In our last blog entry we were shedding light on some of the largest solar power plants worldwide. So it's time to look at the question of the storage of energy too. Climate change and global warming have been driven by burning the “classic” energy storage materials: coal, oil and natural gas.
Consulting Wikipedia for energy storage reveals:
All forms of energy are either potential energy (e.g. Chemical, gravitational, electrical energy, etc.) or kinetic energy (e.g. thermal energy). A wind-up clock stores potential energy (in this case mechanical, in the spring tension), a battery stores readily convertible chemical energy to operate a mobile phone, and a hydroelectric dam stores energy in a reservoir as gravitational potential energy. Fossil fuels such as coal and oil store ancient energy derived from sunlight by organisms that later died, became buried and over time were then converted into these fuels.
Renewable energy sources like wind, solar or water energy have the limitation of a possible temporal unavailability or great variations. That is why scientists and companies alike put a lot of research into storage technologies, which should come at a reasonable price and compensate power generation fluctuation over several days. Only hydro storage power plants are currently used in large commercial applications and can store energy at the gigawatt-hour (GWh) scale. The cost of storing a kilowatt hour (kWh) is about EUR$50 in hydro storage. Compared to other options, such as batteries (about EUR$1000/kWh), this price is still very cheap.
The increasing research and political debate on a global renewable energy system shows a future demand of new central energy storage including pumped storage plants. How big is the potential when nature protection aspects are taken into consideration? How can climate and nature protection be harmonised? Which technologies are best suitable from an environmentalist point of view? These and other questions of energy storage will be the topic of an upcoming conference in Berlin on February 21st 2011: Energy Storage & Nature Conservation - A conference on how central energy storage can be extended and developed in an ecologically compatible way .
One technological concept presented last October by German scientist and professor Eduard Heindl from the university in Furtwangen, sounds promising, but also needs to be tested to be environmentally sustainable: Hydraulic Hydro storage. The basic idea is to lift a large rock mass and to store the potential energy. If necessary, the rock mass is lowered again and potential energy is transformed into electricity. A detailed description of the process can be found here. There is also a (german) presentation available by Prof. Heindl himself.
Image of Prof. Heindl's presentation of a Hydraulic Hydro storage facility.
This concept is one of many and it outlines the need for new concepts of energy storage for the 21st century.
