ASHP with RHI - Restrictions on Other Heat Sources?

[Barnacles]

Hello all,

I was just chatting to my neighbour and we got on to the subject of her ASHP. She's had it operational for about 2 or 3 years and qualified for RHI for which she is receiving her payout from Rishi & Co. We'd been talking about firewood and I asked if she needed any, she said that she wasn't allowed to have a wood-burning stove (or any alternative source of heating!) under the conditions of the RHI agreement. Does that sound right?

 

She mentioned how much she was spending on electricity each month to run the ASHP and I almost passed out! I suggested that she should consider PV panels to help power the ASHP and again she said that under the RHI agreement she couldn't install a PV system. This seems utterly illogical to me, is my neighbour misinformed?

 

Thank you,

Paul.

[JohnMo]

No ideas to your questions, but the way you run the ASHP has a huge impact on the energy consumption and costs, small changes seem to go a long way. Not letting your house get too cool for one, then just setting the flow temp to drip feeds to keep with the heat losses.

[PhilT]

The RHI scheme doesn't forbid solar panels or wood burners with heat pumps, it just doesn't provide financial support for solar panels. It might for certain types of biomass

Edited January 25, 2024 by PhilT

[Gary68]

The RHI just states it has to be the main source of heating and/or DHW, I'm not aware of anything that says you cant use a woodburner to supplement if you need to.

 

I had PV before I had an ASHP which I get RHI for and had more added afterwards, RHI doesn't cover PV at all it covers solar thermal, and you could have solar thermal and an ASHP as the same time and get RHI for both.

Edited January 25, 2024 by Gary68

[Wil]

Phil is correct, I’m on the RHI and have both standalone woodburners and solar panels. No relevance of either to the RHI. Mine were there before the HPs, and were mentioned in the heat calcs for the MCS cert.

[Barnacles]

Thanks for the replies everyone. It didn't make sense to me that she shouldn't be allowed to have a stove or PV installed. I'm going to nip over tomorrow and give her the good news, she'll be delighted. I'll mention the solar thermal too, I've a feeling that she may have a spare coil on her cylinder to accommodate it.

 

I think the person who set up the ASHP should be flogged! Last winter she was paying over £1500 per month to run her ASHP and it's not even a large house. I went and had a look at it and found that it was set to output water at 23 deg C so it had been running virtually the whole day without actually heating the house. The DHW was set to come on for 30 minutes at midnight so it had been using the immersion to heat the water instead. The room thermostats were all set badly too so we configured all of those. She's now paying more like £300 per month but that still sounds very high to me. I think she needs to get an expert to set the system up properly.

[Bozza]

So for the RHI you have to make an annual declaration of certain things including to the effect that you haven’t changed anything significant with your heating set up.   Well I do anyway and assume others do.  I would imagine if you were wishing to change something material about how you heat your house eg introduce fossil fuels, that would impact upon the assessment that was used to calculate the RHI payments.  As the RHI payments / funding is calculated upon the continued use of the ASHP and estimated heat calc for an individual property.  

 

So if I decided to rip out my ASHP and install fossil fuels clearly I shouldn’t be entitled to the RHI.

 

theoretically someone in receipt of RHI could alter or change their heat source and not tell them.  There’s a word for that though  - fraud - this is why you have to submit an annual declaration.

 

So it’s not that she’s not allowed to make changes, just that she’d need to declare them with the potential that her RHI reduces or is removed following recalculation.

 

bit like someone receiving disability benefit whose circumstances changes thus need reassessing to see if they are still entitled to it, or not.

 

 

 

 

 

 

 

Edited January 25, 2024 by Bozza

[Bozza]

“She's now paying more like £300 per month but that still sounds very high to me”

 

if that means her annual cost is £3600 there’s definitely a problem with the house (insulation etc) or the set up. 

[Gary68]

Quoting cost isn't useful, much better to quote usage in kwh, £300 a month at 30p per unit is 33kwh per day, that is relatively normal for a heat pump in the depths of winter.  My house has used 950kwh in Jan so far that's 40kwh a day, 30kwh of that will be the heat pump.

 

So depending on location, outside temp, heat loss of house, size of house etc, her usage may be correct.

