Ronski's Solar & battery DIY build with whole house backup

b0rn2sk8 said:
So how long until you pull the trigger on a heat pump? That £7500 grants got to be burning a hole in your pocket!
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Once I've got the the solar sorted I'll then look into the heat pump a bit more. We've got two local Heat Geek installers, so I'll see what they come up with and if their willing to work with me, prior to looking elsewhere.

I've already got some SWA run from the garage to the most likely place for the heat pump, it was an off cut, so seemed sensible to throw it in the ground ready for a heat pump.

When I re-plumbed the house back in 2005 I set every room up as a zone, so each radiator has its own feed and return to two central points with zone valves (its easy to remove the zone valves), although a lot of this is in 15mm plastic, but I'm hoping that will be OK. Our boiler will be 20 years old next year, so it would be prudent to take advantage of the grant and get it replaced with a heat pump.
 
15mm plastic should be fine, I’ve got 10mm plastic although my heat loss is relatively low (under 6kw).

As you’ll say you’ll want to take the zone vales off and run it open loop but that’s a very easy change. Can you get your boiler below 50c with your current radiator set up?

Edit: what’s your primary flow and return pipe size?
 
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I've not tried lowering the CH flow temp, so I've no idea on that score. 22mm plastic feeding the upstairs zone valve manifold, and 22mm copper to the down stairs manifold.

Pretty much all of the radiators are over sized for the rooms, and 450 high, so worse case I could fit taller radiators, but also hoping they are sufficient.

Our gas bill last year was £780, which for a detached 5 bed house I think is pretty low. So ROI for a heatpump is unlikely for a long time unless I can really get the costs down.
 
Ron-ski said:
I've not tried lowering the CH flow temp, so I've no idea on that score. 22mm plastic feeding the upstairs zone valve manifold, and 22mm copper to the down stairs manifold.
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That should be fine - they probably want to run 28mm from the heat pump to the cylinder location and onto where the CH pipes split between the two zones.

For my 4 bed detached (2002 build), I've got a single run of 22mm covering the whole house which T's off 10mm runs to each rad, all in plastic. It's not quite the worst case scenario but not far off, the main redeeming feature is the low heat loss.

Ron-ski said:
Pretty much all of the radiators are over sized for the rooms, and 450 high, so worse case I could fit taller radiators, but also hoping they are sufficient.

Our gas bill last year was £780, which for a detached 5 bed house I think is pretty low. So ROI for a heatpump is unlikely for a long time unless I can really get the costs down.
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I doubt there would be an ROI in reality for most people the running costs at a 50C flow temp are pretty much the same. However your average electricity unit cost is very low which makes things more interesting. Of course you can design a system to run at lower flow temperatures but you tend to increase retrofit costs as a result and sometimes its not practical due to existing pipework runs being too narrow.

I got a cheap big box installer to do mine (Octopus) and the cost to me for mine was only £3500 and it would have cost more to update the gas system I had to something modern (e.g. unvented cylinder).

I did consider a heat geek and a couple of other local installers but their pricing was higher and while they pitched a lower flow temp system with the associated lower running costs. I didn't go for it because it would have taken years to break even compared to Octopus when paying full whack for electric and as you know, my average unit rate is extremely low.

I could have replaced rads myself to get the costs down from the local installers but I just went with the big box installer in the end.
 
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My current boiler is a floor standing Worcester Bosch combination boiler (it was the biggest I could find back then), I'm hoping the tank will fit in the floor space that occupies, plumbing to the ASHP would be pretty straightforward once I've temporarily removed some kitchen cabinets, also the current heating plumbing goes off in two different direction from here. It's also central to all places hot water is required.
 
The weathers forecast for 20 to 24 mph winds tomorrow, so I took today off work, and cracked on with the last four roof brackets, it got a bit windy late afternoon and I was knackered, so I'll finish fitting the roof rails on Sunday.

Had to take off three ridge tiles in the middle, then I could slide the tiles either way to fit the each end hook.

