And the winner is….Thermal storage (for now)
Thursday, December 13, 2007 at 08:37AM
Toby Considine in Background, Microgrids and Distributed Systems

Energy storage is about to get big. New Technologies. Demand Response. $100 a barrel oil. All the old pressures are getting stronger. Grid reliability. Microgeneration and microgrids. Unreliable but attractive renewables. The incentives for energy storage have never been as good. Hydrogen. Vanadium redox. New technologies for energy storage are just over the horizon.

But I am guessing the old fashioned low tech thermal storage will be the first big winner. Well, maybe a little higher tech than it used to be. Peter Drucker observed that a new technology must be an order of magnitude better in either price or performance than a pre-existing technology with market standing to supplant that existing technology. The existing technology can always leverage its market position, its market penetration, and the current producer’s experience to make its own leap forward.

New market conditions are placing a premium on energy storage. Time of day pricing is becoming more common and the price differentials are only going to get bigger. New sources for thermal energy to store are coming out of the new things we do in buildings. New ways to use thermal storage are coming to market.

The needs of the power grid are leading to ever larger price differentials between different times of day. The more sensitive systems in today’s buildings require that buildings establish their own reliability. The greater cost of both minor outages and of using energy at the wrong time now swamp the energy lost during storage. The economic case for buying energy when it is cheap, to be available when needed is getting easier to make.

There are new sources of thermal energy to harvest. Building chillers can harvest heat from office space. Data centers throw off huge amounts of heat that can be stored for reuse. If we can use this energy, then it will be worthwhile to gather and store this energy.

We now can use even moderate-temperature thermal energy for purposes other than heating and cooling. Old models made ice during the night to take advantage of cheap energy, or collected heat from the sun during the day. Stored thermal energy was used only to cool during the day or heat at night. New microprocessor controlled Stirling engines have improved the efficiency and efficiency of low power electrical generation. Prototypes have generated electricity off temperature differentials of 6C, although production units seem to require five times that.

In the short term, thermal storage will create reliability. In the mid-term it will midwife markets based around energy storage and temporal displacement. In the long term, those markets will be the playing field upon which new technologies complete. But I in the short term, I’m betting on thermal storage.

Note: immediately after writing this, I read about a system using black-top roads for thermal energy collection with geostorage. Perhaps some other time….

Article originally appeared on New Daedalus (http://www.newdaedalus.com/).
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