SunWorks Guide: How to Store Solar Energy
Solar energy, being derived from the sun, is easily one of the most renewable resources available, however it does have limitations. The maximum availability of the sun doesn’t always correspond with the high-energy demands of society. Solar energy can be harnessed only during the day and when it’s not cloudy. While the development of night solar panels is being explored, there’s little at the current moment to remedy this limitation. The question of how to store solar energy has been pursued for a while and there are various methods to achieve this.
In fact, energy storage is growing rapidly in the U.S. and, according to an Energy Storage Association report, is expected to grow sixfold between 2020 and 2025, when it could reach nearly 7.5 gigawatts annually.
How to Store Solar Energy Efficiently
How Does Energy Storage Work?
Energy storage is a means to capture electricity and deliver it when it’s most needed. Unfortunately, some energy is lost when converted and retrieved, so 100% efficiency can’t be achieved in this manner. However, it can contribute to increased system efficiency as well as resilience.
The types of solar energy storage available include:
Electrochemical batteries store solar energy through a chemical reaction involving the flow of lithium ions through an electrolyte. When photovoltaic cells collect sunlight, they produce electricity, and an inverter converts direct current to alternating current. Electricity is then sent into your house; that which isn’t used is directed to a battery if you have one (if not, electricity is sent to the grid).
When demand exceeds supply, meaning you need more electricity than is output by your solar energy system, the battery will automatically discharge power. Discharging the battery requires a reversal of the chemical reaction within it. A solar energy battery avoids pulling power from the grid and can provide backup power if needed; but whether you benefit from it depends on energy usage, production, utility rates, and other factors.
Other Storage Methods
- Thermal Storage: A thermal energy storage system can use water, molten salt, or other medium to absorb the sun’s heat and retain until it is needed. The medium is stored in an insulated tank. To generate energy, the heat is released in a process that usually involves boiling water.
- Mechanical Storage: Mechanical energy storage systems convert excess power into mechanical power using potential energy. They include flywheels, which spin to generate electricity, or compressed air pumped into tanks or underground reserves to generate electricity upon release.
- Pumped-Storage Hydropower: When the demand for energy is low, water is pumped uphill into a reservoir. During times of high demand, water is released downhill and turns a turbine. This process of generating electricity has been around since 1929. While a mature storage technology, it has significant infrastructure, permitting, and capital investment requirements
Other storage methodologies being studied include solar fuels. These could include hydrogen or methane to store solar energy in chemical bonds. Energy is then released when the fuel is combusted or consumed. Virtual storage requires no additional devices. A building itself can act as an energy storage vessel, holding warm or cool air that’s built up through intentional heating or cooling prior to anticipated peaks in demand.
Best Solar Energy Storage Solutions for Homes
Your home can become a virtual power plant by investing in solar. So far, lithium-ion batteries provide the most versatile, affordable option for residential use. Lithium-ion batteries aren’t as cheap as lead-acid batteries, but they have a longer lifespan (15-30 years) and are more efficient. Most standard solar batteries can also hold a charge for anywhere from one to five days.
Contact Sunworks USA
At Sunworks USA, we have helped make investing in solar practical for the average homeowner. We offer several plans and work with a network of solar finance partners. Free consultations are available to discuss possible solar solutions for your home, including photovoltaic panels, potential savings and other benefits, and battery storage options. Call 866-600-6800 today to get started.