Source: Hacker News

Year-end wrap-up

Coal makes a bit of a comeback, if only by accident.

Solar panels have gotten so cheap that it’s possible to spend more on their support system while still turning a profit.

Credit: Bilanol

On Tuesday, the U.S. Energy Information Administration released full‑year data on how the country generated electricity in 2025. It’s a bit of a good‑news/bad‑news situation.

• Bad news: overall demand rose appreciably, and a fair chunk of that was met by additional coal use.
• Good news: solar continued its run of astonishing growth, generating 35 % more power than a year earlier and surpassing hydroelectric power for the first time.

Shifting Markets

Overall, electrical consumption in the U.S. rose by 2.8 % (≈ 121 TWh). Consumption had been largely flat for several decades, with efficiency gains and the decline of industry offsetting the effects of population and economic growth. Year‑to‑year changes were driven by factors ranging from heating and cooling demand to the global pandemic.

Given that history, the growth in demand in 2025 is a bit concerning, but it isn’t yet a clear signal that the long‑term drivers of growth have fully kicked in.

These drivers include:

• The switch to heat pumps
• Electrification of transportation
• Growth in data centers

The first two involve a more efficient overall use of energy, but they replace direct fossil‑fuel use with electricity, thereby increasing grid demand.

How the demand was met

If demand had grown more slowly, the additional 85 TWh generated by expanded utility‑scale and small‑scale solar installations would have easily covered it. In reality, utility‑scale solar covered only about two‑thirds of the rising demand (or 73 % when wind power is included). With no new nuclear plants on the horizon, the shortfall was filled by fossil fuels.

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Hydropower has become the first energy source to be passed by solar power. It won’t be the last.
Credit: John Timmer

Fossil‑fuel market complications

In the recent past, any increase in demand would have been met by additional natural‑gas generation, thanks to abundant domestic production. However:

• High demand and increased tariffs have led to rising costs and long delays for gas‑fired turbine hardware.
  (S&P Global article)
• President Trump reversed Biden’s block on new facilities that export natural gas in liquid form, causing the domestic market to compete with international sales, which pushes prices higher.
  (EIA article)

Because of these pressures, coal became more economically viable than in recent years, and coal‑generated electricity rose by 13 %. Energy Secretary Chris Wright also ordered several coal plants slated for closure to remain available.
(Ars Technica article)

It is unclear how many of those plants are actually generating power; they would not have been kept open if demand could be met more economically without them. The administration’s promotion of natural‑gas exports likely had a stronger impact on coal use.

Net result

• Coal, solar, and wind all produced more power in 2025.
• Demand rose by more than any single source’s increase, but by less than the combined increase of those three sources.
• The excess generation displaced natural‑gas generation.

What’s coming next?

While the Trump administration has been hostile to renewable energy, there’s only so much it can do to fight the economics. A recent analysis of planned projects indicates that the US will see another 43 GW of solar capacity added in 2026—far more than the 27 GW added in 2025. That will be joined by 12 GW of wind power, with over 10 % of that coming from two offshore wind projects that the administration has repeatedly failed to block. The largest wind farm yet built in the US, a 3.6 GW monster in New Mexico, is also expected to begin operations in 2026.

That means wind and solar are well‑positioned to outpace hydropower as they provide an ever‑larger share of US electricity. It’s also likely to keep them ahead of any increase in coal power that occurs next year. Combined with hydropower, the growth in wind and solar should push renewable energy to nearly a quarter of the US electricity mix, barring a massive increase in demand.

Another major factor that will boost renewables is the rapid expansion of battery storage, which reduces the risk that excess solar power goes to waste. Often, the two are co‑located so that the batteries can use the same transmission infrastructure after solar stops producing. The EIA foresees 24 GW of new battery capacity being added to the grid, much of it in California and Texas. Of the 6.3 GW of new natural‑gas generation expected in 2026, 2.8 GW are expected to be combustion turbines, which are often used to compensate for the variability of renewable power.

The US is near a key pivot point, with wind and solar nearly (but not quite) growing fast enough to offset a significant rise in demand, and is likely to reach that point within the next few years. Grid operators are building the sort of support facilities that will blend in well with a future dominated by renewables. Unfortunately, market dynamics are causing a rise in coal use that could offset trends that would otherwise reduce our carbon emissions.

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John Timmer is Ars Technica’s science editor. He holds a B.A. in Biochemistry from Columbia University and a Ph.D. in Molecular and Cell Biology from the University of California, Berkeley. When physically separated from his keyboard, he tends to seek out a bicycle or a scenic location for communing with his hiking boots.