Attendees take pictures of the new Tesla Energy Powerwall Home Battery during an event in Hawthorne, Calif. (Patrick T. Fallon/Reuters)

One of the key technologies that could help wean the globe off fossil fuel is probably at your fingertips right now: the battery.

If batteries can get cheaper and store more power safely, electric cars and solar- or wind-powered homes become more viable, even on cloudy days or when the wind isn’t blowing. Discussion of such technological solutions will be one of the more hopeful aspects of United Nations climate talks this month in Paris.

“If you are serious about eliminating combustion of fossil fuels to power anything — a house, a city, a state — you can’t do it without [energy] storage,” which usually means batteries, said Carnegie Mellon University battery expert and inventor Jay Whitacre.

While batteries have been around for more than 200 years, this year the technology has amped up.

In October, an international team of scientists announced a breakthrough in overcoming major obstacles in next-generation energy storage and creating a battery that has five to 10 times the energy density of the best batteries on the market now. In September, Whitacre won a $500,000 invention prize for his eco-friendly, water-oriented battery. And in April, Elon Musk announced plans for his Tesla Motors to sell high-tech batteries for homes with solar panels to store electricity for nighttime and cloudy-day use, weaning the homes off dirtier power from the burning of coal, oil and gas.

“The pace of innovation does seem to be accelerating,” said JB Straubel, chief technical officer and co-founder of Tesla with Musk. “We’re kind of right at the tipping point where the current performance and lifetime of batteries roughly equal that of fossil fuels. If you are able to double that, the prospects are huge.”

At its massive Nevada Gigafactory, Tesla has started producing what it calls “powerwalls” to store energy in homes. They can’t make them fast enough for customers worldwide.

In November, a Texas utility said it would give wind-generated electricity free to customers at night because it couldn’t be stored. That’s where Tesla hopes to come in — not just in cars, but in homes. Within 10 years, Straubel figures, it will be considerably cheaper — and cleaner — to get energy through wind and solar power and store it with batteries than to use coal, oil or gas.

“What has changed is the Gigafactory,” said Venkat Srinivasan of the Joint Center for Energy Storage Research at the Lawrence Berkeley National Laboratory, near Berkeley, Calif. “Two years ago I didn’t think anyone would have thought you’d invest $5 billion in a big [battery] factory.’”

Tesla is using existing technology, just mass-producing and marketing it. That’s one of two key changes in the field. The other is work to make the battery itself much more efficient.

Start with that lithium-ion battery in your pocket. It was invented by John Goodenough, a professor at the University of Texas. His next task is a safer battery that uses sodium, a more plentiful element that can produce a faster charge.

“Now I hope to help free yourself from your dependence on fossil fuels,” he said on the same October day he was awarded part of a $1 million prize from Israel for innovation in alternative fuels. “I believe in the next year there will be a breakthrough,” he said. “I’m hopeful, but we’re not there yet.”

— Associated Press