Octopus Heat Pumps

QrizB

Screwdriva said:

1961Nick said:

The source did suggest that there will be smart tariffs tailored for Octopus heat pumps & that should achieve parity with the cost of gas heating.

Yes, I'm aware of the ambition. It's just that the Heat Geek elite installers I know claim that the Daikin pumps Octopus currently install cost more to run than gas to heat the home. Could it be them smearing the competition? Sure. But I'd like to know end user SCOP numbers to corroberate that myself.

SCOP is a standardised number and is published by all reputable manufacturers in their product literature.

If we know the model of heat pump, it should be trivial to look up the SCOP.

And it might just be me, but I am always put on guard by anyone claiming to be "elite"!

Edit to add:

If we assume that Octopus are fitting the Dailin Altherma 3H HT high-temperature heat pumps (that can give a flow temp of 70C), the brochure is here:
https://www.daikin.co.uk/content/dam/dauk/document-library/Brochures/Heating/Heating Installer brochures/Daikin Altherma 3 H HT_767.pdf

SCOPs are on pages 9 and 11, and (for 55C flow temp) look to be 3.57 or 3.58, depending on model.

At a 35C flow temp, whch would require underfloor heating, the SCOPs are 4.51 or 4.71.

Considering the current (October 2023) Ofgem cap, with electricity at 27.35p/kWh and gas at 6.89p/kWh, and assuming a gas boiler efficiency of 90%, you're looking at 7.661p (HP) vs. 7.656p (gas) per kWh of heat.

So yes, by a strict reading of the numbers, the heat pump appears more expensive but the margin is tiny - I had to go to three decimals to get a difference ...

Screwdriva

QrizB said:

SCOP is a standardised number and is published by all reputable manufacturers in their product literature.

If we know the model of heat pump, it should be trivial to look up the SCOP.

And it might just be me, but I am always put on guard by anyone claiming to be "elite"!

Edit to add:

If we assume that Octopus are fitting the Dailin Altherma 3H HT high-temperature heat pumps (that can give a flow temp of 70C), the brochure is here:
https://www.daikin.co.uk/content/dam/dauk/document-library/Brochures/Heating/Heating Installer brochures/Daikin Altherma 3 H HT_767.pdf

SCOPs are on pages 9 and 11, and (for 55C flow temp) look to be 3.57 or 3.58, depending on model.

At a 35C flow temp, whch would require underfloor heating, the SCOPs are 4.51 or 4.71.

Considering the current (October 2023) Ofgem cap, with electricity at 27.35p/kWh and gas at 6.89p/kWh, and assuming a gas boiler efficiency of 90%, you're looking at 7.661p (HP) vs. 7.656p (gas) per kWh of heat.

So yes, by a strict reading of the numbers, the heat pump appears more expensive but the margin is tiny - I had to go to three decimals to get a difference ...

Therein lies the issue. Heat pump installations are incredibly sensitive to installer skill/ competence. I believe that's where the "Elite" comes from i.e. they assure an installation SCOP based on a system designed flow temperature of X degrees (usually 45 degrees or lower). I'm not sure Octopus do this but could be unaware if they do? 

My point here is not to take a cheap shot at heat pumps but rather the acceptance of a lower standard of installation. If the Daikin's are capable of SCOPs of 3.5 and higher then why not provide as assurance that the installation will achieve this? And why go with the Daikins when the AroTherm+ can achieve SCOPs of 5+?

On the boiler front, the latest generation of boilers like the Worcester Bosch 4000 and Viessmann 100 are 94% efficient. The V200 I own slightly more.  They all have incredibly low modulation (When weather compensated, the WB 4000 15kW can modulate down to 1.9 kW, like the Viessmann 200), which really saves alot of £. We reduced our gas consumption by 31% last winter. Combine that with the Octopus Tracker tariff and the savings are substantial if not hard to beat.  

QrizB

Screwdriva said:

My point here is not to take a cheap shot at heat pumps but rather the acceptance of a lower standard of installation. If the Daikin's are capable of SCOPs of 3.5 and higher then why not provide as assurance that the installation will achieve this? And why go with the Daikins when the AroTherm+ can achieve SCOPs of 5+?

You need to comare like with like.

At 55C flow temp, most models of Arotherm+ have a worse SCOP than the equivalent Altherma. See page 6 of:

https://www.vaillant.co.uk/downloads/aproducts/renewables-1/arotherm-plus/arotherm-plus-spec-sheet-1892564.pdf

To get a SCOP of >5, you need the 10kW Arotherm+ and a 35C flow temp. The smaller models are worse than the equivalent Althermas.

Screwdriva said:

Therein lies the issue. Heat pump installations are incredibly sensitive to installer skill/ competence. I believe that's where the "Elite" comes from i.e. they assure an installation SCOP based on a system designed flow temperature of X degrees (usually 45 degrees or lower).

