Yale Environment 360 has an article on the need to expand the electricity grid in order to allow maximum use of renewable energy - Pumping Up the Grid: Key Step to Green Energy.
As America gets serious about the twin crises of oil dependency and climate change, many analysts believe that wind power — and eventually solar power — will make the largest carbon-free contributions to a new energy supply. But America’s aging electrical transmission system is renewable energy’s Achilles heel, and unless a broad policy consensus to upgrade our electrical grid is forged soon, the potential of wind and solar power will be vastly diminished.
Three things are needed to solve the challenge of renewable energy transmission: good technical planning, permitting and siting processes that can win public support, and broad agreement on how to pay the high cost of new power lines. Of these issues, the last one — gaining agreement on how transmission costs are spread among players — is currently the most contentious. To solve it, policymakers must come up with a plan to allocate these costs as broadly across the electricity system as possible — utilities, renewable energy generators, and consumers — since ultimately the whole system and all its users will benefit from a 21st century grid.
Today, achieving a national consensus on the importance of a better electrical transmission system is the single most important step toward vast expansion of clean, low-cost sources of energy. With every passing day, we can generate more and more energy from wind and solar power. The challenge now is getting it to the population centers where it is most needed.