Laptop running on solar?

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Laptop running on solar?

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chez

Joined: 13 Aug 2006
Posts: 35935
Location: The Hive of the Uberbee, Quantock Hills, Somerset

Posted: Sun Dec 10, 06 4:49 pm Post subject: Laptop running on solar?
I am looking in to running my laptop off of a solar panel, as it's the bit of electrical kit that is on for the longest in the house; at first glance there are various ready made, pretty expensive kits out there that will do it; but has anyone made their own and if so, any hints or tips?

pricey

Joined: 28 Feb 2005
Posts: 6444

Posted: Sun Dec 10, 06 5:05 pm Post subject:
I know HWH, runs her's on solar, well batteries that are charged by solar. Ask her for more info, or she may be along soon. We are very interested in using this method when we get to Portugal for all are LV stuff and I am at the moment trying to source a good quality cable to do the whole house.

hardworkinghippy

Joined: 01 Jan 2005
Posts: 1110
Location: Bourrou South West France

Posted: Mon Dec 11, 06 10:14 am Post subject:

Hi Chez,

Our first four panels were 10 watts each and in the summer they charged a laptop battery each day, which lasted about and hour and a half. We also used them for lighting and music. In the winter we had just music and lights

.

I tried wth just two 75watt panels, for three years I had limitless computer use in the summer (apart from the laptop overheating!) but the energy supplied in the winter was not reliable enough - possible because the batteries were running at a much lower temperature too.

When we built the new house, we put together a larger system especially for the laptop with 4 x 75 watt panels fed through a controller and three 120ah batteries (4 or even 5 in the summer.) The batteries also provide lighting for 7 lights upstairs but we're careful to switch them off if we're not using them.

This time of year, around the solstice it's possible to use the computer every day, but you have to keep an eye (in our case it's an ear, because ours beeps) on the controller and decide between using different appliances because you can't watch telly, surf and charge the electric fence batteries at the same time.

Now, we have doubled our solar system and use the new panels for all the lights in the house and for recharging tools, leccy fencing and I can use the computer from it too of course if I need to.

The addition of two small wind turbines has meant that we've never run out of electricity since we bought them. We disconnected them this year to do the foundations for our extension and the reduction in power is very noticable, but I don't want to re-route the cables which means adding more thick cable and making joins so we'll just have to put up with it for this winter. It's also a valuable experience, to see how the system operates without them. (I could write a lot more here, but I don't want to bore you!)

Solar alone in the winter is a challenge and if you depend on the laptop to earn your living (as I do) then it can make your life quite stressful.

If you have enough money, then it's relatively simple. Get a system with a panel, a bigger controller than you think you'll need, a good leisure battery, decent battery clips and the right size of cables. Your laptop will get a charge. If you're battery's always full, get another (the same size) and so on...so that eventually you can balance out the system and use the energy you have for your laptop, charging phones, cameras, lighting etc.

There are figures around to help you design a system sizes of panels vs. batteries etc, they are useful as a guide but no two systems are the same and your own experience is invalable, so just use your common sense and build up your system to your requirements.

If you need any help, just ask. There are a lot of people in here who know a lot about the technical details, where to find things etc.

Irene

chez

Joined: 13 Aug 2006
Posts: 35935
Location: The Hive of the Uberbee, Quantock Hills, Somerset

Posted: Mon Dec 11, 06 5:33 pm Post subject:

Hi Irene

Thanks very much for that - I am going to digest it and then get my OH to have a look - he's the one that really understands that there electrickery - and see what's what. From your description, it doesn't sounds half as complicated as I thought that it would, particularly if we make the solar part of the equation a 'stand alone' system. Yes, we do need computers for work - so it's important to get it working right!

With thanks,

- Chez

arvo

Joined: 04 Dec 2006
Posts: 3321
Location: Somerset

Posted: Fri Dec 22, 06 1:47 pm Post subject:

Hi HWH,

I'm Chez's OH and I'm fascinated by what you guys have gotten up to, as its exactly what we're aiming to achieve in our house in Wales.

I currently (no pun intended) don't get my head around 2 things:

1) how are you charging one set of batteries from two sets of power (wind & solar)? Does it all just go into one inverter?
2) how do you switch from battery to grid? Have you got two sets of wiring in, or have you got some kind of switch?

Sorry to pester, but you've already put in exactly what we're planning and it'd be great to learn a little from your experience.

Cheers

Arvo

Treacodactyl
Downsizer Moderator

Joined: 28 Oct 2004
Posts: 25795
Location: Jumping on the bandwagon of opportunism

Posted: Fri Dec 22, 06 1:52 pm Post subject:
If you have the time it might also be worth having a look at the INEBG solar section here: https://itsnoteasybeinggreen.org/forum/viewforum.php?f=28

hardworkinghippy

Joined: 01 Jan 2005
Posts: 1110
Location: Bourrou South West France

Posted: Sat Dec 23, 06 3:09 pm Post subject:

Arvo,

We're not connected to the grid at all, so I don't now anything about the technical side of that, but it's mentioned in INEBG in Treacodactyl's post above and somebody in this or that forum might be able to help you.

I don't want to be grid connected, because if the grid goes down, then you've no electricity and that happens here a lot. Also, we pay no standing charges.

For using the wind & solar together, I wired the controller from the windgenerators into the controller for the solar panels using a plan sent by the supplier (Rutland engineering) and it works very well. The controller is the black one on the bottom which is connected to the black controller and the little silver controller on the top (40amp) is for our new array of solar panels (which I'm using to type this). Here's a photo of the control panel.

The middle white thing is the distribution box full of really thick wires because we try to use DC anywhere we can without going through an inverter - almost all computer stuff is DC, so I just buy cheap and cheerful DC voltage changers for the appliances or use a small (300 watt) inverter for my printer, external hard disk etc.)

We've also a larger inverter fixed to a wall which we use for hand tools, shearing equipment etc.

I hope that helps.

Irene

arvo

Joined: 04 Dec 2006
Posts: 3321
Location: Somerset

Posted: Sat Dec 23, 06 3:31 pm Post subject:
HWH, Thanks ever so much for that. It gives me some start points. I'm not sure I'll manage to be entirely DC though! The idea of feeding one controller into another never occurred to me and will be really helpful I think. Next project up though will be the woodburner to connect into our terrifyingly complex heating system! Thanks again, Arvo

aussie

Joined: 05 Jan 2007
Posts: 18
Location: Australia

Posted: Fri Jan 05, 07 7:25 am Post subject:
Interesting reading. I run my home on four panels, with a small inverter to run a laptop (desktops draw too much power). Everything else, including the lights, stero, and even irrigation pumps for a large, as in as big as a tennis court, vegetable garden, is 12 volt. Works fine.

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