Thirty Indian power plants dangerously low on coal

Near-Field Thermophotovoltaics captures radiated energy across a nanoscale gap, using thin-film photovoltaic cells and indium gallium arsenide to boost power density and efficiency, enabling compact Army portable power from emitters via radiative heat transfer.

Key Points

A nanoscale TPV method capturing near-field photons for higher power density at lower emitter temperatures.

✅ Nanoscale gap boosts radiative transfer and usable photon flux

✅ Thin-film InGaAs cells recycle sub-band-gap photons via reflector

✅ Achieved ~5 kW/m2 power density with higher efficiency

With the addition of sensors and enhanced communication tools, providing lightweight, portable power has become even more challenging, with concepts such as power from falling snow illustrating how diverse new energy-harvesting approaches are. Army-funded research demonstrated a new approach to turning thermal energy into electricity that could provide compact and efficient power for Soldiers on future battlefields.

Hot objects radiate light in the form of photons into their surroundings. The emitted photons can be captured by a photovoltaic cell and converted to useful electric energy. This approach to energy conversion is called far-field thermophotovoltaics, or FF-TPVs, and has been under development for many years; however, it suffers from low power density and therefore requires high operating temperatures of the emitter.

The research, conducted at the University of Michigan and published in Nature Communications, demonstrates a new approach, where the separation between the emitter and the photovoltaic cell is reduced to the nanoscale, enabling much greater power output than what is possible with FF-TPVs for the same emitter temperature.

This approach, which enables capture of energy that is otherwise trapped in the near-field of the emitter is called near-field thermophotovoltaics or NF-TPV and uses custom-built photovoltaic cells and emitter designs ideal for near-field operating conditions, alongside emerging smart solar inverters that help manage conversion and delivery.

This technique exhibited a power density almost an order of magnitude higher than that for the best-reported near-field-TPV systems, while also operating at six-times higher efficiency, paving the way for future near-field-TPV applications, including remote microgrid deployments in extreme environments, according to Dr. Edgar Meyhofer, professor of mechanical engineering, University of Michigan.

"The Army uses large amounts of power during deployments and battlefield operations and must be carried by the Soldier or a weight constrained system," said Dr. Mike Waits, U.S. Army Combat Capabilities Development Command's Army Research Laboratory. "If successful, in the future near-field-TPVs could serve as more compact and higher efficiency power sources for Soldiers as these devices can function at lower operating temperatures than conventional TPVs."

The efficiency of a TPV device is characterized by how much of the total energy transfer between the emitter and the photovoltaic cell is used to excite the electron-hole pairs in the photovoltaic cell, where insights from near-light-speed conduction research help contextualize performance limits in semiconductors. While increasing the temperature of the emitter increases the number of photons above the band-gap of the cell, the number of sub band-gap photons that can heat up the photovoltaic cell need to be minimized.

"This was achieved by fabricating thin-film TPV cells with ultra-flat surfaces, and with a metal back reflector," said Dr. Stephen Forrest, professor of electrical and computer engineering, University of Michigan. "The photons above the band-gap of the cell are efficiently absorbed in the micron-thick semiconductor, while those below the band-gap are reflected back to the silicon emitter and recycled."

The team grew thin-film indium gallium arsenide photovoltaic cells on thick semiconductor substrates, and then peeled off the very thin semiconductor active region of the cell and transferred it to a silicon substrate, informing potential interfaces with home battery systems for distributed use.

All these innovations in device design and experimental approach resulted in a novel near-field TPV system that could complement distributed resources in virtual power plants for resilient operations.

"The team has achieved a record ~5 kW/m2 power output, which is an order of magnitude larger than systems previously reported in the literature," said Dr. Pramod Reddy, professor of mechanical engineering, University of Michigan.

Researchers also performed state-of-the-art theoretical calculations to estimate the performance of the photovoltaic cell at each temperature and gap size, informing hybrid designs with backup fuel cell solutions that extend battery life, and showed good agreement between the experiments and computational predictions.

"This current demonstration meets theoretical predictions of radiative heat transfer at the nanoscale, and directly shows the potential for developing future near-field TPV devices for Army applications in power and energy, communication and sensors," said Dr. Pani Varanasi, program manager, DEVCOM ARL that funded this work.

