Crane falls on west Michigan power plant

Polycrystalline Tin Selenide Thermoelectrics enable waste heat recovery with ZT 3.1, matching single crystals while cutting costs, powering greener car engines, industrial furnaces, and thermoelectric generators via p-type and emerging n-type designs.

Key Points

Low-cost tin selenide devices that turn waste heat into power, achieving ZT 3.1 and enabling p-type and n-type modules.

✅ Oxygen removal prevents heat-leaking tin oxide grain skins.

✅ Polycrystalline ingots match single-crystal ZT 3.1 at lower cost.

✅ N-type tin selenide in development to pair with p-type.

So-called thermoelectric generators turn waste heat into electricity without producing greenhouse gas emissions, providing what seems like a free lunch. But despite helping power the Mars rovers, the high cost of these devices has prevented their widespread use. Now, researchers have found a way to make cheap thermoelectrics that work just as well as the pricey kind. The work could pave the way for a new generation of greener car engines, industrial furnaces, and other energy-generating devices.

“This looks like a very smart way to realize high performance,” says Li-Dong Zhao, a materials scientist at Beihang University who was not involved with the work. He notes there are still a few more steps to take before these materials can become high-performing thermoelectric generators. However, he says, “I think this will be used in the not too far future.”

Thermoelectrics are semiconductor devices placed on a hot surface, like a gas-powered car engine or on heat-generating electronics using thin-film converters to capture waste heat. That gives them a hot side and a cool side, away from the hot surface. They work by using the heat to push electrical charges from one to the other, a process of turning thermal energy into electricity that depends on the temperature gradient. If a device allows the hot side to warm up the cool side, the electricity stops flowing. A device’s success at preventing this, as well as its ability to conduct electrons, feeds into a score known as the figure of merit, or ZT.

 Over the past 2 decades, researchers have produced thermoelectric materials with increasing ZTs, while related advances such as nighttime solar cells have broadened thermal-to-electric concepts. The record came in 2014 when Mercouri Kanatzidis, a materials scientist at Northwestern University, and his colleagues came up with a single crystal of tin selenide with a ZT of 3.1. Yet the material was difficult to make and too fragile to work with. “For practical applications, it’s a non-starter,” Kanatzidis says.

So, his team decided to make its thermoelectrics from readily available tin and selenium powders, an approach that, once processed, makes grains of polycrystalline tin selenide instead of the single crystals. The polycrystalline grains are cheap and can be heated and compressed into ingots that are 3 to 5 centimeters long, which can be made into devices. The polycrystalline ingots are also more robust, and Kanatzidis expected the boundaries between the individual grains to slow the passage of heat. But when his team tested the polycrystalline materials, the thermal conductivity shot up, dropping their ZT scores as low as 1.2.

In 2016, the Northwestern team discovered the source of the problem: an ultrathin skin of tin oxide was forming around individual grains of polycrystalline tin selenide before they were pressed into ingots. And that skin acted as an express lane for the heat to travel from grain to grain through the material. So, in their current study, Kanatzidis and his colleagues came up with a way to use heat to drive any oxygen away from the powdery precursors, leaving pristine polycrystalline tin selenide, whereas other devices can generate electricity from thin air using ambient moisture.

The result, which they report today in Nature Materials, was not only a thermal conductivity below that of single-crystal tin selenide but also a ZT of 3.1, a development that echoes nighttime renewable devices showing electricity from cold conditions. “This opens the door for new devices to be built from polycrystalline tin selenide pellets and their applications to be explored,” Kanatzidis says.

Getting through that door will still take some time. The polycrystalline tin selenide the team makes is spiked with sodium atoms, creating what is known as a “p-type” material that conducts positive charges. To make working devices, researchers also need an “n-type” version to conduct negative charges.

