Selling Electricity to the National Grid

Catbells

I am thinking about getting an air source heat pump. Initial research says I will use approximately 12000 kWh per year (3 bed rooms) and the heat pump will generate around 36000kWh per year. This means a lot of spare electricity left over to sell. I understand three meters are necessary including measuring in/out flowing electricity.

How much could be made selling the electricity to the National Grid?

PeterGr

Air sourced heat pumps do not generate electricity. They use the refrigeration cycle to transfer heat from the ambient air to use internally. They consume electricity, but the advantage is they deliver more energy than they consume.

WhoIsThat

Catbells wrote: »

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How much could be made selling the electricity to the National Grid?

Some people get well over 50p/kWh, guaranteed for 25 years.

But the money tree has been heavily pruned, and will be killed off entirely in a few months.

https://www.moneysavingexpert.com/news/2018/12/government-confirms-end-of-solar-panel-payments/

But you will need to connect your off grid hut to the grid

matelodave

As PeterGR says, heat pumps dont generate electricity, they transfer heat from somewhere else very efficiently.

So for every kwh or leccy that yoy put into a convention heater, you'll get 1 kwh of heat, but with an air source heat pump you'll get around 3.5kwh of heat out.

You cannot sell this but you can claim what's called the RHI (Renewable Heat Incentive) whic is based on how much heat you need (based on an up to date EPC) compared to how much you generate and how much energy you consume (based on the efficiency of the the unit and heating system)

We had an ASHP fitted eight and half years ago before the RHI was established but started claiming RHI when it was introduced in April 2014. We get just over £700 a year for seven years but ours is based on a "deemed" efficiency of 2.5%.

According to our EPC we need 12,500kwh for heating plus 2, 750kwh for hot water = 15,250kwh plus everything else we've got that uses leccy (we are all electric) so theoretically we need around 18,000kwh a year.

We actually use a total of around 7000kwh a year. Our non heating average but including hot water from the heat pump) is around 3500-4000kwh which means the heat pump is only using about 3000-3500 to heat our 140 sq.m detached bungalow.

My wife always uses the tumble dryer both in the summer and winter but we do have energy saving lightbulbs but we aren't really all that frugal with our consumption

Since then they've faffed about with the RHI in the past couple of years with the payment amounts and way it's calculated which also takes into account the type of heating that you've got. You do need to get the sum worked out properly - have a look on the Ofgem RHI and MCS websites to get a better idea of what you might get.

Make sure you get a whole system design - just bunging a heat pump on an existing heating system to replace an oil or gas boiler will not work properly and could increase your costs dramatically. The heating and hot water systems have to be sized correctly to take advantage of the lower flow temperatures of the heat pump - trying to run it like a conventional boiler will considerably reduce it's efficiency.

For us we've benefited greatly, I reckon we save around £800 or more a year on our leccy bill plus we'll get £5k RHI over seven years. The 11kw heat pump, hot water tank and installation cost us around £7k eight years ago. I guess an oil system would have cost us around £3k at the time.

We did have underfloor heating installed at the same time but we'd have had that even if we'd got an lpg or oil boiler.

Catbells

Thank you all. My apologies for not replying earlier. I will read your answers thoroughly but first impressions is that ASHP is not going to be viable for me at my age -66. Also the intrusion on my Georgian semi would be huge, disruptive and expensive. My ideal plan is to get some payback from the Nat Grid for any alternative system I install. I misunderstood how ASHP work - thanks for telling me. What about geothermal? Or is that the same principle of simply generating heat and not electricity. If so there’s not much incentive to go green.

ajbell

Solar panels?

matelodave

Geothermal as a heat source is similar to an airsource heat pump (they are call Ground Source Heat Pumps) unless you live over a hot spring and can extract enough heat to drive a steam turbine to generate electricity from it.

There are really only three ways to generate leccy in thsi country. Solar voltaic panels, either on a roof or on frames if you've got a big enough garden.

Wind turbine, so you need enough clear space around it and to live in a fairly windy place. Or there's hydro elctricity where a fast flowing stream or river can drive a water powered generator.