ASHP or Oil Boiler

[ProDave]

1 hour ago, Carrerahill said:

I know for a fact that a developer is currently installing 164 No, 305W Peak, solar panels on a building, connected to nothing. Reason being that the LA accepted their existence, but little do they know they don’t go anywhere. Why on earth I hear you ask, well what is the benefit to them? They saved £40,000 or something on the inverters, connection back to the MSB etc. etc. and the install time. If that is their attitude, why would they want to waste any money on things they can just slap in without design?

This is a BUILDING CONTROL fail for not checking they were not being hoodwinked.  Then having found this deception, crawled over every mm of every single house on the developments looking for other breaches of building regs.

[Nickfromwales]

On 19/07/2021 at 13:43, richo106 said:

Ive been recommended to speak to Nu-Heat has anybody dealt with these?

Absolute total and utter garbage for designs and system principles. I wouldn't EVER go to them for a quote for UFH, not even for supply only. They made a proper mess of a £2m build and it cost a fortune trying to retrospectively delete all of their errors in a nearly completed project. They didn't even know what kit they'd installed on site, and the plans the client had been issued for M&E reference were toilet paper.

Wunda or any others!

[PeterW]

Don’t hold back @Nickfromwales… 

[Nickfromwales]

43 minutes ago, PeterW said:

Don’t hold back @Nickfromwales… 

You can (expletive deleted) off too  

[patp]

There are lots of costings being thrown around in this thread but no one has used the running costs of an ASHP where solar power (or wind/water) power is part of the equation. Surely an a heat pump powered by solar must be cheaper than fossil fuel powered systems?

[Nickfromwales]

4 hours ago, patp said:

Surely an a heat pump powered by solar must be cheaper than fossil fuel powered systems?

Erm….?. 
Solar power won’t be man enough to run a heat pump for heating in winter unless it’s a 20+ kWp array with a very good south facing setup. 
When you need heat, it’s winter, therefore 25% max ( usually a lot less ) PV output. 
 

So, in a nutshell, no.

Edited July 24, 2021 by Nickfromwales

[SteamyTea]

6 hours ago, patp said:

no one has used the running costs of an ASHP where solar power (or wind/water) power is part of the equation

It is easy enough to run the numbers and see what comes out.

While the performance in mid winter may not be good, all months except December and January, PV could me a major contributor to the energy demand of a heat pump.

The trouble is that matching the times that PV generates in with the times that you need the HP to run.  This is not a problem for DHW as that is stored, though parasitic heat loss can eat away any advantage on a badly designed system.

Space heating is a lot harder as you need a way to store the energy for later.  This is usually done 'in the slab', but would mean that you may get an unacceptably high temperature when you don't want it, or the HP is cycling too often.

So what would normally happen is that you have to work with averages and accept that at some times you are importing energy, possibly and a high cash price i.e. 6 PM.

We are now getting fairly close where a combination of PV, Battery Storage and HPs together with some software could probably make a very cost effective system.

[fiaraziqbal]

On 20/07/2021 at 12:50, SteamyTea said:

Ok, to clear this up, and stop you trolling, can you show us your heat loss calculations for your house, and your DHW useage. Then show us all why it is not possible to have a HP system deliver the same outputs.

Then show us the difference in running costs, and installation cost, rather than vague and misleading statements.

If you are not willing, or able (which we both know is the real reason) to supply this information, then you don't have anything to contribute.

that tiggles!

[Mr Punter]

Would a carbon tax on gas and a corresponding subsidy on electric persuade people?  I wonder if 5p per kWh would have a significant impact?  It would more than double the cost of gas, but you would save a bit on your electric.

[Kelvin]

On 27/07/2021 at 17:50, Mr Punter said:

Would a carbon tax on gas and a corresponding subsidy on electric persuade people?  I wonder if 5p per kWh would have a significant impact?  It would more than double the cost of gas, but you would save a bit on your electric.

 

Unless you address the insulation problem in older houses then it’s pointless. That’s what should be addressed and new builds should be built to better insulation standards. 

[SteamyTea]

On 27/07/2021 at 17:50, Mr Punter said:

Would a carbon tax on gas and a corresponding subsidy on electric persuade people?  I wonder if 5p per kWh would have a significant impact?  It would more than double the cost of gas, but you would save a bit on your electric.

Some of us have been saying this for a couple of decades now.

 

A quick look at the levelized wholesale costs of solar and wind shows that in 2019 solar cost £0.08/kWh and wind £0.05/kWh. (https://ourworldindata.org/grapher/levelized-cost-of-energy?time=latest&country=~GBR).  I am assuming that retail gas prices are at £0.03/kWh.

