Cost of going completely off grid for power

MouldyOldDough

What would it cost to go completely off grid for power and what would be the best way to provide heat and light?
Presumably ground source for heating and solar with a large battery? 

[Deleted User]

Something for you to think about. I have a 7kWp array and a battery. On a poor day last December my total daily output was just 350Wh: yes, one third of a kWh. Furthermore, my total output for the month was only 87.7kWh.

Solar is great when the sun shines but to run a home off grid you need either an enormous array or a massive battery that stores energy to carry forward to the Winter season. Neither are practicable nor affordable imho.

MattMattMattUK

MouldyOldDough said:

What would it cost to go completely off grid for power and what would be the best way to provide heat and light?
Presumably ground source for heating and solar with a large battery? 

It depends on your location, how much land you have etc. 

You would need around 7 acres in rotation to heat via biomass, ideally coppice in rotation just for heat and cooking.

With solar and wind you would probably want 40kW solar minimum, probably closer to 100kW, in summer it would produce far more than you needed, but in winter production would be way down, ideally also at least 10kW installed wind turbines. On top of that probably 5-10 Powerwall 2s. Ideally also a gas generator and several thousand litres of LPG to get you through cold dark still parts of winter.

All in cost you are looking at £80-200k to maintain a normal modern life off grid, as well as needing significant space. In short if you are wealthy enough to be able to afford it, you are wealthy enough to not need to worry about energy prices.

ProDave

Going totally off grid is expensive, needs a lot of space and a lot of resources.  NOT possible for the vast majority of houses in the UK.

If you want to see what is involved I suggest you have a look and thorough read of this blog. He is off grid because of his remote location.  https://lifeattheendoftheroad.wordpress.com/

Look down the right hand side for the renewable energy posts.

The best you can do in most settings is reduce your energy usage and install some generation such as solar PV but you will never go off grid completely.

MouldyOldDough

I was just thinking about the current power price - due to increase further

Plus the reliabilty of supply (if Putin did cut Europe off) - we don't rely on Russian gas, directly but we do take a fair amount from Europe

I know that we could have more to worry about than heating and lighting but just thought that it would be quite beneficial not to rely on anyone else

MouldyOldDough

Dolor said:

Something for you to think about. I have a 7kWp array and a battery. On a poor day last December my total daily output was just 350Wh: yes, one third of a kWh. Furthermore, my total output for the month was only 87.7kWh.

Solar is great when the sun shines but to run a home off grid you need either an enormous array or a massive battery that stores energy to carry forward to the Winter season. Neither are practicable nor affordable imho.

I have seen 5.8kWh batteries at around £2500 - which would seem good value

But would this be enough to run a 3 bed house - requiirements of a heat pump - during dark hours ?

I mean - LED bulbs use very little - a TV around 50watts - 3kW cooker is a different matter

Presumably heat pump output would provide hot water and heating ?

MattMattMattUK

MouldyOldDough said:

Dolor said:

Something for you to think about. I have a 7kWp array and a battery. On a poor day last December my total daily output was just 350Wh: yes, one third of a kWh. Furthermore, my total output for the month was only 87.7kWh.

Solar is great when the sun shines but to run a home off grid you need either an enormous array or a massive battery that stores energy to carry forward to the Winter season. Neither are practicable nor affordable imho.

I have seen 5.8kWh batteries at around £2500 - which would seem good value

But would this be enough to run a 3 bed house - requiirements of a heat pump - during dark hours ?

The thing is there is a lot more to domestic supply batteries than just capacity. Generally the cheaper ones are no good for an off grid situation, they are designed for a mild amount of load shifting. 

ProDave

MouldyOldDough said:

Dolor said:

Something for you to think about. I have a 7kWp array and a battery. On a poor day last December my total daily output was just 350Wh: yes, one third of a kWh. Furthermore, my total output for the month was only 87.7kWh.

Solar is great when the sun shines but to run a home off grid you need either an enormous array or a massive battery that stores energy to carry forward to the Winter season. Neither are practicable nor affordable imho.

I have seen 5.8kWh batteries at around £2500 - which would seem good value

But would this be enough to run a 3 bed house - requiirements of a heat pump - during dark hours ?

I mean - LED bulbs use very little - a TV around 50watts - 3kW cooker is a different matter

Presumably heat pump output would provide hot water and heating ?

People talk of batteries as if they are a magical energy source.  They are NOT.  They are energy storage.  To use your 5.8kWh of stored energy, something must have generated 5.8kWh of energy to charge them in the first place.

Solar PV is NOT going to do that for at least 3 months of the winter.  About the only thing that might is a wind turbine, but we are not talking the little things you might put on a boat, but quite large tall structures that will cost a lot of money and need planning permissions.  Not what most UK homes would be able to do.

MouldyOldDough

I have seen a US based estimate of 800kWh per month average useage of electrical power - I currently use 120kWh electricity (winter) !

MattMattMattUK

MouldyOldDough said:

I have seen a US based estimate of 800kWh per month average useage of electrical power - I currently use 120kWh electricity (winter) !

US usage is always insanely high, but does yours also account for an alternative source of heat such as gas, or is 120kWh your entire domestic energy consumption? 

ProDave

MattMattMattUK said:

MouldyOldDough said:

I have seen a US based estimate of 800kWh per month average useage of electrical power - I currently use 120kWh electricity (winter) !

US usage is always insanely high, but does yours also account for an alternative source of heat such as gas, or is 120kWh your entire domestic energy consumption? 

We live in a house that uses about 50kWh of electricity per week for heating in winter, but this is not your average house.