At the risk of winding up the many, many former contributors to this:
Would you do it all over again if you got the choice?
What do I want ? How much output, how much storage? (Moderate users, 2-4 occupants. SE facing garage and SW main roof but with 2 dormers in it to reduce area quite a lot). Sunnyish southern England. {adds - gas CH/HW}
No EVs currently (pun deffo intended).
Is there a specific standard/grade of panel/inverter/battery.other gubbins that is far better than others?
What should we avoid?
Ive completed my first year, for those interested:
3.9kw of panels on south roof, south of england
10.4kw battery
myself and my son in the house, gas ch, fan of gadgets and computers
recorded use sep23-sep24
3638 KW which i calculate would have cost me £967.35
I'm on Flux tariff and actual costs over the year -£586.79
total saving £1554.14
This is taking advantage of energy saving sessions, free electricity etc etc, approx 7 year payback based on that calc
6.2KW array, 15 panels, 11 on east facing, and 4 on west facing, ( not ideal, I know ) 10KW battery pack. We are now just over two years in and roughly ( very rough ) half paid for. Yes I'd do it again, in a flash.
Hello All, hoping for a sense check on a recent quote I've had, usage in the property is around 3100kwh per year, looking at my smart meter data for the last 6 weeks can't see any 30min peaks above 2kwh, but this is the warmer months, I'd look further but clicking in my energy providers website is awful and you cant easily export 30min data.
Quote is:
10 x Tiger Neo N-type 430 watt panels
Sunsynk 5kw Hybrid Inverter
Sunsynk 5.32kwh Battery
Claims will generate 3,900ish kwh per year which exceeds the current usage but that generation obviously wont perfectly match the demand I expect, happy to hear any feedback on this quote!
The numbers seem right in terms of generation.
Battery is very low capacity for any load shifting so hope your in all day to allow you to make use of the power.
Flux rates have been tightened and no longer makes sense to use flux instead of battery
Flux rates have been tightened and no longer makes sense to use flux instead of battery
Did you mean grid instead of battery? If so I'd agree - ideally you need enough battery to get you through a murky winter day without drawing from the grid away from the cheap overnight period, whatever that is from your energy provider of choice
Estimated generation is easy to check by sticking your details into PVGis and see if you get the same ballpark.
https://re.jrc.ec.europa.eu/pvg_tools/en/
Is that the max number of panels you can fit? If not I'd look at maxing that out as the incremental cost per panel is small for a given array.
Is anyone on here using a Huawei system? If so, did the latest app update and inverter/battery updates throw your set up into a spin?
Would you do it all over again if you got the choice?
Absolutely. NW England here with 10 S facing panels and 10 W facing 7.47 kWp with two Solar Edge inverters (two inverters because we added 6 west facing panels when we rebuilt the garage) and Tesla PW2. 6.64 MWh output last year which is about just over half of our requirements (we charge two EVs). My advice would be to install as many panels as you can (panels are cheap scaffold is not) and get home battery storage. In fact even if you can't fit panels to your roof get home battery storage and a time based tarrif like Intelligent Octopus Go especially if you have an EV. I reckon the Tesla PW2 will have paid for itself in 3-4 years not taking into account that it maximises our use of solar.
Anyone got any experience of Fox Ess PV and battery systems?
Thank you for the replies trail rat and the purist:
Battery is very low capacity for any load shifting so hope your in all day to allow you to make use of the power.
I do WFH and understand need to move some household items like washing machine and dishwasher to midday to capitalise on energy generated
Is that the max number of panels you can fit? If not I’d look at maxing that out as the incremental cost per panel is small for a given array.
No, I shopped the quote from one firm with another and they came back with an almost like for like and another with 16panels, 2 batteries a bigger inverter, but for now its out of budget.
I think I am right in saying that if I did go 10 panels, inverter and battery, I can always add to this?
One other question, when I shopped the quote the other firm came back cheaper with the same brands used for panels and battery, but they had quoted on a smaller 3.6kw inverter. They claimed on the phone this should be fine with the 4.5kw system, some googling suggests this is down to needing approval for 5kw from the DNO and not for 3.6kw. Will this smaller inverter have any real world impact to my ability to export energy? I assume no impact to battery charging.
