Generators?

[steve_earwig]

Solar power, here we come!

[lozz]

How do the rails fasten on?
do they just clip under the slates...

i applied for solar power here..but 'survey said..no good not sure why.

[steve_earwig]

Ah, they aint slates, they're metal boards. There are brackets hooked under the boards and fastened to the battens - this pattern http://www.aussieroofing.com/jbracket.htm although they're unavailable here, so we've had to have some existing brackets modified to do the job. Then the rails are bolted to those. I would have taken a picture of the brackets but the only place I can actually take a picture of the roof is from next door's balcony, which is accessed through a bedroom with a baby sleeping in it (shhhh)

Perhaps Castle Lozz points the wrong way

[Welly]

Oooh, get you!

FREE electrickery, you can leave stuff switched on and laugh at it, well during the day, like

[steve_earwig]

I'm not sure about free, this lot's costing a packet Still, better of like this than the money evaporating in the bank.

I've been wondering about that very idea, being able to run stuff like the air con without worrying about the cost, but I think what it'll come down to is the more power I can feed into the grid the sooner this'll pay for itself, so I'll probably end up being more stingy with the juice, not less...

Anyway, I could do it at night too, in theory, as there'll be 6Kwh worth in the batteries. Although I suspect I'd need to disconnect the house from the mains in order to use it without a power cut...

[benczuk]

the more power I can feed into the grid the sooner this'll pay for itself, so I'll probably end up being more stingy with the juice, not less...

I was of the impression that in the UK you got paid feed-in even for the energy you used.. (i know that doesn't affect you Steve) anyone know different?

[Bailes1992]

I keep thinking about getting an old lawnmower engine, putting it in a unistrut frame, fitting it with a pulley, fitting a few alternators wired in parallel and using it to feed an inverter.
I could also get a special replacement carburetor to run it off LPG or propane.

I can't think of any way to control the throttle though.
I could get a lawnmower engine with an automatic throttle linked to engine speed that keeps the lawnmower engine at one solid speed. They are very basic though. There's a fan running from the crank to push air over the engine. The throttle holds itself open naturally. The speed of the air is what holds the throttle closed. So the faster the engine spins the more it closes the throttle. The engine slows down, so does the air speed and the throttle opens.

Some cheaper generators actually use the same method to maintain a constant 3000rpm. Only issue is if you remove a load very quickly the engine speed can spike and take out any sensitive electronics.

[steve_earwig]

That's why you want an inverter, it doesn't matter if the engine under/over revs, the electronics sort it out.

The throttle holds itself open naturally

It grew like that? There's a spring holding the throttle wide open with a vane on top of the throttle in the stream of air from a fan. Once the engine is spinning the fan pushes the vane to shut it, the faster the engine turns the more it pushes on the vane, shutting the throttle until it reaches equilibrium at the right speed. Obviously if the engine is put under load the revs drop, the fan pushes on the vane less so the spring increases the throttle until it either reaches equilibrium again or the load drops,whereupon the engine speed increases so the fan closes the throttle.

Just by the by, I have 4 40-ish year old 2-stroke Flymos, 2 with JLO engines, 2 with Tecumsehs. On one of the Tecumsehs (mv100s with a Dellorto carb) the throttle spring has gone weak so it idled ok (it has a variable throttle controlled with an extra spring) but on full throttle it sounded like it was going to explode, so I lengthened the second spring. Now it bounces on full throttle, the revs rise and fall a few times until it settles down and runs fine until I hit some taller grass, then it bounces again. Spares? Hahahaha.

I reckon you could run some alternators off a lawn mower engine, it wouldn't matter what the revs did as the electronics would sort it out. Thinking about it though, I don't suppose you could run many off of a lawnmower engine. Alternators are rated at, what, 100 amp? 100 amps at 12 volts, 1.2Kw, lawnmower engines make maybe 3 to 5Kw, so maybe 2 considering nothing's 100% efficient? And then there's the inverter...

[Welly]

Sam Bailes, seen yesterday:



On a more serial note, we're being warned in the UK that power cuts are a possibility this winter due to over-demand so having some form of alternative power might be prudent.

I like those little 'suitcase' Honda generators, not sure if they pop up on ebay much? prolly a bit pricey but they are super-quiet and a piece of piss to frig up when needed.

[Bailes1992]

I think you could get a lawnmower engine to be quiet if needed. You'd probably have to fit it in some sort of box to remove the resonance and maybe fit a large muffler.

I much prefer the thought of using an inverter, it's safer for electronics.

[markw]

Whatever method is used, if it's to be hooked up to the house circuits and not used as a stand alone, please make sure it has the proper isolation fitted.

I used to work for my local Electricity Board (in the good old days when it was a service...not a steam roller, money making machine....) and several times when out on a shutdown, I've come across a section of line that mysteriously was still live.
It happens when Mr 'I'm-not-sitting-in-the-dark', plugs his little Genny in to a wall socket to keep his lights and freezer running, but didn't switch his consumer unit main switch off, so doesn't realise he's back feeding all the network on that phase!

[Bailes1992]

I'm a nearly qualified electrician by trade.
Just my AM2 left to do next week!

[steve_earwig]

Both my generators expressly forbid just plugging them into the mains, I can think of a few downsides, not just electrocuting the engineer - so you'd also be powering all the houses on your phase too? Won't that kill your generator? What about when the power comes back, won't there be an almighty big bang? Or will your generator work backwards, with the alternator spinning the motor to destruction? (Yeah, I know, it's a laugh though innit?)

That's one of the things I didn't like about most pv systems, when there's a power cut it must be isolated, so you'd have all these panels on your roof but still wouldn't be able to switch anything on. That's why I'm getting some eff off batteries with mine and another inverter. Actually, just the other night I was lying awake thinking that we didn't have a power cut here for a few months and maybe I will just be wasting money. Then we had not one but two power cuts the very next day. Thank you Elektra, I knew I could('nt) rely on you

[Bailes1992]

That's something that I was thinking about the other day actually.

All these new houses have solar power. Does that mean during the day, if you were to have a powercut you'd be powering up other peoples houses?
Or does the inverter see the power has failed and shut the system off?

[steve_earwig]

It shuts the system down. I couldn't believe it when I first heard that, I think I'd go nuts!