Solar power

[V8Granite]

I’ve been playing with Solar power for a little while and seeing how it works for why I want it for.

So I had an 80watt Monocrystaline mobile flexible panel I was using to separately charge my Defendwr auxiliary panel. It ran through a PWM solar controller which isn’t very efficient but was cheap. This Also had a little usb connector and charged phones, trickle charged car batteries and recovered a completely dead battery on the wife’s TT.

I then fitted the solar controller and old ML battery into the shed so it had indoor, outdoor lighting and usb charging. It worked great but I needed to put the solar panel on the roof every 4 weeks or so. I never ran this set up through winter though but even on a cloudy day it would see 0.5amps of trickle charge and on a sunny day it was sat at 3.5 amps at lunch and probably averaged 2amp of charge.

I’ve now fitted a permanent 30 watt monocrystaline panel wired into the same PWM controller which will keep the battery permanentky charged. It’s a 105ah lead acid battery so that’s about 55ah of true 12v power now it’s a little old.

I then fitted a MPPT solar controller, which instead of capping off any voltage above 13v to charge with but converts it and is about 30% more efficient, to the Defender to charge mainly the auxiliary battery. I’ve wired a plug to my main battery aswel though so I can always charge up either battery if they are flat. This will still use my 80watt mobile portable solar panel as I use my roof rack all the time and would end up damaging it. This will permanently run a small fridge, my rear lighting and also some internal lighting I’m yet to install.

It’s making me think about what else to do with Solar. I was against the government schemes as I saw that as a way to inflate panel prices and waste government money but that’s my own issue. I may be able to grab a larger solar panel soon to run an inverter to charge my RC batteries and power tool batteries etc but need to make that all easily switched so will take some thought.

Solar is an exciting future and Elon Musks solar roof (which seems to have stalled sadly) would be a fantastic way to reduce grid load for all these horrific winey electric cars that are coming .

Exciting times ahead in domestic power.

Dave!

[Mito Man]

I’ve mentioned mine before whilst troubleshooting it. I built a log store with a 250w solar panel and a 1.3 kwh all in one battery generator - a nice juxtaposition for the past and the future.


Lithium battery didn’t like the cold and seemed to go into a protection mode below -10 this winter but insulating it’s cubby fixed that, however the solar panel was covered in snow/ice for 2 weeks so it wouldn’t have worked anyway. I’d say ideally for it to be fully self sustainable it requires another solar panel and a 4 kwh battery but it’s far cheaper and simpler to just have a small silent generator


It’s mainly used to run a 4g router as I’m not there most of the time but I’ve used it for 2 day weekends a few times running lights, radio, charging stuff and it’s good.

[KiwiDave]

We put our house on solar and a battery system mid/late last year. So far, knocking the hell out of the power bills - estimated 8yr payback. Array sits on our garage roof and gets borderline zero shade all day which is nice.

[V8Granite]

What load does your one draw when running in the background Mito ?

Nicely done Dave, some countries have really jumped on these and New Zealand is one of them. How well does yours work in low light conditions etc? The biggest surprise to me was how little light was needed to still give out a decent charge.

Dave!

[KiwiDave]

Tbh I'm not sure I could provide an accurate answer to that Dave - even on a gloomy day like today there's zero shading it til way late in the day so I assume it would be working better than a panel among trees in bright sunlight. I can see if we have some tech sheets for the panels if you like?

off the top of my head we went as big an array as we could without needing to install twice the gubbins to process it all. Inverter - is that the right name for it? We maxed that out which means in winter we'll still draw from the grid, in summer we should be selling a bit back (though those projections were made on the 19/20 year and I reckon it will now be influenced differently by more WFH etc). Adding an extra array and the extra gubbins downstream almost doubled the cost so we opted not to.

[Barry]

I'd love to get involved with roof panels, house battery etc but the set up costs/payback is still putting me off at the moment. Also looking at heat pump too, but I think I'd be limited to air source due to ltd land space around my house.

[Swervin_Mervin]

I'd love to get involved with roof panels, house battery etc but the set up costs/payback is still putting me off at the moment. Also looking at heat pump too, but I think I'd be limited to air source due to ltd land space around my house.

Same here. I actually considered ASHP as well for our current renovation, but it's still a bit too spendy for me.

It's a shame that the Tesla roof tiles thing hasn't really taken off - that's a feckin' brilliant idea and if someone could nail that tech, then it's something I'd be more than happy to see being putting into new/retrofit schemes.

