Solar Generated Electrics.....

[Gashead86]

Morning All,

Hoping someone may be able to help me out here, have looked all over the web and am getting a little lost to say the least! Electrics are not my strong point....

I am looking to build a new garden shed, what I would like to do is incorporate some basic electrics to allow me to run a light and a couple of sockets for using my power tools out in said shed.
Ideally, I don't really want to run a supply out to the shed, and thus I am looking at alternative ways of generating the electrics....

Solar seems like the most obvious solution and of course it is environmentally sensible as well. But after doing a bit of research I am getting a little lost with it all..

All I really need is a very basic installation of a small solar panel to operate the few things listed above. Will I need a battery to take the solar energy in and then operate my appliances from said battery? Or is there a solar instal that feeds a type of fuse board that I can then draw from?

Hope that makes sense???

Could just doing with it being perhaps explained in a way I can fathom it! And perhaps even pointing in the direction of what would be best for me...

Thanks massively in advanced anyone who can help!

 

[big-all]

forget running mains power tools off solar
you may have a chance off charging battery tools but these cost pence to charge in the house

 

[Gashead86]

Oh really??

That's a shame, was hoping there would be a way to harvest a decent amount of energy.

 

[ericmark]

Caravan and narrow boat forums are the best way to get on hand info on solar cells used without a mains supply. The size matters as to get all the power a solar panel can produce you need a very clever regulator which alters the solar panel voltage to extract maximum power and also pulse charges the battery to cram into it as much power as it can without causing damage in the shortest time it can to use available daylight. Often these also have an auto switch to switch lights on at night. However they are more expensive than the simple type and also use power to work. So step one is to work out what power you need.

Most people have the option of taking the battery to a mains supply to charge it should the solar panel not keep up, and caravanners tend to use them in the summer months.

Another big question is lead acid or alkaline batteries. Lead acid is cheaper but main draw back if left discharged they will be damaged. Alkaline batteries are harder to charge and more expensive but are not damaged by leaving in a discharged state. Again size matters, and VRLA battery below 14 Ah will rarely last more than a couple of years but a 110 Ah battery could well last 10 years.

In the main people stop at 160 Ah 12 volt as over that size too heavy to carry so for a narrow boat having 4 x 160 Ah is common normally three in parallel and one for engine starting. With inverters the higher the input voltage the better as the current is reduced however once over 75 volt DC then it becomes low voltage not extra low voltage so 48 volt seems to be the maximum voltage used to power domestic inverters.

If we look at the 13A supply then we are looking at least 3 x 160 Ah batteries which are expensive. As a result likely a generator would be a better option. The problem with 12 volt is batteries are not 12 volt but will range from 11.5 to 14.8 volt depending on state of charging. So to run a 12 volt TV from a battery you still need an inverter to convert the varying voltage from battery to a steady 12 volt for TV. So may as well use a 230 volt TV and a 12 to 230 volt inverter.

Some items have a very wide input voltage this site does LED bulbs for caravans and boats with a 10 ~ 36 volt DC input so lights can work direct from battery.

So step one is work out power requirements. Until you know both the maximum power required and the kWh required you can't really progress. In the main heating needs to be oil or gas although you can have electric control of those heaters. Power tools are really just not worth it. May as well use cordless power tools and charge batteries in the house.

Ask the caravan and boating guys and girls they have a lot more experience.

 

[PBC_1966]

Unless we're talking about a shed which is miles away from the house, then running power to it from the house is really the only way to go (unless you just settle for battery-powered tools and charge them in the house, of course). Any sort of solar installation involving batteries and inverters to power regular a.c. power tools would end up costing you far more, not just initially but also in maintenance over the years.

Also, as far as the environment is concerned, even if you did go down the solar route, you would be doing nothing to help it. Any environmental advantage gained by not drawing an occasional small amount of power from the grid would be more than offset by the energy used in the manufacture, installation and maintenance of the solar system.

In short, unless you want to let yourself in for a whole lot of expense and trouble - not just now but in the future as well - forget about it and just plan on running power to the shed from the house.

 

[JohnW2]

In short, unless you want to let yourself in for a whole lot of expense and trouble - not just now but in the future as well - forget about it and just plan on running power to the shed from the house.

I agree with what everyone has said. A simple/practical compromise, which would not involve running power to the shed, would be to use solar panel+battery for lighting, and used house-charged battery power tools (albeit they would represent capital outlay, if the OP does not alteady have them).

Kind Regards, John

 

[JohnD]

If you use LED lanterns in the shed, they will run off batteries and last a long time with better light than an old battery torch. They are often sold cheap on the camping shelves of supermarkets and hardware stores for a couple of pounds. I have several in my carport.

And you can use rechargeable tools, charging them in the house.

How much money is it worth you spending for anything fancier? £500? £1,000?

You might consider including an underground conduit or duct in your build, in case you decide to get it wired in future.

 

[Gashead86]

Hi All, thanks for the info.

I think I am heading down the avenue of simply installing power to the shed rather than generating my own. Seems sensible as the shed won't be far from the house and my brother in law is a spak.. So won't be too expensive.

 

[ban-all-sheds]

That's a shame, was hoping there would be a way to harvest a decent amount of energy.

How big is the shed roof?

 

[leeco]

You would need about 500w of solar and a battery bank of about 400ah and then a inverter to give you 240v which could cost you upto £1000 even more depending on if you want quality gear.

My off grid setup on my boat cost me over £2k

Or you could buy some SWA cable and take a feed from your house fuse board which would cost maybe £60

 

[PBC_1966]

You would need about 500w of solar and a battery bank of about 400ah and then a inverter to give you 240v which could cost you upto £1000 even more depending on if you want quality gear.

Also, we don't know exactly what sort of power tools we're talking about here. You'd want a good quality sinewave inverter for motors, which for any given power will cost quite a bit more than a non-sine inverter. And if you want to be able to run something like a decent-sized circular saw or equivalent, the inverter will have to be able to cope with the start-up surge. By the time you'd finished installing something of that caliber, you'd could probably easily be looking at nearer £2000.

 

[ban-all-sheds]

https://en.wikipedia.org/wiki/Solar_power_in_the_United_Kingdom#Solar_resource