, not having a garden is a HUGE disadvantage as well.

The best thing to is to prioritise your power needs, consider when you go on your hols, you unplug everything except the fridge freezer right?
Same applies for your power outage, the fridge is one of the most important needs, keeps your food chilled for longevity and if its a freezer make ice cubes too .

After that I see the needs are for information ( TV, or PC, you should have a windup radio in case) or for your bathing needs, get a shower, and be quick getting clean ).

Cooking isn't much of an issue , you can have a BBQ in a grassy area, or have a small portable gas camping cooker in your kitchen like you do in a caravan.

In a real SHTF situation food would run out first and you'd need to keep you food levels maxed out, any meats or dairy products would be not only used first but if the fridge goes, would be the first to spoil.

For small homes, I'd suggest a small window solar panel available fairly cheap from somewhere like Maplins for example :

www.maplin.co.uk...

You can get better but the price goes up after that.

Or a company called Makro occasionally does cheap petrol gennies about £50(ish) for the real emergencies like powering the fridge at night if you don't have enough batteries to power the thing.

Also you'd have to turn all the setting to the minimum to keep the power consumption down , Unlike me I have my fridge turned to 2degrees and the freezer -22degrees, I think I would have to get a genny for it though incase.

I'd reccomend getting solar panels for your small equipment like Ipods and mobile fones anyway, just to cut down on your home power consumption , unless your cheap like me and charge them at work .

The mistake I've seen a lot of people make when buying an emergency generator is not getting one with sufficient grunt to provide the starting current of motorised appliances like refrigerators, water pumps etc.

Virtually all household mains appliances with motors start 'direct-on-line' which means the instantaneous starting current at switchon, better known in the business as locked rotor current, can easily be 3 or 4 times the running current and this can stall the generator if it doesn't have the legs and momentum to get through it. The speed of the governor reaction to load changes is also a critical factor for the same reason (you don't really want the frequency going up to 70Hz or more when a large load switches off). The better flywheel effect of a larger generator provides more stability but the penalty is they will generally run well below their peak efficiency loading (70-80% rated output).

Hello Plumranch

What equipment would you need to have a solar/ batteries/ inverter system in order to mains power and would you need more than one system if you wanted to power say, TV, fridge, freezer, pump for central heating and not forgetting the kettle for essential tea...

Originally posted by plumranch
What happens if you use too small a generator? When both the freezer and the refrigerator kick in at the same time plus maybe the well pump, the generator quickly is overloaded, heats up the circuit breaker and you are back in the dark. Then you unplug a few appliances and start over.

You'll have to determine which appliances are to be permanently powered such as freezer/water pump/electric shower. Add up the max power consumption for those as your start point, then add up the wattage consumption for ancilliary devices and add a margin for extra capacity on top and you have a good estimate on what output you'll need.

reply to post by mumblyjoe

What equipment would you need to have a solar/ batteries/ inverter system in order to mains power and would you need more than one system if you wanted to power say, TV, fridge, freezer, pump for central heating and not forgetting the kettle for essential tea...

Good question but based on my many years of practical experience:

-4 to 6 high power solar panels mounted however you want but keep them pointed at the sun and in the sun.

-a charge controller. These go from a simple relay to computer regulators.

-a battery bank. Assuming a 24 volt system, at least 8 L16 batteries. Larger is better. 48 volts is better than 24v. Adding batteries later is possible but discouraged.

-inverter in the range of 3000- 5000KW (most will rev up higher for short periods). These can be sized the same way as the generator. 2 inverters are required to do 240v. American. One inverter for each 110v leg.
-the electric range and electric dryer are the only appliances which usually are 240v. So you may be able to do with just 110v.

-a backup charging system hooked to the grid to help keep it charged durring dark periods.

-a large disconnect switch, proper grounding and some gauges.

The more you do yourself the better you'll understand the system.

[edit on 4/8/09 by plumranch]

reply to post by Taikonaut

You'll have to determine which appliances are to be permanently powered such as freezer/water pump/electric shower. Add up the max power consumption for those as your start point, then add up the wattage consumption for ancilliary devices and add a margin for extra capacity on top and you have a good estimate on what output you'll ne

One problem I had is when you add all these up it usually ignores starting amps. That is often 2X running amps. So then if 2 appliances start at once the generator disconnects because it can only produce so much KW before the breaker pops.

So make sure you know starting amps for any motored appliance.

You can get one that runs on Natural gas. They will automaticly turn on if your power drops. And you only need them to run the important things like the furnace and fridge.

Might be a bit "out there" but any you guys thought of a steam generator, if you have access to plenty of wood combustibles, been doing a bit of research and like the idea, have to get in touch with a few mates and see if we can construct one are selves... just an idea

reply to post by foxhoundone


Like one of these?



The alternator used there is based on the Scoraig Wind axial-flux wind turbine design that uses a hand-made stator sandwiched between dual N40 Neodymium magnet rotors and apparently producing 2kW/hr

Here's a link to the steam-section at the Otherpower.com forums...quite possibly THE best collection of alt.power technical knowledge going

reply to post by Taikonaut


Thanks TK yep that's just the ticket, been pondering for a while now about alternate energy supply and have come up with a solution me thinks, and a steam boat would be ideal. Disconnect the prop and attach a dyno/Genni for powering the house replace the prop and have the boat for hunting, that steamer generator can be used as a pump i assume and it looks mannish portable, thanks for links i will follow up, A mate of mine runs the old steam trains here i know him and his firman quite well i will have to pump them for information on how to stoke and run steam engine

reply to post by foxhoundone


Have a look at this design of steam-engine...even the twin cylimder version is capable of powering a small launch (there used to be a photo of the inventor chugging across the water in such a craft on his website, but has since updated the images and aint there anymore) and is compact enough to create a small steam-genny setup with an axial-flux alternator attached



I've stumbled on what could be the perfect mobile steam source too..

greensteam.com...



[edit on 5-8-2009 by Taikonaut]