Will this smaller inverter have any real world impact to my ability to export energy? I assume no impact to battery charging.
Our inverter is that size, note that you can easily exceed its capacity and then you're topping up from the grid. A couple of hobs and the oven, for example.
What he said.
Also bigger than 3.6 inverters tend to have actual fans rather than pasive heat sinks.
There can be an issue with noise pending your site.
Do not let them put batteries outside. Batteries no matter what they tell you do not like being below 10 degrees and their charge and discharge rates slow down to a stop below about 6. Ideally you want the battery and inverter in the same insulated and adjustably vented area.
You want to keep the heat in the winter for the batteries and you want to get rid of the heat in the summer.
(Unless of course you have onboard heating)Cooling ala power wall but then your power efficiencies go into that )
Trail Rat - that’s not true of all batteries. Our LG RESU 12 pair functioned perfectly down to minus 13. They’re bolted to the outside of the house. They’re now in an Un-insulated enclosure along with the inverter. Fine in both hot and cold weather.
Also, whilst our inverter is rated to max 6kW (7kW actually) the fans don’t kick on until the load exceeds 70A. Everything below that is silent.
Most LG packs are rated for normal function at temp ranges from -10 - +50, so ours may not have used the normal full power at5kW, but it was close.
That's true. If your using NMC tech you want it outside. Preferably as far from your house as possible.
If they are proposing to fit NMC battery's in this day and age. Ask them to reconsider.
NMC is fine so long as the battery thermal circuit is designed for the environment it’s in. NMCs are used in everything from Tesla M3s all the way to house batteries and phones.
Tesla M3 moved to life4po a while back. - 2021 siting safety as a key driver.
To anyone looking at fitting batteries .... I suggest looking up the differences before you sign up.
I wouldn't be having NMC near my house .
Not all M3s. the LR and Performance kept the NMCs and it varies to this day. As ever with Tesla, safety will be A factor but price will be the main driver.
One bad batch of cells (from 7years ago) doesn’t make a substantial case. My cells were produced in 2022 and are obviously fine. 2 years further on and they’re still at 99% state of health (same as when they were new) despite being charged and discharged every day.
Whilst the electrolytes in LiFePo batteries are not flammable, they can still catch fire and have done in several M3 standard ranges. The fire is less energetic in the initial phase, but once it gets going, it’s still going.
Most manufacturers list a slightly higher risk in NMC and slightly higher degradation if used to capacity.
Thank you Ransos and Trail Rat, I'll keep it spec'd to the 5kw inverter.
I assume the battery will end up being fitted in my loft, manufacturer spec gives operating range -20c to 60c so should be okay, my loft does get hot, but not 60c!
Time to haggle on the price before getting an install date.
Battery in the loft isn't allowed in new install because MCS cartel.
They didn't receive guidance in time so went to NMC guidelines. Basically they don't want them anywhere near your house.
Mines in the attic because it predates the guidance and I was much happier to have life4po up there. -it was between there and the garage. The attic had much less thermal swing
I have a quote for a Tesla power wall and the installer wouldn't put that against the house even.
end up being fitted in my loft
Without googling I think there is a recent BSI recommendation not to fit batteries in lofts. There may be instances where its fine and IIRC it was a response to (a very small number) of home battery fires. Just may be worth looking into before you commit. From a couple of experts I have spoken to they claimed that after feedback these things can become law in future.
https://givenergy.co.uk/industry-update-home-battery-installations-in-lofts/
Mine are in my garage and I just wrap them in a cheap cylinder blanket when the weather starts to cool, tends to keep them around high 20's normally with spikes when charging from the grid or solar.
Battery in the loft isn’t allowed in new install because MCS cartel.
It is allowed with certain battery types and in certain circumstances although as I said above, this may change in future.
It is allowed with certain battery types and in certain circumstances
Has it been revised ? Initial guidance was blanket ban on doing so .
The bs referred to by the MCs states
The following locations are strictly prohibited:
Unsuitable locations:
Rooms in which persons are intended to sleep.Routes used as a means of escape that are not defined as protected escape routes, including landings, staircases and corridors.
