Hi KS, re your questions......
"This is a bit foreign to US utility structure. Here you either 1) grid-tied - though some states have deregulated or "unbundled" certain costs- you basically are served by one, franchised poles and wires company, 2) off-grid, or 3) grid-tied with AC Coupling. Can you explain the EDF arrangement that you have a bit?"
France has several regimes with what you can do with the main electricity supplier, here its EDF, a government run monopoly.
When PV on roofs became main stream and supported by the European Union, France EDF would pay you a flat rate per year for Exporting your PV or Wind etc to the main utilities Grid. They would also pay you for every kw of power you produced/exported. However over the last 4 years or so, the rates for exporting your Electricity are now so low that as an investment/return basis the figures do not add up anymore on new installs. And before you ask, New Installs here in France are still, yes still, very very expensive compared to say the UK.
Plus all the connection charges and inspection charges, and that all the connected equipment must be certified and be approved by EDF, and installed by appropriately EDF approved installers. So Installing any domestic Grid tied exporting energy creation makes no financial sense any more.
And any PV on Domestic house's roofs must be installed into the roof and not above the roof, and checked to see that it is.
You can still connect to the main utility grid with grid tied equipment, and this is called "Self auto consumption" and if you back feed or export then no monies are due, you get nothing.
But again the Paper work is pretty horrendous and certification etc charges are still expensive. Equipment needs EDF/French approval, and unfortunately the SMA Sunny Island is not approved, and so can not be connected direct to the gird in any manner.
As I said earlier, I have installed changeover switches on our main fuse boxes, so our own Sunny Island created Mini Grid is separate and independent of the Main utilities Grid incoming supply.
So as I join more PV etc to our own independent Mini Grid, by Ac Coupling to our Mini Grid, our reliance on the main Utilities grid EDF becomes less and less.
As I also said earlier the Utilities company, EDF charge nearly 50% of our consumption bills in local and state taxes, loads of distribution charges, and rental of the EDF equipment.
We now mostly just use the EDF cheap night tariff as a sort of standby generator, as it still cheaper than a good generator and its fuel costs, but just as oil costs fall. If Fuel costs keep on falling I will need to reavaluate this part of the equation.
This arrangement is now cost effective for us, as most of our gear is second hand used stuff, just wisely chosen.
We therefore hope that in about 4 years we will separate totally from the main utilities Grid, EDF.
The concept of self generation and self consumption is openly discussed on the European Navitron Sustainability Forum and the figures nearly add up as a normal domestic arrangement, but what is holding everything back is Battery technologies and the present battery prices.
I know folk use to say that the main Grid utilities supplier was supplying electricity at a fair price for the Country/Nation. Sorry that does not wash here in Europe anymore as I think Governments just see another Tax source and the Utilities in France and the UK just want to make loads of money for themselves.
Nothing wrong with that I here you say, well there is when there so called prices that they are charging are now more expensive than my own Sustainably produced Electricity.
EErrr Rant over.
Trust this helps KS.