Energy Weekly Review 2026-07-17
Week In Review
The week’s most striking pattern is a clean-power sector where individual records are beginning to compound into infrastructure. Two independently reported perovskite milestones — Longi’s 35.5%-efficient perovskite-silicon tandem cell and a perovskite triple-junction cell holding 27.3% for more than 770 hours — signal that the long-standing trade-off between headline efficiency and operating stability is finally softening. Meanwhile, a July 10 Nature paper on how lithium dendrites crack solid electrolytes removes one of the last physics-level unknowns blocking commercial solid-state batteries.
At the grid scale, projects that used to be discussed as speculative are now getting formal approvals and hard timelines. New South Wales granted final planning consent to the A$1.8 billion Stratford Pumped Hydro and Solar project on a former coal mine, while Australia’s transmission operator Transgrid opened a pathway for 900 MW of grid-forming battery storage to substitute for retiring synchronous generation. In Brazil, the Ministry of Mines and Energy accelerated the 1,500-km, ±800 kV Maranhão–Goiás HVDC line by two years to a 2028 completion, unlocking 5 GW of renewable capacity for the country’s populous southeast.
The theme of “firm clean power” got the most concrete week it has had in years. Four US advanced microreactors reached first criticality by the July 4 deadline set in a 2025 executive order, a pace MIT Technology Review described as “a big milestone” for the domestic nuclear sector. Fervo Energy’s Cape Station in Utah, meanwhile, has emerged as the most productive enhanced geothermal system ever tested, with its first 100 MW scheduled to reach the grid this fall. Ocean Winds’ 30 MW EFGL floating array off France reached full power, the first commercial floating wind farm designed as nature-inclusive infrastructure.
Cost and materials work is following behind these headline milestones. A team at Spain’s Instituto de Tecnología Eléctrica introduced new PEM electrode designs and digital durability tools targeting cheaper green hydrogen. Taken together, this week’s stories suggest a clean-energy build-out that is no longer paced primarily by science risk but by permits, transmission, and manufacturing scale — problems that are hard, but tractable.
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Longi Sets 35.5% World Record for Perovskite-Silicon Tandem Cell
Longi Green Energy Technology announced a 35.5% conversion efficiency for a two-terminal crystalline silicon-perovskite tandem solar cell on July 14 at its 2026 Solar and Storage Innovation Technology Conference at Shanghai Jiao Tong University. According to pv magazine, the result was independently certified by the European Solar Test Installation (ESTI), part of the European Commission’s Joint Research Centre in Italy.
The 35.5% figure is significant because it pushes tandem architectures closer to the roughly 42% theoretical ceiling for two-junction devices and, more practically, well past the roughly 29% single-junction limit of silicon alone. That extra headroom is what makes perovskite tandems attractive as a next-generation module technology rather than a lab curiosity: for a given rooftop or utility-scale plot, more of the incoming light is turned into electricity.
Longi is one of the world’s largest silicon module producers, and its willingness to run these certification events publicly suggests the company is preparing manufacturing lines rather than just chasing a line-item on efficiency charts. Cell-level records historically take three to five years to translate into commodity modules, but the gap between records in the lab and shipped products has been narrowing quickly in the tandem space.
Source: pv magazine
Nature Study Explains How Dendrites Crack Solid Electrolytes
A paper published in Nature on July 10 resolves a long-standing mystery in solid-state battery research: how soft lithium dendrites, only microns wide, manage to physically split the hard ceramic electrolytes that were supposed to stop them. The authors combined in-operando imaging with a mechanics model to show that dendrites exploit pre-existing microstructural defects in the ceramic and drive cracks open through wedge-like stress concentration at the tip.
The finding matters because dendrite penetration is the failure mode that has kept solid-state batteries out of high-volume production despite years of investment. If the crack propagates, the two electrodes short-circuit — and unlike a conventional wet lithium-ion cell, a shorted solid-state cell has no self-healing pathway.
With a mechanistic picture in hand, cell engineers can now target specific mitigations: densifying the ceramic near grain boundaries, applying compressive prestress, or engineering the anode interface to spread current more evenly. The result strengthens the case that solid-state batteries — which promise higher energy density and better safety margins than liquid-electrolyte cells — will be commercially viable rather than perennially “five years away.”
Source: ScienceDaily / Nature
NSW Approves A$1.8 Billion Stratford Pumped Hydro and Solar Project
The New South Wales government approved the Stratford Pumped Hydro and Solar project on July 15, the state’s first pumped hydro project to secure final planning consent in six years. The A$1.8 billion development will site a 300 MW pumped hydro station with 12 hours of storage and a 320 MW solar farm on the former Stratford coal complex in the Gloucester Valley, roughly 100 km north of Newcastle.
