Yes, not only do they need to pay for transmission charges, they also need to pay for generation charges. When the sun isn't shining, that's too late to go build a power plant to supply electricity. They have peakers standing by in case electricity is needed and even if those don't generate any electricity, it still costs money to have them available and on stand by.
We can go down that rabbit hole
Originally, the scheme was FIT (or in the case of Ontario, MicroFIT, for installations 10MW or smaller). FIT was a true subsidy scheme, rewarding individuals and developers with absolutely obscene levels of compensation for every kWh produced by their panels. These rates were as high as $0.80/kWh at the onset of the program. Our local 10MW farm gets paid $0.42/kWh. This obviously had an impact on rates (despite some claims to the contrary by complete morons who must be wholly innumerate).
As the price of panels was driven down by the production shift to China, the FIT subsidies became less popular and this was replaced by Net Metering, which I believe is what Jeff is on. Net metering, simply, credits you full retail for every kWh you put on the grid and, if you export more kWh than you consume, you'll actually make money.
Now, proponents of net metering will argue that it's fair, that those kWh are being displaced, but those kWh are not worth full retail cost. The grid operator isn't paying full retail to the nuke or gas plant down the road, they are paying either a fixed per kWh rate (Bruce here currently receives $0.082/kWh) or a market rate, which varies based on demand. This is the wholesale cost.
During the day, high penetrations of solar drive down the market cost, this is reflected in the compensation paid to commercial solar installs, from which the grid operator buys, but not in the price paid to residential net metering customers who get the much higher full retail rates credited to their bills. People with storage can game the system even more by charging using either their own excess capacity, or by the grid when power is cheapest, and then using the battery to avoid the most expensive periods, which are becoming the morning/evening ramps when demand increases, solar isn't on the grid yet or is signing off and gas peakers are fired up and paid a premium.
A fair scenario is paying people who want to have their solar grid connected whatever market rate is for their exported kWh and charging them a delivery fee, with a net usage variable component, like we pay here in Ontario, based on kWh moved, to cover transmission and distribution costs. If they want to be a generator, they'll get paid like one. People with batteries would still be able to avoid the peak periods, but they'd be forced to pay for transmission, and any power they export wouldn't be at a premium.
That appears to be the way things are headed, which only makes sense.
Another thing coming down the pipe that I heard mumblings about after the Texas disaster was that wind farms will have to secure their own backup capacity (gas) for when they can't deliver. That will be a game changer if that starts happening.