Zhao’s team recently reported making an n-type single-crystal tin selenide by spiking it with bromine atoms. And Kanatzidis says his team is now working on making an n-type polycrystalline version. Once n-type and p-type tin selenide devices are paired, researchers should have a clear path to making a new generation of ultra-efficient thermoelectric generators. Those could be installed everywhere from automobile exhaust pipes to water heaters and industrial furnaces to scavenge energy from some of the 65% of fossil fuel energy that winds up as waste heat. 

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Sustainable Cannabis Cultivation leverages greenhouse design, renewable energy, automation, and water recapture to cut electricity use, emissions, and pesticides, delivering premium yields with natural light, smart sensors, and efficient HVAC and irrigation control.

Key Points

A data-driven, low-impact method that cuts energy, water, and chemicals while preserving premium yields.

✅ 70-90% less electricity vs. conventional indoor grows

✅ Natural light, solar, and rainwater recapture reduce footprint

✅ Automation, sensors, and HVAC stabilize microclimates

In the seven months since the Trudeau government legalized recreational marijuana use, licensed producers across the country have been locked in a frenetic race to grow mass quantities of cannabis for the new market.

But amid the rush for scale, questions of sustainability have often taken a back seat, and in Canada, solar adoption has lagged in key sectors.

According to EQ Research LLC, a U.S.-based clean-energy consulting firm, cannabis facilities can need up to 150 kilowatt-hours of electricity per year per square foot. Such input is on par with data centres, which are themselves 50 to 200 times more energy-intensive than a typical office building, and achieving zero-emission electricity by 2035 would help mitigate the associated footprint.

At the Lawrence Berkley National Laboratory in California, a senior scientist estimated that one per cent of U.S. electricity use came from grow ops. The same research — published in 2012 — also found that the procedures for refining a kilogram of weed emit around 4,600 kilograms of carbon dioxide to the atmosphere, equivalent to operating three million cars for a year, though a shift to zero-emissions electricity by 2035 could substantially cut those emissions.

“All factors considered, a very large expenditure of energy and consequent ‘environmental imprint’ is associated with the indoor cultivation of marijuana,” wrote Ernie Small, a principal research scientist for Agriculture and Agri-Food Canada, in the 2018 edition of the Biodiversity Journal.

Those issues have left some turning to technology to try to reduce the industry’s footprint — and the economic costs that come with it — even as more energy sources make better projects for forward-looking developers.

“The core drawback of most greenhouse environments is that you’re just getting large rooms, which are harder to control,” says Dan Sutton, the chief executive officer of Tantalus Labs., a B.C.-based cannabis producer. “What we did was build a system specifically for cannabis.”

Sutton is referring to SunLab, the culmination of four years of construction, and at present the main site where his company nurtures rows of the flowering plant. The 120,000-square foot structure was engineered for one purpose: to prove the merits of a sustainable approach.

“We’re actually taking time-series data on 30 different environmental parameters — really simple ones like temperature and humidity — all the way down to pH of the soil and water flow,” says Sutton. “So if the temperature gets a little too cold, the system recognizes that and kicks on heaters, and if the system senses that the environment is too hot in the summertime, then it automatically vents.”

A lot is achieved without requiring much human intervention, he adds. Unlike conventional indoor operations, SunLab demands up to 90 per cent less electricity, avoids using pesticides, and draws from natural light and recaptured rainwater to feed its crops.

The liquid passes through a triple-filtration process before it is pumped into drip irrigation tubing. “That allows us to deliver a purity of water input that is cleaner than bottled water,” says Sutton.

As transpiration occurs, a state-of-the-art, high-capacity airflow suspended below the ceiling cycles air at seven-minute intervals, repeatedly cooling the air and preventing outbreaks of mould, while genetically modified “guardian” insects swoop in to eliminate predatory pests.

“When we first started, people never believed we would cultivate premium quality cannabis or cannabis that belongs on the top shelf, shoulder to shoulder with the best in the world and the best of indoor,” says Sutton.

