Power Storage Technology
One of the major obstacles to renewable solar and wind power replacing non-renewable combustion
power generation is the problem of storage. Wind is not constant and solar is available
only half the time. Without storage, they cannot completely replace the 24 hour availability and controllability of combustion
generated "baseload" power which is easily adjusted to meet varying demand.
Here is a very good overview of current power storage
technology and ideas.
DOE Case Studies: Energy Storage Technologies
DOE Hydrogen Sorption Center of Excellence
In April 2004, DOE announced an initiative to help lead the United States to its hydrogen-powered future.
Three new centers of excellence, supported by DOE's Office of Energy Efficiency and Renewable Energy, were
named in the area of hydrogen storage. These centers leverage the expertise of the DOE national laboratories
in partnership with academia and industry.
The DOE Hydrogen Sorption Center of Excellence, coordinated by the National Renewable Energy Laboratory (NREL),
is one of these centers. The other two are dedicated to hydrogen storage via metal hydrides (coordinated by
Sandia National Laboratories) and chemical hydrides (coordinated jointly by Los Alamos National Laboratory
and Pacific Northwest National Laboratory)...(more)
U.S. DOE Hydrogen Storage Program
Hydrogen storage is a key enabling technology for the advancement of hydrogen and fuel cell power
technologies in transportation, stationary, and portable applications. DOE's efforts focus primarily
on the R&D of on-board vehicular hydrogen storage systems that will allow for a driving range of
greater than 300 miles while meeting packaging, cost, safety, and performance requirements to be
competitive with current vehicles. While automakers have recently demonstrated progress with some
prototype vehicles traveling more than 300 miles on a single fill, this driving range must be
achievable across different vehicle models and without compromising space, performance or cost...(more)
Concentrated Solar Thermal power generation uses existing steam turbine technology with the addition of technology to concentrate the sun's
heat to provide the steam. This method has the potential to quickly and relatively inexpensively replace carbon combustion power. Thermal storage
in the form of hot oil or molten salts will enable rapid deployment.
Compressed Air Storage
One storage method uses underground caverns and even large tanks to store
air compressed by renewable power. Later, that compressed air can be used to drive turbines to regenerate electricity on demand.
Another storage method uses batteries to store renewable power. Because the amount of electricity
needing to be stored is so large, the batteries must be very large. One of the best candidate technologies
is very similar to car batteries in that it uses metal plates immersed in electrolyte solutions.
Flow or Zinc Redox Batteries
Flow batteries are so named because the electrolyte solution is held in large tanks and pumped through the
plates. The electricity stored is only limited by the tank size.