Denham Capital invests in BioTherm Energy

By PR Newswire


CSA Z463 Electrical Maintenance

Our customized live online or in‑person group training can be delivered to your staff at your location.

  • Live Online
  • 6 hours Instructor-led
  • Group Training Available
Regular Price:
$249
Coupon Price:
$199
Reserve Your Seat Today
Denham Capital, a leading energy-focused global private equity firm, announced that it will invest equity of up to [US] $150 million, in BioTherm Energy, a South African developer, owner and operator of renewable and clean energy generation projects.

Commenting on Denham Capital's investment, Buyelwa Sonjica, South Africa Minister of Minerals and Energy said, "Having opened BioTherm's first plant just over a year ago, we are delighted with this substantial investment by Denham Capital, a major foreign investor, in a business that will generate more electricity in South Africa, contribute to the reduction of greenhouse gasses and create more jobs in the South African economy."

The Minister opened the 4.2 MW biogas to power plant, based at the PetroSA facility in Mossel Bay, east of Cape Town, in September 2007. At that time, it was the first private sector renewable power generation project in Southern Africa funded under the Clean Development Mechanism of the Kyoto Protocol, under which the project earns carbon credits because of its contribution to the reduction of greenhouse gasses. Under the European carbon-trading scheme these credits are in turn sold, primarily to European industries, which need to reduce the cost of their compliance liabilities.

The opportunity for small scale, on-site generation in South Africa has grown significantly and BioTherm Energy has secured, and is continuing to develop, a substantial pipeline in waste gas co-generation, biomass and combined heat and power projects, many of which qualify for carbon credits under the Kyoto Protocol. These projects can generate electricity much more rapidly than conventional large-scale power projects, thereby providing needed relief to the South African power system.

Dr. Louis van Pletsen, a Partner and Head of the London Office of Denham Capital, said, "Denham Capital will provide the necessary equity capital for BioTherm Energy to develop, invest or acquire projects totalling approximately 300 MW, equivalent to the electricity needed to supply about 500,000 households. Private sector investment from companies such as BioTherm Energy will be essential in addressing South Africa's energy deficit." He added, "Our investment in BioTherm reflects the range and geographic reach of Denham Capital's energy investment strategy."

Charles Liebenberg, co-founder and CEO of BioTherm Energy, said that a partnership with Denham Capital will allow BioTherm Energy to continue its aggressive expansion programme. He went further to say, "For years South Africa has had cheap energy and an unfortunate result of this is inefficient usage. BioTherm Energy's projects ensure that all forms of energy can be best harnessed to avoid waste, reduce carbon emissions and provide reliable power. The Power Conservation Programme, which will ration electricity supply to all consumers, reflects the severity of the power crisis in South Africa which BioTherm can help address."

BioTherm Energy is targeting energy intensive industries where industrial processes release significant amounts of waste energy both as heat and gasses. BioTherm Energy utilises this wasted energy to produce electricity and/or steam, which it sells to the host site or to third parties, including Eskom, the South African public electricity utility.

BioTherm Energy is also instituting multi-level sustainability in all of its projects through the participation of Black Economic Empowerment partners and community-based development programmes.

"Our investment in BioTherm reflects our strong belief in the potential for innovative solutions to the South African power crisis," said Scott Mackin, a Partner at Denham Capital. "We are delighted to be working to develop this exciting and valuable business, with a highly skilled and committed management team with a proven track record. We believe BioTherm Energy is well positioned to deliver much needed additional clean and reliable power to the Southern African economy."

Related News

U.S Bans Russian Uranium to Bolster Domestic Industry

U.S. Russian Uranium Import Ban reshapes nuclear fuel supply, bolstering energy security, domestic enrichment, and sanctions policy while diversifying reactor-grade uranium sources and supply chains through allies, waivers, and funding to sustain utilities and reliability.

 

Key Points

A U.S. law halting Russian uranium imports to boost energy security diversify nuclear fuel and revive U.S. enrichment.

✅ Cuts Russian revenue; reduces geopolitical risk.

✅ Funds U.S. enrichment; supports reactor fuel supply.

✅ Enables waivers to prevent utility shutdowns.

 

In a move aimed at reducing reliance on Russia and fostering domestic energy security for the long term, the United States has banned imports of Russian uranium, a critical component of nuclear fuel. This decision, signed into law by President Biden in May 2024, marks a significant shift in the U.S. nuclear fuel supply chain and has far-reaching economic and geopolitical implications.