[Mito Man]

What load does your one draw when running in the background Mito ?

The router is the only thing which is always connected at 2 watts. It’s hard to get a precise figure when I’m there as I opted to run everything on DC (not using the AC inverter increases efficiency by 25%) so all of my items are rechargeable and I just plug them in as they need it.

[V8Granite]

I'd love to get involved with roof panels, house battery etc but the set up costs/payback is still putting me off at the moment. Also looking at heat pump too, but I think I'd be limited to air source due to ltd land space around my house.

Same here. I actually considered ASHP as well for our current renovation, but it's still a bit too spendy for me.

It's a shame that the Tesla roof tiles thing hasn't really taken off - that's a feckin' brilliant idea and if someone could nail that tech, then it's something I'd be more than happy to see being putting into new/retrofit schemes.

From what I read and saw the Tesla solar tiles are comparable to a high quality slate roof in total expenditure. That’s if you add in the solar panels after a slate roof so for a roof replacement or new-build they could make financial sense.

I’m surprised it’s not being pushed more though as this would take a huge load off the grid and in the summer months do a really good job of car charging etc for the day to day driving. Also all the tests I’ve seen are in the US and although they get more sun, their kwh usage is far higher than ours too.

Dave!

[V8Granite]

What load does your one draw when running in the background Mito ?

The router is the only thing which is always connected at 2 watts. It’s hard to get a precise figure when I’m there as I opted to run everything on DC (not using the AC inverter increases efficiency by 25%) so all of my items are rechargeable and I just plug them in as they need it.

That panel should be more than adequate all year round.

There was a lot of talk of lead Crystal batteries which are a true 12v till the last amp but I think there were some kind of copyright issues with them sadly as the technology seemed really clever.

Dave!

[Swervin_Mervin]

I'd love to get involved with roof panels, house battery etc but the set up costs/payback is still putting me off at the moment. Also looking at heat pump too, but I think I'd be limited to air source due to ltd land space around my house.

Same here. I actually considered ASHP as well for our current renovation, but it's still a bit too spendy for me.

It's a shame that the Tesla roof tiles thing hasn't really taken off - that's a feckin' brilliant idea and if someone could nail that tech, then it's something I'd be more than happy to see being putting into new/retrofit schemes.

From what I read and saw the Tesla solar tiles are comparable to a high quality slate roof in total expenditure. That’s if you add in the solar panels after a slate roof so for a roof replacement or new-build they could make financial sense.

I’m surprised it’s not being pushed more though as this would take a huge load off the grid and in the summer months do a really good job of car charging etc for the day to day driving. Also all the tests I’ve seen are in the US and although they get more sun, their kwh usage is far higher than ours too.

Dave!

Yeah - I was hoping it would have progressed more by now tbh, as it's always been our intention to re-roof at some point and I quite fancied the idea. After this latest round of works the roof and patio will be the last big jobs, but it seems like solar tiles will still be some way off, over here at least.

[Simon]

Friend of mine in America has a Model 3, 2 powerwalls, and a fully covered roof in solar panels. Just after install it was putting out 8kw. Not sure what it runs on a sunny day. But that's normal panels, not solar tiles.

[V8Granite]

I wonder if there are a few with the full Tesla package in the U.K.

Dave!

[KiwiDave]

I'd love to get involved with roof panels, house battery etc but the set up costs/payback is still putting me off at the moment. Also looking at heat pump too, but I think I'd be limited to air source due to ltd land space around my house.

We have four wall mounted air source heat pumps, running from two external compressors. They're hidden away neatly outside behind cladding in voids where decking and facades have been used to disguise the house being built into a hill so it looks almost non-existent from the outside. They're excellent things to be honest and work flawlessly, though I suspect you'd see them hit a brick wall in a British winter, efficiency drops a lot when temps get super low.

[Carlos]

Our gas fitter was mumbling recently about the ban on gas heating in new homes from 2025 which was the first I've heard of it .

If that is the case we must be about to see an acceleration in development of the powerwalls for night/winter heating. I don't know of anyone without gas heating.

[V8Granite]

Our gas fitter was mumbling recently about the ban on gas heating in new homes from 2025 which was the first I've heard of it .

If that is the case we must be about to see an acceleration in development of the powerwalls for night/winter heating. I don't know of anyone without gas heating.

It will massively affect a huge part of the country. I believe we can handle 10% hydrogen mix in our gas but any more than that and we will have to re-engineer it. I don’t know if it will make emissions better or worse though in the interim where the gas is mixed.

Dave!