Don’t worry Greta, we’ve got this….

[V8Granite]

Being a cat, it would simply come out the side through its own hole

Dave!

[KiwiDave]

Stuff and things... This is how a lot of systems in America work.

Dave!

Pretty much how ours works. Our power bill dropped to about 25% of what it was as soon as we switched our solar system on. Only reason we didn't go bigger is we'd need a second inverter (max capacity of the first currently) and the wiring from the street as well as both circuit boards in the house would need upgrading, so that bill got pretty big for marginal gains.

If we ever build a place though...

[jamcg]

Nice!
When we do our extension later this year (well if it even comes off as our architect had a massive stroke 2 weeks ago) part of my plans are for the biggest solar array I can get on my south facing roof, a battery storage unit (thinking 6kw at the moment) and a change over unit that will run the immersion heater from the solar array when it's got excess power.
When we get planning consent I'll start serious investigations on panels and batteries as I've only looked briefly.
My mate who will be fitting and wiring it all suggested maybe a pumped system like you've created but I'm not keen on pumping water onto the roof of the house really.
Been mulling over for a long time (a lot longer than the little doom goblin has been in the news for) but only recently had the funds along with the solar and battery prices becoming sensible has enabled the thought to become reality. Hopefully it will save us money in the long term and mean that we are a bit more environmentally friendly.
The wife wants a hot tub (I keep telling her it's just a filthy sex pond) so maybe I can create something similar for that.

Wet pumped solar panels for hot water run glycol not water- they run it through a special solar cylinder which has 2 heating coils, one for the solar at the bottom and one higher up for your boiler. They’re a bit of a bitch to be honest- and also massive initial outlay and then there’s ongoing maintenance.

To use them properly you need to have a cold cylinder in the morning and allow the panels to do as much if the heating as possible. If you have your boiler heat the tank for morning showers or baths then there’s nothing for the panels to heat- and I f you don’t use them correctly you’ll get crystals forming in the panels if the glycol is allowed to overheat, which blocks the pipework and has a massive effect on efficiency. Aside from this you’re supposed to have your fluid changed every 5 years and it’s not a particularly easy thing to do.

Basically I’d say pv is the way to go. If it’s not heating the water via an immersion heater, it’s doing something else so us always working, rather than sitting stagnant

[V8Granite]

Kiwi-Dave, do you have any fancy graphs or pictures of your set-up ?

Jamcg, do you fit or see many of the solar water heaters ?

Dave!

[jamcg]

I’ve fit maybe 5/6 in the past 15 years

[drcarlos]

Nice!
When we do our extension later this year (well if it even comes off as our architect had a massive stroke 2 weeks ago) part of my plans are for the biggest solar array I can get on my south facing roof, a battery storage unit (thinking 6kw at the moment) and a change over unit that will run the immersion heater from the solar array when it's got excess power.
When we get planning consent I'll start serious investigations on panels and batteries as I've only looked briefly.
My mate who will be fitting and wiring it all suggested maybe a pumped system like you've created but I'm not keen on pumping water onto the roof of the house really.
Been mulling over for a long time (a lot longer than the little doom goblin has been in the news for) but only recently had the funds along with the solar and battery prices becoming sensible has enabled the thought to become reality. Hopefully it will save us money in the long term and mean that we are a bit more environmentally friendly.
The wife wants a hot tub (I keep telling her it's just a filthy sex pond) so maybe I can create something similar for that.

Wet pumped solar panels for hot water run glycol not water- they run it through a special solar cylinder which has 2 heating coils, one for the solar at the bottom and one higher up for your boiler. They’re a bit of a bitch to be honest- and also massive initial outlay and then there’s ongoing maintenance.

To use them properly you need to have a cold cylinder in the morning and allow the panels to do as much if the heating as possible. If you have your boiler heat the tank for morning showers or baths then there’s nothing for the panels to heat- and I f you don’t use them correctly you’ll get crystals forming in the panels if the glycol is allowed to overheat, which blocks the pipework and has a massive effect on efficiency. Aside from this you’re supposed to have your fluid changed every 5 years and it’s not a particularly easy thing to do.

Basically I’d say pv is the way to go. If it’s not heating the water via an immersion heater, it’s doing something else so us always working, rather than sitting stagnant

He did only suggest it but it does sound a ballache, I hadn't looked at the technicalities of the pumped systems but they sound worse that my initial flawed assumptions now. Like you say the PV system will be either running the house (as best it can) charging the battery or heating the water, so therefore extracting maximum efficiency out of it.

My thoughts were for basically the system that Dave! mentioned.

The whole build will hopefully go up on the House projects thread as it's the first time I've opted for something like an extension vs moving and it's new to me. It should prove interesting as the biggest build I've undertaken to date was my little office in my garage.

[KiwiDave]

Kiwi-Dave, do you have any fancy graphs or pictures of your set-up ?

I hope you'll forgive my lack of full blown technical knowledge to fully describe the system by the fact I just went on the garage roof specifically to take these shots for you

This is the panel array on the garage roof - North facing, slight incline. Excuse the house next door, they're in the middle of repainting their place. We meanwhile, obviously need some cleaner on the roof...