If you double those wholesale numbers you get an idea of what retail prices are.  So to level the playing field, to the same as the solar you would need to add £0.13p/kWh (ish) to gas.

An average house gas usage, according to UK Power, is 12,000 kWh/year, so that would add £1560/year to a bill.  This is the highest tax, to levelise it to wind would add £840.

We could reduce the cost of wind power by 20% if we allowed onshore wind again, but I think this government is still against that (the new farm subsidies are going to be about not building on farm land).

If we assume that because of the RE energy mix, we put a tax of £1000/year on average to peoples bills (£20/week or the same price as 8 Costa Coffees) it will change the thinking about fitting a heat pump.  The people it will hurt most are the ones that already have a heat pump as they will just see a price increase.

Another way to look at is, is how much RE generation would that £1000/year buy.  Assuming that RE generation costs on average £500/kW, and there are 35 million households, then that is 2kW installed capacity per household, or 70MW of installed capacity each year.  Assuming a capacity factor of 25% (which is very low) then that is 15 GWh extra each year of actual generation (10% extra each year).  That seems pretty cheap to me as in less than a decade we would have 100% RE generation to cover domestic usage.  This is not so far off from what this government has said anyway, and they are doing that without putting a huge tax burden on consumers.

 

Road fuel prices have risen 30% in the last year, has not stopped people using cars  (though last year was a little peculiar).  An average UK driver does ~8000 miles a year, this is, at 50 MPG (5.6 litres/100 km) an increase of £215/year.

Edited August 13, 2021 by SteamyTea

[Wil]

Political minefield and bit of a stretch to put £1000-£1500 a year onto people's bills.

 

Most here would probably cope, but what about those already in fuel poverty? 

[SteamyTea]

52 minutes ago, Wil said:

Political minefield and bit of a stretch to put £1000-£1500 a year onto people's bills.

 

Most here would probably cope, but what about those already in fuel poverty? 

What is fuel poverty these days. The definition was changed a while back.

But I tend to agree, any government that introduces a policy that directly hits people in the pockets is onto a looser. 

Suck a policy could be introduced gradually though, and hope it gets lost in general cost of living rises.

 

I don't know what the alternative is though, subsidies skew the market too much, and generally benefit people that are already cash rich or wealthy.

Legislation, along with taxation, is too blunt a tool.

 

This week's comic has a bit about it, so may post it up later.

[ProDave]

27 minutes ago, SteamyTea said:

What is fuel poverty these days. The definition was changed a while back.

 

I think "fuel poverty" is where you spend more than 10% of your income on heating.

 

My pet one is "Council tax poverty"  I spend more than 10% of my income on council tax, and no amount of home improvements, bettter insulation etc will do a thing to reduce that bill.

[SteamyTea]

23 minutes ago, ProDave said:

I think "fuel poverty" is where you spend more than 10% of your income on heating.

 

My pet one is "Council tax poverty"  I spend more than 10% of my income on council tax, and no amount of home improvements, bettter insulation etc will do a thing to reduce that bill.

The definition used to be more than 10% if household income, then it changed to 8% of free household spend.

It is a total nonsense as there is nothing special about 10%, or 8%.

What is important is stopping low income household getting into ongoing and permant debt, either by policy i.e cost of living rises, or lifestyle choices i.e addiction or lack of education. If we think it is expensive to bail out even the reckless, try the alternative of not bailing them out.

[joth]

4 hours ago, Wil said:

Political minefield and bit of a stretch to put £1000-£1500 a year onto people's bills.

 

 

Reminds me of when we cycling in patagonia in 2011.  The locals went on strike (we got barricaded into the town we were in) because the prices of natural gas had doubled. "Gosh that's awful" I thought, "why has that happened?". 

Answer: the govmt had just reduced the subsidy on gas from 90% to 80%. The locals didn't see the fact the government were covering 80% of their gas bill, they just saw the prices doubling. There was rioting. All the while, we stayed in sheds made of cardboard with corrugated plastic roofs, with the heating set to "24/7".  In a place with one of the lowest annual average temperatures in the world.

We have multiple generations in the world that consider combustable fuels a human right. It's going to be very messy few decades globally; whatever the starting point, try and cost people out of petrochemicals, they're going to rebel.

 

[Gone West]

3 hours ago, ProDave said:

I spend more than 10% of my income on council tax, and no amount of home improvements, bettter insulation etc will do a thing to reduce that bill.

Very true, and if your home improvements increase the value of your house, and you sell it they will try to increase your banding.

[ValleyBoy1958]

If I had an ASHP and it managed a COP of 3 all year round then it would use 5000 kWh of electricity p.a. to heat our house, which at an optimistic 15p/kWh equates to £750 p.a. If I was on mains gas currently, then at 4p/kWh  I would be paying £200 p.a. If the installation cost of an ASHP is of the order of £7000 - £12000 and having one caused my heating bill to increase almost 4-fold where is the incentive for me to change?