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SaskPower 2019-20 Annual Report highlights $205M net income, grid capacity upgrades, emissions reduction progress, Chinook Power Station natural gas baseload, and wind and solar renewable energy to support Saskatchewan's Growth Plan and Prairie Resilience.

Key Points

SaskPower's 2019-20 results: $205M income, grid upgrades, emissions cuts, and new gas baseload with wind and solar.

✅ $205M net income, up $8M year-over-year

✅ Chinook Power Station adds stable natural gas baseload

✅ Increased grid capacity enables more wind and solar

SaskPower presented its annual report on Monday, with a net income of $205 million in 2019-20, even as Manitoba Hydro's financial pressures highlight regional market dynamics.

This figure shows an increase of $8 million from 2018-19, despite record provincial power demand that tested the grid.

“Reliable, sustainable and cost-effective electricity is crucial to achieving the economic goals laid out in the Government of Saskatchewan’s Growth Plan and the emissions reductions targets outlined in Prairie Resilience, our made-in-Saskatchewan climate change strategy,” Minister Responsible for SaskPower Dustin Duncan said.

In the last year, SaskPower has repaired and upgraded old infrastructure, invested in growth projects and increased grid capacity, including plans to buy more electricity from Manitoba Hydro to support reliability and benefiting from new turbine investments across the region.

The utility is also exploring procurement partnerships, including a plan to purchase power from Flying Dust First Nation to diversify supply.

“During the past year, we continued to move toward our target to reduce carbon dioxide emissions 40 per cent from 2005 levels by 2030, as part of efforts to double renewable electricity by 2030 across Saskatchewan,” SaskPower President and CEO Mike Marsh said. “The newly commissioned natural gas-fired Chinook Power Station will provide a stable source of baseload power while enabling the ongoing addition of intermittent renewable generation capacity, and exploring geothermal power alongside wind and solar generation.”

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U.S. Utility Spending Shift highlights rising transmission and distribution costs, grid modernization, and smart meters, while generation expenses decline amid fuel price volatility, capital and labor pressures, and renewable integration across the power sector.

Key Points

A decade-long trend where utilities spend more on delivery and grid upgrades, and less on electricity generation costs.

✅ Delivery O&M, wires, poles, and meters drive rising costs

✅ Generation spending declines amid fuel price changes and PPI

✅ Grid upgrades add reliability, resilience, and renewable integration

Over the past decade, major utilities in the United States have been spending more on delivering electricity to customers and less on producing that electricity, a shift occurring as electricity demand is flat across many regions.

After adjusting for inflation, major utilities spent 2.6 cents per kilowatthour (kWh) on electricity delivery in 2010, using 2020 dollars. In comparison, spending on delivery was 65% higher in 2020 at 4.3 cents/kWh, and residential bills rose in 2022 as inflation persisted. Conversely, utility spending on power production decreased from 6.8 cents/kWh in 2010 (using 2020 dollars) to 4.6 cents/kWh in 2020.

Utility spending on electricity delivery includes the money spent to build, operate, and maintain the electric wires, poles, towers, and meters that make up the transmission and distribution system. In real 2020 dollar terms, spending on electricity delivery increased every year from 1998 to 2020 as utilities worked to replace aging equipment, build transmission infrastructure to accommodate new wind and solar generation amid clean energy transition challenges that affect costs, and install new technologies such as smart meters to increase the efficiency, reliability, resilience, and security of the U.S. power grid.

Spending on power production includes the money spent to build, operate, fuel, and maintain power plants, as well as the cost to purchase power in cases where the utility either does not own generators or does not generate enough to fulfill customer demand. Spending on electricity production includes the cost of fuels including natural gas prices alongside capital, labor, and building materials, as well as the type of generators being built.

Other utility spending on electricity includes general and administrative expenses, general infrastructure such as office space, and spending on intangible goods such as licenses and franchise fees, even as electricity sales declined in recent years.

The retail price of electricity reflects the cost to produce and deliver power, the rate of return on investment that regulated utilities are allowed, and profits for unregulated power suppliers, and, as electricity prices at 41-year high have been reported, these components have drawn increased scrutiny.

