Green Energy

A research group led by Prof. Ye Jichun at the Ningbo Institute of Materials Technology and Engineering (NIMTE) of the Chinese Academy of Sciences (CAS) has developed high-performance monolithic perovskite/black silicon (b-Si) solar cells with a tunnel oxide passivated contact (TOPCon), achieving a certified power conversion efficiency (PCE) of 28.2%. Results were published in Joule. Perovskite/silicon tandems offer a promising pathway to increase the PCE of solar cells with relatively low cost, and are thus predicted as an emerging focus in the field of high-efficiency solar cells. However, most reported monolithic perovskite/silicon tandems either suffer from high costs and limited light trapping, or have trouble in achieving high-quality perovskite films, leading to a great challenge in optimizing the performance of perovskite/b-Si solar cells. To address this issue, the researchers developed the first monolithic perovskite/Si tandem solar cells based on industry-relevant b-Si with TOPCon structures. Combined with the TOPCon, the surface reconstruction of the b-Si contributes to an excellent trade-off between high-level surface passivation and broadband light trapping. The reconstructed nanotexture of b-Si can significantly increase the moisture resistance and promote the wetting of perovskite. In addition, the b-Si guides the vertically aligned crystal growth of perovskite through nanoconfinement effect, reducing carrier recombination and facilitating carrier collection. Moreover, b-Si alleviates the film strains, thus improving the stability of the device. With an open-circuit voltage of 1.80 V, fill factor of 81.8%, and a short-circuit current density of 19.2 mA/cm2, the prepared monolithic perovskite/b-Si TOPCon tandem solar cells yield a remarkably high certified PCE of 28.2%, which is among the highest reported values for perovskite/Si solar cells with either TOPCon or double-side-textured Si to date. The novel strategy in this work can shed light on the development and fabrication of high-performance perovskite/b-Si tandem solar cells.

An eco-friendly hydrogen combustor for domestic gas turbines that reduces carbon dioxide emissions has been developed and will be undergoing field testing.

The Korea Institute of Machinery and Materials, an institute under the jurisdiction of the Ministry of Science and ICT, has developed a hydrogen co-firing combustor for gas turbines used in power generation. This is the first time that such technology has been developed in South Korea, and KIMM has plans to perform a demonstration of its application to power plants.

Since July 2020, the research team led by Dr. Minkuk Kim, head of the Department of Zero-carbon Fuel and Power Generation at the KIMM Institute of Carbon Neutral Energy Machinery, has been developing an eco-friendly combustor for domestic gas turbines with 30% hydrogen co-firing, in collaboration with 13 industrial, academic, and research partners. A project for field demonstration will be started in 2023 with Korea East-West Power Company and Doosan Enerbility.

Hydrogen is highly reactive fuel so there is a risk of high temperatures and flashback. In order to prevent such outcomes, KIMM improved a fuel injection method, including fuel split, staging and modifying fuel holes. These were applied to the heavy duty gas turbine developed by Doosan Enerbility. As a result, it was possible that NOx and combustion instability were suppressed to the same level of the original LNG gas turbine while burning a mixture of 30% hydrogen fuel.

In the past, many efforts were made to promote the development of hydrogen co-firing combustors, but performance verification was difficult because there were no proper combustion test facilities in South Korea. So the combustor developed by KIMM was transferred to the German Aerospace Center (DLR) during the development process, and it successfully passed combustion tests in a high-pressure environment. These conditions mimic the actual operating conditions of the gas turbine, and its performance was verified accordingly. The development of hydrogen co-firing technology by domestic research institutes and its application to domestic gas turbines is a meaningful moment on the road to carbon neutrality in South Korea.

When gas turbines use fuel blended with 30% hydrogen, CO2 emissions can be reduced by 10.4% compared to 100% LNG power generation. KIMM plans to increase the percentage of hydrogen contents in fuel over 50% thereby 21.4% reduction of CO2 by 2024. In addition, the team is focusing its research efforts with the goal of developing a 100% carbon-free hydrogen combustion technology by 2030.

KIMM also held a briefing on the development of a 300MW class gas turbine hydrogen co-firing combustor at the main office in Daejeon on October 12th. During this meeting, KIMM shared the details of their work on the core technology of modifying the hydrogen combustor. They also shared the results from Doosan Enerbility’s high-pressure combustion test results and announced Korea East-West Power Company’s Korea Institute of Future Convergence Technology’s plans to conduct power plant demonstrations of the hydrogen gas turbine.

At the briefing session, KIMM President Sang Jin Park stated, “In order to transition to an eco-friendly and carbon-free energy society, it is essential to develop hydrogen fuel conversion technology for medium and large-sized gas turbines and to conduct demonstrations at power plants. Currently, developments of combustion and turbine system are in their final stages. A decision of turbine manufacturers Doosan Enerbility and Korea East-West Power Company to test the new engine’s performance has made it possible to secure domestic hydrogen turbine technology that much sooner.” He also emphasized, “In order for domestic technology to be commercialized in a timely manner without failing, the government’s interest and support in selecting a demonstration site are necessary. This is because such a process is otherwise impossible through the will of the private sector alone due to the nature of the power generation industry.”

