Should I go off-grid?

HertsLad

I live in quite a modern house down a road with lots of other houses on the outskirts of town. I believe the house has been supplied with electricity and gas ever since it was built. Until about five years ago, I used ebico to supply my energy. It was great because there was no standing charge. By not heating my house and using gas only for the gas cooker, I managed to get my gas cost down to about £40 per annum. Then, I fear, ebico could no longer find an energy company prepared to supply customers without a standing charge. As a result, ebico became expensive and I moved to eon. The standing charge is 8p per day for each of gas and electricity but only for about 1 more week. Then I will be subject to massive cost increases (approx 100%) and there's almost nothing I can do about it, apart from start producing my own energy.

I wonder if my objective should be to move off-grid but then there are costs of doing that. Eon said it would be £143 to de-energize the gas and £91 for electricity. I assume similar charges would be made if I change my mind and want to sign up again. As a first step, I may stop using natural gas because I can modify the gas cooker to run on propane and maybe make a wood burning 'stove' to boil water in the garden. Most of my hot water, though, comes from solar thermal panels and rain water.

I bought the panels pre-owned from a first owner who seemed to have given up, having spent about £5000 some 10 years ago. They work for me by heating one or two buckets of water (10L per bucket) which I use for washing clothes by hand. That's from one of the panels. If two panels were used, in autumn, winter or spring, they would probably heat up 40L or 60L water which would be enough for me to have a shower so I am pleased with my purchase at a cost of £150. I don't think I would be pleased if I was younger with a family and paid £5000.The likely contribution to hot water would be unlikely to justify the original cost, which is why the original owner gave up. In summer it's a different story. The panels can produce plenty of hot water.

My electricity use is about 3kWh per day and I am hoping I can supply most of that through PV panels, not yet installed. I also bought a generator for emergency use.

People living in isolated areas and on house boats may often survive off-grid I assume. But it seems a big step to take in a modern house. Has anyone else here, taken that step? I am outraged by the recent increase in energy costs. I no longer want anything to do with these suppliers. That's what is motivating me to think of alternatives.

QrizB

Hi HertsLad, I enjoyed your no-heating thread on the Energy board (you seemed to get an unjustified amount of stick from others).

It sounds to me as though going off-grid for gas would be fairly easy. Electricity is trickier as solar PV tends to generate too much energy in the summer and not enough in the winter, and there's no cheap way to store electricity for periods of weeks or months.

Running a generator for 3kWh/day through the winter months is likely to cost more in fuel than paying the annual standing charge plus buying power from the grid, even without the capital and operational costs of the generator.

Verdigris

It can be done but you'll need to do a lot of reading to integrate it all. Remember that when you need most solar electricity you'll get the least.

I'm about to renovate a bungalow and I aim to be a net exporter of green electricity from a share in a windfarm and solar panels. However, I shall be "borrowing" the electricity grid to do this, via a smart meter, so I can get SEG export payments and benefit from cheap overnight electricity to charge storage batteries. I'll also be running an electric car from it, too. It will cost quite a lot to achieve, but the 50p a day standing charge is a small price to pay, to have reliable heating, power and motoring, for little ongoing costs and hopefully no carbon footprint.

Good luck.

HertsLad

QrizB said:

solar PV tends to generate too much energy in the summer and not enough in the winter, and there's no cheap way to store electricity for periods of weeks or months....Running a generator for 3kWh/day through the winter months is likely to cost more in fuel than paying the annual standing charge plus buying power from the grid, even without the capital and operational costs of the generator.

I agree. The generator is only intended for emergency use if I go off-grid. And for camping trips, to avoid site fees for electricity. If it needs to be used very often, it will be very expensive. The electricity standing charge will be about £140 per year. So if I can limit my electricity to £60 then the total cost of electricity will be £200, i,e. lower than for the past few years. What I need to find out is whether I can generate enough power through just 6 PV panels to provide most of my 3kWh per day needs. I may be able to reduce power consumption if I stop using my small freezer, for example. At least I can keep using electricity if this is all proved wildly optimistic.