In 2021, demand for consumer goods and the energy needed to produce them has been outpacing supply, though power demand sliding in 2023 with milder weather has also been noted. This difference has contributed to higher prices for fuels used by electric generators, especially natural gas. The increased cost for fuel, capital, labor, and building materials, as seen in the U.S. Bureau of Labor Statistics’ Producer Price Index, is increasing the cost of power production for 2021. U.S. average electricity prices have been higher every month of this year compared with 2020, according to our Monthly Electric Power Industry Report.

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India Thermal Power Coal Imports surged 17.6% as CEA-monitored plants offset weaker CIL and SCCL supplies, driven by Saubhagya-led electricity demand, regional power deficits, and varied consumption across Uttar Pradesh, Bihar, Maharashtra, and Gujarat.

Key Points

Fuel volumes imported for Indian thermal plants, tracked by CEA, reflecting shifts in CIL/SCCL supply, demand, and regional power deficits.

✅ Imports up 17.6% as domestic CIL/SCCL deliveries lag targets

✅ Saubhagya-driven demand lifts generation in key beneficiary states

✅ Industrial slowdowns cut usage in Maharashtra, Tamil Nadu, Gujarat

The receipt of imported coal by thermal power plants, where plant load factors have risen, has shot up by 17.6 per cent during April-October. The coal import volumes refer to the power plants monitored by the Central Electricity Authority (CEA), and come amid moves to ration coal supplies as electricity demand surges, a power update report from CARE Ratings showed.

Imports escalated as domestic supplies by Coal India Ltd (CIL) and another state run producer- Singareni Collieries Company Ltd (SCCL) dipped in the period, after earlier shortages that have since eased in later months. Rate of supplies by the two coal companies to the CEA monitored power stations stood at 80.4 per cent, indicating a shortfall of 19.6 per cent against the allocated quantity.

According to the study by CARE Ratings, total coal supplied by CIL and SCCL to the power sector stood at 315.9 million tonnes (mt) during April-October as against 328.5 mt in the comparable period of last fiscal year.

The study noted that growth in power generation during the April-October 2019, with India now the third-largest electricity producer globally, was on account of higher demand from Pradhan Mantri Sahaj Bijli Har Ghar Yojana or Saubhagya Scheme beneficiary states. Providing connection to households in order to achieve 100% per cent electrification has in part helped the sector avert de-growth, as part of efforts to rewire Indian electricity and expand access.

Large states namely Uttar Pradesh, Bihar, Punjab, West Bengal and Rajasthan have recorded over five per cent growth in consumption of power. These states along with Odisha, Madhya Pradesh and Assam accounted for 75 per cent of the beneficiaries under the Saubhagya Scheme (Household Electrification Scheme). The ongoing economic downturn has led to a sharp fall in electricity demand from industrialised states. Maharashtra, which is also the largest power consuming state in India, recorded a decline in consumption of 5.6 per cent.

Other states namely Tamil Nadu, Telangana, Gujarat and Odisha too recorded fall in power consumed, echoing global dips in daily electricity demand seen later during the pandemic. These states house large clusters of mining, automobile, cement and other manufacturing industries, and a decline in these sectors led to fall in demand for power across these states. - The demand-supply gap or power deficit has remained at 0.6 per cent during the April-October 2019. North-East reported 4.8 per cent of power deficit followed by Northern Region at 1.3 per cent. Within Northern Region, Jammu & Kashmir and Uttar Pradesh accounted for 65 per cent and 30 per cent respectively of the regions power supply deficit.

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Space solar power promises wireless energy from orbital solar satellites via microwave or laser power beaming, using photovoltaics and rectennas. NRL and AFRL advances hint at 24-7 renewable power delivery to Earth and airborne drones.

Key Points

Space solar power beams orbital solar energy to Earth via microwaves or lasers, enabling continuous wireless electricity.