Beneath the array in the corner of the mini-garage not big enough for actual cars is the main part of the electronics. This is the inverter, its isolation and specs:







The battery unit and specs:





Plugged into the inverter is a dongle with 4G SIM card in it, which talks back to the company who installed it and gives them analytics and information about systems status. The general idea is as they learn over time they can tweak the algorithm and make performance better. Whether they do of course is different, but the one outage we did have they were calling us within about 20secs of it happening to update on what they were doing. The dongle:



Then there's this on the main circuit board into the house, which in essence, using our internet network keeps the systems talking to itself - the system appears on my list of users on my network alongside things like the heat pumps etc. We have two main circuits which flip over to running off the battery in the event of an outage from the grid. That's the main lighting areas and the fridge and freezer and a few other power points running on the same circuit.



Hardest part of the install was connecting the gubbins in the garage to the circuit board in the house. The house itself has no roof void, just ceiling, liner and insulation then metal roof so there's nowhere to store stuff and route anything. It's made retrofitting things into the house super difficult - wired network and heatpumps have been a proper PITA. The main run from the garage goes along the apex of the roofline outside, then enters the house through the roof and goes down into the void between the gib into the back of the circuit board. Aiming to get the feed into the void with little indication of where it was from the roof side took them ages, all while we stood there and said 'we don't want holes in the ceiling or a plastering job after this'

As mentioned above the system is enough to provide 70-75% of the power we use (probably more thinking about it, I'm just basing that on the change in power bills, but part of that will be line rental which is a static cost) and if we wanted more panels it meant a second inverter and approaching double the cost. We opted not to, but if we ever start charging EVs at home or if I ever put in that hot tub I want we may regret that. I can't remember the exact details now either, but the install electrician for the heatpumps basically said if we add much more to the house it'll need a rewire and a new line running from the street. Thankfully the hot tub is already wired in if I want to add one.

Total cost was the equivalent of about 16k GBP (based on .50cents to 1GBP) and we estimate about a 7yr break even point.

I can take some grabs of the analytics if needed/of interest but I'd have to dig the paperwork out from install to find the full details of the system beyond the info above.

[V8Granite]

That’s pretty impressive, the 5kw inverter especially.

So you can run the house during a blackout on the inverter and battery alone ?

I’m guessing you have AC on if it covers 75% of your electricity needs ? I believe the U.K. average is about 18kwh a day of consumption.

Dave!

[Jimexpl]

That’s pretty impressive, the 5kw inverter especially.

So you can run the house during a blackout on the inverter and battery alone ?

I’m guessing you have AC on if it covers 75% of your electricity needs ? I believe the U.K. average is about 18kwh a day of consumption.

Dave!

Kiwi houses have surprisingly poor efficiency regulations, even on new builds, so even if Kiwidave has upgraded over standard, they get a lot of heat loss/gain in a building.
One of my good mates and his wife are heavily involved in passiv house over there and it’s really difficult to get items like low loss windows without paying through the nose or importing them.

[Carlos]

I've considered a PV set up a few times but can't get past the pay back time given the assumption nothing breaks or wears out during that period.

I suspect if I was doing a new build or renovation that included electric heating/water it's much easier to justify.

Cool set up though.

[KiwiDave]

That’s pretty impressive, the 5kw inverter especially.

So you can run the house during a blackout on the inverter and battery alone ?

I’m guessing you have AC on if it covers 75% of your electricity needs ? I believe the U.K. average is about 18kwh a day of consumption.

Dave!

Erm, yes approx 36-48hrs from battery alone for the circuits it 'backs up'. Our cooker is gas (and to touch the points below, what that means is there's a 9kg gas tank hidden under the deck that ALWAYS runs out mid cooking) and we have the BBQ so figure cooking is taken care of, so main things to worry about in event of an outage is keeping the food chilled and being able to see what we're doing. Doesn't often get much below 10 degrees here even in winter, so if it went at a bad time and we're cold we can generally stay warm by keeping wrapped up and throwing some extra blankets on the bed. Haven't had a proper outage in the 2yrs we've had the panels fitted yet so the only example of it kicking in was during simulated testing during electrical sign off.

I just checked, today we generated 18.1KW of energy and used 16.8 as of 9:45pm. We've had our two home offices running, a dehumidifier downstairs (a different story), did a load of washing of towels and dried them in the dryer. AC run for about 7hrs.

Kiwi houses have surprisingly poor efficiency regulations, even on new builds, so even if Kiwidave has upgraded over standard, they get a lot of heat loss/gain in a building.
One of my good mates and his wife are heavily involved in passiv house over there and it’s really difficult to get items like low loss windows without paying through the nose or importing them.

This. We have double glazing here in NZ now, complete with a pressure release hole in the frame between the layers so when a massive wind gust hits the window the glass doesn't pop out. Genuine sealed double glazing or triple glazing as per Europe is almost unheard of. Amusingly since our building code required double glazed windows to be fitted, the knock on effect is all new builds get so damp inside there's water running down the windows (and sometimes walls) almost constantly. I don't know anyone in a new build who isn't running a heat pump/AC or a dehumidifier.