Challenges still exist, but they pale in comparison to the obstacles that American companies with an interest in adopting greener solutions persistently face, and in provinces like Alberta, an Alberta renewable energy surge is reshaping the opportunity set.

Although cannabis is legal in a number of states, it remains illegal federally, which means access to capital and regulatory clarity south of the border can be difficult to come by.

“Right now getting a new project built is expensive to do because you can’t get traditional bank loans,” says Canndescent CEO Adrian Sedlin, speaking by phone from California.

In retrofitting the company’s farm to accommodate a sizeable solar field, he struggled to secure investors, even as a solar-powered cannabis facility in Edmonton showcased similar potential.

“We spent over a year and a half trying to get it financed,” says Sedlin. “Finding someone was the hard part.”

Decriminalizing the drug would ultimately increase the supply of capital and lower the costs for innovative designs, something Sedlin says would help incentivize producers to switch to more effective and ecologically sound techniques.

Some analysts argue that selling renewable energy in Alberta could become a major growth avenue that benefits energy-intensive industries like cannabis cultivation.

Canndescent, however, is already there.

“We’re now harnessing the sun to reduce our reliance on fossil fuels and going to sustainable, or replenishable, energy sources, while leveraging the best and most efficient water practices,” says Sedlin. “It’s the right thing to do.”

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Clean Electricity Standard (CES) sets utility emissions targets, uses tradable credits, and advances decarbonization via technology-agnostic benchmarks, carbon capture, renewable portfolio standards, upstream methane accounting, and cap-and-trade alternatives in reconciliation policy.

Key Points

CES sets utility emissions targets using tradable credits and benchmarks to drive power-sector decarbonization.

✅ Annual clean energy targets phased to 2050

✅ Tradable credits for compliance across utilities

✅ Includes upstream methane and lifecycle emissions

The Biden Administration and Democratic members of Congress have supported including a clean electricity standard (CES) in the upcoming reconciliation bill. A CES is an alternative to pricing carbon dioxide through a tax or cap-and-trade program and focuses on reducing greenhouse gas emissions produced during electricity generation by establishing targets, while early assessments show mixed results so far. In principle, it is a technology-agnostic approach. In practice, however, it pushes particular technologies out of the market.

The details of the CES are still being developed, but recent legislation may provide insight into how the CES could operate. In May, Senator Tina Smith and Representative Ben Ray Luján introduced the Clean Energy Standard Act of 2019 (CESA), while Minnesota's 100% carbon-free mandate offers a state-level parallel, and in January 2020, the House Energy and Commerce Committee released a discussion draft of the Climate Leadership and Environmental Action for our Nation’s (CLEAN) Future Act. Both bills increase the clean energy target annually until 2050 in order to phase out emissions. Both bills also create a credit system where clean sources of electricity as determined by a benchmark, carbon dioxide emitted per kilowatt-hour, receive credits. These credits may be transferred, sold, and auctioned so utilities that fail to meet targets can procure credits from others, as large energy customers push to accelerate clean energy globally.

The bills’ benchmarks vary, and while the CLEAN Future Act allows natural gas-fired generators to receive partial credits, CESA does not. Under both bills, these generators would be expected to install carbon capture technology to continue meeting increasing targets for clean electricity generation. Both bills go beyond considering the emissions resulting from generation and include upstream emissions for natural gas-fired generators. Natural gas, a greenhouse gas, that is leaked upstream of a generator during transportation is to be included among its emissions. The CLEAN Future Act also calls for newly constructed hydropower generators to account for the emissions associated with the facility’s construction despite producing clean electricity. These additional provisions demonstrate not only the CES’s inability to fully address the issue of emissions but also the slippery slope of expanding the program to include other markets, echoing cost and reliability concerns as California exports its energy policies across the West.

