Pumped Hydroelectric Storage: Putting Gravity to Work

by Chad Redman

Damming natural flowing rivers is an ancient and effective method for generating renewable energy. However, sufficient rivers are a scarce resource and modern dams produce an array of undesirable environmental effects. In response to the drawbacks of traditional dams, the main commercial technique for storing potential energy in water is pumped hydroelectric storage (PHS). Traditionally, these facilities use a massive pump and two reservoirs, one elevated above the other. During off-peak hours, excess energy produced from sources such as wind farms and nuclear power plants is used to power a pump which moves water into the elevated reservoir. When energy demand rises, the water is released back into the lower reservoir, spinning the pump which effectively becomes a generator. Continue reading

Flywheel Kinetic Energy Storage: Energy in Motion

by Chad Redman

Rapidly spinning masses known as flywheels are used for energy storage in a wide variety of applications, including transportation, sport, and grid level electricity. Focusing on grid solutions, flywheel energy storage systems (FESS) comprise massive rotors magnetically suspended in a stator, which acts as a motor when the flywheel needs to be spun up and a generator when the kinetic energy of the flywheel needs to be converted into electricity. Through the use of magnetic bearings and a vacuum chamber for the flywheel housing, FESS are highly efficient for short-term energy storage. Continue reading

Redox Flow Batteries: For Grid Level Storage

 

by Chad Redman

Current energy storage technologies are often overlooked in favor of the next promising development that will be commercialized sometime in the future, but economical large scale energy storage is already possible with current equipment. Redox flow batteries (RFBs) are a type of large battery that utilizes reduction and oxidation reactions to charge and discharge liquid electrolyte solutions. The advantage of RFBs over other battery types is realized in scale; RFBs can easily expand and store more energy by using larger storage tanks for the electrolyte solutions. However, the power that can be produced by an RFB is determined by the architecture of cells within the RFB. Unlike a standard Li-ion or lead-acid battery, only a small percentage of the energy within an RFB is accessible as power at any given moment. Continue reading

Redox Flow Batteries: For Grid Level Storage

by Chad Redman

Current energy storage technologies are often overlooked in favor of the next promising development that will be commercialized sometime in the future, but economical large scale energy storage is already possible with current equipment. Redox flow batteries (RFBs) are a type of large battery that utilizes reduction and oxidation reactions to charge and discharge liquid electrolyte solutions. The advantage of RFBs over other battery types is realized in scale; RFBs can easily expand and store more energy by using larger storage tanks for the electrolyte solutions. However, the power that can be produced by an RFB is determined by the architecture of cells within the RFB. Unlike a standard Li-ion or lead-acid battery, only a small percentage of the energy within an RFB is accessible as power at any given moment. Continue reading

Liquid Air Energy Storage

by Chad Redman

Asymmetrical energy production and consumption over the course of the day creates challenges all around the globe, which is why effective and efficient energy storage technologies are the subject of widespread research and development. Liquid Air Energy Storage (LAES) is one fascinating method for storing excess, cheap off-peak energy, and taking advantage of it when energy production falls and demand rises in the evening. The Energy Storage Association describes the systems behind LAES, including ways in which waste from unrelated processes can be turned into valuable energy. Continue reading