Energy Storage: What Is It & How Does It Work?
Energy storage is growing in importance in our green energy future. Renewable energy is often intermittent, meaning that it must be stored when it’s produced for use later when it is needed. Advances in energy storage may reduce the cost of electricity and the carbon footprint of energy production.
What Is Energy Storage and Why Is It Important?
It’s helpful to know exactly what energy storage is. It means having a way to capture energy at the time it is produced and save it for use at a later date. A solar panel produces electricity all day, but to use that energy at night, you need a way to store it. We are going to explore various technologies that define what stored energy is.
How Does Energy Storage Work?
How is energy stored? Energy storage is a rapidly evolving field of innovation as it is a key component to green energy. How energy storage works is the important question. Here are the leading approaches.
Battery Energy Storage
Batteries are an electrochemical way to store energy. Chemicals interact in a controlled fashion to produce electricity. A battery has some basic parts:
- Positive electrode that collects negatively charged atoms
- Negative electrode that collects positively charged atoms
- Electrolyte that is a chemical solution that reacts to create atoms with a positive and negative charge
When you connect a device, such as a lamp, to a battery, it both creates a circuit and initiates chemical reactions in the electrolyte. The positive electrode contains atoms with extra electrons. When you complete the circuit to the negative electrode, you start a chemical reaction that creates positive ions, that is atoms with more protons than electrons. The extra electrons in the negative electrode flow to the positive, recombining in a second chemical reaction. The flow of those electrons is the electricity that powers the lamp.
We can store energy in batteries because this chemical reaction is reversible. When you charge the electrolyte with wind, solar, or another source of power, it holds the charge until a circuit is created and the power is then discharged.
It is worth looking at battery storage as a key component for some renewable residential and commercial customers.
Solar Energy Storage
Solar energy storage is a system that includes photovoltaic cells for collecting the energy of the sun connected to a battery or bank of batteries. In considering solar energy pros and cons for your home, you will want to include the purchase and maintenance costs for solar collectors and how energy is stored from them.
You can still benefit from solar energy storage and renewable solar energy without investing in your own equipment. Renewable energy plans source your power from green energy sources like solar at scale.
Pumped Hydroelectric Storage
Many industries require “dense” power, which is a large amount of electricity in a certain space and time. Manufacturing a car takes more energy than powering a lamp on your desk.
You might ask: What is hydropower? It is an example of dense, yet renewable and affordable on-demand electricity. Hydro power is kinetic energy that is generated by water in a high place flowing downward to a lower place and passing through turbines that spin.
Pumped hydropower is a variation on this model. When demand for power is low, the plant uses the excess electricity to pump water up into a higher reservoir where it waits ready to flow during times of high demand. Engineers are working on closed systems that use solar power to pump water up to a reservoir during the day to be released at night when the energy is needed.
Thermal Energy Storage
Storing thermal energy collects cold or warmth in water, rock and chemical solutions during one time for use during another. A simple example is heating steel drums of water in the sun during the day to collect heat, and then relying on that heat during the cold of the night as it dissipates. Stored heat and cold can be used hours, days, even months after it is collected.
Compressed Air Energy Storage
These systems use energy to compress air into tanks. Compressing takes kinetic energy, that is power that is moving something. When it is released, it can turn the blades of a turbine and create electricity, another form of kinetic energy. Engineers are working on newer systems that also take advantage of the heat that is generated during compression that is released during release and expansion.
A flywheel is a device that takes advantage of inertia. When you apply energy to start a wheel spinning, it keeps spinning for a while after you stop. Imagine turning your bike upside down and spinning its wheel with your hand. When you stop, that wheel keeps going for quite some time. Commercial flywheels are very heavy and strong. It takes significant energy to get them started spinning, but they can keep going at a high speed for a long time. As they spin down, they generate electricity.
What Energy Storage Devices Are Available for Homes?
If you’re wondering how to store electricity for your home, batteries are the most accessible and practical form of energy storage for residential use. It’s possible to use your EV charger installation to charge other household batteries.
Geothermal energy is a form of energy storage using heat stored deep inside the earth to power your home.
Some thermal storage approaches can be adopted as do-it-yourself projects. Current commercially available thermal energy storage systems are scaled for larger facilities and are outside the budgets of the average household.
Learn How Constellation Can Lower Your Energy Costs
Switching to an energy supplier such as Constellation may lower your energy costs. In addition to saving on energy, customers in Maryland, Atlanta, Dallas and Houston can take advantage of home services, which can help keep your systems running at peak efficiency.