Much of the reluctance to support renewable power has centered on cost and intermittency. The discussion of cost is becoming more and more moot as costs continue to fall but intermittency continues to plague the industry as a whole. Imagine a power resource that used no fuel, used no water and produced power in a non-intermittent, reliable fashion. That type of energy is exactly what the utilities would like so they can better manage their portfolio and not have to hedge fuel and water pricing into the future. The environmental community would likely support it as well due to its sustainable qualities. The next question that needs to be asked is, whether it is truly sustainable? That is, can the power be delivered in a cost effective manner?
Water is often the forgotten element of sustainability because it is always available to those in the Western world and continues to be a cheap commodity. In the desert southwest and in many other areas around the world it is becoming a more pressing concern as we deplete the aquifers more quickly than they can be recharged. Power generators like nuclear, coal, gas and solar thermal utilize steam to generate power and use considerable amounts of water for every electron that is generated. To put the amount of water utilized into context, if a power plant was to generate enough power for approximately 100,000 average US households, about 700 million gallons of water would be utilized on an annual basis. Given that we reside in the desert southwest where water is at a premium, one must ask if this is the best use of our resources?
It would appear that if a resource capable of addressing all these concerns existed it could be considered the Holy Grail of energy. Unlike the Holy Grail there need not be further discussion about whether there is such an energy resource. EnviroMission is developing the Solar Tower, a technology capable of delivering cost competitive energy in a reliable, non-intermittent manner. It does this while consuming no water or any fuel.
The fundamental operating principles are illustrated below:
Solar Tower technology uses solar insolation (indirect) and radiation (direct) to heat air beneath a large translucent collector (greenhouse) that in turn creates a constant flow of air to drive turbines at the base of the tower. The collector is open at the periphery allowing air to continuously flow from the outside toward the middle of the collector. One of the many strengths of the Solar Tower technology is its ability to generate utility scale electricity reliably throughout the day and at night without the use of water. The collector has the ability if desired to capture more than enough fresh water to provide for all on-site needs via its large collector area.
The first Solar Tower in the US is planned for Arizona and is scheduled to commence construction late in 2014. The Solar Tower would not only generate power with all the desired characteristics but will also generate significant economic benefits to the State and La Paz County; the region the project is sited. It is expected approximately 1500 workers will be employed during construction with a further 40 being employed on an ongoing basis.
Solar Tower development is coming and when delivered, it will provide the type of energy that the often disparate factions of the industry could unanimously support.
Chris Davey, EnviroMission