Solar Panels

[chris11256]

Morning All,

 

Does anyone here have any solar panel knowledge? My current school has a bank of solar panels installed on the roof, hooked up to two Sunny Boy 2500 inverters along with a metre next to them. However the whole system is 'off', both the inverter units are off and we don't know how to get them live & working. I've had a look with our site officer and from our perspective everything is cabled up, but they just don't work.

 

Does anyone have any suggestions? Business Director is very very keen not to have to pay to get external people in to look at them. Apoligies if I've put them in the wrong forum.

Edited March 17, 2021 by chris11256

[southhamster]

Do you have any ights/display on? They are driven by the DC side. Normally each inverter is linked to at least one string of panels in series so a break will stop it but unusual for both to be broken. I've seen one where squirrels chewed the cables through! Do you have a DCclamp meter to check for current/voltage? With AC off you could check the removable link underneath is ok. SMA are really solid inverters so unusual to see 2 faulty.

[southhamster]

Oh yes and check the obvious! Should be large rotary DC isolators near the inverters and possibly secondary ones as well?

[MatthewL]

Personally I would keep well away and get an electrician in, they are likely to still be producing electricity and you could get a shock if you start prodding and probing around. If you have a power cut would you start messing with the incoming supply?

 

Health & Safety at work act, the electricity at work regulations are two things that spring to mind.

[southhamster]

Completely agree but checking switches is ok.

[chris11256]

Thanks both, I'll have a word with the site officer. As far as he's aware they've never worked since we moved into our current building(2012 or so).

[mavhc]

you can install a Sunny windows program and connect via bluetooth sometimes

[southhamster]

If they've worked possibly the DC is not even connected! There should be a notice by each inverter with system details and installer name. You could try SMA support in Milton Keynes for a local PV enginer.

[chazzy2501]

Behold our monster install. (112Kw)

 

https://monitoringpublic.solaredge.com/solaredge-web/p/kiosk?guid=08b64b50-4fac-46cf-bd04-4db23825b1cf

[chris11256]

Update on this. Went up to the roof with the site officer again to check the basics and traced the cables from the inverters to the panels. Turns out that at some point the panels been completely disconnected from the inverter. So we hooked them back up and within a few minutes the inverters sprang back to life, just need to sort things out with our energy provider! Edited March 23, 2021 by chris11256

[jmak]

Update on this. Went up to the roof with the site officer again to check the basics and traced the cables from the inverters to the panels. Turns out that at some point they'd been completely unplugged. So we hooked them back up and within a few minutes the inverters sprang back to life, just need to sort things out with our energy provider!

IT support init.

It's got a plug....

[chris11256]

it's quite funny really, having never worked with solar panels before, we assumed it was a deeper problem....

[mavhc]

Have you tried turning it on?

[chris11256]

Have you tried turning it on?

Yes, the inverters took a few minutes to properly come on and start running. Today were going to take some readings and see how much power they generate,

[strawberry]

Yes, the inverters took a few minutes to properly come on and start running. Today were going to take some readings and see how much power they generate,

 

This is where you find they were unplugged for a reason. No power being produced but the water tank in the roof is now glowing a funny colour and the cold tap in the sixth form is tingly to touch.

[mavhc]

Let me try again:

[chris11256]

This is where you find they were unplugged for a reason. No power being produced but the water tank in the roof is now glowing a funny colour and the cold tap in the sixth form is tingly to touch.

 

Thats what we're going to find out today, am going to trace the cables through the floor & see where they go.

[JordanT91]

This is where you find they were unplugged for a reason. No power being produced but the water tank in the roof is now glowing a funny colour and the cold tap in the sixth form is tingly to touch.

My thoughts exactly! Surely something as expensive as solar panels would only be disconnected for a good reason. It's all well and good trying to save money but for something like that the experts should be called!

[chris11256]

My thoughts exactly! Surely something as expensive as solar panels would only be disconnected for a good reason. It's all well and good trying to save money but for something like that the experts should be called!

 

This is now our next step, now that we know they're actually working and not completely dead we're going to look for someone to check them.

[localtech]

Give these guys a call fitted my panels and very approachable hopefully they will come your way. Solar Panels Installer, Battery Storage: Kent, Sussex, Surrey, London (tlgec.co.uk)

[Rob_D]

My thoughts exactly! Surely something as expensive as solar panels would only be disconnected for a good reason. It's all well and good trying to save money but for something like that the experts should be called!

You say that but I think it was about 2 years after install that once of our site team was on the roof and noticed that the solar array was all set up but hadn't been turned on.

[XiJ]

Get multiple quotes. Look at how many kWh you are using. Decide whether you want battery storage (more money, more time for ROI but much more flexible)

The companies providing quotes should give you a breakdown of panels, inverter type, battery capacity and an estimated ROI for each year. Probably from https://www.opensolar.com (you can do your own if you want too)

 

You can’t have battery storage / inverter in the loft anymore. Has to be external, in a room away from the dwelling or in a ‘fire proof’ room. Ours are in the garage.

 

For me, I just wanted to generate to cover my own use and use the battery through peak periods. Over summer we’re generating way more than needed and now we’re in the export tariff I’m making £25-30 this year (export - grid import - gas use). Over a typical year I’ll probably pay nothing for electric.

 

You’ll need to register with your DNO who will say how much they can accept into the grid - but your installer will help you through this.

 

If you around Yorkshire ish I can recommend a couple of installers. MCS certified of course.

 

Happy to offer any advise I can along the way, just drop a DM if needed.

[southhamster]

Here is my biological method for fault finding on PV solar panels. Weird but true. Today I noticed some flies on one of my PV arrays; strangely a lot of them were clustered round one cell of the left panel. Then I remembered that's where a faulty cell is! They must like the extra warmth from the higher resistance - I've noticed it thaws out first on a frost sunny day. Clever flies!