Corridors, shafts, stairs or lobbies of protected escape routes.
Firefighting lobbies, shafts or staircases.
Storage cupboards, enclosures or spaces opening into rooms in which persons are intended to sleep.
Outdoors (ground-mounted or wall-mounted in a suitable enclosure) within 1 m of:
escape routes;
doors;
windows; or
ventilation ports.
Voids, roof spaces or lofts.
Within 2 m of stored flammable materials and fuel storage tanks or cylinders.
Cellars or basements that have no access to the outside of the building.
If it was me I wouldnt install in a loft, although not everbody has the luxury of a garage or "external" space.
I think also if its not prohibited now, it may become so in future and moving them then would be a bugger if it became retrospective.
I will ask where they are thinking of putting the battery then! After asking for the inverter to be increased to the 5kw version, I got the add ons offered to me of Bird Protection and Optimisers, My street has no issue with birds so think I'll be fine, Optimisers could increase output from 3850 to 3900 they said which seems tiny for the cost outlay!
I will ask where they are thinking of putting the battery then!
Might be worth having a think about where you want it to be rather than letting them talk you into putting it where it's easiest for them to fit it. Bird protection is probably worth it if you have the likes of pigeons or starlings in the area but I've seen one install where they'd used shiny aluminium rather than the usual black mesh and it looked horrendous - I'd rather have had the birds. Optimisers might be useful if you're going to have any shading affect the array - but then only on certain circumstances. If shading could completely block at least one panel in a string while the others are unshaded (eg shade from a chimney stack or tree) then it's worth thinking about as the one shaded panel affects the whole string. If the shading encoraches on all the panels in the string uniformly then they'll have less effect.
it’s worth thinking about as the one shaded panel affects the whole string
That's hasn't been the case with modern panels with bypass diodes for quite some time... Like 10s of years my parents 2008 install has them - Hence I have never seen the draw for optimisers other than extra cost for installer and extra data for the user.
First post on forum in years, but the ST hive mind has always been a go-to for knowledge.
Looking at options for me, have read from start to end, but nothing really fits my needs.
Live in Shropshire in a single story converted barn in a conservation area, which may limit one roof aspect. But have total of 7 small'ish roofs (6m x 3m) two of which have small velux's in . There's are three W facing and three E and one S facing (though unlikely to be able to use that one). Basically three apex's parallel to each other, and one at 90⁰. All in the open, though the adjacent roofs give a bit of shade to the next early hours in winter.
We currently heat and hot water via LPG, (no mains gas ). boiler coming towards the expected end of life replacement, hot water is tank and it does have a separate electric connection though its never been used, and a freestanding log burner for heat only. Heating is via wet underfloor only which to use effectively has been really expensive, so tend to rely on wrapping up and the log burner. Only two of us, and both work similar days, and use about 3800KwH leccy a year. All the heating and electrics are coming up to 20 years since conversion.
We need two cars, and are open to electric for these on replacement, and commutes are about 30 miles return in opposite direction, not really heavy car users, so fuel bill combined is about £200 month.
Will hopefully live long enough to see a ROI, and only see bills being tighter as things go on currently, so just planning ahead while I have some spare income.
Open to all suggestions, and problems anyone sees, as nice to see that most would do it all over again. And any recommended installers this way. In no real rush, and waiting to see what the budget takes away too.
Thanks. Mark
so, my install was done in august 2023
I noticed a roof leak in the winter of that year, relatively light, i keep a cat litter tray under it in the loft and check/empty every few months, noticed it due to some staining on my bedroom ceiling.
I can see in the lower part of the pitch of the roof, the felt has been disturbed and is hanging down/ strip missing.. don't ask me how, i just know it wasn't leaking and i hadn't noticed it missing before. And i also understand a proper repair involves pulling up a lot of roof to replace from the bottom up essentially...... i haven't attempted a bodge yet
My installer was at the end of the country, so i wanted to get a 3rd party assessment before getting on the installer's case. The 3rd party is mate of mine, and unreliable, and still hasn't visited. Subsequently, in my year window of install, it seems the installer no longer exists (dual fuel solutions ltd)
I do have the HIES? insurance stuff? not sure if that just covers hardware or what, obviously house insurance etc
essentially, what would be the best way forwards do you think?
