The sun produces enough energy in an hour and a half to power the world for a year. That’s a lot of potential energy. However, one of the main challenges, apart from capturing this energy, is storing it to use it when it’s needed. This post discusses common ways to store solar energy.
This is the most common way to store solar energy for residential users.
During the day, solar panels generate electricity. Some of this electricity is used to power the home, and the rest is either sold back to the grid or stored in a battery to power the home at night or on cloudy days when the solar panels aren’t producing energy.
There are many different types of solar batteries available on the market but the two most common are lead-acid and lithium-ion. In general, lead-acid batteries are cheaper but have a shorter lifespan and are less efficient than lithium-ion batteries.
Pumped Hydroelectricity Storage
This is a storage method that uses excess energy to pump water uphill into a reservoir. When energy is needed, the water is released and flows downhill through a turbine to generate electricity.
This is currently the most common type of grid-level energy storage and has been used for decades. The main downside to pumped hydroelectricity storage is that you need a large reservoir and suitable geography to make it work.
Compressed Air Storage
This is another storage method that uses excess energy to compress air into underground tanks. When energy is needed, compressed air is released, powering a turbine to generate electricity.
This is a relatively new storage method and there are only a few facilities in operation around the world. The main downside to compressed air storage is that it’s not as efficient, especially compared to pumped hydroelectricity storage.
This method also requires the use of fossil fuel to heat compressed air, which negates some of the environmental benefits of using solar energy.
This is a storage method that uses excess energy to spin a flywheel. When energy is needed, the flywheel is released, spinning a generator to produce electricity.
The problem with this storage method is that it’s expensive to build and maintain a flywheel. In addition, flywheels have short discharge times, meaning that they can’t provide energy for very long periods of time.
Thermal Energy Storage
This storage method uses excess energy to heat up a storage medium, such as molten salt or water. When energy is needed, the heated medium is used to generate electricity.
Thermal energy storage is currently one of the cheapest and most efficient ways to store solar energy. The main downside is that it requires a lot of space and it can take a long time to heat up the storage medium.
Hydrogen Energy Storage
Hydrogen Energy Storage uses energy to split water molecules to produce hydrogen gas. Hydrogen is then used (in a number of ways, including as fuel) to generate electricity or heat when required.
This is a relatively new storage technology and there are some safety concerns with using hydrogen gas, as it’s very flammable and can be dangerous to store and transport.
Superconducting Magnetic Energy Storage
In this energy storage method, electricity is used to generate a magnetic field in a coil. The coil is made from a superconducting material that has been cooled below its critical temperature, significantly reducing its resistance. As a result, the electricity can flow much more efficiently.
This is a very new storage technology and there are no commercial facilities currently in operation. The main downside to superconducting magnetic energy storage is that it’s very expensive to build and maintain.