Solar Panels UK - is it worth it?

[Drew57]

Would a mobile-on-wheels and stuff-the-snorkel-out-the-window do?

Although my understanding of those is that they cool the room, but there comes a point where (given they are pumping hot air to outside) they have to pull air from the room, and that has to cause fresh (hot) air to be pulled in from outdoors, so the cooling effect plateaus

Whereas a split unit will do all the waste-heat part outside, and all the cooling part indoors.

When we were in the USA last month, my son-in law needed to cool his garage when the temperature reached 93F outside & we remembered they had one of those a/c type of units in storage from a previous house. After fitting/temporarily sealing the outlet tube to the window opening, within a few hours the garage was extremely cold & if the doors were closed it remained so. The air exiting via the pipe was very hot at all times & the only other waste product was a small amount of water condensation via a smaller pipe into a bowl.

 

[scdoubleu]

I’m tempted by either a multi-branch ac install or maybe air-air heat pump (capable of reverse-cycle) to cool upstairs if we get another August like last. Would be run when the Solar is available.
Anyone aware of any domestic systems that would play nice with home Solar and PW?

We've had a/c in the bedrooms since 2010, and solar/PW since late '21. As of this year we now have a/c in all rooms of the house, with the intention of ditching the gas boiler completely.

Solar + PW works perfectly with a/c in the summer. We'll find out next winter if going all-in on air-air heat pumps was the right decision.

 

[scdoubleu]

Would a mobile-on-wheels and stuff-the-snorkel-out-the-window do?

Had one of those for my office years ago. It worked, but was ridiculously noisy.

 

[phil4]

Would a mobile-on-wheels and stuff-the-snorkel-out-the-window do?

That's where I got to, the cost of having proper split aircon fitted runs to many many thousands... where as a couple of portable units at a few hundred pounds each, while not ideal, dealt just fine with last summers hot couple of weeks. Unless the price were greatly reduced or I was rebuilding, I don't think the extra costs are really worth it.

 

[ACarneiro]

We've had a/c in the bedrooms since 2010, and solar/PW since late '21. As of this year we now have a/c in all rooms of the house, with the intention of ditching the gas boiler completely.

Solar + PW works perfectly with a/c in the summer. We'll find out next winter if going all-in on air-air heat pumps was the right decision.

Last winter was my first with pretty much full-electric heating (A/C in the main two bedrooms upstairs and kitchen and lounge downstairs)
It makes clear financial sense if you have a battery to power the AC on cheap electricity. Currently gas is more expensive per kWh than IO cheap electric (for the first time ever, as far as I can tell) so it’s a no brainer.
If you have no battery storage it may be less clear cut, especially as the COP will drop in the depths of winter.
You’re going to need to get a reliable, competent HVAC engineer to properly work out the correct kit for your space. Domestic AC is still a bit of a novelty in the UK, most installers are used to dealing with commercial spaces.
Also, in my experience it works better at keeping a temperature constant. It takes a lot longer to heat the house from cold, so although I barely use any gas now I still have it available for if and when the house needs a boost on those REALLY cold winter days.

 

[yessuz]

Last winter was my first with pretty much full-electric heating (A/C in the main two bedrooms upstairs and kitchen and lounge downstairs)
It makes clear financial sense if you have a battery to power the AC on cheap electricity. Currently gas is more expensive per kWh than IO cheap electric (for the first time ever, as far as I can tell) so it’s a no brainer.
If you have no battery storage it may be less clear cut, especially as the COP will drop in the depths of winter.
You’re going to need to get a reliable, competent HVAC engineer to properly work out the correct kit for your space. Domestic AC is still a bit of a novelty in the UK, most installers are used to dealing with commercial spaces.
Also, in my experience it works better at keeping a temperature constant. It takes a lot longer to heat the house from cold, so although I barely use any gas now I still have it available for if and when the house needs a boost on those REALLY cold winter days.

what is AC consumption?

I will have 10 kwh on 8 kwp and wonder how much sense it will make to move from gas.

However this comes back to the cost/investment ratio. if my winter gas will be like 100 pounds (so 600 a year) - how many years it will take to pay it back. but it is really appealing...

btw I moved my gas to Tracker rate - it is like 4.5p/kwh - almost half the IO off peak power rate...

 

[ACarneiro]

what is AC consumption?

I will have 10 kwh on 8 kwp and wonder how much sense it will make to move from gas.

However this comes back to the cost/investment ratio. if my winter gas will be like 100 pounds (so 600 a year) - how many years it will take to pay it back. but it is really appealing...

btw I moved my gas to Tracker rate - it is like 4.5p/kwh - almost half the IO off peak power rate...

I’d say a “steady state” keeping the house warm is around 1.5 to 2.5 kW depending on how cold it is…

Interesting about the tracker rate but I would imagine that will go up in the winter, just when you’re using more of it.

Agree on the RoI but again there are less tangible benefits and to me reducing emissions and being less likely to be directly giving money to Mr Putin do have a significant non-monetary value.
And besides, I fitted the AC also as a slide of comfort in the summer (new builds are bloody heat traps!) so the winter heating is kind of an added bonus

 

[Arran]

Last winter was my first with pretty much full-electric heating (A/C in the main two bedrooms upstairs and kitchen and lounge downstairs)
It makes clear financial sense if you have a battery to power the AC on cheap electricity. Currently gas is more expensive per kWh than IO cheap electric (for the first time ever, as far as I can tell) so it’s a no brainer.
If you have no battery storage it may be less clear cut, especially as the COP will drop in the depths of winter.
You’re going to need to get a reliable, competent HVAC engineer to properly work out the correct kit for your space. Domestic AC is still a bit of a novelty in the UK, most installers are used to dealing with commercial spaces.
Also, in my experience it works better at keeping a temperature constant. It takes a lot longer to heat the house from cold, so although I barely use any gas now I still have it available for if and when the house needs a boost on those REALLY cold winter days.