Mine are in my garage and I just wrap them in a cheap cylinder blanket when the weather starts to cool, tends to keep them around high 20’s normally with spikes when charging from the grid or solar.
Is this common practice? This will be our first winter since getting a solar system so I'm interested to hear what people do.
Am I missing something in this calculation ... ???
If you have a 10kWh battery and charge it for 7p/kWh during the night, then if your daytine tariff is (conveniently) 27p/kWh you are saving 20p/kWh, or a total of £2 per day, or £730 per year. If your battery cost £7300 (other assumptions available) it'll take you 10 years to break even. Is there some other factor that I'm ignoring ?
Is there some other factor that I’m ignoring ?
Solar generation.
Solar generation.
How does that factor in ?
I do have the HIES? insurance stuff? not sure if that just covers hardware or what, obviously house insurance etc
essentially, what would be the best way forwards do you think
Not sure at all, but two things pop to mind:
1) Were the installers registered with HIES? If not then obvs no cover there.
2) You're already over 12 months since the install and as you didn't report the leak earlier they could easily argue that it's outside the insurance window.
..... You may just have to get a roofer in and get it fixed yourself.
yup, HIES registered
and yes i know ideally within the first year it would've been good to raise the issue :S
Re, DRJ
solar generation, instead of 7p a unit, its free, plus your export income, on flux,for example, peak export is much higher than the cheap import
How does that factor in ?
I generated 4753kwh last year, roughly £950 on tracker rate I didn't have to buy in.
I noticed a roof leak
AAMOI how did they install the panels - by drilling through roof tiles and relying on rubber seals around the fixing? Or by taking up tiles and installing the fixing without damage (if you see what I mean) ?
solar generation, instead of 7p a unit, its free, plus your export income, on flux,for example, peak export is much higher than the cheap import
Yes, I get that. I'm not (for once) being argumentative :-). I'd just like to see a detailed modelling of how a battery functions in a domestic system, taking into account the times it gets charged and the times it gets discharged. For me it's a bit academic at the moment cos we have a legacy FIT which is ludicrously generous, and which I don't want to compromise by changing my installation. But I'm curious to keep my finger on the pulse to see what might be possible in the future.
Is this common practice? This will be our first winter since getting a solar system so I’m interested to hear what people do.
Not sure. I may be a bit OTT but I have installed Home Assistant and in the depths of winter I noticed the battery temps were dropping quite low in between force charges from the panels or the grid so I just went for this cheap option to keep the temp a bit more consistent, which cant hurt. I dipped into a couple of FB forums and others had build insulation boxes around them etc. Suppose it depends how cold they get in the depths of winter. Ours our in the garage.
How does that factor in ?
Well, being wildly optimistic*, you would fully charge the battery with free solar so you'd save £2.70/day which would reduce the break even point to 7.5 years
* This is assuming >10kWh of solar every day (not going to happen unless you have a BIG array), and you use > 10kWh of power from the battery every day (which is pretty unlikely for some months of the year)
DRJ, this is a good question
I don't know is the answer.. I would have had a nose up the scaffolding but don't like heights, i thought the only way was with brackets hooked under the tiles somehow.. part of the reason id like my mate to get up and have a quicky snoop, as i literally couldn't 😀
if you want to see a decent example of battery control, take a look at "predbat" and there should be some examples of the regime, mine is pretty simple being on flux, just charge as much as estimated to need overnight, although to fill with solar, discharge everything that isnt needed at peak, remain on battery until next charge period, excluding free periods (fill to max capacity in the window, or saving sessions, which dumps as much out). the more interesting agile plans can go up and down throughout the day
10kwh from solar doesn't seem that wild.
We averaged 10.4 from a 4kw array in 2023
I dipped into a couple of FB forums and others had build insulation boxes around them etc. Suppose it depends how cold they get in the depths of winter. Ours our in the garage.
Yes, ours is too. I just spoke to our installer and he said sometimes customers built boxes out of celotex but you need to leave room for airflow.
you’d save £2.70/day
Is it really £2.70 a day or are you assuming the solar is lost if not used. There may be an opportunity cost if that solar could be sold to the grid. We feed in at .15p per kW.