For decades, Russia has been a major supplier of enriched uranium, a processed form of uranium used to power nuclear reactors. The U.S. relies on Russia for roughly a quarter of its enriched uranium needs, feeding the nation's network of 94 nuclear reactors operated by utilities which generate nearly 20% of the country's electricity. This dependence has come under scrutiny in recent years, particularly following Russia's invasion of Ukraine.

The ban on Russian uranium is a multifaceted response. First and foremost, it aims to cripple a key revenue stream for the Russian government. Uranium exports are a significant source of income for Russia, and by severing this economic tie, the U.S. hopes to weaken Russia's financial capacity to wage war.

Second, the ban serves as a national energy security measure. Relying on a potentially hostile nation for such a critical resource creates vulnerabilities. The possibility of Russia disrupting uranium supplies, either through political pressure or in the event of a wider conflict, is a major concern. Diversifying the U.S. nuclear fuel supply chain mitigates this risk.

Third, the ban is intended to revitalize the domestic uranium mining and enrichment industry, building on earlier initiatives such as Trump's uranium order announced previously. The U.S. has historically been a major uranium producer, but environmental concerns and competition from cheaper foreign sources led to a decline in domestic production. The ban, coupled with $2.7 billion in federal funding allocated to expand domestic uranium enrichment capacity, aims to reverse this trend.

The transition away from Russian uranium won't be immediate. The law includes a grace period until mid-August 2024, and waivers can be granted to utilities facing potential shutdowns if alternative suppliers aren't readily available. Finding new sources of enriched uranium will require forging partnerships with other uranium-producing nations like Kazakhstan, Canada on minerals cooperation, and Australia.

The long-term success of this strategy hinges on several factors. First, successfully ramping up domestic uranium production will require overcoming regulatory hurdles and addressing environmental concerns, alongside nuclear innovation to modernize the fuel cycle. Second, securing reliable alternative suppliers at competitive prices is crucial, and supportive policy frameworks such as the Nuclear Innovation Act now in law can help. Finally, ensuring the continued safe and efficient operation of existing nuclear reactors is paramount.

The ban on Russian uranium is a bold move with significant economic and geopolitical implications. While challenges lie ahead, the potential benefits of a more secure and domestically sourced nuclear fuel supply chain are undeniable. The success of this initiative will be closely watched not only by the U.S. but also by other nations seeking to lessen their dependence on Russia for critical resources.

 

Related News

View more

Tesla updates Supercharger billing to add cost of electricity use for other than charging

Tesla Supercharger Billing Update details kWh-based pricing that now includes HVAC, battery thermal management, and other HV loads during charging sessions, improving cost transparency across pay-per-use markets and extreme climate scenarios.

 

Key Points

Tesla's update bills for kWh used by HVAC, battery heating, and HV loads during charging, reflecting true energy costs.

✅ kWh charges now include HVAC and battery thermal management

✅ Expect 10-25 kWh increases in extreme climates during sessions

✅ Some regions still bill per minute due to regulations

 

Tesla has updated its Supercharger billing policy to add the cost of electricity use for things other than charging, like HVAC, battery thermal management, etc, while charging at a Supercharger station, a shift that impacts overall EV charging costs for drivers. 

For a long time, Tesla’s Superchargers were free to use, or rather the use was included in the price of its vehicles. But the automaker has been moving to a pay-to-use model over the last two years in order to finance the growth of the charging network amid the Biden-era charging expansion in the United States.

Not charging owners for the electricity enabled Tesla to wait on developing a payment system for its Supercharger network.

It didn’t need one for the first five years of the network, and now the automaker has been fine-tuning its approach to charge owners for the electricity they consume as part of building better charging networks across markets.

At first, it meant fluctuating prices, and now Tesla is also adjusting how it calculates the total power consumption.

Last weekend, Tesla sent a memo to its staff to inform them that they are updating the calculation used to bill Supercharging sessions in order to take into account all the electricity used:

The calculation used to bill for Supercharging has been updated. Owners will also be billed for kWhs consumed by the car going toward the HVAC system, battery heater, and other HV loads during the session. Previously, owners were only billed for the energy used to charge the battery during the charging session.

Tesla says that the new method should more “accurately reflect the value delivered to the customer and the cost incurred by Tesla,” which mirrors recent moves in its solar and home battery pricing strategy as well.

The automaker says that customers in “extreme climates” could see a difference of 10 to 25 kWh for the energy consumed during a charging session:

Owners may see a noticeable increase in billed kWh if they are using energy-consuming features while charging, e.g., air conditioning, heating etc. This is more likely in extreme climates and could be a 10-25 kWh difference from what a customer experienced previously, as states like California explore grid-stability uses for EVs during peak events.

