Apologies in advance for any ignorance expressed in the following. Also, this is very much a thought exercise and I am no way one soldering iron stroke away from burning down my house.
With that out of the way, would someone mind helping me think through the following?
I have been knocking together super simple 12v devices for my kids during the pandemic. (think a water-pump that drives a waterfall in the bathtub. A motor to cause a cat picture to wave its arm. As series of muffin fans to cool the patio.) I have been using 12v power supplies to do it.
The other week, I hooked the fans up to a 12v solar panel in the yard to see what would happen.
And this got me thinking.
Toys aren’t used very often throughout the day, but the panel is always generating power when it’s in the sun. I understand that you could use a grid-tie inverter to convert power generated the AC power which could be used in a typical house.
Wouldn’t it be cool, since the amperage is so low coming out of a single panel converted to AC to simply connect it to a three pronged plug and plug it into the electrical outlet?
(Insert sound of electrical engineers grinding their teeth)
But there are two reasons this is a bad (terrible) idea:
- You can’t just hook a grid tie inverter to an AC service as the cycles of the inverter AC and line AC aren’t synched which could cause problems for any sensitive device that is pulling current from that circuit.
2)The much bigger issue: you aren’t prepared for a short. If a short happens on that circuit somewhere, it could be fed by amps from both the solar inverter as well as the house AC service. The house circuit breaker could supply 15 amps (or whatever) while the inverter could provide more. That would mean that you are now feeding more than 15 amps through wires in your wall that are not rated for that amount of amps and could start a fire.
The first issue is something that I would need to be solved of course, but I’m especially interested in how the second could be potentially solved with through Emon devices and programing.
As I understand it, you could install a CT clip and base on the line which you would want to “plug” your panel into. You could then monitor how much power was passing out of the panel. You could then program your inverter to limit itself to produce only the amps needed to fill the gap between the amps being drawn from the panel and what the circuit is rated for (in the 15 amp circuit example, if the CT sees 10 amps passing by, the inverter would know to only produce 5 amps.)
So, I’ll pause here and again apologies for my ignorance.
But am I at least thinking about this right?
Thank you so much in advance,