✅ Harvests sunlight in orbit and transmits via microwaves or lasers

✅ Provides 24-7 renewable power, independent of weather or night

✅ Enables wireless power for remote sites, grids, and drones

Earlier this year, a small group of spectators gathered in David Taylor Model Basin, the Navy’s cavernous indoor wave pool in Maryland, to watch something they couldn’t see. At each end of the facility there was a 13-foot pole with a small cube perched on top. A powerful infrared laser beam shot out of one of the cubes, striking an array of photovoltaic cells inside the opposite cube. To the naked eye, however, it looked like a whole lot of nothing. The only evidence that anything was happening came from a small coffee maker nearby, which was churning out “laser lattes” using only the power generated by the system as ambitions for cheap abundant electricity gain momentum worldwide.

The laser setup managed to transmit 400 watts of power—enough for several small household appliances—through hundreds of meters of air without moving any mass. The Naval Research Lab, which ran the project, hopes to use the system to send power to drones during flight. But NRL electronics engineer Paul Jaffe has his sights set on an even more ambitious problem: beaming solar power to Earth from space. For decades the idea had been reserved for The Future, but a series of technological breakthroughs and a massive new government research program suggest that faraway day may have finally arrived as interest in space-based solar broadens across industry and government.

Since the idea for space solar power first cropped up in Isaac Asimov’s science fiction in the early 1940s, scientists and engineers have floated dozens of proposals to bring the concept to life, including inflatable solar arrays and robotic self-assembly. But the basic idea is always the same: A giant satellite in orbit harvests energy from the sun and converts it to microwaves or lasers for transmission to Earth, where it is converted into electricity. The sun never sets in space, so a space solar power system could supply renewable power to anywhere on the planet, day or night, as recent tests show we can generate electricity from the night sky as well, rain or shine.

Like fusion energy, space-based solar power seemed doomed to become a technology that was always 30 years away. Technical problems kept cropping up, cost estimates remained stratospheric, and as solar cells became cheaper and more efficient, and storage improved with cheap batteries, the case for space-based solar seemed to be shrinking.

That didn’t stop government research agencies from trying. In 1975, after partnering with the Department of Energy on a series of space solar power feasibility studies, NASA beamed 30 kilowatts of power over a mile using a giant microwave dish. Beamed energy is a crucial aspect of space solar power, but this test remains the most powerful demonstration of the technology to date. “The fact that it’s been almost 45 years since NASA’s demonstration, and it remains the high-water mark, speaks for itself,” Jaffe says. “Space solar wasn’t a national imperative, and so a lot of this technology didn’t meaningfully progress.”

John Mankins, a former physicist at NASA and director of Solar Space Technologies, witnessed how government bureaucracy killed space solar power development firsthand. In the late 1990s, Mankins authored a report for NASA that concluded it was again time to take space solar power seriously and led a project to do design studies on a satellite system. Despite some promising results, the agency ended up abandoning it.

In 2005, Mankins left NASA to work as a consultant, but he couldn’t shake the idea of space solar power. He did some modest space solar power experiments himself and even got a grant from NASA’s Innovative Advanced Concepts program in 2011. The result was SPS-ALPHA, which Mankins called “the first practical solar power satellite.” The idea, says Mankins, was “to build a large solar-powered satellite out of thousands of small pieces.” His modular design brought the cost of hardware down significantly, at least in principle.

Jaffe, who was just starting to work on hardware for space solar power at the Naval Research Lab, got excited about Mankins’ concept. At the time he was developing a “sandwich module” consisting of a small solar panel on one side and a microwave transmitter on the other. His electronic sandwich demonstrated all the elements of an actual space solar power system and, perhaps most important, it was modular. It could work beautifully with something like Mankins' concept, he figured. All they were missing was the financial support to bring the idea from the laboratory into space.

Jaffe invited Mankins to join a small team of researchers entering a Defense Department competition, in which they were planning to pitch a space solar power concept based on SPS-ALPHA. In 2016, the team presented the idea to top Defense officials and ended up winning four out of the seven award categories. Both Jaffe and Mankins described it as a crucial moment for reviving the US government’s interest in space solar power.

