A quantum mechanical phenomenon, superconductivity occurs in certain materials when cooled to extremely low temperatures. In this state, current flows in bound pairs of electrons that constitute a superfluid, which can move without power dissipation. With exactly zero resistance, current can circulate forever in superconducting circuits, an oddity that is being exploited in the latest applications. A new class of relatively high temperature ceramic super conductors has been discovered that has spurred advances in medical imaging, telecommunications, energy storage, and magnetic levitation.

Superconductive Magnetic Energy Storage systems have proven reliable in providing fast backup power with 98% efficiency.
Maglev Systems use magnetic fields to suspend and propel a train on a frictionless bearing. Several maglev trains are in use around the world, but the experimental JR-Maglev is notable for the use of superconductor technology to generate a stronger repelling force and therefore a wider gap is possible in the track, making it more robust in the presence of dirt, debris, snow and ice.
Superconductors are also being used in a new wave of motors and generators that have a superior efficiency of 99%. Clearly, the energy savings realized by superconductor technology will be part of the solution to global warming in the years to come.

At the largest solar power-generating site in the world, you won’t find acres of solar panels. Kramer Junction, not far from the infamous Barstow, California, is capable of producing 350 MW of solar energy from arrays of parabolic troughs that concentrate sunlight on a pipe of thermal oil, driving a heat exchanger and steam turbine. Built in the mid 1980’s, it is conspicuous as one of the few improvements to come out of the energy crisis of the 70’s. I found this approach interesting because it doesn’t use silicon PhotoVoltaics and it’s fairly efficient. The tracking of the parabolic reflector is computer-controlled so it’s not totally low-tech, but otherwise it could have been designed a century ago. The strategy of using a solar concentrator to generate heat is one that will compete favorably with PV in some applications. Advancing beyond the solar Googleplex, Google recently announced that it will invest hundreds of millions of dollars into renewable energy research, focusing initially on breakthrough technologies such as solar thermal.

The Stirling engine has been rediscovered; capable of generating torque from any source of heat. Patented in 1816, many forms are possible, but it’s generally a closed-cycle, reciprocating piston device. When placed at the focus of a parabolic reflector, the Stirling engine can drive generators with an overall efficiency better than standard solar panels, and comparable to concentrated photovoltaics. I would recommend the Stirling in particular as the most promising jewel from the past to be dusted off and utilized for our energy future.

This entry was posted on Wednesday, November 7th, 2007 at 5:59 pm and is filed under Energy Future. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.