In a TheStar.com interview, well-known venture capitalist Vinod Khosla, claimed that an important investment area would be "next-generation, ultra-high-voltage DC transmission technologies and infrastructure".

In his mind, getting off coal and other fossil fuels means playing to our clean-energy strengths and connecting our energy sweet spots to a large, trans-national grid that can efficiently carry power over long distances.

Such a grid would mean that renewable energy from solar and wind power sources, for example, would still flow throughout the country when one part of the country has decreased solar or wind inputs. Scaling up means the sun always shines and the wind always blows.

It will be interesting to see how the grid for solar power evolves over the next few years. In a press release for the Massachussett's Green Communities Act, they nod in the direction of rooftop solar power grids:

The measure also authorizes utility companies to own solar electric installations they put on their customers’ roofs – a practice that was previously prohibited – up to 50 MW apiece after two years. If utilities take full advantage of this new opportunity, it will poise Massachusetts to meet Governor Patrick’s goal to harness 250 megawatts of installed solar power by 2017.

An ultra-high-voltage DC transmission infrastructure allows ones to imagine a solar-house in Boston collecting the renewable energy required to provide lighting for a clouded over solar-house in Minneapolis and vice versa.