Been looking into Domestic AC, and been struggling to find installers whom aren't quoting £8k+ for a 4 way split system to replace our aging gas boiler. Do you have any suggestions for resources for Domestic AC install & cost?

I tried reaching out to Octopus regarding their heat-pumps, however they're just heat pumps for an existing radiator system.

Currently tempted to grab a Off-Brand Unit like this, and get it installed, all-in for £2.5k; Argo Multi-Split 4 x 9000 BTU Smart Wall Mounted Heat Pump Air Conditioner Bundle - Three Indoor Units Single Outdoor Unit Argo-4MS9K9K9K9K | Appliances Direct

 

[yessuz]

I’d say a “steady state” keeping the house warm is around 1.5 to 2.5 kW depending on how cold it is…

Interesting about the tracker rate but I would imagine that will go up in the winter, just when you’re using more of it.

Agree on the RoI but again there are less tangible benefits and to me reducing emissions and being less likely to be directly giving money to Mr Putin do have a significant non-monetary value.
And besides, I fitted the AC also as a slide of comfort in the summer (new builds are bloody heat traps!) so the winter heating is kind of an added bonus

which I also think to have installed, but first I need my PVs up and running (next week!!!) and then to check the load and power in batteries, just to see i I have enough room to play

 

[scdoubleu]

Been looking into Domestic AC, and been struggling to find installers whom aren't quoting £8k+ for a 4 way split system to replace our aging gas boiler. Do you have any suggestions for resources for Domestic AC install & cost?

The additional 4-way split system we added last month to cover the remaining rooms was £5k. Given the cost to replace our aging gas boiler (25 years, so could fail at any time), I think that was a reasonable figure.

Finding a reputable installer has been a struggle. We've got through a few over the years for servicing our bedroom a/c, but finally found a very good local company last year. Used him to install the 4-way split and can't fault it.

 

[yessuz]

The additional 4-way split system we added last month to cover the remaining rooms was £5k. Given the cost to replace our aging gas boiler (25 years, so could fail at any time), I think that was a reasonable figure.

Finding a reputable installer has been a struggle. We've got through a few over the years for servicing our bedroom a/c, but finally found a very good local company last year. Used him to install the 4-way split and can't fault it.

Since i am in the same area - may you share the name?

 

[Pink Duck]

My former gas boiler made it to 40 years and died while I was waiting for heat pump assessment. Annoyingly had to opt for modern condensing wall-hung 24 kW replacement for £5k. Barely a year old, feels hard to justify another £5k on heat pump to reduce 0.7 tonne CO₂/year. At least the upgrade scheme has been extended to 2028.

 

[scdoubleu]

Since i am in the same area - may you share the name?

Sure. RJD Air Conditioning Services Ltd

 

[thewishy]

Agree on the RoI but again there are less tangible benefits and to me reducing emissions and being less likely to be directly giving money to Mr Putin do have a significant non-monetary value.
And besides, I fitted the AC also as a slide of comfort in the summer (new builds are bloody heat traps!) so the winter heating is kind of an added bonus

I've got an 8 year old boiler, in good shape for the most part (touch wood). It fires an aqua-air unit which covers the old warm air system.

The flow temps needed by the aqua-air unit was too high for a standard heat pump, which brings up the costs a lot and drops the efficiency significantly. So direction of travel for us is towards A2A ASHP and a hot water tank with integrated heat pump.
Shame you don't get any grants for that, even if it does provide more efficient heating than a hi-temp A2W would...

On the plus side "I'd like whole house AC, and it'll provide efficient heating during the winter" is an easier sell than "I'd like to take out a 'perfectly good' boiler and replace it with something which will likely cost the same to run, but will produce less CO2"

I'm moderately concerned about the boiler dying, and getting locked into replacing the boiler and getting stuck with a new boiler, but on the plus side, both systems can be installed independently, so potential job for March or something...

 

[Mrklaw]

put 30% charge into the tesla today, better than I’d expected. Helps having an ok day the day before so your battery tops up quickly too. I’ve gone from 20% to 80% in three days.

 

[Pink Duck]

Out of curiosity I've been running my car SoC down from 94% to 37% this week, with aim of topping back up to 85% from excess manually this afternoon/weekend. Have had Android Tesla app update to version required for charge on excess solar, now waiting on .10 update for Powerwall.

 

[phil4]

I'm starting to get a decent powerwall automation working now. Solcast (dialed down the efficiency as it's estimates are far too high), provides the forecast. Then a bit of jinja syntax in HA to work out what level to set the PW to, and then does so during my offpeak. Calculation is target (80) - (solarforecast - normal house use)/0.27) (two PW, so 27kWh = 100%). There's a few Solcast updates done over night, and just after each it runs that calc setting the PW to the level it needs to.

Works quite nicely.

 

[Pete UK]

put 30% charge into the tesla today, better than I’d expected. Helps having an ok day the day before so your battery tops up quickly too. I’ve gone from 20% to 80% in three days.

Nice one !
Best day so far…..44kW today ! ….plus 44kW in the car since the 2nd July (even while ping pong charging and discharging)….
Exported 14.5kW today as well .
the last few dying moments…..
Think I’ve also worked out which string is which as well. Or at least narrowed it down by the peak rate generation.

 

[MrT3]

Best day so far…..44kW today !

Very impressive. What's the max peak rate you generate? I only got 35.6 kWh today.

 

[Pete UK]

Very impressive. What's the max peak rate you generate? I only got 35.6 kWh today.

View attachment 954106

That looks a lot tider curve than mine. Max peak was 8.15kW very briefly.