 

I am playing the devil's advocate here of course as I do not have mains gas, but rather a wood pellet boiler. I will be getting rid of this shortly and have looked into an ASHP but the cost is out of my league. Hence going back to oil at a fraction of the price.

Edited August 21, 2021 by ValleyBoy1958

[SteamyTea]

11 minutes ago, ValleyBoy1958 said:

If I had an ASHP and it managed a COP of 3 all year round then it would use 5000 kWh of electricity p.a. to heat our house, which at an optimistic 15p/kWh equates to £750 p.a. If I was on mains gas currently, then at 4p/kWh  I would be paying £200 p.a. If the installation cost of an ASHP is of the order of £7000 - £12000 and having one caused my heating bill to increase almost 4-fold where is the incentive for me to change?

Are you sure.

15,000 kWh at £0.15/kWh_e = £750 (this works out at £0.016/kWh_t at a CoP of 3)

45,000 kWhg at £0.04 = £1,800

This assumes that the ASHP delivers, on average, a CoP of 3.

Edited August 21, 2021 by SteamyTea

[Dan F]

Both calculations are wrong aren't they?  Gas is neither 1/4 nor 2-3 times the price of ASHP to  run.

 

Assuming 92% efficient boiler, ASHP COP of 3 and fuel prices quoted, i get:

Gas: £650/yr

ASHP: £750/yr

Edited August 21, 2021 by Dan F

[ProDave]

How can we get so many different answers to the same sum here?

 

@ValleyBoy1958 says a heat pump would use 5000kWh of electricity and at 18p that comes to £900. When you find someone still selling electricity for 15p per kWh please let me know.

 

So his house takes 15000kWh to heat it, a gas boiler might be 90% efficient would consume about 16650kWh of gas at 4p per kWh would cost £666  plus the gas standing charge of about £100 per year = £766

 

So gas is cheaper but not by a lot.  Add in annual boiler service cost for gas and it is even closer.

 

I am not suggesting everyone with gas should be rushing out to buy an ASHP but this does show for a new build without gas, an ASHPis a very viable and competetive heat source.

[SteamyTea]

9 hours ago, ValleyBoy1958 said:

Hence going back to oil at a fraction of the price.

Which flies in the face of decarbonising the UK economy.

 

[joe90]

32 minutes ago, ProDave said:

Add in annual boiler service cost for gas and it is even closer

And the standing charge fir gas! ?
 

I do believe the cost of an ASHP will reduce in the future, like solar panels did , when produced in larger numbers and become more common.

Edited August 22, 2021 by joe90

[ValleyBoy1958]

Apologies for the basic error in my maths! I had a senior moment there and took the 5000 kWh figure rather than 15,000 kWh when calculating the cost for gas ....doh! So ProDave's calculation is nearer the mark but still approx £140 difference between the 2 fuels and assuming a year-round COP of 3. This could be optimistic with what is likely to be a high flow temperature requirement (high for an ASHP that is) without bigger radiators. Even so I believe the capital cost of an ASHP will still frighten off those who currently use gas to heat their home, without some generous subsidies.

 

Re: electricity price: I was paying 15p per kWh until recently (with Bulb until the price shot up) and it is now 18p (after switching to Octopus).

 

Like Joe90 I agree that the cost of an ASHP will definitely reduce in the future but that is no good for me right now! I have had my one shot at RHI with my wood pellet boiler which I now much regret getting. When we first moved here we were using about 3000 litres of oil p.a. but by improving the insulation and eliminating draughts we got this down to 1500 litres before changing to biomass; thereafter we used approx 3000 kg of pellets p.a. The reason for reverting to oil is because the Danish pellet boiler manufacturer has gone out of business as has the installer, and so spares is a major problem, coupled with the fact that my wife would not be able to carry out the routine maintenance of the boiler if anything happened to me. At nearly 75 years of age my time is running out and I might not be around when ASHP's are affordable!

 

It was not an easy decision to revert to oil, as Steamy Tea says, hardly in keeping with decarbonisation. However as it is likely that HM Gov will prioritise those on oil/gas when it comes to ASHP subsidies, maybe those who buy my house in the future will be able to take advantage of that (or even me if I am still around at the time).

[SteamyTea]

6 minutes ago, ValleyBoy1958 said:

thereafter we used approx 3000 kg of pellets p.a

That is about 13,400 kWh/year.

If you use 80% of that in 4 months (winter), that works out at ~90 kWh/day.  That could be satisfied with a 5 kW heat pump, but one would probably have to go to an 8 kW to be on the safe side.

That may change the installation cost.