Link roundup

[ewt]

Don't forget the second Geek Scrapheap Challenge this Saturday at the Pembury! Should be good. Any volunteers willing to carry my stupid old Dell machine from my place to the Pembury (and possibly back again)? I can't carry stuff. And if anyone can bring a spare monitor that would be great - there was only the one last time and that was a bit of a limitation in some ways.

I want a one of these... so neat.

This might be a way to have cheaper-ish solar panels - wire them together and away you go, sort of thing. Glass, though - I'd want them under some sort of protective cover, which is going to decrease the efficiency somewhat. Hmm.

Space-age yurts! Um. I'd definitely include some sort of parabolic solar cooker in the 'infrastructure' package though...

A New World exhibition at the British Museum - watercolours painted by John White in the 1580s.

Comments

[pfy.livejournal.com]

The solar panels look pretty interesting.

Hmm... the biggest solar panels from Maplin work out at about £6.67 per watt (£999 for 150W). These are about £3 per watt, if you include P&P, but they're 6 volt panels, so you'd need double the quantity for a 12V setup. That comes to £6 per watt, so it's still a bit cheaper than Maplin, and you can buy any number of small panels rather than having to buy one big one. Looks like you'd have to make your own frames or mounting kits or whatever, though.

I seem to be getting opinionated in my old age...

[battlekitty.livejournal.com]

You shouldn't need any protection for the solar panels - they're usually made of glass anyway. As pfy says, you'd need a frame, though.

Parabolic solar cooker, huh? Pro's and cons there - I wouldn't think it'd be worth it in the UK - not enough direct light. (Says I on a nice sunny day...)

[karen2205]

What do you mean when you talk about 6 volt and 12 volt setups? /me is out of her depth.

What's the advantage of buying individual solar panels instead of a solar battery charger or a solar powered torch? Presumably they're more flexible and can be used to do other things, but what other things and how?

[ewtikins.livejournal.com]

What about these (http://cgi.ebay.co.uk/Make-a-100w-panel-40-Siemens-Powermax-6A-solar-cells_W0QQitemZ220093520428QQcategoryZ41981QQssPageNameZWD2VQQrdZ1QQcmdZViewItem?hash=item220093520428)?

[pfy.livejournal.com]

Actually, I'm wrong. It's still £3 per watt, because when you wire two of the panels in series, you double the voltage and the current stays the same. That makes it a rather better deal than I thought. The other ones you linked to are still cheaper, though, by the sound of it.

[pfy.livejournal.com]

A lot of electrical stuff is designed to work with a power supply that generates 12 volts of electrical potential (if you remember GCSE physics lessons, you probably got given an analogy about voltage from a generator being the electrical equivalent of water pressure from a pump). Car batteries are normally 12V, so anything that's designed to plug into a car cigarette lighter socket will work on that voltage, as will most appliances designed for caravans and motorhomes.

Because there are plenty of existing batteries and appliances that work on 12V power, it's pretty much the standard voltage for off-grid power setups. Most general-purpose solar panels will put out 12V. The ones Ewt linked to are 6V modules, though, which means you'd have to wire two together to get 12V out (but see my other comment for why I got the total power output wrong above).

What's the advantage of buying individual solar panels instead of a solar battery charger or a solar powered torch?

Single-purpose solar-powered gadgets are handy, but having general-purpose panels will be useful if you are working on a larger scale (e.g. running several appliances, home lighting, etc. on solar power).

You mentioned solar battery chargers. If you think about it, just about all solar-powered things involve a battery or backup power source somewhere, because people usually want their stuff to keep working when it gets dark.