One of my favorite ideas to help solve the problem of climate change was presented in the December 2007 issue of Scientific American entitled “Solar Grand Plan”. According to the article, this plan could provide 69% of all US electricity and 35% of our total energy by 2050, and the development costs would only average 10 billion a year over 40 years. Once developed the costs would be almost zero as no "fuel" is required. The plan would eliminate the need for all imported oil, thereby reducing our huge trade deficit and easing Middle East tensions. If sufficient wind, geothermal, and biomass were added to the mix, we could provide 100% of the electricity and 90% of our nation’s energy needs by the year 2100.
So how do we pull off this miracle? First a few facts:
Light coming from the sun brings with it an amazing amount of energy. For example there is enough power in only forty minutes of sunlight striking the earth to provide all of humanity with its energy needs for a year.
In the American South West there are 250,000 sq. miles of land suitable for solar power. But we need only a tiny fraction of that. For example, if we had had the necessary solar collectors, it would have taken only 2.5 % of that land to have provided our entire nation’s energy usage for the year 2006.
Well, this sounds wonderful you say, but aren’t their problems with solar? How do we get all that power from the South West to New England or Washington State, or Chicago? Aren’t those awfully long distances for electric power? And what about nighttime when there is no sun? And didn’t someone say that solar requires lots of water, an item in short supply in our SW deserts?
So let me answer each question in turn.
First, getting the power from where it’s made to where it’s needed. Anytime you pass electricity through a wire or cable, a certain percentage of that power is lost in what’s called the “resistance” of the wire. So the longer the cable, the more power is lost. For really long distances, direct current or DC lines are more efficient with less power loss than the traditional alternating current or AC lines. So, for example, to get all this solar power to New England with manageable power loss, we could build DC transmission lines, than tap into the traditional AC power grid once we get near our destination.
But there is something even more special about direct current. If you cool the right material to super low temperatures, all the resistance disappears and you get what’s called superconductivity. Result – no power loss at all! (More about this later.)
Second, night time power
So what about nighttime power when there is no sun? To cover nighttime power needs we could install extra solar cells to collect the required night time power during the day, then store that power until it’s needed. Ordinary rechargeable batteries won’t work because we would need to store way too much power. But there are other solutions.
One interesting solution is use the extra electricity to “split” water (two parts hydrogen and one part oxygen), then save the hydrogen, letting the oxygen (the stuff we breathe) go into the air. Why hydrogen? It turns out that hydrogen would just love to recombine with the oxygen again creating huge amounts of energy. And, unlike coal, oil, or gas, the only byproduct is harmless water. So we’d store the hydrogen, then “burn” it at night when we need the power. Since hydrogen at room temperature is a gas, and gasses take up a lot of space, the best way to store the hydrogen is to chill it to such a low temperature that it becomes a liquid.
Now things get really interesting! It turns out that liquid hydrogen is cold enough that if we ran it through the right kind of hollow DC electric cables, the cables would become super-conductive with zero power loss.
With all this information, let’s build our new US power system. In a small portion of the south west we build our solar plants. We add facilities that, during the day, use a portion of that solar power to extract hydrogen from water and liquefy it. At the same time we construct some heavily insulated, underground, superconducting “pipes” designed to carry power to the far reaches of the country. The inner part of the pipe carries the super cold liquid hydrogen while the out shell carries the DC electricity. The solar electricity provides power during the day. The liquid hydrogen gets piped to old power plants that have been converted so that their turbines, now burning hydrogen rather than coal or gas, can provide power during the night.
There are still some problems, however, that must be addressed. I will attempt to do so in my next release.