QrizB

HertsLad said:

QrizB said:

solar PV tends to generate too much energy in the summer and not enough in the winter, and there's no cheap way to store electricity for periods of weeks or months....Running a generator for 3kWh/day through the winter months is likely to cost more in fuel than paying the annual standing charge plus buying power from the grid, even without the capital and operational costs of the generator.

I agree. The generator is only intended for emergency use if I go off-grid. And for camping trips, to avoid site fees for electricity. If it needs to be used very often, it will be very expensive. The electricity standing charge will be about £140 per year. So if I can limit my electricity to £60 then the total cost of electricity will be £200, i,e. lower than for the past few years. What I need to find out is whether I can generate enough power through just 6 PV panels to provide most of my 3kWh per day needs. I may be able to reduce power consumption if I stop using my small freezer, for example. At least I can keep using electricity if this is all proved wildly optimistic.

Try PVGIS and see how many watts of panels you need in your location, to generate 3kWh/day for most of the year.

https://ec.europa.eu/jrc/en/pvgis

At my end of the country, I would need at least 1.1kW of solar panel to generate 1095kWh/yr (3*365). But that would only give me 3kWh/day as a monthly average from March to September. Double that - 2.2kWh - would take me from February to November and 3kW of panel would get me 3kWh/day throughout an average year.

Then you need to understand that half of years are below average; this past December was unusually dull, for example.

You say "6 PV panels" - do you already have these, or have you yet to buy them? It seems an oddly-specific number. If you have them, do you know their rated watttage?

theoretica

Would you generate enough excess power over the summer that the export back to the grid would cover the standing charge?  If so, no point going off grid.

[Deleted User]

HertsLad said:

QrizB said:

solar PV tends to generate too much energy in the summer and not enough in the winter, and there's no cheap way to store electricity for periods of weeks or months....Running a generator for 3kWh/day through the winter months is likely to cost more in fuel than paying the annual standing charge plus buying power from the grid, even without the capital and operational costs of the generator.

What I need to find out is whether I can generate enough power through just 6 PV panels to provide most of my 3kWh per day needs. I may be able to reduce power consumption if I stop using my small freezer, for example. At least I can keep using electricity if this is all proved wildly optimistic.

If only solar PV worked like that. I have a 7kWp array that on a nice cool summer’s day can output 50kWh. On a poor cloudy December day my lowest daily output so far is 250Wh. A battery would help but these are expensive compared to the cost of 6 panels. Without one you might struggle to use 50% of what your panels might generate. Remember there are 2 conflicting issues: one, your total usage in kWh per day and, two, your maximum power demand in kW. For example, an oven and kettle might need 6kW which your 6 panels could not provide

Patrol

This is my December PV generation with 17 (5.44kW) panels, daily kW on the left scale. As others have mentioned you would need 3kW stored to get by each day as you couldn't rely on generation to keep up with peaks of use. You'd also need more than 3kW of battery to see you through a lower generation spell or accept regular use of the generator.



Taking Christmas day as an example you are also going to be limited to very few hours a day with any electricity.


As for the gas side, have you worked out what mains + standing charge is per year compared to amount of propane. Might not stack up financially but if outraged and no longer wanting to be tied into them at least you'd understand the financial implications.

Ectophile

You need to think what you will do in the winter, with short days, and low sun.  On sunny days, you can still get a useful amount of power from solar panels.  But over this last winter we have had periods of days on end with no sun, and heavy cloud.

On one such grey day, I checked my solar output around midday.  It was about 160W total from 18 solar panels.  That was just about keeping up with powering a laptop and some lighting, with nothing left to charge the battery.

Reed_Richards

The further you diverge from mainstream ideas of what is necessary for comfort in the way of heating and hot water then the smaller the number of people your house might appeal to if you wanted to sell-up. 

Verdigris

As they say in the army, "any fool can be uncomfortable".