That's part of the reason, it really comes down to politics though. The grid could easily keep up with demand, but the regional transmission organizations that price the power such as PJM, NYISO, etc. are making it unreasonable for new construction of typical generation plants, but make it affordable to install solar and wind due to the subsidizing. They know the grid demand, and set the prices, which is why alot of the old nuclear and coal plants are shutting down. Power generation is profitable around $25/MWh, and that's the goal for the cost for our company to produce power. If you were to price the cost of solar energy, without the subsidies it's around $50/MWh. Nobody would install it or own it. The price of natural gas is the primary driver for low power costs. New 1300MW combined cycle plants can be constructed and put online within 2 years, and they are cookie cutter designs. GE/westinghouse can stamp these out like building a 500 acre home.
The whole solar/wind debate is all a bunch of BS, it's again people trying to go "green", so they are promoting people to build these micro grids and have their own reliable power, so much that the power companies are even paying people via SREC to generate their own power through solar. The demand on the grid although you think has gone up over the past few years has actually gone down, due to more efficient things such as LED bulbs, VFD controls for motors, digital controls for home appliances, etc. And alot of big companies that used to use alot of power are no longer around since the we decide to import so much shit that barely anyone manufactures anything in the USA anymore like the good old days.
Funny, I know Texas is off the grid from the rest of the transmission operators, and then there's this small dinky town known as Vineland, NJ (actually the largest city in NJ physically) which has it's own municipality for production and transmission of electricity. Things like this have always existed, but the government is now promoting micro grids on a residential level.
A new big wind farm just got approved for down in the Delaware river, so you'll soon be seeing ground breaking here.
Salem County residents hope new wind port will bring jobs, boost economy
My personal opinion, in 20 years when all these solar panels shit the bed, our kids kids will be stuck figuring out how to dispose of them or recycle them. Nobody has thought that far ahead, but I think if somebody could start a business in solar panel "refurb/recycling", they would have a flourishing business in the next 10 years.