Right now, many utilities are making money from net metering arrangements, that generally pay a fixed retail rate for PV power backfed into the grid. It works because the PV power is often coming during periods of high or even peak demand, when the marginal cost of power is above the retail rate on average. The generators making that peak power (who may or may not be utilities) are seeing their market share decrease, so they are often lobbying to make net metering less favorable....with varying levels of success.
In the future with higher rates of PV penetration, it seems likely that this trend will get to the point that some low cost power sources will need to be curtailed on some sunny days, so the value of the backfed power may start to consistently drop below the retail rate. One reason this may occur will be large scale adoption of utility solar in big farms, which will happen when they make a reasonable profit for investors at the daytime **wholesale** electricity rate, which is starting to happen in many locations.
When there is a ton of utility solar feeding the grid at a reasonable wholesale rate, that the distribution utility can sell to customers with the retail markup (which covers their grid costs + regulated profits), then your rooftop array feeding power in at the retail rate (and it should be pointed out, not needing much grid service to the send the juice to your neighbors AC unit) might start to look like an outdated, anachronistic loss leader...which is limiting how much solar **they** can push into the grid at a higher profit.
At that point...the powers that be may well align toward shifting net metering arrangements to something more like a wholesale or time of use rate, likely with much less favorable payback for YOU.
Voters are willing to defend existing net metering arrangements because renewable energy is popular...efforts to paint rooftop owners as wealthy free-riders on grid services have mostly failed. Now efforts to neuter net metering are often by stealth...by claiming to make it stronger or more competitive or free-er or some malarkey. And those are also failing with 'truth' campaigns before the vote.
But the soft underbelly is that American's think we are **already** making a lot of renewable power...many people surveyed 'guess' much higher rates of renewable adoption than is actually the case. By the time (utility) solar+wind reach 20%, it is possible they might think that renewable energy is 'all done', and if the utility fielding the 20% solar and wind says they need to change net metering to make even more of it....the voters might not come out as they do now.
And rooftop owners will be like early adopters everywhere...helping to make the future happen, but left with a bigger bill than they hoped for when it arrives.