A majority of states have adopted clean energy, electricity, or renewable portfolio standards, with some considering revamping electricity rates to clean the grid, leaving legislators with plenty of examples to consider. As they weigh their options, legislators should consider if they are effectively addressing the problem at hand, economy-wide emissions reductions, and at what cost, drawing on examples like New Mexico's 100% clean electricity bill to inform trade-offs.

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Germany renewable energy milestone 2019 saw wind, solar, hydropower, and biomass outproduce coal and nuclear, as low gas prices and high CO2 costs under the EU ETS reshaped the electricity mix, per Fraunhofer ISE.

Key Points

It marks H1 2019 when renewables supplied 47.3% of Germany's electricity, surpassing coal and nuclear.

✅ Driven by high CO2 prices and cheap natural gas

✅ Wind and solar output rose; coal generation declined sharply

✅ Flexible gas plants outcompeted inflexible coal units

In Lippendorf, Saxony, the energy supplier EnBW is temporarily taking part of a coal-fired power plant offline. Not because someone ordered it — it simply wasn't paying off. Gas prices are low, CO2 prices are high, and with many hours of sunshine and wind, renewable methods are producing a great deal of electricity as part of Germany's energy transition now reshaping operations. And in the first half of the year there was plenty of sun and wind.

The result was a six-month period in which renewable energy sources, a trend echoed by the EU wind and solar record across the bloc, produced more electricity than coal and nuclear power plants together. For the first time 47.3% of the electricity consumers used came from renewable sources, while 43.4% came from coal-fired and nuclear power plants.

In addition to solar and wind power, renewable sources also include hydropower and biomass. Gas supplied 9.3%, reflecting how renewables are crowding out gas across European power markets, while the remaining 0.4% came from other sources, such as oil, according to figures published by the Fraunhofer Institute for Solar Energy Systems in July.

Fabian Hein from the think tank Agora Energiewende stresses that the situation is only a snapshot in time, with grid expansion woes still shaping outcomes. For example, the first half of 2019 was particularly windy and wind power production rose by around 20% compared to the first half of 2018.

Electricity production from solar panels rose by 6%, natural gas by 10%, while the share of nuclear power in German electricity consumption has remained virtually unchanged despite a nuclear option debate in climate policy.

Coal, on the other hand, declined. Black coal energy production fell by 30% compared to the first half of 2018, lignite fell by 20%. Some coal-fired power plants were even taken off the grid, even as coal still provides about a third of Germany's electricity. It is difficult to say whether this was an effect of the current market situation or whether this is simply part of long-term planning, says Hein.

Activists storm German mine in anti-coal protest

It is clear, however, that an increased CO2 price has made the ongoing generation of electricity from coal more expensive. Gas-fired power plants also emit CO2, but less than coal-fired power plants. They are also more efficient and that's why gas-fired power plants are not so strongly affected by the CO2 price

The price is determined at a European level and covers power plants and energy intensive industries in Europe. Other areas, such as heating or transport are not covered by the CO2 price scheme. Since a reform of CO2 emissions trading in 2017, the price has risen sharply. Whereas in September 2016 it was just over €5 ($5.6), by the end of June 2019 it had climbed to over €26.

Ups and downs

Gas as a raw material is generally more expensive than coal. But coal-fired power plants are more expensive to build. This is why operators want to run them continuously. In times of high demand, and therefore high prices, gas-fired power plants are generally started up, as seen when European power demand hit records during recent heatwaves, since it is worth it at these times.

Gas-fired power plants can be flexibly ramped up and down. Coal-fired power plants take 11 hours or longer to get going. That's why they can't be switched on quickly for short periods when prices are high, like gas-fired power plants. In the first half of the year, however, coal-fired power plants were also ramped up and down more often because it was not always worthwhile to let the power plant run around the clock.

