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Storing Electricity
When we are using independent electrical power we most commonly get our electricity from two sources: a generator and renewable energy from solar panels. Both of these sources have limitations.
Sophisticated modern generators, such as Eniquest’s range of diesel generators, are extremely quiet; however, even they make some noise. And all generator unavoidably produce exhaust fumes and heat, so the less time a generator runs the better. Generators are at their most efficient when they are producing lots of power – when the demand on them is very low they are much less efficient. A generator is at its best when it runs for as short a time as possible, while producing lots of power.
Solar energy is the best form of renewable energy to use on a small scale at any location because it’s relatively cheap, scalable, reliable, low maintenance, long-lasting and sunlight is available anywhere. Solar panels can collect a lot of energy, but they can’t provide electricity for our high-powered appliances. We could install enough solar panels to match our maximum power demand, but this would be very expensive and would take up a lot of space, and still wouldn’t help us at night when solar panels don’t produce any energy.
The Advantages of Storing Electricity
The solution to the limitation of both generators and renewable energy from solar panels is to store the electricity that they make. When electricity from the solar panels is stored, we can use it when we need it, and we can take as much power as we want from the storage. We can store the steady, but relatively low-powered flow of solar energy that we collect during the day, and use it at night or whenever we need it, and we can concentrate it in storage for use with high-powered equipment.
When electricity from the generator is stored, we can retrieve it silently and unobtrusively from the storage when we need it. When the storage needs recharging the generator does it quickly at a time that is most convenient, so that any disturbance from noise or exhaust fumes is minimized.
Energy Storage Mediums
There are many ways of storing energy, and they nearly all involve changing the electrical energy to another form of energy to store it and then back to electricity again when we want to use it.
Some energy storage mediums are:
Heat:
Electricity can be used to heat and melt salts. The energy is converted back to electricity by using the heat from the molten salt to make steam to run a steam-turbine generator. This storage method is used in concentrated solar power plants that use molten salt heat storage.
Gemasolar molten-salt heat storage concentrated-solar power plant in Seville, Spain
Gravity:
Electricity can be used to pump water into high-level reservoirs. The energy is converted back to electricity by running the water through a hydro-turbine which is connected to an alternator.
Wivenhoe Power Station in Queensland, Australia
Inertia:
Electricity can be used to spin a flywheel to a high speed. The energy is converted back to electricity by using the flywheel to turn an alternator.
Chemical:
Electricity can be used to cause chemical reactions that can be reversed to produce electricity. Rechargeable storage batteries and fuel cells use chemical energy storage.
The best way to store electrical energy for independent power plants is to use rechargeable batteries in a storage battery bank.