Edited January 25, 2024 by Gary68

[Post and beam]

  On 25/01/2024 at 14:51, Barnacles said:

Last winter she was paying over £1500 per month to run her ASHP and it's not even a large house

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 But this is surely the crucial sentence.

[JamesPa]

  On 25/01/2024 at 16:55, Post and beam said:

 

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  On 25/01/2024 at 16:55, Post and beam said:

 

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Edited January 25, 2024 by JamesPa

[sharpener]

  On 25/01/2024 at 17:50, JamesPa said:

Edited 25 minutes ago by JamesPa

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A bit too much by the look of it!

[Barnacles]

The house is a 3 bedroom cottage that has recently been completely renovated. There is a MVHR system and the whole place was extensively re-insulated and underfloor heating installed. I'd say it still isn't super air-tight but for an old house I'd say it should perform reasonably well.

 

I have no idea what the actual energy consumption was in terms of kWh but I could ask and find out, she did say that her electricity price was fairly standard so I'd assume around 30p per kWh.

 

  On 25/01/2024 at 14:58, Bozza said:

So for the RHI you have to make an annual declaration of certain things including to the effect that you haven’t changed anything significant with your heating set up.   Well I do anyway and assume others do.  I would imagine if you were wishing to change something material about how you heat your house eg introduce fossil fuels, that would impact upon the assessment that was used to calculate the RHI payments.  As the RHI payments / funding is calculated upon the continued use of the ASHP and estimated heat calc for an individual property.  

 

So if I decided to rip out my ASHP and install fossil fuels clearly I shouldn’t be entitled to the RHI.

 

theoretically someone in receipt of RHI could alter or change their heat source and not tell them.  There’s a word for that though  - fraud - this is why you have to submit an annual declaration.

 

So it’s not that she’s not allowed to make changes, just that she’d need to declare them with the potential that her RHI reduces or is removed following recalculation.

 

bit like someone receiving disability benefit whose circumstances changes thus need reassessing to see if they are still entitled to it, or not.

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That makes sense. So if she installed a small stove in one room and used it for 3 or 4 months of the year, in theory her RHI shouldn't be affected too much and as long as she declares it on her annual declaration she should be all good.

[ReedRichards]

I already had a wood burning stove when my heat pump was installed.  I'm sure that made no difference to my RHI application.  But I only use my wood burner for the occasional damp day when we feel like a fire or in the event of a prolonged power cut.

 

Be that as it may, your neighbour appears to be spending way too much to run their heat pump 

[HughF]

Our whole house is running between £50-75 a week depending on how cold it is outside, that’s 115m2, heated to 22-22.5 24/7.

 

Not unreasonable to have a £300/mo electric bill, especially if they’ve set her DD payment to cover the worst month. We’re on prepayment (reasons) so we don’t have to worry about paying the same amount every month so the energy co can pay their shareholders.

[Wil]

AIUI the log burner is treated like any other plug in single room heater (as in it’s ignored for RHI) unless it contributes to the central heating.

 

I wrote a long post to say £300 a month is not unheard of in the depths of winter depending on the amount of heating she’s using. It is a bit of a worry in a newly renovated property, so definitely sounds like it could do with some help setting up or user education on running it.

 

For reference my leaky 300m2 5 bed used 1.02MWh(e) for heating and DHW in December (plus the log burner pretty much every night in the living room). At a cost of £302 apparently. Comparing to July when we used 81kWh(e) for DHW for £19.85 apparently (not including for solar DHW).

I need to have a better look at my totals for annual, but I’d reckon around the 2k mark for heating and DHW across the year. 

 

£1500 a month or even £300 a month across the year is completely unrealistic in your neighbour’s case for a renovated 3bed.

[RichardL]

  On 29/01/2024 at 10:31, Wil said:

...£300 a month is not unheard of in the depths of winter depending on the amount of heating she’s using

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+1 This, concur - I get very similar numbers when its near/below freezing.
So far comparable with oil and I'd only expect that behaviour for 2-3 months a year - 6 tops.

If it did that for 12 months I'd be phasing the radiators and oil boiler back in.
 

[HughF]

Yes, but there’s a big difference between ’paying 300/mo’ in a direct debit because the energy company have decided that’s what they want odd you, and actually using 300 quids worth of electric.

 

Most people haven’t actually got a clue how this stuff works, hence why I said what I said.