Because gas prices were particularly low in the first half of 2019, some gas-fired power plants were more profitable than coal-fired plants. On June 29, 2019, the gas price at the Dutch trading point TTF was around €10 per megawatt hour. A year earlier, it had been almost €20. This is partly due to the relatively mild winter, as there is still a lot of gas in reserve, confirmed a spokesman for the Federal Association of the Energy and Water Industries (BDEW). There are also several new export terminals for liquefied natural gas. Additionally, weaker growth and trade wars are slowing demand for gas. A lot of gas comes to Europe, where prices are still comparatively high, reported the Handelsblatt newspaper.

The increase in wind and solar power and the decline in nuclear power have also reduced CO2 emissions. In the first half of 2019, electricity generation emitted around 15% less CO2 than in the same period last year, reported BDEW. However, the association demands that the further expansion of renewable energies should not be hampered. The target of 65% renewable energy can only be achieved if the further expansion of renewable energy sources is accelerated.

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Montana New Energy Economy integrates grid modernization, renewable energy, storage, and demand response to cut costs, create jobs, enable electric transportation, and reduce emissions through utility-scale efficiency, real-time markets, and distributed resources.

Key Points

Plan to modernize Montana's grid with renewables, storage and efficiency to lower costs, cut emissions and add jobs.

✅ Grid modernization enables real-time markets and demand response

✅ Utility-scale renewables paired with storage deliver firm power

✅ Efficiency and DERs cut peaks, costs, and pollution

Over the next decade, Montana ratepayers will likely invest over a billion dollars into what is now being called the new energy economy.

Not since Edison electrified a New York City neighborhood in 1882 have we had such an opportunity to rethink the way we commercially produce and consume electric energy.

Looking ahead, the modernization of Edison’s grid will lower the consumer costs, creating many thousands of permanent, well-paying jobs. It will prepare the grid for significant new loads like America going electric in transportation, and in doing so it will reduce a major source of air pollution known to directly threaten the core health of Montana and the planet.

Energy innovation makes our choices almost unrecognizable from the 1980s, when Montana last built a large, central-station power plant. Our future power plants will be smaller and more modular, efficient and less polluting — with some technologies approaching zero operating emissions.

The 21st Century grid will optimize how the supply and demand of electricity is managed across larger interconnected service areas. Utilities will interact more directly with their consumers, with utility trends guiding a new focus on providing a portfolio of energy services versus simply spinning an electric meter. Investments in utility-scale energy efficiency — LED streetlights, internet-connected thermostats, and tightening of commercial building envelopes among many — will allow consumers to directly save on their monthly bills, to improve their quality of life, and to help utilities reduce expensive and excessive peaks in demand.

The New Energy Economy will be built not of one single technology, but of many — distributed over a modernized grid across the West that approaches a real-time energy market, as provinces pursue market overhauls to adapt — connecting consumers, increasing competition, reducing cost and improving reliability.

Boldly leading the charge is a new and proven class of commercial generation powered by wind and solar energy, the latter of which employs advanced solid-state electronics, free fuel and no emissions or moving parts. Montana is blessed with wind and solar energy resources, so this is a Made-in-Montana energy choice. Note that these plants are typically paired with utility-scale energy storage investments — also an essential building block of the 21st century grid — to deliver firm, on-demand electric service.

Once considered new age and trendy, these production technologies are today competent and shovel-ready. Their adoption will build domestic energy independence. And, they are aggressively cost-competitive. For example, this year the company ISO New England — operator of a six-state grid covering all of New England — released an all-source bid for new production capacity. Unexpectedly, 100% of the winning bids were large solar electric power and storage projects, as coal and nuclear disruptions continue to shape markets. For the first time, no applications for fossil-fueled generation cleared auction.

By avoiding the burning of traditional fuels, the new energy technologies promise to offset and eventually eliminate the current 1,500 million metric tons of damaging greenhouse gases — one-quarter of the nation’s total — that are annually injected into the atmosphere by our nation’s current electric generation plants. The first step to solving the toughest and most expensive environmental issues of our day — be they costly wildfires or the regional drought that threatens Montana agriculture and outdoor recreation — is a thoughtful state energy policy, built around the new energy economy, that avoids pitfalls like the Wyoming clean energy bill now proposed.

