The top 12 most viral Canary stories of the year analyzed controversies, answered burning questions, reported on a wild policy shift and featured new ideas in clean energy industries, including electric vehicles, solar, nuclear and heat-pump technology. Did your favorites make the list?

In tension-building reverse order, here are this year’s top hits.

12. Why is California wasting millions on hydrogen fuel pumps?

The California Energy Commission plans to spend a total of $279 million on building out a network of more than 100 hydrogen filling stations in the state. But, as this article makes clear, electric vehicles have crushed the fuel-cell competition in the race to zero-emissions driving. So what’s the point of that funding?

11. Will the Biden administration let one company kill U.S. solar?

Early this year, one tiny solar panel manufacturer, Auxin Solar, threw the industry into chaos. It petitioned the U.S. Commerce Department to impose new tariffs on modules from Cambodia, Malaysia, Thailand and Vietnam. ​“We’re talking about freezing the largest sources of supply for the U.S. market,” said one insider. ​“It’s going to be madness.” This article kicked off a solar saga; the latest installment had the Commerce Department proposing tariffs that would kick off in June 2024.

10. EV battery recycling is costly. These 5 startups could change that

How will the clean energy industry handle electric vehicles’ spent batteries? These companies are recovering the valuable metals in used batteries to make new ones in a variety of ways.

9. Chart: These countries have the most electric vehicles per capita

Electric vehicle sales are booming. But what countries are leading the race to electrify their cars? Click for the chart, stay for the Will Ferrell Super Bowl ad reference.

8. Chart: How much oil does the U.S. actually import from Russia?

Russia’s invasion of Ukraine compelled many of us to scrutinize the large volumes of Russian fossil fuels in global energy markets. So just how much oil was Russia sending to the U.S. before the invasion? It was the third-largest foreign supplier in 2021, so more than a drop in the barrel.

7. These new double-duty heat pumps can warm both air and water

Startup Harvest Thermal has a hybrid heat pump that could help reduce strain on the grid. The company’s software can direct their devices to use electricity to heat water during the middle of the day when demand is low and solar energy floods the grid. Water that’s preheated by clean, cheap energy acts as a thermal battery and can be used later for a hot shower or to warm a room.

6. Bill Gates’ nuclear startup wins $750M, loses sole fuel source

The advanced nuclear-fission startup TerraPower has investor backing but not a reliable supply of the fuel it needs, high-assay low-enriched uranium (HALEU). That’s because the only facility able to supply commercial quantities of HALEU is in Russia. ​“When Russia invaded Ukraine, it became very clear…that using Russian fuel is no longer an option for us,” said Jeff Navin, TerraPower’s director of external affairs.

5. As California guts solar net metering, batteries emerge as a moneymaker

In December, California weakened its net-metering regime. Instead of paying rooftop-solar owners the retail rate for electricity they send to the grid, utilities will pay them based on the power’s value to the grid, which varies hour by hour. It’s a structure that incentivizes solar-plus-battery systems that allow customers to feed the power to the grid when it’s most lucrative.

4. U.S. schools can subscribe to an electric school bus fleet at prices that beat diesel

How can more schools adopt electric school buses? One way is to simplify the process by subscribing to a fleet instead of buying one. Companies Highland Electric Fleets and Thomas Built Buses lease electric buses to school districts at subscription fees designed to be less than the cost of owning diesel fleets.

3. A 100 MW solar farm in Texas will mount panels directly on the ground

Readers stampeded to this story — and for good reason. Erthos, a company that forgoes steel racking for its solar arrays, says its approach could save up to 20 percent of the cost of installing utility-scale solar. That’s a discount to make hearts race in the clean energy industry.

2. Finally, a heat-pump water heater that plugs into a standard outlet

Water heaters snapped up the No. 2 spot on our list; who knew they could be so hot? Most highly efficient heat-pump water heaters need a 240-volt outlet. But Rheem rolled out a version that can plug into the more ubiquitous 120-volt socket. It’s a huge win for home electrification. And I want one.

1. This tiny fusion reactor is made out of commercially available parts

Fusion reactors that use magnets can occupy hundreds of acres. But nuclear startup Avalanche Energy plans to scale down a fusion reactor to the size of a fire extinguisher. This story came out seven months before news of a nuclear-fusion breakthrough (using lasers) at a U.S. government lab. Don’t expect either approach to power your home anytime soon, however.