gustyturbine

Thanks JohnMo, that is pretty much as I thought. At least in winter I'll be able to import cheap night rate electricity and use that during the day. The heat pump will soon use that up though so I'll use the heat pump until 05.30 in the morning. I should have a full battery then for the days consumption when the heat pump will consume again in the late afternoon/evening. Regardless, it will be much better than what I currently have.

Quick update - I'm having my solar and battery fitted on the 15th of July. Following the installation of the 10.4kw PV and 13.5kw/hr battery I'm going to jump across to Octopus. That will allow me to charge my EV and house battery at night and run the heat pump until 05.30am on cheap rate 7.5p per unit electricity. I can then export PV power at 8p and use/top up the battery during the day. The one thing I'm not sure of is how the battery will deal with a heat pump load as I'm unclear on what the heat pump really pulls during winter. In hindsight I wish now I'd not fitted a Combi heat pump but 10 years ago I could have foreseen this issue.

Right, nothing is ever easy! So, my heat pump has the internal 185ltr DHW tank with an inline 3,6 or 9kw immersion setting. The tank can't take a second immersion. The Boro VB100 tank that sits externally is a buffer for the heating system. I think mine is more awkward as it's a Combi heat pump. so, I think the best option for me is to use the PV to charge the battery and use that to run the heat pump. I'm not sure how the control will operate yet and I need to work out how long my battery will last for. How annoying 😞

I'm with you there Conor. The only reason my GSHP runs in summer is for DHW. I definitely need to stop that heat pump running in summer as it costs financially. There is a point when you're heating water that you won't use for sure and then export makes sense. I'll be jumping across to Octopus once the PV is on.

I've just discovered that my heat pump has an internal hot water tank (185ltrs) with the external Boro VB100. I've contacted Sweden to see if this can take an emersion controlled by the Eddi. If not then maybe a tank replacement is required (larger) that has this ability so I export very little.

Thanks Dave Jones. Worcester Bosch have told me that they feel it's not possible. I need to see if my VB100 cylinder can take an immersion. I'm begging to think that my PV installer might know more when they attend to complete the survey. Having an Eddie control my DHW is key for me so the GSHP runs much less in the summer months.

To provide further information my hot water store is Boro VB100. The heat pump is Worcester Bosch greenstore Combi 11.

Hi all, I had a GSHP installed around 12 years ago and it's been brilliant. I'm now in a position to install PV as I also have an EV. I'm keen to use an Eddie to heat my DHW and limit export. Does anyone have experience or knowledge about ease of integration. My installer tells me that he thinks my DHW heater is external to my tank and can be set to either 3,6,9 kW. He's not sure if an Eddie heater can be added. It may need a new tank? Maybe it depends on the manufacturer or model number? I'm not sure. Does any have any valuable tips and knowledge? Thanks in advance.

TBH I'm not too worried about not being MCS certified. My main aim is to generate the majority of what we use as a family. The DNO also told me that some car chargers don't like too much PV. I have no idea if there is any truth in that either!!

Thanks for the comments all and guidance. I visited the network operator on a separate issue today and we briefly discussed the export limit. They agree that I can export 3.68kw (not 3.9 as I thought) but insisted I could NOT fit 10kw and restrict export to 3.68. They seemed to think that it can cause issues with voltage etc but I'm not convinced.

Yes, you do have a very relevant point there actually. 20 or so in that room.

From memory we have from upstairs working down - Flooring carpet/underlay, 22mm Chipboard, Wolf/Pozi joists with 100mm Rockwool between, Soundboard (plasterboard) below joist with wet plaster skim.

We recently managed to get planning permission in west Wales. It was a battle from start to finish. Initially the Town Council objected following letters of objection submitted by residents (loaded with lies and tittle tattle). We had discussions with the planning officer and he seemed fairly happy with the plans but suggested we move the property 1.5mtrs forward down our field to reduce the roofline. We agreed to this and revised the plans. Spoke at the next Town Council meeting and they liked the changes so no objections. The local member then spoke with the planning officer and he then has a complete change of opinion. Then we needed to drop the roofline still further and hide the build from view. TBH we agreed to all of the demands and shot the letters of objection down in flames. However, for us to get planning we ticked every box the planners wanted. The costs involved and the hoops you need to jump thorough are ridiculous. Even the 10% of valuation costs that go the LA when you sell the property for the first time S106 agreement. It's like bribery. You'd never get away with it in business however the LA can do what they like. I wonder why nobody is building houses? Anyway, we got there and we are actually happier with the design following the changes we made to the design. I wonder if you initially need to submit with a higher roofline than you actually want so you can reduce it when they request and you walk away with the roofline you wanted. It's a game others play with your time, life and money. Good luck and don't give up.