They might be right. In October, the Air Force Research Lab announced a $100 million program to develop hardware for a solar power satellite. It’s an important first step toward the first demonstration of space solar power in orbit, and Mankins says it could help solve what he sees as space solar power’s biggest problem: public perception. The technology has always seemed like a pie-in-the-sky idea, and the cost of setting up a solar array on Earth is plummeting, as proposals like a tenfold U.S. solar expansion signal rapid growth; but space solar power has unique benefits, chief among them the availability of solar energy around the clock regardless of the weather or time of day.

It can also provide renewable energy to remote locations, such as forward operating bases for the military, which has deployed its first floating solar array to bolster resilience. And at a time when wildfires have forced the utility PG&E to kill power for thousands of California residents on multiple occasions, having a way to provide renewable energy through the clouds and smoke doesn’t seem like such a bad idea. (Ironically enough, PG&E entered a first-of-its-kind agreement to buy space solar power from a company called Solaren back in 2009; the system was supposed to start operating in 2016 but never came to fruition.)

“If space solar power does work, it is hard to overstate what the geopolitical implications would be,” Jaffe says. “With GPS, we sort of take it for granted that no matter where we are on this planet, we can get precise navigation information. If the same thing could be done for energy, especially as peer-to-peer energy sharing matures, it would be revolutionary.”

Indeed, there seems to be an emerging race to become the first to harness this technology. Earlier this year China announced its intention to become the first country to build a solar power station in space, and for more than a decade Japan has considered the development of a space solar power station to be a national priority. Now that the US military has joined in with a $100 million hardware development program, it may only be a matter of time before there’s a solar farm in the solar system.

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California Wildfire Smoke Impact on Solar reduces photovoltaic output, as particulate pollution, soot, and haze dim sunlight and foul panels, cutting utility-scale generation and grid reliability across CAISO during peak demand and heatwaves.

Key Points

How smoke and soot cut solar irradiance and foul panels, slashing PV generation and straining CAISO grid operations.

✅ Smoke blocks sunlight; soot deposition reduces panel efficiency.

✅ CAISO reported ~30% drop versus July during peak smoke.

✅ Longer fire seasons threaten solar reliability and capacity planning.

Smoke from California’s unprecedented wildfires was so bad that it cut a significant chunk of solar power production in the state, even as U.S. solar generation rose in 2022 nationwide. Solar power generation dropped off by nearly a third in early September as wildfires darkened the skies with smoke, according to the US Energy Information Administration.

Those fires create thick smoke, laden with particles that block sunlight both when they’re in the air and when they settle onto solar panels. In the first two weeks of September, soot and smoke caused solar-powered electricity generation to fall 30 percent compared to the July average, according to the California Independent System Operator (CAISO), which oversees nearly all utility-scale solar energy in California, where wind and solar curtailments have been rising amid grid constraints. It was a 13.4 percent decrease from the same period last year, even though solar capacity in the state has grown about 5 percent since September 2019.

California depends on solar installations for nearly 20 percent of its electricity generation, and has more solar capacity than the next five US states trailing it combined as it works to manage its solar boom sustainably. It will need even more renewable power to meet its goal of 100 percent clean electricity generation by 2045, building on a recent near-100% renewable milestone that underscored the transition. The state’s emphasis on solar power is part of its long-term efforts to avoid more devastating effects of climate change. But in the short term, California’s renewables are already grappling with rising temperatures.

Two records were smashed early this September that contributed to the loss of solar power. California surpassed 2 million acres burned in a single fire season for the first time (1.7 million more acres have burned since then). And on September 15th, small particle pollution reached the highest levels recorded since 2000, according to the California Air Resources Board. Winds that stoked the flames also drove pollution from the largest fires in Northern California to Southern California, where there are more solar farms.

Smaller residential and commercial solar systems were affected, too, and solar panels during grid blackouts typically shut off for safety, although smoke was the primary issue here. “A lot of my systems were producing zero power,” Steve Pariani, founder of the solar installation company Solar Pro Energy Systems, told the San Mateo Daily Journal in September.

As the planet heats up, California’s fire seasons have grown longer, and blazes are tearing through more land than ever before, while grid operators are also seeing rising curtailments as they integrate more renewables. For both utilities and smaller solar efforts, wildfire smoke will continue to darken solar energy’s otherwise bright future, even as it becomes the No. 3 renewable source in the U.S. by generation.

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