The project is being developed by Gloucester Coal, a subsidiary of Yancoal Australia, and reuses infrastructure and voids from mining operations that ended in 2024. Building storage on decommissioned mine land solves two problems simultaneously: it accelerates permitting on already-disturbed ground, and it gives a fossil-fuel workforce a plausible transition target. The state projects roughly 350 construction jobs and 10 permanent operations jobs.
At 3.6 GWh of stored energy — the 300 MW power block over its 12-hour discharge window — the project is forecast to deliver around 13 percent of NSW’s 2034 long-duration storage target on its own. The state expects operation as early as 2029.
Source: NSW Government
Transgrid Opens 900 MW Pathway for Grid-Forming Batteries in NSW
Australian transmission network operator Transgrid published an updated assessment on July 15 that formally routes 900 MW of grid-forming battery storage into the state’s minimum system strength requirements. The pathway sits on top of the 5 GW of grid-forming capacity already identified in the initial portfolio and is targeted for the Sydney West region by the early 2030s.
Grid-forming inverters differ from conventional grid-following inverters in that they can establish their own voltage and frequency reference rather than tracking one from a large spinning generator. This makes them a plausible substitute for the synchronous condensers and thermal plants that have historically provided system strength — a critical service as coal generation retires.
Notably, Transgrid’s report cites a 38% surge in synchronous condenser costs as part of the economic case for using batteries for the same service. If the assessment is upheld after a one-month consultation ending late August, grid-forming BESS would move from “priority research topic” to a formally credited operational resource in the National Electricity Market — a globally important regulatory precedent.
Source: Energy Storage News
Ocean Winds’ EFGL Floating Wind Farm Reaches Full Power Off France
Ocean Winds announced on July 10 that its 30 MW Éoliennes Flottantes du Golfe du Lion (EFGL) project reached full power, becoming the first fully operational commercial floating offshore wind farm in France. The array consists of three 10 MW turbines mounted on semi-submersible floaters, sited 16 km off the Occitanie coast in water depths that would preclude conventional fixed-bottom foundations.
EFGL is projected to generate about 110,000 MWh per year — enough for roughly 50,000 people — over a 20-year design life. What makes the milestone notable beyond its size is the design philosophy: Ocean Winds describes EFGL as the world’s first floating wind farm operating on nature-inclusive principles, with structural features intended to serve as artificial reef habitat and mooring hardware designed to support benthic biodiversity.
The Mediterranean and the deep U.S. Pacific and Atlantic shelves are the natural markets for floating wind, and a 30 MW pilot delivering to a real grid is exactly the reference point that supply chains, insurers, and offtake buyers need in order to move from experimental to serial deployment. Analysts project the floating offshore wind market to grow from roughly $3 billion in 2026 to $25 billion by 2031.
Source: Ocean Winds
Four US Advanced Microreactors Reach First Criticality by July 4
MIT Technology Review reported on July 9 that four privately developed advanced microreactor designs achieved first criticality within a single 30-day window — a pace of parallel first-of-a-kind reactor starts with no historical precedent in the US nuclear industry. Antares Nuclear’s Mark-0 was first, becoming the first non-light-water reactor to go critical in the US in more than four decades. Valar Atomics, Deployable Energy, and Aalo Atomics followed, all before the July 4 deadline the Department of Energy set under a 2025 executive order.
Each reactor represents a distinct design lineage — high-temperature gas, molten salt, and metal-cooled variants are all represented — and each was licensed under the DOE’s Reactor Pilot Program authorization rather than the traditional Nuclear Regulatory Commission pathway. That regulatory delta is a large part of why so many designs advanced in parallel: the pilot program deliberately traded some of the NRC’s licensing volume for schedule certainty.
The immediate follow-on question is scale. Criticality is a milestone but not a product; Valar reported generating 100 kilowatts on July 1, which is a laboratory-scale output. The pathway from these first-of-a-kind cores to megawatt-scale commercial units — and, eventually, to gigawatt-scale fleets — will still be measured in years and require conventional NRC engagement. Even so, the collective demonstration reframes the pace at which the US nuclear sector is capable of moving.
