The market for home energy storage in batteries is evolving quickly. These six points from a recent forum lay out the importance and future of energy storage for our homes.
Talking Tech at Georgia Tech
The MIT Enterprise Forum Atlanta hosts a series of events each year. The group’s most recent forum, titled “Charging Into the Future: The Impacts of Improved Battery Storage Technologies”, focused on how the evolving technology of batteries is changing everything from vehicle emissions to energy consumption in our homes.
The image above shows the participants in the panel discussion. From left to right, they are Jonathan Goldman (Moderator) of Georgia Tech’s VentureLab; Gleb Yushin, Professor of the School of Materials and Engineering at Georgia Tech; Ben Wrightsman, the Chief Operations Officer and Chief Engineer at the Battery Innovation Center; Carlos Restrepo, VP of R&D for Sonnen U.S.; and Michael Austin, VP of BYD America.
There were a number of key take-aways from the discussion:
1. The Race is On to Balance Battery Attributes
Gleb Yushin is an expert in the chemical composition of batteries. In his comments, he compared different types of batteries so the audience would appreciate the strengths and weaknesses of each. The various chemical compositions in batteries deliver various combinations of power, capacity and the number of times the battery can be cycled (charged, discharged and recharged).
A battery with the right balance of power, capacity and cycles may be appropriate for a car but not appropriate for storing energy in a home because the requirements are difference. The chemical compounds in the batteries may also be expensive so the price of a battery may be prohibitive for some uses. For example, you might pay a significant amount for the battery in a Tesla Model S because you like the other attributes of the car though you wouldn’t pay that amount of money for a battery that sits in your home.
2. Simple is the Bridge to Energy Independence
In his remarks, Michael Austin noted the importance of repurposing and recycling batteries. His company produces a relatively simple iron-phosphate battery. An iron-phosphate battery doesn’t deliver the power that a lithium ion battery (in the Tesla Powerwall) delivers though iron-phosphate batteries are inexpensive, easy to maintain and offer a very high number of cycles.
As you can see in Michael’s slide above, the iron-phosphate batteries his company produces often start out powering buses and cars. They deliver such a high number of cycles that they can be taken out of vehicles and repurposed to energy storage in homes. They’re bulky so they’re a good, low-cost solution for homes that have some room for the battery storage. In a smaller home, like a condo, it may be best to opt for a more compact battery like Tesla’s lithium ion battery – unless you plan ahead for your energy storage.
3. Batteries Without Renewable Energy
It’s more and more common to see on-site renewable energy sources like PV (solar) panels paired with batteries to store energy that can be used when the renewable energy sources like sunlight and wind aren’t available. That doesn’t mean you must have an on-site renewable energy source to have batteries. You could invest in batteries to avoid the peak costs for power consumption from your power company.
For example, as the cost of home energy storage in batteries drops, it may make sense (if it doesn’t already) for you to buy a battery storage system that you charge using off-peak (lower rate) power from your power company. Your power company may offer a plan where you can buy significantly cheaper power overnight when the power company doesn’t have to meet the peak loads during the day when we’re using heating and cooling systems plus all of our gadgets.
4. Battery or Generator?
If you live in an area where the power grid is not stable, you could probably benefit from energy storage in batteries. This is true for rural areas that lose power for short periods of time when power lines are knocked down by tree branches.
Relying on a gas generator is similar to relying on a battery – you get a limited amount of power from the fuel you’re using to run the generator. A battery backup should require less up-front expense and on-going maintenance costs so it might be a better solution for properties that are subject to short power outages and brownouts.
5. Peak Shaving
As battery technology and controls evolve, our society should become more and more efficient when it comes to storing energy. Now, we waste power because we don’t have storage capacity that’s always available. As we begin to connect cars, home energy storage batteries and other devices to the “internet of things“, we should be better able to capture extra power so that it can be used when needed. That means you may have an electric vehicle in your garage sometime soon that functions as a battery back-up in case of a power outage.
Having lots of options for storing excess power is important for avoiding the cost of power generation. Power plants are extremely expensive to build, operate and maintain. They also tend to use significant amounts of water.
If we can store excess energy to be used later during peak demand (like the power demand from air conditioners on a hot afternoon), we won’t need to build so much power generation capacity. We’ll be able to “shave” the peak demand with power that was stored when we had excess capacity.
Power companies in states like California are using grid-scale solutions to do this now. That means they’re using huge battery packs the size of trailers to store excess power to meet peak demand later. As our technology evolves, that power for peak shaving might come from a vehicle in your garage.
6. Safety Remains a Key Concern for Home Energy Storage
Safety will always be a key concern for home energy storage. There are two critical aspects to consider when you invest in home energy storage in a battery: 1) the safety record of the type of battery you choose, and 2) the proper installation and maintenance of the system.
Not all batteries are created equal and some are more likely to experience a failure… which Michael Austin refers to as a “rapid disassembly”. Even if you choose a battery with an excellent safety record, an improper installation (just like any electrical component) can result in significant damage to your home. It’s worth finding experienced professionals to design, coordinate, install and maintain any home energy storage solution.
We’re still at the front of the market for home energy storage in batteries so there’s a lot of room for improvement. Early investors will pay a premium for battery technologies compared to people who invest later though it’s possible to get the numbers to work now – you can save money on some situations now rather than waiting.
It will be exciting to see what innovations emerge and how they contribute to lowering the cost of home energy storage. It’s exciting because these technologies will help protect home owners from rising energy costs and help all of us travel further down the road to energy independence.
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