This is assuming >10kWh of solar every day (not going to happen unless you have a BIG array),
We have a relatively small 4.8KWp array, WSW facing so not optimal and even in this cloudy and dull year we'll be averaging about 9KWh per day by the end of Dec.
As above I run predbat on Home Assistant which takes care of the battery charging and discharging, factoring in our typical usage and expected solar generation. If you're not geeky enough to be into that sort of thing you can just hand control back to Octopus via Intelligent Flux and they'll take care of it.
We averaged 10.4 from a 4kw array in 2023
Even in Nov-Feb??!
We def don't get that from out 4kW array (E?W though). Also it should be remembered that some of that power will be used by the house as it's being produced.
Oh.. and AFAIA a 10kW battery actually gives you less than 10kW of power (plus it uses some power to run iteslf).
We have a relatively small 4.8KWp array, WSW facing so not optimal and even in this cloudy and dull year we’ll be averaging about 9KWh per day by the end of Dec.
4.8kW ain't small.... it's bigger than the standard 4kW install!
I guess we lose a lot over the winter with an E/W split as we've averaged 150ish kWh/month every October for the last 13 years. It's good in the summer as you get power early and late but obvs a bit crappy in the winter.
(I am considering putting in a separate 4-5kWh as a ground mount in our paddocks now!)
In 2023 I used 3881kw and I generated 3744kw. The joy of batteries is load shifting -i don't have worry about when it was generated really it just has to add up.
I almost always charge at less than I export. But I cannot import at peak anywhere near the cost of export.
due to work I cannot use what I generate so I load shift across the peak periods when I return home and am not generating sufficient solar -5-7pm
I charge for free march-october and then Nov Dec Jan Feb I charge over night to varying degrees.
When I worked from home I had solar without batteries (no FIT payment). When I went back to work it quickly rendered the solar useless without batteries without FIT so I had batteries fitted.
That said. What I saved when I fitted counteracts the quotes I had when FIT payment was available. Which were in the 2x,xxx range and panels were in the 150-200w range.
I have the spreadsheet that says this is working currently and on track for just over 5 years payback* on current tariff (subject to change.... Previous version of flux when there was a bigger gap between export and off-peak it was 4.5 years)
Solar at my place has been so good to us DESPITE the internet saying north east Scotland its pointless. I have installed solar thermal this year in the south aspect dormer and in the days when the sun is out even in October I'm getting 50c in the tank... . Plan to install more PV on the north aspect for summer peak generation so I'm less reliant on the battery -which is 3.6kw limited due to inverter.
Can stick up 3kw of solar for 700quid in parts these days. Mental.
* My parents solar system was installed 2008 and still going strong and generating almost the same numbers as when it was new.
Today is a good autumn day - I've generated 14kwh I've stuck 9k to consumption -the battery is full - I didnt charge last night and exported 5kwh and at early 3pm I'm still generating and exporting 2kw
Let's be clear 2023 was a VERY sunny year. May, June were 800kWh compared to the usual 550-600. On our 5.5kWp array, A good autumn day will be 21-22kWh, but an average day will be 6-9kWh. Over a week, that average will be around 12kWh/d.
We import whatever we need between 2-5 in the morning (the max being around 15kWh) and then export pretty much everything which isn't being used to keep the batteries full.
This way we on average import around 10kWh and export and 2kWh over each winter day (average) Which costs around £1. Total charge per month in the winter is £30 for power and £17 for the standing charge. All of that cost is made through the summer with excess export.
Let’s be clear 2023 was a VERY sunny year.
Location dependant.
Year on year
21/22/23 were within 50kwh of each other with 22 being the peak. 24 is looking to be the lowball at 100kwh below the 21 figure -if I use average Nov/Dec numbers. Largely down to a very poor wet may.
Bit like growing veg really.
Our 24 numbers are going to be around 500kWh down on 2023 and if I extrapolate what we had from September 2022 to December, 2024 is closer to 2022 than 23, but I only have 3 data points for Sep-Dec and 2 for the rest.
