To relocate or add extra PV panels..advice required
Hello, if anybody can offer advice please.
Six months ago we had 11x420w panels fitted on a SSW facing roof, with a 3.6Kw Solax Invertor. The supplier quoted an annual estimated generation figure of 3300Kwh on the MCS certificate. However we will be lucky if we get near 20% of this figure! The reason being, they took no account of the shading from a wood opposite in their calculations. I've had the system looked at by a separate local expert, he thinks that when shading is taken into account we will only get about 775kwh per annum out of the system.
The equipment was supplied under an ECO4 Scheme. Fair enough, we haven't paid for it ourselves, but it should still be fit for purpose and capable of generating a good return on the investment. I raised my concerns with them, and have been offered two solutions. One of which is to fit optimizers to the existing panels, but I'm told that only works if shading is partial and moves with the sun, such as that from an individual tree or chimney. The other option proposed is to relocate the panels on the other side of the house, but that is opposite the path of the sun through the day. (Using a website called Suncalc.org to see this)
My idea would be to double up on the panels already installed. I believe Solax invertors can go up to 200% oversizing on panels, especially as the output of the existing panels is so low. I don't want panels removing and leaving holes in the roof! I didnt kno anything about ASHP and PV systems when this work was originally done, but I do now! Any advice greatly appreciated thanks.
What does your Suncalc website say for June sunshine?
Our neighbours have tall trees but in the 6 months of summer we still get good generation.
This is a day of our generation showing the effects of trees. It’s all the shoulders on what should be a nice smooth curve.
Do you have any photos of the house roof in summer? Is it in sun say 10am to 4pm when the sun is highest?
The optimisers will help if part of the roof is shaded.
Some installers are cowboys I’ve seen panels on north facing roofs with a steep hill on the north too!
If it were me I’d wait a full summer before considering changes, they may not be necessary. Only results will tell.
2kW + Growatt & 4kW +Sunnyboy PV on south-facing roof Solar thermal. 9.5kWh Givenergy battery with AC3. MVHR. Vaillant 7kW ASHP (very pleased with it) open system operating on WC
This is a sun curve once it is above the trees, nice and smooth. Do you have any access via an app to anything from your system? @wesleyp1874
2kW + Growatt & 4kW +Sunnyboy PV on south-facing roof Solar thermal. 9.5kWh Givenergy battery with AC3. MVHR. Vaillant 7kW ASHP (very pleased with it) open system operating on WC
It looks normal up to 10:30!
2kW + Growatt & 4kW +Sunnyboy PV on south-facing roof Solar thermal. 9.5kWh Givenergy battery with AC3. MVHR. Vaillant 7kW ASHP (very pleased with it) open system operating on WC
The same thing seems to happen every day. Builds up and then drops right down. I'll check this weekend but I suspect the sun is out unshaded by the trees opposite for a short time.
Have a look at your roof and where the sun is falling. It’s not rocket science if the sun is on all of the panels you’ll be generating the most. If it’s on half of the area you’ll get half the power if the panels have been wired in two blocks or less than half if they’ve all been wired together. Thats where optimisers come in, to help get the most from your panels.
2kW + Growatt & 4kW +Sunnyboy PV on south-facing roof Solar thermal. 9.5kWh Givenergy battery with AC3. MVHR. Vaillant 7kW ASHP (very pleased with it) open system operating on WC
You can't forecast the annual generation by simple extrapolation from the winter six months. I have a winter tree shading problem (some of the trees are 80m away) which means that my October-March generation is little over one quarter of the annual total https://monitoringpublic.solaredge.com/solaredge-web/p/site/public?name=Liden#/dashboard. The shading problem was allowed for in the output forecast and micro-inverters were fitted.
- 22 Forums
- 2,073 Topics
- 45.5 K Posts
- 41 Online
- 3,353 Members
Join Us!
Trusted Installers
Struggling to find a reliable heat pump installer? A poor installation can lead to inefficiencies and high running costs. We now connect homeowners with top-rated installers who deliver quality work and excellent service.
✅ Verified, trusted & experienced installers
✅ Nationwide coverage expanding
✅ Special offers available
Latest Posts
-
RE: Solar Power Output – Let’s Compare Generation Figures
510kWh of solar PV from my 4kW Hyundai panels and SMA S...
By JulianC , 16 minutes ago
-
RE: Is my Samsung heat pump working too well?
Thats in itself is interesting. I have a Vaillant heat...
By JamesPa , 2 hours ago
-
RE: Jokes and fun posts about heat pumps and renewables
@transparent Not a swell season then ☹️
By Toodles , 5 hours ago
-
RE: 5 Star Service from Havenwise
Oh good! I was wondering when/if you might pick them ...
By Transparent , 1 day ago
-
RE: Air Changes per Hour - ACH and the MCS requirement
update - my old installer insisted on a heat loss of 11...
By MatWin , 1 day ago
-
I agree it's not very helpful. Generally, the max heat ...
By Old_Scientist , 1 day ago
-
RE: Commencing on an ASHP Installation Process
I think therein lies the problem. Ratio of quotes to i...
By JamesPa , 2 days ago
-
RE: Why Your MCS-Certified Installer Might Not Be As Competent As You Think
Hive and most other smart thermostats don't play well w...
By JamesPa , 2 days ago
-
RE: Enabling WiFi: Samsung ASHP on Smart Things App
Thanks for the input. I've been running various experim...
By Grahamh-uk , 2 days ago
-
RE: Radiators downstairs are cooler at the bottom after ASHP install
@melonbuffet Hi, this sounds great is you are getting 5...
By ASHP-BOBBA , 2 days ago
-
RE: Ripped Off: How UK Homeowners Are Paying Gas Prices for Wind Energy
I believe there's another reason that network upgrades ...
By Transparent , 3 days ago
-
RE: What’s the modern take on advised types of insulation?
@jeff I am sorry @jeff if I have misunderstood what you...
By Toodles , 3 days ago
-
RE: Getting the best out of a heat pump - is Homely a possible answer?
@editor Cobbler’s Mantra that!
By Toodles , 3 days ago
-
RE: Renewables & Heat Pumps in the News
Australia Blue, the first wind farm in Western Victoria...
By Morgan , 4 days ago
-
RE: Flow rate discrepancy between ASHP and manifold
That's useful thanks, I hadn't seen that table before. ...
By AshRolls , 5 days ago
-
In principle I agree, @johnmo, but with provisos. The...
By Majordennisbloodnok , 5 days ago
-
RE: Heat pump installation and BUS Grant timings
@jamespa Thats how I understood it too. 🙂
By ASHP-BOBBA , 5 days ago
-
RE: Antifreeze top up for my heat pump - is this a rip off?
@sallyl That sounds about right if they are re-filling ...
By Brendon Uys , 5 days ago
-
I wouldn't be so sure about that. Heat pump designers ...
By JamesPa , 6 days ago