Source: MIT Technology Review
Instituto de Tecnología Eléctrica Advances Cheaper Green Hydrogen
On July 13, Spain’s Instituto de Tecnología Eléctrica (ITE) announced new PEM (proton exchange membrane) electrode designs and a set of digital durability tools aimed at driving down green hydrogen’s stubbornly high production cost. The work targets both material and operational levers: reducing precious-metal loadings on the anode side while giving operators software to run electrolyzers more aggressively without shortening stack life.
PEM electrolyzers are well-suited to variable renewable input because they respond quickly to shifts in power supply, but they have historically been more expensive per kilogram of hydrogen than alkaline systems. Bringing PEM capital and operating costs down closes the gap between the technology best matched to solar and wind and the technology cheapest to deploy at industrial scale.
Electrolyzer prices are already falling rapidly, with projections that green hydrogen costs in some markets could fall by nearly half by 2030 — from roughly US$4–6 per kilogram to US$2–3, according to the sector forecasts cited by ITE. That price band is broadly the threshold at which green hydrogen becomes competitive with grey (methane-derived) hydrogen for refining, ammonia, and steelmaking without subsidy. Incremental research like ITE’s is what the sector needs to hit that number on schedule.
Source: Fuel Cells Works
Perovskite Triple-Junction Cell Holds 27.3% for Over 770 Hours
A separate perovskite result reported this week describes a novel triple-junction perovskite cell that achieved 27.3% conversion efficiency and — crucially — showed essentially no decline in output after more than 770 hours of continuous operation. The stability figure is arguably more important than the raw efficiency number.
Perovskite cells have long faced a “stability wall” in which improved efficiencies have come at the cost of faster degradation under heat, light, and humidity. A 770-hour operational stability run at record-class efficiency substantially blunts the standard objection to perovskite commercialization.
Triple-junction architectures are one plausible successor to today’s tandem designs, adding a third bandgap-tuned absorber to capture parts of the solar spectrum poorly used by silicon and existing perovskite tandems. Getting them to record efficiencies with durable outputs indicates that the perovskite family — not just perovskite-on-silicon — has real headroom.
Together with Longi’s 35.5% silicon-tandem announcement earlier in the week, the result signals that multiple perovskite architectures are converging on manufacturability at once, rather than a single design winning early.
Source: Tech Xplore
Brazil Accelerates 1,500 km, ±800 kV Maranhão–Goiás HVDC Line to 2028
Brazil’s Ministry of Mines and Energy announced on July 16 that State Grid Brazil Holding will bring the ±800 kV Maranhão–Goiás ultra-high-voltage DC transmission line into service in March 2028, two years ahead of the original 2030 schedule. The roughly 1,500 km line will connect the Graça Aranha substation in the northeastern state of Maranhão to Silvânia in Goiás, passing through Tocantins, at a rated capacity of 5 GW.
The project addresses a well-defined bottleneck in Brazil’s electricity system: solar and wind resources in the country’s northeast dramatically exceed local demand, while population and industry are concentrated in the southeast around Brasília, São Paulo, and Rio. Ultra-high-voltage DC at ±800 kV is the standard technology for moving that much power more than a thousand kilometers with acceptable losses.
The total investment is roughly R$20 billion, or about US$3.6 billion. Beyond its energy consequences — up to 12 million people in the receiving region will see new renewable supply — the line is a data point in an ongoing global trend toward long-distance HVDC as the backbone technology for renewable-heavy grids. State Grid’s success in moving the schedule left will be watched by transmission planners in Australia, the US, and Europe, all of whom face the same “generation is far from load” problem.
Source: Rio Times
Fervo Cape Station Emerges as Most Productive Enhanced Geothermal System
Well-test results this year at Fervo Energy’s Cape Station project in Beaver County, Utah, have established the site as the most productive enhanced geothermal generating station in history. According to Utility Dive, a 30-day flow test at Cape Station achieved a peak flow rate of 107 kg/s at temperatures capable of supporting more than 10 MW of electric output from a single well pair — a step-change over previous EGS demonstrations.
Cape Station’s Phase I is targeting first grid power in October 2026, ramping toward roughly 100 MW of operating capacity by early 2027. Phase II, targeted for 2028, would bring the site to 500 MW. Fervo has raised over US$460 million in a Series E led by B Capital to fund construction, one of the largest single financings in the enhanced geothermal sector to date.
Enhanced geothermal systems draw heat from hot dry rock rather than natural hydrothermal reservoirs, which dramatically expands the geographies where geothermal is technically viable. If Cape Station’s Phase I hits capacity on schedule this fall, it will provide the first commercial-scale operating reference for EGS anywhere in the world — a milestone likely to shape the financing conditions for the next generation of geothermal projects.
Source: Utility Dive