Solar panels on workshop roof ?

[CompoSimmonite]

I'm at the planning stage of a new shed / workshop and it's be easy to make the roof south facing so I could have solar panels on it (house roof faces E/W so not suitable).
These would be a DIY fitment rather than any of the "deals" that various companies offer.
They would be sited around 20-30 feet from house.
I'd want them to feed into the domestic mains via the appropriate inverter unit.

Questions -

Has anyone done a DIY installation of a "feed in" type ? I assume it's need some sort of professional checking, testing and certifying before it could be connected to the mains.
Would there be any problem having them such a distance from the house ? I suspect not as there isn't really any different in length of wiring needed than on the top of a house.

Cheers.

Paul h

 

[rtbcomp]

You would have to buy approved equipment and have it checked, if not installed, by a professional. The consequences of getting it wrong could be fatal to anyone working on the infrastructure.

For solar panels on a shed roof I doubt very much whether it would be cost-effective to install a feed-in system. I would use it to charge a car battery and fit 12v lights in the shed, use it to charge my power tools, phone &c&c

 

[Shox Dr]

Why do you say that RTB. It will depend on panel output? The cost of panels are a fraction of what they charge to install for a payback tariff

 

[rtbcomp]

I'm assuming his shed doesn't have as much roof area as a house and the current feed-in tariff arrangement isn't the gravy train it used to be.

 

[CompoSimmonite]

Quick search finds this kit on eBay -
http://www.ebay.co.uk/itm/151883761228?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT
Seller says all fully mcs approved (Microgeneration Certification Scheme - http://www.microgenerationcertification.org/)

Not interested in the feed in tarrif but rather reducing the bills

 

[piman]

Hello Rtbcomp,

I was on an American website the other day and someone said how cheap solar equipment was, he mentioned a 20Kw set and it's price. The reponse by someone else said it would take him 55 years to pay back as his utility cost was $15 a Kwh. Just shows how much more we pay, in part due to the solar\wind subsidies and the abysmal government 'organisation' of our power industry.

Alec

 

[Wendelspanswick]

What kind of electric meter do you have? If you have the spinning disc analogue type you have the added benefit of the panels 'reversing' the meter if your input exceeds your output!

 

[Shox Dr]

Do you know what are the highest consumers of electricity in the house/household. You'd be surprised!

 

[Wendelspanswick]

If you fitted the kit yourself you wouldn't qualify for the FIT scheme but as you say that's not what interests you.
We didn't want panels on the house roof and the workshop faced the wrong way so we built a lean to and put a 4kw array on that. It's ideally suited as we pitched the roof at 33 deg due South with no shading.

 

[CompoSimmonite]

I've been trying to find fitting instructions of a kit but it seems each installation is different so each step is listed separate rather than all together.
For connection to the mains all I can see is use a spare 16A MCB

 

[CompoSimmonite]

If you fitted the kit yourself you wouldn't qualify for the FIT scheme but as you say that's not what interests you.
We didn't want panels on the house roof and the workshop faced the wrong way so we built a lean to and put a 4kw array on that. It's ideally suited as we pitched the roof at 33 deg due South with no shading.

Thanks.
Is 33 deg the angle recommended or was it just how the roof ended up ?
My wife really likes the idea so an seriously going to look into a system.

 

[Wendelspanswick]

Thanks.
Is 33 deg the angle recommended or was it just how the roof ended up ?
My wife really likes the idea so an seriously going to look into a system.

33 deg is a good figure to go for, a steeper angle makes more effective use of the panels in the summer but what happens in the summer is that the panels overheat and so have a reduced output.
A lower angle makes better use of the winter sun but it's available for such a short period it's not really effective.
During the winter months the panel output is negligible, but from February round to October the output ramps up and down with the peak being from about April though to August.
http://solarelectricityhandbook.com/solar-angle-calculator.html

 

[Gareth J]

We have panels on a shed roof probably 6-8m high and another, similar distance away from the consumer unit. So I don't think your distance will be an issue. They were installed by a certified company so we get the FiT.

It would have been cheaper to self install for sure but the money gained by getting the FiT far outweighs savings. Unless you go the battery storage route to really make use of the energy you generate -a kind of semi off grid setup using battery power in preference to grid electric. But then with the cost of the batteries, you'll be at a similar price to the certified install.

 

[Dave3066]

Whatever you do you'll need to tell your local energy network operator to inform them that your generating electricity. If that electricity makes it onto the grid the network operator has no way of knowing if the transmission lines are dead when they switch of the supply for maintenance or have to repair a line that has broken. That might sound petty for a single 4 kw installation, but if enough people install their own systems without telling the network operator there could be a significant supply on that part of the network that the operator thinks they have isolated. Just something else to think about.

 

[Gareth J]

Whatever you do you'll need to tell your local energy network operator to inform them that your generating electricity. If that electricity makes it onto the grid the network operator has no way of knowing if the transmission lines are dead when they switch of the supply for maintenance or have to repair a line that has broken. That might sound petty for a single 4 kw installation, but if enough people install their own systems without telling the network operator there could be a significant supply on that part of the network that the operator thinks they have isolated. Just something else to think about.

I think, anything plugged into the grid needs to be approved. Part of the approval is a check to make sure that if the grid is off, the panels won't try to poke electric back onto the grid.

You need to inform them also so they can check grid capacity. Every consumer unit is entitled the 3.68kw of capacity but exceed that any the local grid company may well charge you mega bucks to upgrade bits of the grid.

 

[Wendelspanswick]

Whatever you do you'll need to tell your local energy network operator to inform them that your generating electricity. If that electricity makes it onto the grid the network operator has no way of knowing if the transmission lines are dead when they switch of the supply for maintenance or have to repair a line that has broken. That might sound petty for a single 4 kw installation, but if enough people install their own systems without telling the network operator there could be a significant supply on that part of the network that the operator thinks they have isolated. Just something else to think about.

That would be correct apart from the fact that the inverter he's looking at needs a supply from the network to operate. No 220v in from the network means no 220v out from the panels.

 

[p0689109]

Come on then Shox Dr what is the answer.

 

[ukracer]

Do you know what are the highest consumers of electricity in the house/household. You'd be surprised!

The wife?????

 

[Shox Dr]

Do you know what are the highest consumers of electricity in the house/household. You'd be surprised!

Come on then Shox Dr what is the answer.

It was a question to the Compo'. I know what ours are; The Fridge and the Freezer. They use between 45-50units/pw all yr round, we only use a total of 60-70 in summer, 90max in winter.

And yes the other people in the house don't help

 

[CompoSimmonite]

Now daughter is at uni I've noticed both gas & electricity bills have reduced - plus toilet roll lasts longer