Governors' Wind Energy Coalition

Another possible milestone of technology passed quietly not long ago. It might be the beginning of the end for fossil fuels and the key to reaching the goal of a green power grid. If so, it will certainly be among the most important stories of the year — bigger than space tourism, bigger than the Arizona election audit, bigger than the discovery that the amazing Simone Biles is human, not a god.

A Boston-area company, Form Energy, announced recently that it has created a battery prototype that stores large amounts of power and releases it not over hours, but over more than four days. And that isn’t the best part. The battery’s main ingredients are iron and oxygen, both incredibly plentiful here on God’s green Earth — and therefore reliably cheap.

Put the two facts together, and you arrive at a sort of tipping point for green energy: reliable power from renewable sources at less than $20 per kilowatt-hour.

Some readers of this column will be experts in battery technology, and for them it may be useful to note that the history of battery engineering is littered with duds that were heavy on hype and big on disappointment — including earlier iron-air cells.

Use of renewable energy sources, especially wind and solar, has grown dramatically over the past generation, but renewables still comprise a small slice of the total U.S. energy budget. Storage is holding them back. People need electricity all the time, not just when the sun shines or the wind blows.

The cost of storage is critical. Utilities will change sources if the price is right. Coal used to be king in the power sector, but cheap natural gas has cut coal’s share of the energy diet in half since 2005. Renewables will never meet their potential until battery storage for green power is cost-competitive.

At Tesla, Jaramillo understood that electric vehicles are a limited solution to greenhouse emissions as long as batteries are charged by burning fossil fuels. His new venture looked at past disappointments in battery technology to find the most promising for a new approach.

According to its announcement, Form Energy has the process working well under lab conditions. The next step is to build a warehouse-size battery plant to support an electric utility in Minnesota. If successful, a one-megawatt battery will be able to power the entire utility for nearly a week between charges by 2024.

Then we’ll begin to know just how important this is.

If iron can take over large-scale storage from lithium, it will cool the flame under that kettle. The United States can aim for self-sufficiency in storage batteries. And this truly will be a blockbuster story of 2021.