Of course, this is applicable where Tesla is able to charge by the kWh for charging sessions. In some markets, regulations push Tesla to charge by the minute amid ongoing fights over charging control between utilities and private operators.

Electrek’s Take
It actually looks like an oversight from Tesla in the first place. It’s fair to charge for the total electricity used during a session, and not just what was used to charge your battery pack, since Tesla is paying for both, even as some states add EV ownership fees like the Texas EV fee that further shape costs.

However, I wish Tesla would have a clearer way to break down the charging sessions and their costs.

There have been some complaints about Tesla wrongly billing owners for charging sessions, and this is bound to create more confusion if people see a difference between the kWhs gained during charging and what is shown on the bill.

 

Related News

View more

India is now the world’s third-largest electricity producer

India Electricity Production 2017 surged to 1,160 BU, ranking third globally; rising TWh output with 334 GW capacity, strong renewables and thermal mix, 7% CAGR in generation, and growing demand, investments, and FDI inflows.

 

Key Points

India's 2017 power output reached 1,160 BU, third globally, supported by 334 GW capacity, rising renewables, and 7% CAGR.

✅ 1,160 BU generated; third after China and the US

✅ Installed capacity 334 GW; 65% thermal, rising renewables

✅ Generation CAGR ~7%; demand, FDI, investments rising

 

India now generates around 1,160.1 billion units of electricity in financial year 2017, up 4.72% from the previous year, and amid surging global electricity demand that is straining power systems. The country is behind only China which produced 6,015 terrawatt hours (TWh. 1 TW = 1,000,000 megawatts) and the US (4,327 TWh), and is ahead of Russia, Japan, Germany, and Canada.


 

India’s electricity production grew 34% over seven years to 2017, and the country now produces more energy than Japan and Russia, which had 27% and 8.77% more electricity generation capacity installed, respectively, than India seven years ago.

India produced 1,160.10 billion units (BU) of electricity–one BU is enough to power 10 million households (one household using average of about 3 units per day) for a month–in financial year (FY) 2017. Electricity production stood at 1,003.525 BU between April 2017-January 2018, according to a February 2018 report by India Brand Equity Foundation (IBEF), a trust established by the commerce ministry.

#google#

With a production of 1,423 BU in FY 2016, India was the third largest producer and the third largest consumer of electricity in the world, behind China (6,015 BU) and the United States (4,327 BU).

With an annual growth rate of 22.6% capacity addition over a decade to FY 2017, renewables beat other power sources–thermal, hydro and nuclear. Renewables, however, made up only 18.79% of India’s energy, up 68.65% since 2007, and globally, low-emissions sources are expected to cover most demand growth in the coming years. About 65% of installed capacity continues to be thermal.

As of January 2018, India has installed power capacity of 334.4 gigawatt (GW), making it the fifth largest installed capacity in the world after European Union, China, United States and Japan, and with much of the fleet coal-based, imported coal volumes have risen at times amid domestic supply constraints.

The government is targeting capacity addition of around 100 GW–the current power production of United Kingdom–by 2022, as per the IBEF report.


 

Electricity generation grew at 7% annually

India achieved a 34.48% growth in electricity production by producing 1,160.10 BU in 2017 compared to 771.60 BU in 2010–meaning that in these seven years, electricity production in India grew at a compound annual growth rate (CAGR) of 7.03%, while thermal power plants' PLF has risen recently amid higher demand and lower hydro.

 

Generation capacity grew at 10% annually

Of 334.5 GW installed capacity as of January 2018–up 60% from 132.30 GW in 2007–thermal installed capacity was 219.81 GW. Hydro and renewable energy installed capacity totaled 44.96 GW and 62.85 GW, respectively, said the report.

The CAGR in installed capacity over a decade to 2017 was 10.57% for thermal power, 22.06% for renewable energy–the fastest among all sources of power–2.51% for hydro power and 5.68% for nuclear power.

 

Growing demand, higher investments will drive future growth

Growing population and increasing penetration of electricity connections, along with increasing per-capita usage would provide further impetus to the power sector, said the report.

Power consumption is estimated to increase from 1,160.1 BU in 2016 to 1,894.7 BU in 2022, as per the report, though electricity demand fell sharply in one recent period.

Increasing investment remained one of the driving factors of power sector growth in the country.

Power sector has a 100% foreign direct investment (FDI) permit, which boosted FDI inflows in the sector.

