The costs for maintaining the grid are the same when solar/wind are undercutting them. Fewer paying customers. Then what?
Transformers going up in one big ball of flame...
True that. IMHO the way to handle that is for your state to not do "net metering" -- which is solar political lingo for paying back the solar resident at the same rate per kWh for power sold to the grid that he pays for power bought from the grid. Also have flat monthly fees everybody pays for grid upkeep before charging a rate per kWh usage.
For example, Alabama doesn't do net metering. After I decided to sell power to the grid half a year ago I started getting back 4.4 cents per kWh, which is over 1/4th how much I pay for power (after fuel rider and tax is added to the standard rate). In the past 12 months, the true per kWh purchase rate we paid (after rate riders and state tax added) ranged between 14.0 cents to 16.7 cents per kWh (with only one month below 15 cents and 5 months above 16 cents). IMHO it'd be unreasonable for me to get the full per kWh amount for selling power to the grid since I wouldn't be able to so without the power company maintaining the lines and such.
Another thing are the flat monthly fees. All residential power consumers here default to a fee rate in which the first $15.60 of each month's statement are the flat monthly fees everyone pays even if no power is pulled from the grid. That's a $14.50 flat fee to stay connected, plus a 50 cent natural disaster fee (which I've seen go up and down between 50 cents and 75 cents, changed infrequently) to help pay for fixing downed lines. Plus a 4% state tax on top to make it $15.60 before pulling power from the grid. Is that $15.60 per residence enough for maintaining the grid? I don't know. Just putting that info out there.
Lastly, those of us who sell power to the grid in Alabama have extra fees added. For example, I pay a demand charge, like businesses do, in my case it's $1.50 X whatever the highest demand I had on the grid that month. In both January and February that was 23kW X $1.50 = $34.50 that non-solar users didn't have to pay. I'm not fussing. IMHO it's fair to expect me to pay for grid upkeep. It's part of my analysis on seeing if it's feasible to sell power to the grid even if it means adding fees.
I agreed to it knowing that usually 4 months out of the year the extra fees would be more than what I get back or the grid sell. The other 8 months out of the year I get back more than the fees (in part because I'll sell more with more sunny weather, and in part because I won't have as many bursty times I need a lot of power making a high demand charge on my bill). I expect the net over the year to lower my power bills about $150 to $200 annually.
Some states had net metering and didn't expect solar residences to pay for upkeep. But even California has done away with net metering (much to the howl of solar users there who expected others to foot the bill for grid upkeep).