My point was that for most of the UK (the vast majority of the population is in the south), the 2023 numbers aren't the best example. as it's likely to be around 90% of that. Also, a lot of people's equipment was brand new in 2023 and will be dirtier, less efficient etc, so it shouldn't be banked on.
I switched my North facing 12 panel 5.4Kw system on on Thursday this week after the safety sign-off and meter change. No battery so just selling back to the grid. Incorporating a battery wasn’t cost effective at this point. I’m in Auckland so just in time for spring and summer. Electricity prices and connection fees have gone crazy this year which was the proverbial straw.
$14000 outlay with a future proof 6KW inverter (I’ve north facing garage roof space that will take up to eight more panels if/when I can afford it.
No idea how long it will take to pay for itself because who knows what electricity will cost here in 3-4 years time.
I hear that in Australia because around 20% of households have solar the buy back rates have bombed and some electricity companies are really struggling to stay solvent
NZ uptake of solar is currently at around 4% of households so we won’t have that problem for a while.
On an Mtb theme given this forum
I’m off to Rotorua for 5 days riding on Tuesday
I’m in Auckland so just in time for spring and summer.
Thank god for that! I was thinking that you must be mad to spend that money on a North facing array in the UK!!
Also, a lot of people’s equipment was brand new in 2023 and will be dirtier, less efficient etc,
My array is 13 years old and I cannot see any discernible reduction in output numbers despite never cleaning it!
I suspect a few days less sunshine would have a much bigger effect on your numbers.
Ours get cleaned twice per year and we can usually see a 5-10% restoration in Max power when they are. Ours are at 30deg, so if you have a higher incline, they might self clean better.
I’ve just been inspired to check how things are going on my system. Heading into late spring here in Australia and 2 full months to the end of year. Solar wise I’ve generated an eye watering 16mWh and used 9mWh excluding charging the car. Interestingly enough, I’ve pulled 22% of that 9mWh from the grid, but only at deeply discounted rates ($0.08 kWh) or free. We are electric everything. 18kW on the roof in a mix of north (60%), South (30%) and the rest East. East has been the best addition as it just kicks out that couple of kW first thing when you need it. House battery does the arbitrage thing of its own accord depending on weather forecast. The car has gobbled 5.5 mwh, of which 1.6mwh came off the solar.
I clean mine periodically when ever I see bird poo basically. see no increase. Conversely I also see no decrease in the lead up.
I don't have the resolution on my data to pick up the cooling effect of the cleaning though.
I bought a long pole and water-fed brush thing to clean the dust off mine once a year, but when I told my installer he said not to bother - it makes no difference and you are more likely to damage them/knock one of the fixings or something. Ours are in-roof and quite steep (maybe 50degrees?) so maybe that's part of the reason. I certainly couldn't see a difference in figures before/after i cleaned them even though I could see the dust from ground level.
TBH I can't see people at solar farms going around washing the panels down!
[....in the UK. I believe they do in desert based solar farms cos of the think layer of dust/sand that builds up - we have rain to do that for us]
Hope your using de-ionised water !
Interesting to see the subject of cleaning coming up - my father's panels (installed around 2011) are happily charging his newly installed battery during the day, but I'm convinced the output is down because he has lichen growing across a couple of the panels. AND with these older panels they operate in series so that a restriction on one panel restricts all the others by the same amount (or that's what I was told back when we had our panels installed in 2013)
I've seen grime collecting on my panels recently - not washing off with the rain quite like it used to.
I'm sure we're coming to the point in the lifecycle where panels that have been installed for 10+ years need a bit of a clean-down, but they're not an easy thing to get to....
This is the same for me. From the ground it’s hard to tell how dirty they are but once you’re up on the roof it’s quite obvious and it doesn’t wash off with the rain.
How do you get to them if they're on the roof?
Are you climbing into the roof?
Sorry, but **** that! Mine are on a low stable block which I can reach fairly easily* with some step ladders and I'm still not cleaning them!
* I can actually see what they're like as they're not far away
Almost every web site I've seen says don't bother in the UK unless you live next to a power station or motorway in which case it may help a little.
If it makes you feel better then fine but anyone who pays to have them cleaned needs a talking too!
(Other than the waste of money, the thought of a window cleaning tool on the end of a long pole being dropped on every panel is quite frightening!)
