Part of the issue is, are we talking about Transmission or Distribution grid ties?
Where are the most losses? How do we deal with large area variations when the sun goes behind clouds or the storm front blows through? How do you deal with islanding? What about remote generation tied into a remote spur that requires upsizing the spur? One of the issues with using a variable output power source is maintaining grid stability. Ramping up and down hydro is not a 5 second operation. Gas Turbines are 15 minutes to bring online. Coal and biomass may take 6-12 hours for large power shifts.
Grid stability may initially go down before it comes back up. Unfortunatly I don't not know of any quick responding, large capacity power absorbtion / storage / regeneration technologies that are commercially available and economically viable yet. Flywheel systems are beginning to address this but they are not wide spread yet.
How many substations are setup to take power From the distribution system and push it back into the transmission lines to be used somewhere else?
I'm just doing my job of stirring the pot.