That sounds dangerously like marketing snake-oil. We might have to agree to differ!

Netexporter

 Combine that with the Octopus Tracker tariff and the savings are substantial if not hard to beat.  

Although will still be putting CO2 into the atmosphere, albeit at a lesser rate.

Screwdriva

QrizB said:

That sounds dangerously like marketing snake-oil. We might have to agree to differ!

How is providing a binding agreement (as an example, your installation will achieve a minimum SCOP of 3.8 as agreed or else your money back) snake oil? This is what the Heat Geek guys offer - I believe at a premium - to their customers. 

Netexporter said:

Although will still be putting CO2 into the atmosphere, albeit at a lesser rate.

I think you'll find the grid has a long way to go before it is CO2 neutral. Our wind generation capacity will eventually get us to a more "green" cold weather electricity supply in a decade or so, but the current difference between burning gas at home and at the power plant isn't as substantial as you might think.  There is also an analysis to be had about the CO2 intensity of manufacturing a heat pump and the batteries that store the energy needed to power it affordably vs. a modern, efficient gas boiler. 

To be clear, I'm not arguing against heat pumps - they definitely have a place in our energy ecosystem. I'm arguing against sub-optimal heat pump installations.

Reed_Richards

Surely "elite" just means they have paid a sum of money to Heat Geek to be designated as such.  They get training for their money but there is no guarantee that they understood this training or that they follow it subsequently. 

A Heat Geek is someone who has undergone our in-depth heating system design course.

Heat Geek Elite: This certification ensures knowledge of heating systems and system design to absolutely maximise efficiency, and is simply the best in the industry.

  

1961Nick

Martyn1981 said:

mickyduck55 said:

Reed_Richards said:

Screwdriva said:

With a SCOP of 3 or below, it’s going to be difficult for end users to save £ when compared to an efficient gas setup. 

Yes, you'll just be doing your little bit to save civilization by creating less CO2 when running your heating.

No hard data but with my usage removing the gas standing charge will help, last year I used very little gas as I have an ASHP / AC in my living area.  WHEN my full ASHP heating is installed I will need to replace my gas hob with electric so yes some cost and Im a low user so no ££ savings.  I like to think Im helping to save the planet although short of a nuclear war despite all we do it will probably outlast me 

Similar here, gas demand is low, but including the ~£100 standing charge for gas (we'd have to replace the gas oven), I think we'd work out better.

Very much planning in the next year or two to get a small PV expansion, and batteries. Hopefully that would allow us to use cheap rate leccy for most of the ASHP heating Dec-Feb, and a growing contribution from PV during the other heating months.

A big factor will be what level leccy prices fall back to over the next 2-3yrs as gas prices and shortfalls ease, as Europe quickly reduces its demand. Plus of course what gas prices go back to.

Obviously both PV and batts aren't free, but using them for more purposes all helps.

I think we're going to see a much higher proportion of the green levy apportioned to gas in the future which will improve the case for heat pumps. There's also talk about decoupling the marginal price of electricity from gas as well.

Meatballs

Screwdriva said:

QrizB said:

That sounds dangerously like marketing snake-oil. We might have to agree to differ!

How is providing a binding agreement (as an example, your installation will achieve a minimum SCOP of 3.8 as agreed or else your money back) snake oil? This is what the Heat Geek guys offer - I believe at a premium - to their customers. 

Netexporter said:

Although will still be putting CO2 into the atmosphere, albeit at a lesser rate.

I think you'll find the grid has a long way to go before it is CO2 neutral. Our wind generation capacity will eventually get us to a more "green" cold weather electricity supply in a decade or so, but the current difference between burning gas at home and at the power plant isn't as substantial as you might think.  There is also an analysis to be had about the CO2 intensity of manufacturing a heat pump and the batteries that store the energy needed to power it affordably vs. a modern, efficient gas boiler. 

To be clear, I'm not arguing against heat pumps - they definitely have a place in our energy ecosystem. I'm arguing against sub-optimal heat pump installations.

Even without renewables in our grid heat pumps would make a significant impact. The following analysis is with a COP of just 3:

And we are nearly 50% renewables and are still improving...

Sub optimal installations isn't great, but the cumulative CO2 emissions of gas is probably worse. Any and all delays make things harder to hit the temperature limits.

Screwdriva

Meatballs said:

Sub optimal installations isn't great, but the cumulative CO2 emissions of gas is probably worse. Any and all delays make things harder to hit the temperature limits.

Fair enough. I'd only add that the latest crop gas boilers are much more efficient & that batteries and heat pumps have an embedded carbon cost that are not factored into the above diagram. I don't know what those carbon values are and haven't found any studies that state these values so I can't be more specific sadly. 

Netexporter

Even a 100% efficient boiler is putting a lot of CO2 into the atmosphere. There is embedded carbon in the making of the boiler, too. The greener the electricity supply becomes the dirtier a boiler looks.