Solar power gimmick?

ratronic

Searching thru eBay for 100W solar panels I came across these Grid tie inverters. These seem plug & play, you just wire up your solar array then plug the inverter into an existing outlet. Since I am entirely ignorant when it comes to solar has anyone here had experience using these?

Beau Schwabe

I have a total of 2340 Watts of solar on my roof, and from an individual house circuit testing basis using a watt meter to test with, I would say, yes they do work. (See diagram:

)

What I would stress as a rule of thumb, make sure that the grid tie unit is rated for at least twice your input wattage. Also make sure that they are running in a cool place and don't take on a lot of external heat. I had a unit in the attic and it could not keep up with the attic heat and eventually died a slow death.

Another thing, I would avoid a large grid tie unit as opposed to several smaller grid tie units. Only because if you have a failure, it's not a complete failure, and it's easier to replace individual units.

ratronic

Thanks for the info Beau maybe I shouldn't have put gimmick in the thread title. I know a lot of planning has to go into setting a system up. I didn't know the interface (grid tie inverter) could be plugged in. I am thinking of a much smaller version of yours to slightly

reduce my carbon foot print and maybe save some money on the electric bill.

davejames

...I'm guessing any inverter tied back on to the power grid would need to output a true sine-wave and not the "modified" wave type? How do the inverters sync their phase with other units anyway?

And I'm guessing before attaching anything to the house power input, the local power company would need to be involved?

ratronic

From what I have gathered so far they internally sync the output (a lot claim pure sine wave) of the inverter to the frequency and phase of the power grid it's plugged into. As far as how the rest works I'm still figuring it out.

Beau Schwabe

"How do the inverters sync their phase with other units anyway?" - They don't sync with other units, they sync with the mains. They do this on the zero cross, where there is a 'window' in the output power from the grid tie unit that it is not supplying power to the grid.

"And I'm guessing before attaching anything to the house power input, the local power company would need to be involved?" - As long as you are not generating more than the power company is supplying it makes things much easier. The only thing I had to do was contact a licensed Electrician to inspect my connection. If I had to do over, I would pay someone to install a secondary breakout panel that would be strictly dedicated to a Solar interface.

NWCCTV

Why not tie in to the power companies grid? If you generate enough power your meter will run backwards and the power company will send you a check. Yes, a professional electrician would need to be involved but if you are generating that much power I think it would be worth it. I myself had thought of doing this also. However, living in the Pacific Northwest the ROI would take close to 30 years. I do not plan on being here past the next 15 so I scrapped that idea.

ratronic

NW I live in Bakersfield, Ca. and it's currently 101 degrees. I feel guilty for not capturing some of that sunlight and maybe save some money too!.

Beau Schwabe

"Why not tie in to the power companies grid?" - That is essentially what you are doing

"If you generate enough power your meter will run backwards and the power company will send you a check" - Once you reach that point the rules change and there is a lot more involved in getting that setup properly. Some states and power companies have very specific rules you must follow before getting paid back.

NWCCTV

Some states and power companies have very specific rules you must follow before getting paid back.

Yes, I understand this. But, even in CA it might be worth looking in to. I first had the idea about 12 years ago when I was in Tucson and watched a Discovery Channel program about a couple outside Tucson that were doing this and they would get a check for around $200.00 per month from the power company. It would just be nice to get back some of those outrageous payments that have been made to them. I have often thought of creating a water mill on the side of my house that would capture all the rain water and convert it to energy. Problem is I do not think I could get it flowing fast enough!!! A giant windmill in my backyard also crossed my mind. I just do not think my neighbors nor the city would like that too much!