Resources > Solar and storage: An ideal pair

Solar and storage: An ideal pair

• Factsheet

Before installing battery backup, Florida homeowners Steven Murphy and Betty Jo Henson lost power for two weeks during Hurricane Charley in 2004. “It was miserable,” Betty Jo said. “We didn’t want to go through that again.” Now, the couple has solar, plus a 10 kW battery that powers six circuits in their home.

Why pair solar with battery?

Solar alone, won’t keep the lights on

Natural disasters such as winter storms, hurricanes, and wildfires mean you need to be prepared in a grid emergency. So it’s no surprise that the adoption of home battery storage has grown steadily over the last decade.

Last year saw the largest number of battery storage installations in U.S. history, with a 40% increase over the prior year. New battery storage technologies and partnerships between battery vendors and solar installers are making it easier to install solar and storage together.

How does battery storage work?

Most rooftop solar systems are connected to the electric grid. This means that when the power goes down your solar system automatically shuts off. It does so as a safety measure so that it won’t feed electricity onto powerlines being worked on by technicians. So even if you install solar, you would still lose power without battery back-up.

Batteries paired with solar panels allow you to store the electricity the panels generate and use it later. They can power your home when the sun sets or the grid goes down.

The majority of home battery systems sold today use batteries made with the chemical lithium, called lithium-ion batteries. These batteries generally offer the best mix of safety, longevity, and low maintenance. Lithium-ion batteries are similar to what you will find  in electric vehicles and consumer electronics. These batteries are built as stationary appliances with robust safety features and monitoring controls.

Batteries store electricity as Direct Current (DC). This is different from the kind your appliances use, Alternating Current (AC). You will need a device that changes the electricity from DC to AC. This is called an “inverter.” Some batteries come with an inverter built in. Other systems will require you to buy one separately.

To get more in-depth information about batteries, inverters and what will work best for your home and budget, download the full Battery Storage Guide here.

Security & affordability

Adding battery storage to your solar system keeps essential home systems like refrigerators, medical equipment, and Wi-Fi online during an outage. It provides a level of security and peace of mind that you cannot put a price tag on.

Battery storage may also provide a financial benefit. Some utilities vary the cost of electricity throughout the day. This is called  “time of use” pricing. You can use your battery to store less expensive electricity and use that electricity when rates are higher.

Virtual Power Plant programs

Many states and utilities are beginning to adopt programs that chain together residential energy resources like batteries and smart devices. These are called Virtual Power Plants (VPP). Using a VPP serves as an alternative to turning on expensive gas-powered power plants when demand for electricity spikes. Joining one of these programs not only helps keep the lights on for everyone, it pays you for the power you share. Click here to learn more and see if there is a program in your service area.

Pros & cons of battery storage

Pros

• Protect your home and family from power outages and grid failures.
• Meet your critical energy needs in an emergency, especially if you rely on refrigeration, medical equipment or a well pump.
• Unlike gas-powered generators, you can refuel them for free from the comfort of your home. (Plus they are clean and quiet.)
• Enjoy increased independence from your utility.
• Save money if your utility charges more at certain time of day
  (see page 20 if the full guide).
• Protect the value of your solar system from net metering changes
  (see page 20 if the full guide).
• Join other cost saving and revenue earning programs like Virtual Power Plants.

Potential drawbacks

• The initial cost to install batteries is still relatively high, though it has been declining steadily year over year.
• With a complex system, there is a learning curve. You will need a certified and trusted installer to do the work.
• Added maintenance for your home (see page 23 of the full guide).

Thankfully Solar United Neighbors has a qualified team of professionals to answer any solar question you have. Click here to contact our Free National Solar Help Desk.

More resources

• Got questions? Our Solar Help Desk can talk with you
  about any solar issue you have and it’s always free!
  
• Get the most out of your system by joining
  a Virtual Power Plant program.
  
• Are you ready for the next blackout?
  Compare solar to gas when powering your home.