Things to Consider Before Installing a Battery Energy Storage System

Things to Consider Before Installing a Battery Energy Storage System

Solar battery storage is a backup power supply that allows you to shift excess solar energy to peak consumption times, reducing your electric bills. It’s also ideal for areas with utility rates that don’t compensate you fairly for solar net energy metering.

Battery storage is available in two different configurations. The most common use is a DC-coupled system that requires an intelligent inverter.

How Much Energy Do You Want to Store?

In its most basic form, solar energy storage systems accumulate clean power generated by rooftop photovoltaic panels and store it as electricity in electric batteries. Unlike mechanical systems like pump hydro or flywheels that store energy mechanically, battery storage uses a chemical reaction to accumulate and release energy.

A standard home battery system like Tesla’s Powerwall offers 13.5 kilowatt-hours (kWh) of energy storage capacity. This is enough to run a refrigerator, lights, and other appliances for 67.5 hours, according to EnergySage.

Home batteries also have intelligent software that optimizes charging based on solar production, usage history, and utility rate structures to reduce or avoid demand charges altogether. This is the primary way that ESS can save homeowners money. However, there are other reasons to install one.

How Many Batteries Do You Need?

The number of batteries you need for a backup system depends on the amount of electricity your house’s load uses. To size a battery, find the wattage of each appliance or system in your home and estimate how much they run daily. You can then use that information to calculate a daily energy usage number (kWh) and the battery capacity needed to provide backup power for a few days.

Suppose you’re using solar energy storage for resiliency. In that case, you want enough batteries to avoid peak pricing hours and energize your household during grid outages or when the sun isn’t producing electricity. Additionally, you can take advantage of state or local incentives that help make batteries more affordable.

Do You Need a Backup Power Supply?

You can install solar without battery storage if you’re OK with drawing electricity from the grid during power outages or are in a location that doesn’t experience frequent blackouts. But, paired with solar panels, battery energy storage can lower your electricity cost by reducing or eliminating demand charges.

Energy storage reduces costs by storing electricity when it’s cheap to generate (like during the daytime) and discharging it when it’s expensive to consume (like during the peak summer days when everyone is running their air conditioners). Mechanical energy storage technologies like pump hydro storage and flywheels can also lower utility costs, but these solutions require a substantial upfront investment. Moreover, they’re more expensive than lithium batteries.

Do You Need a Battery Monitoring System?

Combined with solar panels, battery energy storage systems charge during daylight and discharge at night to replace utility electricity. This helps to eliminate peak demand charges from the electric utility during high usage periods. Intelligent battery software also coordinates with weather patterns, usage history, and utility rate structures to optimize when energy is consumed.

During an outage, battery storage systems power critical loads for extended periods. Installers will review your energy needs, including lighting, appliances, and other electrical equipment you want to keep running, to determine how much of your battery’s capacity should be reserved. Battery energy storage systems are rated in kW and kWh, and onboard sensors maintain appropriate operating temperatures and monitor performance. Most AC-coupled units have integrated inverters, making installation simple and inexpensive.

Do You Need a Battery Safety System?

Lithium batteries are flammable, so a battery safety system is crucial to keeping them safe. It monitors the cells and sometimes controls cooling fans to keep temperatures in check.

It also ensures that the cell voltage remains within its safe limits and protects against short circuits and reverse polarity connections, common causes of batteries failing. Finally, it monitors the battery for thermal runaway, where a failed cell can heat up and vent with flame.

BESS manufacturers test their batteries under extreme conditions to ensure they work correctly, even in the most challenging environments. This is because they must be able to deliver the performance needed under demanding conditions without compromising on functional safety. This testing includes dropping them from great heights, exposing them to extreme mechanical loads, and testing them for fire resistance.

Do You Need a Battery Charger?

Battery chargers vary in how they manage the process of charging batteries. A simple charger delivers a constant voltage to the battery while charging, and once the charge current falls below a minimum value for some time, it moves into float mode.

Many chargers provide multiple battery banks or bays to charge up several different types and sizes of batteries simultaneously. This can save you time and help ensure each battery receives a full charge.

Some chargers work well with disposable batteries, while others are designed for lead-acid batteries like those used in cars and power sports equipment. Before installing, check that your charger supports your specific battery type and size. Choosing the right size is also essential; it’s easy to overcharge your battery and shorten its life.

Do You Need a Battery Disposal System?

Millions of batteries are bought and used yearly in the United States. Batteries are sold in various chemistries, types, and sizes to fit their uses. When they are no longer helpful, they must be managed correctly to prevent risks to public safety and the environment.

Fortunately, standard AA, AAA, C, and D alkaline batteries no longer contain mercury and can be discarded with regular household trash. However, rechargeable and automotive batteries must be returned to battery retailers or taken to household hazardous waste collection points for management.

Large solar batteries are also being used to power electric vehicles and energy storage systems that can be installed on buildings. These batteries use lithium, a critical mineral with limited supply. When improperly disposed of, these batteries leak toxic heavy metals into the soil and groundwater, contaminating ecosystems and endangering human health.