I went 100mm Rockwool and I was extremely disappointed. Maybe I just expected too much but you can hear conversation between floors even if you can't make out the words.

Agreed, that is what I was told during my last build.

The trouble is that our Building Control will not allow a cavity to be full filled with insulation. We must have an air gap. 😞

Hi all, many thanks for the valued comments and I am questioning the SIP idea. TBH initially I was going block (again) as it's the common practice around here. Insulation board on the outer face of the inner skin. Building regs insist on the 50mm air gap within the cavity so generally the cavity has 100mm PIR board. Most local trades are either blockers or chippy's building factory built TF. If I went block I was going to use block and beam floors for sound insulation (3 kids). However, factory built TF or stick built seems to get a lot of positive feedback on here. My current house used Pozi/wolf joists and the sound transfer is disappointing and I hear kids talking upstairs. I'm guessing that TF factory built allows for a faster build but on site could work out cheaper. My only concern with factory built TF is issues with water leaks etc in bathrooms can cause problems. Block and beam would be more tolerant. Hanging heavy object with block walls is easy. TF means you need to be more careful and plan ahead? I'm also concerned though that lowering energy demand for a modern build is essential imo. My PV at 10kW wasn't saying that I needed a 10kW ASHP as I also have an EV. I just want to be generating as best I can rather than importing at current prices. Thanks all.

Hi Kelvin, Many thanks for the comments. The SIP's quote was from SIP suppliers following supply of my architects drawings. Most TF houses around here are built panels off site although I'm sure some are stick built. I'm off to Google MBC. Thanks.

Hi all, I recently managed to get planning permission in Aberaeron despite many NIMBY objections. I have built once before with brick and block. It went well although with my GSHP and a family of 5 running costs are fairly hefty. So, the next build!! Initially I was thinking block inner and outer skin with partially filled cavity due to driving rain in these parts (100mm PIR board) inside cavity, partially clad externally with dark timber and smooth render the rest. Heating ASHP, 10kW PV with MVHR. 3g with no horrible trickle vents. Now, I'm considering a SIP build to reduce energy costs. I suppose my concern living in a very exposed part of the world is that would driving rain manage to get through the membrane and wet the SIP's in time. would it make sense to still build a block or brick outer skin? If I did this then I can see costs escalating quite considerably. How do SIP houses compare against TF? I know that SIP's are much better from an airtightness point of view. I would hope that MVHR would stop mould building up. Thoughts and experiences welcome. Thanks all.

I can't comment as I can't see the difference. On a similar note when I last built the units arrived initially with a silver edge spacer. We ordered bronze so they went back. Second delivery the edge spacers looked like they'd been cut with a hammer so the bright, burred joint looked awful against the bronze colour so they went back. The next delivery didn't come Argon filled and didn't have the correct coatings. 4th time, more than happy. if you are not happy stick to your guns.

I'd hope that 4k would be high spec with handing it over to 1 contractor. Seems expensive with my limited building knowledge but when I built I didn't pay anything like that. Granted mine was a new build.

Neuffer came back with a rough figure of between 70-80k. Rationel was 33k. I understand German quality but how do people afford 70-80k on windows alone. Stroll on.

Has anyone had experience of installing second hand panels from decommissioned grid scale solar sites? The cost saving seems tempting. I'd consider buying a few spare panels for stock but from what I can gather inverters seem to cause issues from a reliability point of view.

Thanks TonyT. I guess my question would be that if my export is restricted to 3.6kw would that add cost wise to install 10kw through MCS approved installer.

Thanks for the information. I suppose that financially I could install non MCS for 6kw separately and 3.6kw MCS accredited. That would allow export of 3.6kw if I'm not using it. Cheapest option possibly?