Important potential investments not currently ready for prime time are also on the horizon, including small and highly efficient nuclear innovation in power plants — called small modular reactors (SMR) — designed to produce around-the-clock electric power with zero toxic emissions.

The nation’s first demonstration SMR plant is scheduled to be built sometime late this decade. Fingers are crossed for a good outcome. But until then, experts agree that big questions on the future commercial viability of nuclear remain unanswered: What will be SMR’s cost of electricity? Will it compete? Where will we source the refined fuel (most uranium is imported), and what will be the plan for its safe, permanent disposal?

So, what is Montana’s path forward? The short answer is: Hopefully, all of the above.

Key to Montana’s future investment success will be a respectful state planning process that learns from Texas grid improvements to bolster reliability.

Montanans deserve a smart and civil and bipartisan conversation to shape our new energy economy. There will be no need, nor place, for parties that barnstorm the state about "radical agendas" and partisan name calling – that just poisons the conversation, eliminates creative exchange and pulls us off task.

The task is to identify and vet good choices. It’s about permanently lowering energy costs to consumers. It’s about being business smart and business friendly. It’s about honoring the transition needs of our legacy energy communities. And, it’s about stewarding our world-class environment in earnest. That’s the job ahead.

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China Renewable Energy Law drives growth in wind power, solar thermal, and photovoltaic capacity, supporting grid integration and five-year plans, even as China leads CO2 emissions, with policy incentives, compliance inspections, and national resource assessments.

Key Points

A legal framework that speeds wind, solar thermal, and PV growth in China via mandates, incentives, and grid rules.

✅ 2018 renewables: 1.87T kWh, 26.7% of national power

✅ Over 100 State Council policies enabling deployment

✅ Law inspections and regional oversight across six provinces

China leads renewable energies, installing more wind power, solar thermal and photovoltaic than any other country, as seen in the China solar PV growth reported in 2016, but also leads CO2 emissions, and much remains to be done.

The effective application of Chinas renewable energy law has boosted the use of renewable energy in the country and facilitated the rapid development of the sector, as solar parity across Chinese cities indicates, a report said.

The report on compliance with renewable energy law was presented today at the current bimonthly session of the Standing Committee of the National Peoples Assembly (APN).

Electricity generated by renewable energy amounted to about 1.87 trillion kilowatts per hour in 2018, representing 26.7 percent of Chinas total energy production in the year, aligning with trends where wind and solar doubling globally over five years, the report said.

Ding Zhongli, vice president of the NPC Standing Committee, presented the report to the legislators at the second plenary meeting of the session.

An inspection of the law enforcement was carried out from August to November, as U.S. renewables hit 28% record showed momentum elsewhere. A total of 21 members of the NPC Standing Committee and the NPC Environmental Protection and Resource Conservation Committee, as well as national legislators, traveled to six regions at the provincial level on inspection visits. Twelve legislative bodies at the provincial level inspected the law enforcement efforts in their jurisdictions.

The relevant State Council agencies have implemented more than 100 regulations and policies to foster a good policy environment for the development of renewable energy, as seen in markets where U.S. renewable electricity surpassed coal in 2022. Local regulations have also been formulated based on local conditions, according to the report.

In accordance with the law, a thorough investigation of the national conditions of renewable energy resources was undertaken.

In 2008 and 2014 atlas of solar energy resources and wind energy evaluation of China were issued. The relevant agencies of the State Council have also implemented five-year plans for the development of renewable energy, which have provided guidance to the sector, while countries like Ireland's one-third green power target remain in focus within four years.

The main provisions of the law have been met, the law has been effectively applied and the purpose of the legislation has been met, and this momentum is echoed abroad, with U.S. renewables near one-fourth according to projections, Ding said.

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