7.5¢/kWh for "excessive" generated power is excellent. Go ahead and overbuild your system.
Around here we get 2.5¢/kWh for any power we put on the grid, limited to the amount we draw from the grid at 11.5¢/kWh. Is better to get 2.5¢ than to throw it away.
Meanwhile my PV system will have batteries because it isn't worth giving the power to TVA.
The problem with a blanket "go ahead and overproduce" is that you have to run calculations and see if it is worth it.
When sizing a system.....it can be simplified down to a total system cost per watt.
Currently I pay ~12.5 cents per kwh. So any and all production up until that point....I am directly saving (putting in my pocket basically) 12.5 cents for every kwh I produce.
If I produce more than I use.....now I am saving (putting in my pocket)about 40% less per kwh. So that pushes out the ROI by oversizing. So some number crunching needs done.
Make sure you are adding generation and transmission for your overall cost.
Also be weary of that, they'll buy back, but I've heard of companies starting to charge transmission on the buyback. Since you're using their lines.
My coop dont charge a distribution for the power they buy back. I will directly get credited 7.5 cents per kwh.
If they don't buy back or I use everything produced, totally OK with that. Our local co op has been great over the years. Not many grid down days and they have always fixed things real quick.
Now looking into methods of ground mounting panels with angle adjustment for different times of year. The prebuilt mounting system/ kits seem to get pricey quickly. Not into roof mounting with the amount of snow we can get in some winters. Seems being able to set panels almost vertical on a ground mount would also help with sluffing the snow off versus a low angle roof trying to pull it off with a roof rake, and work well with snow reflection feeding the backside of the Bifacials.
Just thinking out loud, reading this thread with interest.
Yes, coop's are good in that we rarely have outages....and when we do they are short-lived.
IF you are liking an adjustable ground mount...I would look no further than Sinclair sky-rack
Sinclair Designs & Engineering - Michigan's leading Solar Racking Manufacture
The latest thing is the bifacial PV panel which is partially sensitive on the backside. Can sometimes make power from that which is reflected from the ground.
Have been some interesting experiments in mounting these panels vertical. Good yield early and late in the day. Area under the curve of production is similar but not quite as good as "optimal angle" mounting. Depends on your latitude.
I saw those experiments too of vertical mounting. Yes total production is less.....but a combo of vertical and horizontal can really flatten a curve and have good production ALL day. But from what I saw the single biggest benefit of vertical was still allowing use of the land between the panels for farming crops that dont get tall. Like hay being the biggest one
Probably worse than that. The Federal Grid Tie law says the utility only has to pay the Audited Incremental Cost of Generation. They don't have to pay more than it would cost to produce a kWh themselves. For TVA that is about 2.5¢/kWh. Most TVA associated utilities charge around 10¢/kWh for the power delivered to one's home. The difference is the cost of that distribution grid.
Long ago I wise experienced engineer told me, "The biggest cost in running an electric power utility is the cost of money." In other words, "interest".
The federal regulations dont apply to a non-profit coop. They are not bound by any net metering regulations or public utility stuff.
But also, the rural coop's dont actually generate power themselves. They have to directly buy it off someone. In my case here in ohio....they purchase the electric from buckeye power.....and buckeye power sets the rate in which they will credit my coop for people overproducing on solar. That rate is simply passed on to me.
