Electricity is mostly generated at an amount that meets what is demanded, as it is tricky to store surplus energy. Nevertheless it’s feasible to store smaller quantities of energy for personal and domestic uses. Batteries and fuel cells both produce electricity by employing electrochemical reactions. Flywheels store energy as they spin.
The battery
A convenient store of energy is the electric cell or battery. These are used each day to power torches, radios, toys and lots of other gizmos. The most common form of battery contains carbon and zinc separated by a solution of ammonium chloride. When the battery is attached to an electric circuit, its stored chemical power is changed into electric energy. The battery continues to supply an electrical current until all the chemicals have reacted with one another. Then, the battery is said to be ‘flat’. Batteries comprising nickel and cadmium (Nicads) can be recharged by passing a tiny electrical current thru the battery for one or two hours. This makes them last much longer.
Flywheels
Space stations use solar generating panels and fuel cells as their energy source. This energy is then stored in batteries. These batteries are large and expensive and need to be replaced each 5 years. But new space stations and satellites may use flywheels to store the energy. These can last as long as 20 years. Flywheels are employed in engines, but now scientists are designing far more efficient versions. When energy is used to spin a flywheel, the energy is converted to kinetic energy. The flywheel stores the energy mechanically in the form of kinetic energy. The quicker the flywheel spins, the more energy it stores. This energy can be converted to electricity. The new flywheels will be as small as just fifteen centimetres across, and made of highly strong, yet lightweight, materials. They will spin up to 600,000 times each minute, and can store 8 times more energy than a battery of the same mass.
Fuel Cells
It’s feasible that in the near future, car engines, batteries in laptops and even power stations might be replaced by fuel cells. Fuel cells date back to 1839, but until recently, only the US State Aeronautics and Space Administration (NASA) made use of them.
All fuel cells are energy converters, and work on identical elementary principle. They have two electrodes separated by an electrolyte, a substance that conducts electricity. A fuel like hydrogen enters at one electrode and oxygen enters at the other. They undergo a reaction, which produces an electrical current. When the fuel is hydrogen, the only waste product is pure water.
Fuel cells have many advantages. They convert energy much more efficiently than typical power sources: as an example, a fuel cell is two times as efficient as a vehicle gas engine and produces virtually no pollution. Additionally, they do not contain moving parts, so don’t produce any noise or vibration. An operating fuel cell is so very quiet and does not have wear and tear. However , there are a considerable number of issues to beat. Now, fuel cells are extremely costly, although this is thanks to the fact that only small numbers are being made. The price will fall once large quantities are produced. There are also issues of trustworthiness with some fuel cells. Additionally, some larger fuel cells have a poor power to weight and volume ratio. This suggests that for their weight or volume, they produce relatively small quantities of power.
Sarah Green is an environmental campaigner, activist, and robust disciple of being energy self-sufficient. In her free time, she reports on alternative DIY energy blueprints and kits, for example the ben ford homemade energy download.