Connecting backup power to your house Featured

If the cuts are at night, where anyone with an EV is charging their vehicle, a noisy petrol generator might be an issue?

You can get dual fuel and linked Honda inverter gennies:

I did have a look at natural gas powered generators a while ago as I do have mains gas and thought that might be cheaper than LPG and save lugging bottles around.

there is an irony in using a petrol or LPG genny to charge an EV...... :-)

Talking of gennys, you can get inverters that run on 12 volts and most car alternators can supply around 100A so that's potentially an opportunity to run a 1kW inverter from an idling car engine.....

I'm not sure on the legal aspects in leaving an idling car unattended on yoru driveway or roadside......

Yes, I wondered about Part P. How - if at all - does one get the necessary paperwork?

Legal on your drive, but not on the highway.

If you were going to go that route though, how about a second-hand car engine (possibly running off mains gas) and an alternator sized to run your whole house, in a home-made acoustic and thermal enclosure, with the heat being captured and used for your domestic heating and hot water?

I have thought of that myself, as well as taking heat out of the exhaust. Would be very efficient.

However an alternator at full tilt producing just 12V is not so efficient and I'd be tempted to look at alternative means of power generation. Or modify the alternator to make it far more efficient.

We did it for a remote classroom, used a marinised petter diesel 10kVA generator to provide power and took the coolant from the water cooled exhaust manifold. This circulated to radiators in the classroom. It was practical, inefficient but less choice then.

Nowadays one might take the engine and permanent magnet 13kW alternator from a honda civc IMA and find the most economic speed to max out the alternator. If the house has a battery or EV so much the better to use the load. I suppose one could expect 30% of the energy out as electricity 30% as heat to coolant and 30% to exhaust, much of the latter two flows could be dumped into the house radiators. The engine would only need to run for sufficient time to charge the battery.

For my purposes a Honda eu22i would be ideal if they produced a water cooled version, I only need to produce a few hundred kWh in 150 days of winter and the heat would be useful. Probably only 300 hours of run time on the generator means it would easily see me out.

Interesting, but somewhat over-engineered - and $5K! My battery inverter is a similar build quality and a lot less than that (even with battery) - probably because there's orders of magnitude less stuff in there.

I've seen videos of some of the smaller Jackery units. Look quite nice, and useful if you need to keep the basics alive while an electrician works on the consumer unit etc. Not sure they're going to power a lot more than the router, etc - possibly not the fridge, for example. Although this kind of thing:

It's actually a good thought though: I have a pair of 2kWh LiFePO4 batteries that are about 25kg each, so a trolley arrangement might be a good way to mount them. Maybe even take the inverter as well.

It is more an issue if you get a power cut when not paying attention - eg out of the house, or in the middle of the night. A UPS won't really help cover the gap unless the genset has auto start - it may be flat before you notice. Maybe in that case you don't care about the computers, but you do want the fridge and the aquarium pump to keep going.

I was pondering a similar rationale... :-)

You would probably want to only changeover certain circuits (eg sockets and lighting) so any changes would be in addition to the existing CU, and hence be neither a CU 'replacement' nor a new circuit.

Theo

Brian Gaff snipped-for-privacy@gmail.com wrote

Wrong, they breed like flys.

How dare you ?

The krauts haven't.

Nope, generators work fine.

Not feasible in Britain more than there is already.

What makes sense is nukes. You buggers should have been building more for decades.

By building nukes.

Plenty of quiet ones.

F*ck green.

Thats bullshit with the quiet ones.

Somene on here a few years ago kindly calculated that a Dinorwig type reservoir, the size of Wales, would keep the UK (or England) going for about 30mins(?).

The last true coal power station remaining has a new lease of life thanks to the German owners. I wonder if we are expected to export its output.

Still we have fusion on its way - mind you it's been on its way ever since I was a school kid.

Get on with those nuclear builds.

There are plenty of quiet ones.

Makes more sense to just get a no longer MOTable car for peanuts and leave it in the drive.

I wasn't considering a 12V alternator.

Some people will go to a massive amount of trouble to avoid walking 7 metres. Bill

No hills to push water up, I am already 'up' - the highest point for miles. You need an awful lot of batteries to store a worthwhile amount.

My backup plan is simple - none, or nothing special. Living room fire works with no power, just gas, hob and oven can be lit with matches. Laptop will run for a good while on battery, and I have a few candles in stock, batteries for the torches.

Fridges and freezers should be good for 4 to 8 hours. If things become even more desperate, caravan in drive has it own heating system and lighting, able to run on it's own LPG and I have a full stock of LPG.

The houses to my rear lost power last night and I quite appreciated the darkness.

Yup... (it also saved a trip to the workshop to get the work light out)

We have not neglected that at all - we have already used the best available sites for pumped storage - at a cost of many billions and decades of years of effort.

Dinorwig alone cost in the order of £3.6B in today's money, and took ten years to build, and has a peak power output comparable to a decent sized thermal power plant (1.7GW), and a capacity of 9.1GWh - or about 20 minutes of UK base load)

The "neglect" is the attention to detail required from the chattering classes to comprehend the magnitude of the challenge that producing grid scale storage represents. It seems to be "energy storage is easy - just scale that up enough"! Then leave it to the techies to figure out how to do it.

So what do you actually propose?

In my case the generator is about 60dB at 7m. The neighbours are a good deal further away than that. If I build it an enclosure, I expect I can significantly reduce the noise further. "Green" is not a relevant concern, business continuity is, as it the ability to heat and eat!

Likewise, but it is butane, so I would be in trouble if it is really cold. :-(

Chris