Name of thingie that connects / controls panels + inverter + generator + ....

lasitter

.... meter / grid connection.

In a grid connected system with all the above components are there units that do "all in one" functions vs separate pieces? Sorry but I find the jobs of the separate bits and how they're strung together and then connected to the grid a bit confusing.

I know that the Automatic Transfer Switch disconnects you from the grid when the power supply gets wonky, but they also serve to prevent backfeeding when linemen are out repairing downed lines. I'm guessing that something does the same thing for solar array only systems, but don't know what that gadget is called. Still just a transfer switch?

And: Where can I find out about utility provisions for purchasing power / generating capacity in emergencies? During outages, do they only want your excess capacity if they can buy it in megawatt increments?

Many thanks.

Cariboocoot

Re: Name of thingie that connects / controls panels + inverter + generator + ....

Yes there are all-in-one packages that contain inverter, charge controller, and AC powered charger. They tend not to be very good due to lack of flexibility in specifications. The 'big companies' don't sell them because of this. Practically unheard of in North America.

With a standard grid-tie system there is only PV & inverter; it's adding the batteries for back-up power that makes them more complicated.

Where can I find out about utility provisions for purchasing power / generating capacity in emergencies? During outages, do they only want your excess capacity if they can buy it in megawatt increments?

You may be a little confused here. When the utility grid goes down (outage) the power company does not want you back-feeding their lines at all. This is why GT systems have anti-islanding circuitry which shuts them down when no grid is present.

Do not confuse with hybrid GTI's which will provide back-up power to selected loads during an outage.

As for your other concerns regarding utility interconnections you have to ask your local power company as it is not the same everywhere as to how much they will allow and what (if anything) they will pay for it.

lasitter

Re: Name of thingie that connects / controls panels + inverter + generator + ....

Cariboocoot wrote: »

You may be a little confused here. When the utility grid goes down (outage) the power company does not want you back-feeding their lines at all. This is why GT systems have anti-islanding circuitry which shuts them down when no grid is present.

I thought by directly addressing backfeeding and safety, that demonstrated that I was already aware of some of the concerns you pointed out.

If the grid were flexible, such that you could break up and isolate areas with downed lines from areas that were in the clear, then it occurred to me that a utility might want a megawatt (some increment) of power if they could control where and when it showed up.

Suppose that you were located in a cluster of 20 rural homes without power, but the power company could push a button and separate your group of homes from the downed lines. And then suppose that via whatever mechanism of control you can imagine, one or more homes could put 50kw or so on line thereby restoring power locally. That would give utilities lots more flexibility in terms of dealing with downed lines. It's pie-in-the-sky now, but as a greater percentage of power generation becomes decentralized, it is something that we could see in 10-20 years.

But thanks for the answer to my "all in one" question. Easy to see how that's true.

Mountain Don

Re: Name of thingie that connects / controls panels + inverter + generator + ....

Then you're into some sort of an equipment sharing and cost of equipment sharing agreement among a group of people whose only commonality is that their addresses are close together. Who gets to say who gets to use how much of the available power?

I have seen enough issues with regular HOA to make me never want to get into any such sharing agreement ever again in my own life. But that is only the opinion of a sometimes cantankerous old fart.

lasitter

Re: Name of thingie that connects / controls panels + inverter + generator + ....

Mountain Don: Good point about the power use. You'd need smart equipment on each home to arbitrate that, I suppose. No telling what sorts of deals might be done by people that need power and don't have a generator. If it were all set up by / controlled by the utility, they could apply a special emergency that would discourage too many hot showers ...

Cariboocoot

Re: Name of thingie that connects / controls panels + inverter + generator + ....

Unfortunately the North American utility grid is not set up to allow isolated 'mini-grids' and so the company's response is bound to be a flat "no" due to the fact they would have no control over it.

But mini-grids in and of themselves are not impossible. Just complicated and expensive. It would no doubt be cheaper and easier for each home to have its own back-up of whatever size is needed and be responsible for it.

Having been on a community water system (the hydraulic equivalent to a micro-grid) I have to say I much prefer having my own well.