These aren't your grandfather's batteries.

On Monday, Tesla officially brought a new energy storage facility online at a plant 40 miles east of Los Angeles. With 396 refrigerator-sized stacks of lithium-ion batteries, the plant uses energy collected from the sun and the electric grid to power 15,000 homes for about four hours in the evening.

The project could be a glimpse into the future of the energy sector. As renewable sources become as cost effective as fossil fuels, power plants like Tesla's can provide a means for harvesting and distributing that energy as needed. And while Tesla is leading the charge with its lithium-ion product, some smaller startups are creating new, innovative types of batteries.

The Tesla project came to be after a natural gas plant in Southern California suffered a methane leak in 2015, according to the New York Times. The California Public Utilities Commission moved quickly to award several contracts for supplemental energy storage, including the one for Tesla's battery operation.

About 10 percent of California's overall energy usage comes from solar, the most of any state. The state has an excess of energy during the day, when solar panels collect sunlight. Battery facilities like Tesla's can be used to store that extra energy and distribute it during the evening hours.

The Powerpack batteries used at the plant are larger, more powerful versions of the Powerwall, the suitcase-sized lithium-ion battery Tesla introduced in 2015 to store solar energy for later use in the home. But they're not the only--or even the best--means of storing huge amounts of energy.

In fact, lithium-ion batteries are quirky in their behavior, says Scott Sklar, professor of sustainable energy at George Washington University and president of clean tech advisory firm The Stella Group. The batteries, which have been sold commercially since 1991, need to be ventilated to avoid overheating, and they're subject to combustion if punctured or shifted too quickly.

Startups have developed innovative alternatives in recent years. Pittsburgh-based Aquion Energy creates sodium-ion batteries that rely on a mixture of manganese oxide and saltwater--creating a product that it says is non-flammable, non-explosive, and non-toxic. The company, which has more than $160 million in funding from investors including Kleiner Perkins and Bill Gates, won a 2016 Platts Global Energy Award for its battery.

Vionx Energy, based in Massachusetts, created a battery that exists in liquid form using an element called vanadium. The company, which began developing the energy storage system for the U.S. military and has raised $63 million in venture capital to date, is close to bringing its product to market--and it says the battery can last for decades.

All of these products have the potential to integrate well with solar, storing energy collected during the day and distributing it at night--either for a particular home or at grid scale.

"We're in a material science renaissance," Sklar says. "People will soon realize they can stop picking favorites--there are a lot of viable options out there."

Sklar adds that while the science behind Tesla's batteries might not be revolutionary, the company's business model could help bring about big changes in the industry. By offering standardized, web-enabled battery banks that come with service contracts, 10-year warrantees, and financing options, Tesla is creating a viable alternative to nonrenewable energy. "That's extremely important to scaling and commercializing battery banks," Sklar says. "So what Musk is doing is much more important than a particular battery chemistry."

Expect to see more companies follow suit in the near future--and even more products to spring up.

"The battery market is very dynamic right now," Sklar says. "I'm sure we'll see brand new [companies] within the next five years."