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If I am reading this right (and I am not an expert at all), if wanted to subsidize my current electric bill I could just buy a few solar panels and a grid tie i

If I am reading this right (and I am not an expert at all), if wanted to subsidize my current electric bill I could just buy a few solar panels and a grid tie inverter that I just plug into any random outlet and as long as my house consumes more energy than the panels provide and I don't exceed the amperage on the breaker I can effectively do this that simply? (even if the ROI doesn't make sense?)

Syonyk 5y ago
It depends entirely on where you live. In the United States, the answer is a very clear "No" almost everywhere - those plug in inverters aren't permitted under NEC. Power companies generally require you to have interconnect agreements for any amount of self generation that could interact with the grid (off grid system, have at it, it touches the house wiring, you need to talk to them). The problem with plugging that sort of thing into a random outlet is that now you've violated the assumptions on the circuit protection. If you have a string of outlets, protected at 20A at the panel, then nothing plugged into any one outlet can pull more than 20A sustained (or the breaker will pop), and the wiring will never see more than 20A sustained. If you plug in another source at the far end of that circuit, outlets in the middle and branches off the main wiring run could be seeing 30A without popping a breaker - and that's a fire hazard. A 20A outlet won't pass 30A forever, and wiring rated for 20A can overheat at 30A sustained. In some other countries, you can install some amount of solar and backfeed it like that, but I'm not familiar with those regulations, not living there.
- stevenhubertron 5y ago
  Thank you for the clarity here.. I thought there was more to the story than this article made it seem.
- mindslight 5y ago
  > the answer is a very clear "No" almost everywhere - those plug in inverters aren't permitted under NEC Of course plug in inverters are not permitted under the NEC, just as kitchen appliances aren't permitted under the NEC, nor are the power lines outside your house permitted under the NEC. The NEC applies to premises wiring, which none of those things are. Plug in devices sold on the consumer market are regulated by UL/ETL/etc, and the power grid is designed by power company engineers working to some other standard. If you look at your service entrance you'll see the wires coming from your house are nice and thick as dictated by the NEC, but connected to a smaller aerial feeder that doesn't meet the sizing requirements of the NEC. Your power company might have some private contractual prohibitions here and you may be opening yourself up to liability from the results of your actions - similar to them getting perturbed if you use a "suicide plug" to power your home from a generator. But it's not generally a priori illegal like you're making it out to be. (Your point about overloading branch circuit wiring is very important though. I'd be more worried about feeding in between the panel and a large load, thereby putting extra current into the intermediate wiring.)

Syonyk 5y ago

It depends entirely on where you live. In the United States, the answer is a very clear "No" almost everywhere - those plug in inverters aren't permitted under NEC. Power companies generally require you to have interconnect agreements for any amount of self generation that could interact with the grid (off grid system, have at it, it touches the house wiring, you need to talk to them). The problem with plugging that sort of thing into a random outlet is that now you've violated the assumptions on the circuit protection. If you have a string of outlets, protected at 20A at the panel, then nothing plugged into any one outlet can pull more than 20A sustained (or the breaker will pop), and the wiring will never see more than 20A sustained. If you plug in another source at the far end of that circuit, outlets in the middle and branches off the main wiring run could be seeing 30A without popping a breaker - and that's a fire hazard. A 20A outlet won't pass 30A forever, and wiring rated for 20A can overheat at 30A sustained. In some other countries, you can install some amount of solar and backfeed it like that, but I'm not familiar with those regulations, not living there.

stevenhubertron 5y ago
Thank you for the clarity here.. I thought there was more to the story than this article made it seem.
mindslight 5y ago
> the answer is a very clear "No" almost everywhere - those plug in inverters aren't permitted under NEC Of course plug in inverters are not permitted under the NEC, just as kitchen appliances aren't permitted under the NEC, nor are the power lines outside your house permitted under the NEC. The NEC applies to premises wiring, which none of those things are. Plug in devices sold on the consumer market are regulated by UL/ETL/etc, and the power grid is designed by power company engineers working to some other standard. If you look at your service entrance you'll see the wires coming from your house are nice and thick as dictated by the NEC, but connected to a smaller aerial feeder that doesn't meet the sizing requirements of the NEC. Your power company might have some private contractual prohibitions here and you may be opening yourself up to liability from the results of your actions - similar to them getting perturbed if you use a "suicide plug" to power your home from a generator. But it's not generally a priori illegal like you're making it out to be. (Your point about overloading branch circuit wiring is very important though. I'd be more worried about feeding in between the panel and a large load, thereby putting extra current into the intermediate wiring.)