High Voltage Direct Current Transmission

In a piece I wrote yesterday on clean energy power density, I mentioned that renewable resources do, in fact, come with a number of limitations, owing mainly to the fact that the infrared, visible, and ultraviolet light we receive at ground level from the sun at its zenith is fixed (1004 Watts/square meter).  The “beauty” of fossil fuels is that they circumvent that limitation; the chemical energy in a gallon of gasoline (that we burn in a few minutes) is the accumulated solar energy over a period of hundreds of millions of years.  In any case, migrating a significant amount of energy consumption in densely populated areas to renewables will mean importing that energy from remote areas, using some sort of high voltage transmission, so as to minimize line losses.

Coincidentally, I just came across this article, which discusses the market over the coming 10 years for High Voltage Direct Current (HVDC) Transmission, and explains why it “is the method of choice for the subsea transmission of electricity, the connection of disparate AC grids and/or the movement of bulk amounts of electrical power over vast distances. In each of these three respects HVDC transmission is superior to its competitor HVAC (high voltage alternating current).”