President Park added, “Unlike LNG heavy duty gas turbine in South Korea, which began as a fast follower, this hydrogen combustor is technologically equivalent to those from leading companies. If we can accelerate its commercialization through demonstration projects will help pave the way for South Korea’s next-generation new growth industry.”

Millions of miles of pipelines and conduits across the United States make up an intricate network of waterways used for municipal, agricultural and industrial purposes.

In a new report, researchers at the U.S. Department of Energy’s Oak Ridge National Laboratory have found potential opportunities in all 50 states to efficiently utilize existing infrastructure to harvest this otherwise wasted energy.

In a first-of-its-kind analysis, ORNL estimates that conduit hydropower, which uses water from structures such as water supply pipelines and irrigation canals, has the potential to add 1.41 gigawatts of electricity to the country’s power grid—enough to power more than a million homes.

“You can think of conduit hydropower as low-hanging fruit, and what has been started is a mere drop in the bucket,” said Shih-Chieh Kao, water power program manager at ORNL. “For all its benefits, the biggest barrier is a general lack of awareness of conduit hydropower’s potential.”

The process for municipalities and other stakeholders to develop conduit hydropower would be relatively easy. Without the need to build new dams, facility operators could install hydropower generators at locations with excess hydraulic head—the height of water needed for hydropower generation. This could be coordinated with planned facility upgrades that replace aging infrastructure with more energy-efficient systems. Rural communities may benefit by adding small hydropower generation to their existing infrastructure for net metering, making them less dependent on the external grid.

Since conduit hydropower taps into existing infrastructure with minimal environmental impacts, the permitting process has been streamlined. Through the Hydropower Regulatory Efficiency Act of 2013 and its amendments in America’s Water Infrastructure Act of 2018, the federal regulatory approval process can be completed in 45 days. To date, more than 350 conduit hydropower projects have been permitted or constructed, with more to come.

Opportunities by state

Scientists at ORNL conducted a systematic analysis of four types of conduits—water supply pipelines, wastewater discharge, irrigation systems and thermoelectric cooling water discharge.

For conduit hydropower to work, the water channel must have sufficient water flow and hydraulic head. Scientists analyzed this data as well as satellite imagery and topography to estimate the overall potential.

The potential for conduit hydropower was highest in five Western states—California, Colorado, Washington, Nebraska and Oregon—all of which have a large number of water conduits. Their hilly terrain also provides the greatest hydraulic head.

Agricultural conduits such as ditches and channels for crop irrigation showed the greatest potential for hydropower among the three business sectors assessed, amounting to nearly half of all conduit hydropower capacity. The highest agricultural conduit potential was seen in Colorado, Washington, Nebraska, California, Oregon and Idaho. Irrigation and topography were primary drivers for this assessment.

Researchers also assessed drinking water supply and wastewater systems in the municipal sector. Conduit hydropower potential here was highest in California, which had twice that of the next-highest state, New York. Colorado, Utah, Washington, Oregon and Pennsylvania also showed potential for capacity generation in this sector.

Opportunities for conduit hydropower from industrial conduits, such as industrial pipelines or canals used at thermoelectric generating facilities, were present mostly in California, Texas, Missouri, New York and Maryland. However, these facilities also pose the greatest uncertainty due to higher economic and regulatory requirements.

“These assessments open the door across multiple business sectors to what is possible,” said Kao. “By further understanding the costs and benefits of conduit hydropower, decision makers can leverage what is already available and deliver on the promise of more renewable energy.”

The ORNL research team will facilitate further discussion with key stakeholders in water supply and delivery to raise the awareness of conduit hydropower and to understand how the community may overcome this hurdle to develop more conduit hydropower projects.

President Xi Jinping has promised a slow and steady end to the growth of planet-warming emissions in China, with energy security taking top priority as the country contends with a flagging economy and tumult on global fuel markets.

In a two-hour speech to kick off the weeklong Communist Party Congress, Xi said that prudence would govern China’s efforts to peak and eventually zero-out carbon emissions. The cautious wording comes after a spate of high-profile power shortages in recent years, and as global energy costs have soared after Russia’s invasion of Ukraine upended trade flows.

The speech made China’s path to decarbonization clear: It won’t stop burning fossil fuels until it’s confident that clean energy can reliably replace them.

“We will work actively and prudently toward the goals of reaching peak carbon emissions and carbon neutrality,” Xi said in his address. “Based on China’s energy and resource endowments, we will advance initiatives to reach peak carbon emissions in a well-planned and phased way, in line with the principle of getting the new before discarding the old.”

China is the world’s largest emitter of greenhouse gases, and Xi electrified climate activists two years ago when he vowed to reach carbon neutrality by 2060 after peaking emissions before 2030. The announcement sparked a massive surge in investment in clean energy by local governments and state-owned firms.

