Energy Storage
The upcoming challenge of integrating a large variety of renewable energy and energy efficiency resources into a reliable urban energy network, is not really a challenge at all. It is only a challenge if we continue to perceive energy as something that must flow when we flip a switch, a perception that stems from the supply-side planning that has been prevalent in power system planning over time. With an urban energy network demand can actually be matched to supply. An interplay between demand and supply can now take place, allowing for flexibility in planning and perception.
This is made possible through the use of energy storage devices. Storage can be the buffer between supply and demand. It can take the excess power produced from renewables and store it, to release it when it is needed. Storage makes renewables dispatchable: available upon demand, or avoiding an increase in supply.
Why Energy Storage matters to Local Governments
Some forms of renewable energy, including wind power and solar power, are intermittent. If power is produced when the demand for power is low, storing energy produced becomes an important link in the production chain. Effective energy storage saves energy from being wasted.
The Technology
There are many different types of energy storage technologies, and these technologies perform different services, for various amounts of power and time-spans. A storage device can store excess energy from one period of time and release it over another time period. For example, storing excess overnight wind power and returning it back to the grid during peak times is termed arbitrage. In very general terms, arbitrage is one of the major roles of energy storage, and the other, is power quality.
Hydrogen
Hydrogen can be derived from either natural gas or water. With Natural gas, the carbon molecules are stripped off the methane molecule, and the hydrogen is captured and stored. The other process is through passing an electrical current across water (electrolysis) to separate the water molecule into oxygen and hydrogen in a hydrolyzer. The hydrogen is captured and stored for later use, and it will be used in fuel cells or burned directly.
More Information on Hydrogen
The Foundation on Economic Trends (FOET) - The Office of Jeremy Rifkin website .Visit the FOET's section, The Hydrogen Economy, for detailed information on what hydrogen is, it's various applications, and for information on various campaigns and organizations focused on hydrogen.