PS. I've got some Wet & Forget to spray the roof with, will likely do that Sunday as well.

2024-08-30-All-roof-brackets-installed.jpg
 
Ron-ski said:
The weathers forecast for 20 to 24 mph winds tomorrow, so I took today off work, and cracked on with the last four roof brackets, it got a bit windy late afternoon and I was knackered, so I'll finish fitting the roof rails on Sunday.

Had to take off three ridge tiles in the middle, then I could slide the tiles either way to fit the each end hook.

PS. I've got some Wet & Forget to spray the roof with, will likely do that Sunday as well.

2024-08-30-All-roof-brackets-installed.jpg
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I see shade. Micro optimisers?
 
Mercenary Keyboard Warrior said:
I see shade. Micro optimisers?
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No, optimisers don't play nice with Victron MPPT solar charge controllers.

The roof I'm doing has 12 panels, they are wired in three parallel sets of four (4S3P), so whilst the four in the above picture would be affected by the shading, the other eight will not, and its only mid to late afternoon the chimney starts shading those four panels (picture was taken at 16:15). Its the main reason I've done those panels landscape, the shadow comes up from the bottom of the roof as the sun goes round.

My garage has some shading around lunchtime from a tree, probably not so much this time of year as the suns higher, more so in the winter, but it still generates pretty well.
 
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Ron-ski said:
No, optimisers don't play nice with Victron MPPT solar charge controllers.

The roof I'm doing has 12 panels, they are wired in three parallel sets of four (4S3P), so whilst the four in the above picture would be affected by the shading, the other eight will not, and its only mid to late afternoon the chimney starts shading those four panels (picture was taken at 16:15). Its the main reason I've done those panels landscape, the shadow comes up from the bottom of the roof as the sun goes round.

My garage has some shading around lunchtime from a tree, probably not so much this time of year as the suns higher, more so in the winter, but it still generates pretty well.
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Can you see the strings (ie each set P) on their own or will they just combine?
Be interesting to see if modern panels cope with shading like that as well as they claim
 
john_smith said:
Solar edge can show each panel.
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I know, and it can show each panel because it has an optimiser on each panel, Tigo can do the same, as can Enphase, as can any other system which uses optimisers or micro inverters, but normal strings of panels can't.

I did initially look at using SolarEdge for the garage system, and Victron for just the battery, but it got way too expensive.

If I used SolarEdge for the WNW roof then that's another inverter, which means another G99 application, and running cables internally back to the consumer unit, although it would have been a better system presuming I got permission for 16kW export.

I've had a SolarEdge system since December 2015, they are 250w panels ;)

This shows this years generation, the two top right get shaded by a boiler flue, left panels are ESE, the right panels are SSW.

2024-08-31-Solar-Edge-panel-layout.jpg
 
Think I'm pretty much ready for the electricians.

Roof rails are done and ready.

2024-09-01-Main-WNW-roof-array.jpg


This is 13:00, and that shadows well out the way at the moment.

2024-09-01-Small-WNW-roof-array.jpg


The rear wall mounts are all bolted in place, and ready for the panels.

2024-09-01-Rear-wall-mounts.jpg


I do need to put some new LED wall lights along the bottom just below the panels, and some conduit up behind the panels to feed the lights.

Also a few things to sort out on the roof, but that can be done after the panels are fitted, or before if I get time.
 
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Ron-ski said:
Think I'm pretty much ready for the electricians.

Roof rails are done and ready.

2024-09-01-Main-WNW-roof-array.jpg


This is 13:00, and that shadows well out the way at the moment.

2024-09-01-Small-WNW-roof-array.jpg


The rear wall mounts are all bolted in place, and ready for the panels.

2024-09-01-Rear-wall-mounts.jpg


I do need to put some new LED wall lights along the bottom just below the panels, and some conduit up behind the panels to feed the lights.

Also a few things to sort out on the roof, but that can be done after the panels are fitted, or before if I get time.
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Top work that ron…..
 
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