Imagine a state where the residents of its too largest cities have no way of getting back and forth except by a crammed highway. Imagine a state famous for its renewable energy potential but the only way of traveling the 120 miles between its most important cities was to burn imported fossil fuels. Sounds like a solar powered train would be the way to go to fix that egregious transportation oversight, and that's exactly the plan of the newly formed Silver Bullet LLC based in Tucson Arizona. They are planning to build a high-speed solar powered train to the will go from Tucson to Phoenix Arizona in "about 30 minutes. I am glad to hear that when they say "high-speed" train they are not aiming for being just fast enough to be a "high-speed" train, but they are seeking to go nearly twice as fast as the minimum speed requirement by European Union standards and 2.6 times faster than the American standard*.
Talk about slick. A very interesting feature is the photovoltaic canopy. I asked Ray Wright, one of the business partners on the project, why did they decided to go for the line instead of one aggregated location. He said the the linear system drastically cuts power losses from transmission and that they are investigating the net effects on cost and logistics of security and maintenance. He suggests it will probably be easier for automated cleaning of the panels this way, but that they are still looking into it. Also he says there is a larger advantage in this which is that you do not need to convert the energy from DC (what solar and wind energy always produce) to AC (which is what our grid uses)** thus avoiding conversion losses as well as transmission losses. Some commentators on the Treehugger article on the subject said that the panels should be next to the tracks and not in a canopy to lower construction costs, but I would imagine that that would put them in far greater risk of damage.
Of course there is always the question of how do you store the energy. Mr. Wright explained that,
An important thing to remember about pv technology is that it functions with light, not with heat. In fact, most solar cells have efficiency loses if it's too hot out which I bet will be a concern of the Silver Bullet. Then again, they seem to be committed to the line of power generation idea which can only work with PV, not with solar-thermal.
Operation is planned to start in 2018, and hopefully they'll have worked out the kinks in their plans and have gone forward to build something that will help Arizona have a brighter future.
*And I always thought we Americans we more obsessed with the newest, biggest and fastest thing, I guess we don't include infrastructure.
^Not a materials standpoint as it'll take a lot of energy to make the metals used for the tracks and trains. Of course it's less material than expanding the I-10, the highway that connects the cities.
**For more info on the AC vs DC front, read up about the War of Currents