Is this grid-tie inverter (for solar, wind power) a bad idea?

[AllGold]

I have been lusting after solar and/or wind power for a long time. Prices have come down a lot. But one of the sticking points has always seemed to be how expensive the grid-tie controller is. This is the doohickey which allows you to put your home power into your home's electric service and will actually spin your electric company meter backwards if you're producing more power than you're using.

Then I stumbled on this:
http://www.amazon.com/Solar-Panel--Simpl..._2?ie=UTF8&qid=1307320689&sr=8-2

or the grid-tie inverter by itself: http://www.amazon.com/Ensupra-Grid-Inver..._1?ie=UTF8&qid=1307320793&sr=8-1

It's a cheap, simple solution (granted, for relatively small amounts of power). I'm not an electrician but I have a nagging feeling that maybe it's TOO simple. Any electrician types want to weigh in?

[cbelt3]

550W capacity ? Not.. Very.. Much.
The big issue has to do with what your electrical utility will accept. This ? Probably won't be noticeable.. but.
Of course WHERE you are located will define the overall payback of your alternate power source. DOE has excellent maps for that purpose.

[mikebw]

Interesting, it looks like they've taken a regular DC-AC converter that you might have in your car, and stuck a "grid tie inverter" sticker on it.

[Filliam H. Muffman]

550 Watts is tiny. Paying an electrician to install it is going to eat up what it will save you for a long time. That is why most people install larger systems, to balance out the costs of the components against the savings. The best payback is for people that can push at least 2000 Watts to the grid (and minimize use during those times). Areas in California get about 30 cents from the utility during peak usage times.

[GGD]

mikebw wrote:
Interesting, it looks like they've taken a regular DC-AC converter that you might have in your car, and stuck a "grid tie inverter" sticker on it.

And put a suicide cord on it to pump AC into a 3-prong male plug.

[JoeH]

GGD wrote:
[quote=mikebw]
Interesting, it looks like they've taken a regular DC-AC converter that you might have in your car, and stuck a "grid tie inverter" sticker on it.

And put a suicide cord on it to pump AC into a 3-prong male plug.
That last item probably violates code in every state even if it only puts out a max of 550 W. The description does say it has "island protection", I assume that means it will shut down if it does not see 120 V AC coming in from the grid. That might suffice to meet the disconnect requirements for generating your own power during an outage.

[Ted King]

mikebw wrote:
Interesting, it looks like they've taken a regular DC-AC converter that you might have in your car, and stuck a "grid tie inverter" sticker on it.

Yeah, it looks a lot like the DC to AC inverter I have in my car.

Assuming:
1. It actually provides 300 Kwh of electricity per year as advertised.
2. Cost of electricity from the power company is 15 cents per Kwh.
3. You install it yourself.
4. It works.

Then: It will take about 17 years for the unit to pay for itself. That's about how long it takes for large home solar panel installations that are professionally installed to pay for themselves (if you don't get any rebates from the power company or government), but considerably longer than a large system that you install yourself.

[AllGold]

It also says the inverter analyzes and synchronizes with the AC power first. Also shuts down if the voltage is too high or too low.

I really don't know if it's safe or not but if so there is finally a cheap way to get 300-500 watts of home-made power into your house. Apparently, you can also use multiple inverters if you have more than 550 watts of power generation.