How you store energy and the energy density that you can store is critical to the development of many green projects.
For example, you can store the energy in a battery; seems simple. The battery construction, energy density and weight (if the application is mobile) all play key roles. The three key factors for comparison terms are $ per watt hour, watt-hour/kg and watt hour per litre. These metrics then can help you define a solution as to the battery type, cost and size/weight.
Lead acid is cheap – $0.17 w/h – but only gives 41 w/h per kilo whereas lithium ion is expensive ($0.47 per kilo) but gives over 125 w/h per kilo as its energy density.
A lot of projects we are seeing involve energy storage but in different ways.
Kinetic Energy Storage such as using photovoltaic energy harvested in daylight where you pump water to the top of a mountain or hill and then release it at night through a turbine. There are many variations of this system, but these take advantage of energy gluts.
Cryogenic where energy is used to convert air into a liquid at very low temperatures below -170°C. This is then stored and when needed the liquid air is allowed to heat and expand driving a turbine to create electricity.
Liquid Salts that are heated to 400°C and are used to retain energy for later release. These hold a higher energy density than most other solutions.
Each of these processes have their own strengths and weaknesses but what they all have in common is the use of technical ceramics. Where extreme conditions prevail and the process uses high temperature corrosive salts, low temperature cryogenic gases, experiences wear or requires electrical insulation, technical ceramics incorporated into the design provide the perfect solution.