Home Solar Electricity on the Cheap

[alexander]

found an interesting company, rosestreet labs, they make high efficiency multiband pv cells. I'm going to contact them to see if they are selling their product to consumers not interested in large quantities and whether i could buy a couple of pannels from them...

[Turtle]

Originally Posted by alexander

found an interesting company, rosestreet labs, they make high efficiency multiband pv cells. I'm going to contact them to see if they are selling their product to consumers not interested in large quantities and whether i could buy a couple of pannels from them...

Roger. I have to go back & make corrections in my shopping list as I said 1 watt panel & I meant 1 Amp which is a 15 watt panel. I thought the price sounded low.

I also checked prices on metal gym lockers, which I think would make a good base cabinet for holding components. Be back later with some sources & prices. (this is my roomy's machine & he's gaming, but on break so pardon my absense on his return. )

[alexander]

well i went ahead and purchaised a controller kit, so i can start programming it, solar here is worthless till the next summer, so i have a few months to play with the kit..

[Turtle]

Originally Posted by alexander

I have one, but its not everybody who can get a free 1000VA battery backup unit from work for free, that at 475W will give 17.5 minutes of life... I am planning on extending that though, the inverter should handle it for my use, but its not an ideal solution, i want an inverter so i can backfeed energy when its being made, and use it when it's being used... battery bank is nice, battery bank and a small electrical bill is nicer.

if you have a link to a good one, i would love to buy it within a couple of days... really, i've been looking for an inverter for a great while, problem is, it has to be state of California certified inverter for it to feed back into the grid...

I found a 1250 watt job, but again I am only talking about a stand-alone system and the connection of inverter to battery is via cables. I found a dandy though that has battery level & amperage use meters right on front. Aims 1250 Watt DC to AC Power Inverter

So in my metal locker I would put the battery in the plastic box in the bottom & above that a shelf for the inverter and an opening cut in the locker side for the inverter face panel & outlets to have outside access. The PV panel could hang on the back of the locker facing a window or detach and set directly in a window track/sill. I'm thinking turn-key system that you can wheel in and start using right away. I found an inexpensive locker for ~$80 (locker ), so that brings the price of components to ~$600 US.

I don't know for sure what my battery's charge was when I started but I ran it down watching too much TV in a day & 1/2. Rats! That 1 amp panel will take days to recharge the 100 amp-hour battery. Still, I saved a teensy bit and every teensy bit counts. ......

[alexander]

Turtle, why in the name of Ronald Neil Stuart, would you use an inverter to charge batteries? You may need a filter, or a crafty vr, but trust me, there is no need to convert the power from DC that PV cells give, to AC and then back to DC to charge batteries

[alexander]

lol i can sketch up a system for you to connect directly to the battery terminals, bypassing the middle man, and increasing your efficiency by a LOT, seriously, inverters are some of the most inefficient electronics components... especially high quality inverters that give you smooth AC.

I'd need the voltage output of the pannels, and the what your batteries run (or at least what you have for batteries and how you are connecting them (serial, parallel, combinations, what have you))

doing some quick math here, even if both inverters operated at 85% efficiency, you still only get about 73% total efficiency at the end, and thats from potential 95-98% that you can get from a direct dc to dc system...

[Roadam]

I was recently looking for an inverter for a small hydro power turbine and as far as I know inverters can be about 94% efficient. But to convert from ac to dc and back again is a waste. You could easily use a bock/boost converter. Buck-boost converter - Wikipedia, the free encyclopedia

[alexander]

yet another correction, hydro power turbines are AC, if you are talking about an inverter, you are talking about an AC to DC inverter, which is a rather simple inverter with a high degree of efficiency, in the simplest form, its 4 diodes and a couple of resistors and maybe a cap for cleanup purpose, 95% would not surprise me. A DC to AC inverters are extremely inefficient, its a lot harder to generate a good 60hz constant AC wave then it is to turn it into a line... You can turn the line into a square pretty easily, but getting those smooth bends, takes a fair knowledge of electronics, if you are not using movable parts... either case, very inefficient...

[alexander]

actually been looking at inverters, apparently they have gotten to be pretty effifient, at least so they claim... still, 95% at third load, 90% at full for a 1500w inverter at $850 from Go Power... which is fairly reasonable, but still it makes no sense to convert it twice to charge some batteries...

[alexander]

if you are looking for a straight inverter, you can go with aims too, aimscorp.net, they are reasonably priced... just remember that if you want to feed back into the grid, you need a pure sine wave inverter...