Our home only has double glazing on the North facing side - all of which is bi-fold and French doors. I can actually see through the gaps just about so it's not exactly air tight, but most of the time the place is a sweat box with sun pouring in all day - we're just about at the point now where the AC needs to be on during the day (otherwise the main living room is 30+ inside with the sun) and then heating kicking in of an evening.

Houses are different here... They need to breathe to work. All the bloody colonials figured that out when they arrived and built what would be a timber cottage in the UK - cold AF in winter without heaps of heating but great in summer and little in the way of damp issues because they're as air tight as a sieve.

[Mito Man]

I remember reading something about increasingly airtight houses causes health problems due to insufficient airflow so certain harmful pollutants could build up. In Sweden when they got strict on air tight buildings with triple glazing everyone would leave one window cracked open a few mm even in winter just to get some airflow which thereby negated all the effort and trouble of making the building so airtight in the first place

[Swervin_Mervin]

I remember reading something about increasingly airtight houses causes health problems due to insufficient airflow so certain harmful pollutants could build up. In Sweden when they got strict on air tight buildings with triple glazing everyone would leave one window cracked open a few mm even in winter just to get some airflow which thereby negated all the effort and trouble of making the building so airtight in the first place

The idea of living in a hermetically sealed box gives me the heebie jeebies. Fuck that - I like to be able to crack the windows open (especially after a night on the ales and curry), and not just get some fresh air/pollutants but also hear the outside world.

[drcarlos]

On the subject of air circulation and sealed boxes we've noticed since we upgrade our windows a few years ago that while it costs less to heat the house now and it stays warmer we do suffer damp to the degree we get growth on ceilings in the eldest's (exacerbated by him keeping the door closed and sitting in there playing his PlayStation to all hours) room and the bathroom. We keep the windows open in the bathroom on vent setting all year around usually.

[Beany]

Quite a lot of double glazing windows have a vent at the top top open, which helps prevent that.

I know it sounds like stating the obvious, but the number of people I've seen who don't know that - and have the vents there - is surprising.

Worth checking, it's very much one of those 'look but don't see' things.

[drcarlos]

Quite a lot of double glazing windows have a vent at the top top open, which helps prevent that.

I know it sounds like stating the obvious, but the number of people I've seen who don't know that - and have the vents there - is surprising.

Worth checking, it's very much one of those 'look but don't see' things.

We have them on our kitchen doors, none of the other windows, we were asked when we bought them but it wasn't explained at the time they might be advisable in a bathroom or sweaty teenagers room. We considered having them added retrospectively but with the impending extension (architect has made a decent recovery and phoned us last week to say although he can't walk our drawings were done!) and the requirement to have new windows we've not bothered and will get them in the new windows.

[Swervin_Mervin]

None of our new Alu windows has those vents. We don't seem to be having any damp issues though thankfully. Maybe it's still just about draughty enough given it's a '30s semi.

[Beany]

Not impossible. I don't have the on my windows, but the building is an old turn of the century converted farmhouse type affair, so it's got more draughts than a board game set

[drcarlos]

After the first couple of race meetings this year I'd been out and run down my leisure battery in the caravan by the Sunday morning, usually I'd fire up the generator and recharge it but I didn't take any fuel with me to the first meeting (I'm more running meetings than racing now really) but had a small 20w solar panel so I plugged that in to the 12v socket and was quite surprised that in direct sun it stopped me needing to scrounge fuel. Again last weekend it again saved us needing a generator assist. I'd been looking at more permanent kits with controllers and flexible panels but after chatting to some other racers they recommended solid panels (flexibles overheat and fail apparently because they don't have any air gaps) and said they could easily off grid on these kits in the summer for a week.
So on Monday I ordered this:
Also ordered an isolator (so I can switch off panel input), glanding kit and some sikaflex to bond it on with.
The ecoworthy kit seems to get good reviews so it was worth the extra £20 over the other brands for a bit of confidence.
Fitted all last night, kind of nerve racking drilling holes in my caravan but went with the old measure twice cut once and my 2 cables came out pretty much exactly where I expected, bonded the gland plate and panel down and commenced wiring. 2 hours later and I was done. The isolator and controller live side by side in a locker by the door, right below where the cables enter and beneath the panel on the roof so runs are minimal. The runs back to the battery (where I also added a fuse for protection, which I had lying around from an old ICE install) follow the built in runs for aerial, 12v and mains cables in the unit where the TV lives and I re-terminated the battery cables while I was there. It's all neat and looks pretty factory.
Connected up and the controller recognised a 12v SLA battery system, switched on the isolator and the panel started to charge the battery picking up system voltage from 12.4 to 13.5v volts in about 5 minutes.
We're away for a week from tonight on a site with hookup but then straight to a race meeting without returning home the following weekend where I'll get to see how good it really is.
My attention has been grabbed by Ecoworthy's top home package as it was kind of what I was looking for when I do my extension.

It's a hell of a step up from a £130 100w kit and the batteries will need proper housing (a bit more DIY than a lot of home kits) but the DIY project and saving about 10k does appeal. I'd also get to say 'look what I did!'. Anyway we'll have the summer with the mobile kit and see how that works out first.