But last year, focus began to return to China’s mainstay fuel of coal after a shortage triggered widespread power curtailments to factories, slowing economic growth. The country vowed to increase mining capacity, and production has risen to record levels this year, keeping storage sites well stocked and reducing imports.

China will also expand exploration and development of oil and gas resources, and increase reserves and production as part of the measures to ensure energy security, according to a congress work report released after Xi’s speech.

China invests more than any other country in clean energy, and is on pace to shatter its record for new solar installations this year. But it hasn’t been able to outrun the growth in energy demand, forcing it to burn more coal and setting a record for consumption last year that is likely to be eclipsed in 2022.

Xi made clear that fossil fuels and renewables will have to work in tandem. “Coal will be used in a cleaner and more efficient way and we will speed up the planning and development of new energy systems,” he said.

He also vowed that China would be actively involved in the global response to climate change. His government was criticized after it broke off climate negotiations with the US in August after House Speaker Nancy Pelosi’s visit to the contested island of Taiwan.

Aeromine Technologies claims that its new rooftop bladeless wind energy unit provides the same amount of power as up to 16 solar panels. Could it become a game changer for generating clean energy on commercial buildings? Aeromine Technologies says its motionless system, which was validated through joint research with Sandia National Laboratories in Albuquerque and Texas Tech University, easily installs on the edge of a building and can generate up to 50% more energy at the same cost as rooftop solar. It’s designed to sit on buildings with flat roofs such as warehouses and distribution centers, manufacturing facilities, office buildings, multi-family residential developments, and big box retail. The company says its patented rooftop wind product is currently being piloted by BASF Corporation – the largest chemical producer in the world – at BASF’s manufacturing plant in Wyandotte, Michigan. Aeromine explains how its rooftop bladeless wind energy unit works:

Aeromine is motionless. The technology leverages aerodynamics similar to airfoils on a race car to capture and amplify each building’s airflow. Requiring just 10% of the roof space needed by solar panels, the stationary, silent, and durable Aeromine unit generates around-the-clock energy in any weather. Aeromine systems consist of 20-40 units installed on the edge of a building facing the predominant wind direction. Designed to work seamlessly with a building’s existing electrical system, the combination of Aeromine’s wind solution with rooftop solar can generate up to 100% of a building’s onsite energy needs, while minimizing the need for energy storage.

It can also be paired with existing solar, so it isn’t necessary to disassemble already-installed solar panels to install the wind unit.

Testing has begun at Diamond Light Source for an energy-saving super-magnet, designed and built by the Science and Technology Facilities Council (STFC), for our next generation of particle accelerator.

Particle accelerators are responsible for some of our greatest scientific breakthroughs in history, such as the discovery of the Higgs boson at CERN’s Large Hadron Collider.

The world needs these powerful and highly complex machines to enable research that is essential for developing important green technologies, such as better solar cells and more efficient batteries.

Beaming at the speed of light

One particle accelerator can use thousands of high-power, tunable electromagnets to bend and focus a beam through the machine, close to the speed of light. However, these consume vast amounts of electricity to operate and cool.

Designed by scientists and engineers at STFC’s Daresbury Laboratory, at Sci-Tech Daresbury, the zero power tunable optics magnet (ZEPTO) is a permanent, tunable magnet that consumes zero electrical power.

ZEPTO offers the same flexibility as an electromagnet but does not require power to produce a magnetic field, which could save dramatically on the cost and scale of future particle accelerators.

The Diamond test

Energy consumption and the associated financial and environmental cost are key challenges faced when building a next generation particle accelerator.

ZEPTO’s successful commissioning at Diamond, the U.K.’s national synchrotron accelerator, kicks off a year-long demonstrator to confirm that it is as reliable and robust as a conventional electromagnet.

During the test, 1 magnet is expected to save an estimated 136 kg of carbon dioxide compared with a conventional electromagnet, with the carbon payback anticipated to be within a year of operation.

Technology for future accelerators

Professor Jim Clarke, Director of STFC’s Accelerator Science and Technology Center, who led the design and development of the ZEPTO magnet, said, “The development of the ZEPTO magnet confirms STFC’s ability to design and build the brand-new technologies required to build the world’s next generation of research facilities more affordably and sustainably.

“I’m so proud to see it installed and running successfully for the first time on an operational facility. This is a significant step in the development for this innovative magnet.”

Making particle accelerators sustainable

The ZEPTO magnet, developed under STFC’s Proof of Concept Fund, is part of STFC’s growing Sustainable Accelerators program. It is just one demonstration of STFC’s commitment to making accelerators sustainable.

Professor Clarke added, “It’s hugely exciting to be applying our expertise to make particle accelerators environmentally and financially sustainable, for the benefit of our environment and economy. This important project is just one example of how accelerator scientists, engineers and technicians at STFC are supporting STFC’s aim to be net zero by 2040.”