We have a lower roof and an upper roof. You can use a small ladder or upstairs window to access the former and then a short ladder to get on the upper roof. My roof is only 30deg on any slope so very easy to walk on. I then sit on the ridge with an extendible brush/hose/thing and scrub them down. The difference is quite something.
Speaking of difference - The first 8 days of November. Last year - 90kwh. This year? 12. 12! And we're not even done yet. It'll be Monday before we get any proper rays! We were also 70kWh down on October for the past 2 years too, mostly driven by the dismal final week!
I can see 3/4 of ours from the loft window and the other I suspect could still reach from there with a camera to aid aim. Makes it easy to see how dirty they are. I can't see how the £300+vat the installer wants to (automatically) monitor them and clean once a year is good value. I'd rather pay the normal window cleaner a lot less or DIY those I can reach easily.
It's not obvious from a distance either. Ours look clean from the ground, but it's like a thin film of dirt (which doesn't wash off with just water) which is stuck to the panel. The closest analogy I can given is you know when you wash a car? Just running a hose over it doesn't really work to clean it even on the sides and roof which're out of the direct airflow and even if the car has been recently washed. Even a jet wash only cleans the areas it's directed at, the high pressure water which goes to the sides, doens't do anything, you just end up with clean lines. This is what I've found every time I've washed them. That's another reason for doing it from the roof ridge, I can get a bit more weight on the brush to clean them.
The first 8 days of November. Last year – 90kwh. This year? 12. 12!
Local news reported that one weather station has had 18 minutes of sunshine in the last 11 days. I'm really hoping they're right about some blue skies on Monday!
20kwh in the last 7 days. Most days hovering around 2kwh. Pants!
i spent a lot of time on my roof this summer doing other work.
i did actually check to see if there was any build up on the panels...
There was not.
They are 3 years old. - Ill monitor rather than arbitrarily apply abrasion when not required.
Abrasive?! It’s a glass panel with dirt on it. Do you clean your windows so you can see through them? Solar panels are no different in that regard. Windows (which are vertical) will look dirty in months. Solar panels (at angles from 60-30deg) will get dirty far sooner. Dependent on where you are, they will get dirty quicker or slower. But I refuse to believe that a glass panel installed 2 years ago has no dirt on it. How much that dirt affects generation is related to two factors, absorption and radiation. My panels are almost certainly more affected by the latter. Coupled with the roof angle and our location surrounded by fields/dirt, this might explain why I see such a difference.
A solar panel should have rain regularly washing over it, whereas windows are generally sheltered from it, so it might be a little clearer?
Sorry Daffy but I'm struggling to see how you can tell such a difference when there are so many variables plus the fact that panel output is constantly varying.
But if it makes you feel better ?
Maybe some panels have a better non stick properties than others.
I know the flat panels on my van DO need cleaning. They get obviously dirty as they are flat. That said I still don't see noticeable output issues unless they are covered in green tree sap. Baked on dust seems to be negligible...and that's on 2*100w panels
But as sharkbait says. What ever makes you feel better.
solar panel should have rain regularly washing over it, whereas windows are generally sheltered from it, so it might be a little clearer?
Our velux windows are on the same roof as the panels, and get dirty quite quickly. But the panels apparently have a coating that means they should clear in the rain.
Who knew. Inspired by ransos post - as I also have velux on the same roof they I DO have to clean regular I Just did some reading and window glass ain't smooth and will hold dirt on.
Most modern solar panels have a polymer hydrophobic coating hence are designed to be self cleaning.
Rather frustratingly as I've only just learned this. It seems I may need to clean my solar thermal regularly....it's standard glass. FML
Anyone tried rain X or any other off the shelf chemical coating ? I know it will still need cleaning but hopefully not as much ? - if it's anything like my velux it'll be down on efficiency quickly
Just coming back to this. I cleaned my panels in July, so thought I’d pop up for a look:
These photos show the array from a distance, from stood next to it, close up and with one small area cleaned with a damp cloth. It rained here on Saturday.
i would be wary about using a coating like rainx or a ceramic. isnt there a chance they would limit uv rays and as such performance?
