Ember Claims Battery Storage And Solar Can (Almost) Do It All

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June 21 is the longest day of the year in the northern hemisphere. Tomorrow, the days start getting shorter again. What better time for Ember, the clean energy advocacy folks, to release its latest battery report. Here’s the headline: “Batteries are now cheap enough to unleash solar’s full potential, getting as close as 97% of the way to delivering constant electricity supply 24 hours across 365 days cost-effectively in the sunniest places.” OK. First things first. Obviously not everywhere on Earth qualifies as one of the planet’s “sunniest places.” To explain that further, Ember has supplied this helpful graphic.

The Ember report focuses primarily on generating enough solar power to operate a typical residence. What is typical, of course, varies a great deal depending on where you are the world. Ember says, “On an average day in a sunny city like Las Vegas, providing 1 kW of stable, round-the-clock power requires 5 kW of fixed solar panels paired with a 17 kWh battery. This combination can deliver a constant 1 kW of solar electricity every hour over a full 24-hour period — and this amount of battery will be sufficient for most regions across the world.”

CleanTechnica readers, being well above average, will instantly realize that many homes, especially in wealthy societies, consume far more than 1 kW of electricity during many hours of the day. According to Google, the typical home on the US uses about 30 kW of electricity a day, which is more than the 24 kW Ember is projecting. But let’s not get lost in the weeds here. What Ember is really saying is that the levelized cost of electricity from solar plus storage is now the lowest of all available energy sources and that solar is getting closer to being dispatchable — meaning it will be there when needed — with every passing month and year. Here’s the synopsis of the report:

The emergence of 24-hour solar generation marks a fundamental shift in how solar fits into the broader power system. With the ability to deliver electricity around-the-clock, solar can now support 24/7 clean energy contracts (PPAs) for industries which require continuous power, not just daytime supply. This is extremely valuable for emerging economies, where solar-powered industrial and economic zones can emerge in sunny areas far from existing grid infrastructure. At the same time, it can also bring substantial potential savings on grid expansion costs – allowing up to five times as much solar capacity to be installed behind the same grid connection, maximizing existing assets and deferring costly upgrades.

As costs continue to fall and deployment accelerates, solar-plus-storage is emerging as the default model for clean power in the sunniest parts of the world — both on and off the grid. To fully realize its potential, energy policy must now catch up, by integrating 24 hour solar generation into planning frameworks, electricity market design, and infrastructure development strategies.

“This is a turning point in the clean energy transition,” say Kostantsa Rangelova, a ‍global electricity analyst at Ember. “Around-the-clock solar is no longer just a technical possibility and distant dream, but an economic reality. It unlocks game changing opportunities for energy-hungry industries like data centers and manufacturing. Solar will be unleashed. The change is new — the costs and quality of grid batteries have improved so much in the last 12 months. Now it’s time for policy and investment to catch up.”

Battery Storage Grew 41 Percent In 12 Months

When it comes to battery storage, Bloomberg agrees. It says that from April 2024 through April 2025, energy storage in the US surged from 18 gigawatts to 25 gigawatts, a 41 percent increase, according to federal data. In Arizona, battery capacity nearly tripled; in Texas, it has almost doubled.

“Renewable electricity is setting records every few days and comprised almost one-third of all US power generation in March. Batteries can make sure those electrons hit at the most opportune time – or at least that they don’t go to waste. Along the way, they’ll drag electricity prices down, speed the retirement of fossil fuel plants and preclude plans for new ones,” Bloomberg says.

Jan Rosenow, head of the energy program at the Oxford Environmental Change Institute, told Bloomberg, “Twenty years ago, the main problem with renewables was that they were so expensive. Now renewables are cheap, but we need to be able to match that supply to demand. For that, battery storage is clearly one of the best tools in the box.” He says there is a surge in grid-scale battery installations and because costs are dropping, more utilities will adopt storage as their default strategy for increasing the capacity of their grids.  “Storage is now where solar was maybe 10 years ago,” he said. “That’s kind of how it feels to me. It’s really mind blowing.”

According to the North American Electric Reliability Corporation, three of the six US major power grids are at risk of power outages this summer. That could place about a third of all Americans at risk of power failures this summer. NERC told Bloomberg this week that the odds of an energy emergency in Texas this summer are down from about 15 percent a few months ago to 3.6 percent today, thanks to increased storage battery capacity.

“Reliability is the ability to react to sudden changes in the grid,” said Chris McKissack, chief executive officer of Fullmark Energy, which is building two storage sites in Texas. “And when it comes to reacting, nothing moves faster than battery storage.”

Last summer, there were no major power outages in the US, a success the Department of Energy primarily attributed to new solar generation and storage. Officials at ERCOT in Texas say batteries have played a critical role in lowering retail prices of electricity, especially in the summer. They expect storage in the state to triple over the next five years.

In 2024, battery storage represented just 2 percent of power capacity in the US. BNEF expects utility-scale battery storage to nearly double this year despite how hostile to renewables the failed administration in Washington tries to be. In all, about 18 gigawatts of new battery storage capacity is expected to be added in the US in 2025. Those batteries are often the most affordable way for utility companies to add capacity. The average price for stationary storage systems in 2024 was $125 per kWh — 19% lower than in 2023 according to BNEF.

All of this good news about storage batteries — both residential and grid scale — does not mention what the source is of the millions of battery cells needed to construct those storage systems. But the answer is clear. China dominates not only the manufacturing of battery cells but also the supply chains for the raw materials that go into making them. China is also by far the largest supplier of solar panels. In the age of tariff diplomacy (which is really the opposite of diplomacy), the implications for the US could be enormous.

The methane, coal, and nuclear industries can see what is happening and no doubt they will unleash their legions of lobbyists to correct what they see as unfair competition by adding financial and regulatory burdens to the solar and storage industries. They see opportunities in powering data centers, thinking renewables and storage cannot meet their need for a stable 24-hour supply of electricity. Perhaps they are right, at least in the short term. But the pace of change is so rapid, even that advantage may soon disappear.