Octopus Heat Pumps

Netexporter

NigeWick said:

Netexporter said:

Interesting about the microbore. 

When the Cosy 6 comes out it won't matter as that heat pump can produce the same temperature as a gas boiler.

Yes, but at a cost in COP. A heat pump will always be more efficient at lower flow temperatures. Also, an overlay underfloor heating system will add a bit of insulation to the uninsulated solid concrete floor. Getting rid of radiators will also be more aesthetically pleasing, as well as making rooms more adaptable in use.

Reed_Richards

Just to echo @Netexporter's comment.  The thing you absolutely have to realise about heat pumps is that even if they can produce the same water temperature as a gas boiler (older type) you don't want them to!  

Heat pumps tend to be set up for a small temperature drop across your radiators, typically 5 C.  To achieve this they pump the water round the heating system a lot faster than with gas or oil.  The reason microbore pipes have been disliked is that they cannot sustain these high flow rates if they get a bit clogged.  If Octopus thinks they can cope with microbore pipes then good for them, but I wonder what they would do if there turned out to be a problem. 

Meatballs

Afaik most octopus installs use a buffer (from pictures I have seen) which helps to eliminate the issues with microbore, but comes at a slight drop in efficiency.

Buffer maybe  helps (slightly as I don't think they use huge ones) with time of use tariffs as it is a small heat store...

saf87

I recently had a survey with octopus. My property is 10mm plastic microbore and they said this was no longer a problem for them and that they will even accept 8mm microbore as long as it's copper. My issue was not having enough space for the cylinder, buffer and expansion vessel. A bit gutted as it was only going to be £1,100 after the grant. 

NigeWick

Screwdriva said:

At a tariff specifically designed for it. I'm curious what the heat pumps efficiency/ SCOP will be when running anything over 55 degrees flow temperature. 

Ask Octopus. Are you sure there's only the one tariff allowed with the Cosy 6?

Screwdriva

NigeWick said:

Ask Octopus. Are you sure there's only the one tariff allowed with the Cosy 6?

When I did ask for SCOP details, I was told "to be announced". The tariff is designed to be lucrative for the Cosy 6 owner, so while it's not exclusive to one tariff, it is likely to be the one that makes the most financial sense. When I asked if Octopus were planning to use financial incentives to overcome suboptimal system efficiency, I got radio silence back. 

1961Nick

Screwdriva said:

NigeWick said:

Ask Octopus. Are you sure there's only the one tariff allowed with the Cosy 6?

When I did ask for SCOP details, I was told "to be announced". The tariff is designed to be lucrative for the Cosy 6 owner, so while it's not exclusive to one tariff, it is likely to be the one that makes the most financial sense. When I asked if Octopus were planning to use financial incentives to overcome suboptimal system efficiency, I got radio silence back. 

They're being very tight lipped about the SCOP - even off the record. My hypothesis of 3 was met with virtually no resistance & the added comment that a customised tariff would ensure parity with the cost of gas heating.

If they have achieved an SCOP of 3 with the capability to flow at over 70C when required, then that's a significant achievement imo.

MarzipanCrumble

Netexporter said:

QrizB said:

Netexporter said:

I can only dream of getting a quote from Octopus for solar or a heat pump.

Have you tried the "quote me" link?

https://octopus.energy/order/heat-pump/details/new-customer/

Yes, frequently. They don't do Wales. I was mildly shocked to find that you can't even get a quote in Cardiff. I live in the middle of nowhere in middlest Mid-Wales, so I can understand it, to an extent. Took nearly a year to get my smart meter fitted because the nearest installers are in Swansea.

I live in Cardiff.  I registered my interest in a HP with Octopus, who emailed me to say 'Not yet, but we hope to have approved installers by end of summer 2023'  - not been contacted yet ......

orbit500

If they have achieved an SCOP of 3 with the capability to flow at over 70C when required, then that's a significant achievement imo.

I will believe that when I see it. I’m sure many here already know this but there is a limit to heat pump efficiency given by:
COP=T1/deltaT where T1=flow temp in kelvin and deltaT=flow-outdoor temp.
so at 70c and 0c outdoor (which is when you’d want 70c flow):
CoP=343/(70-0) = 4.9
in real life more likely 2, I’d say.

Reed_Richards

It's the people who don't know this that you need to reach.  Those who get really enthusiastic about high temperature heat pumps.