Total FDI inflows in the power sector reached $12.97 billion (Rs 83,713 crore) during April 2000 to December 2017, accounting for 3.52% of FDI inflows in India, the report said.

 

Related News

View more

Zapping elderly brains with electricity improves short-term memory — for almost an hour

Transcranial electrical stimulation synchronizes brain waves to bolster working memory, aligning neural oscillations across the prefrontal and temporal cortex. This noninvasive brain stimulation may counter cognitive aging by restoring network coupling and improving short-term recall.

 

Key Points

Transcranial electrical stimulation applies scalp currents to synchronize brain waves, briefly enhancing working memory.

✅ Synchronizes prefrontal-temporal networks to restore coupling

✅ Noninvasive tES/tACS protocols show rapid, reversible gains

✅ Effects lasted under an hour; durability remains to be tested

 

To read this sentence, you hold the words in your mind for a few seconds until you reach the period. As you do, neurons in your brain fire in coordinated bursts, generating electrical waves that let you hold information for as long as it is needed, much as novel devices can generate electricity from falling snow under specific conditions. But as we age, these brain waves start to get out of sync, causing short-term memory to falter. A new study finds that jolting specific brain areas with a periodic burst of electricity might reverse the deficit—temporarily, at least.

The work makes “a strong case” for the idea that out-of-sync brain waves in specific regions can drive cognitive aging, says Vincent Clark, a neuroscientist at the University of New Mexico in Albuquerque, who was not involved in the research. He adds that the brain stimulation approach in the study may result in a new electrical therapy for age-related deficits in working memory.

Working memory is “the sketchpad of the mind,” allowing us to hold information in our minds over a period of seconds. This short-term memory is critical to accomplishing everyday tasks such as planning and counting, says Robert Reinhart, a neuroscientist at Boston University who led the study. Scientists think that when we use this type of memory, millions of neurons in different brain areas communicate through coupled bursts of activity, a form of electrical conduction that coordinates timing across networks. “Cells that fire together, wire together,” Reinhart says.

But despite its critical role, working memory is a fragile cognitive resource that declines with age, Reinhart says. Previous studies had suggested that reduced working-memory performance in the elderly is linked to uncoupled activity in different brain areas. So Reinhart and his team set out to test whether recoupling brain waves in older adults could boost the brain’s ability to temporarily store information, a systems-level coordination challenge akin to efforts to use AI for energy savings on modern power grids.

To do so, the researchers used jolts of weak electrical current to synchronize waves in the prefrontal and temporal cortex—two brain areas critical for cognition, a targeted approach not unlike how grids use batteries to stabilize power during strain—and applied the current to the scalps of 42 healthy people in their 60s and 70s who showed no signs of decline in mental ability. Before their brains were zapped, participants looked at a series of images: an everyday object, followed briefly by a blank screen, and then either an identical or a modified version of the same object. The goal was to spot whether the two images were different.

Then the participants took the test again, while their brains were stimulated with a current. After about 25 minutes of applying electricity, participants were on average more accurate at identifying changes in the images than they were before the stimulation. Following stimulation, their performance in the test was indistinguishable from that of a group of 42 people in their 20s. And the waves in the prefrontal and temporal cortex, which had previously been out of sync in most of the participants, started to fire in sync, the researchers report today in Nature Neuroscience, a synchronization imperative reminiscent of safeguards that prevent power blackouts on threatened grids. No such effects occurred in a second group of older people who received jolts of current that didn’t synchronize waves in the prefrontal and temporal cortex.

By using bursts of current to knock brain waves out of sync, the researchers also modulated the brain chatter in healthy people in their 20s, making them slower and less accurate at spotting differences in the image test.

“This is a very nice and clear demonstration of how functional connections underlie memory in younger adults and how alterations … can lead to memory reductions in older adults,” says Cheryl Grady, a cognitive neuroscientist at the Rotman Research Institute at Baycrest in Toronto, Canada. It’s also the first time that transcranial stimulation has been shown to restore working memory in older people, says Michael O’Sullivan, a neuroscientist at the University of Queensland in Brisbane, Australia, though electricity in medicine extends far beyond neurostimulation.

But whether brain zapping could turbocharge the cognitive abilities of seniors or help improve the memories of people with diseases like Alzheimer’s is still unclear: In the study, the positive effects on working memory lasted for just under an hour—though Reinhart says that’s as far as they recorded in the experiment. The team didn’t see the improvements decline toward the end, so he suspects that the cognitive boost may last for longer. Still, researchers say much more work has to be done to better understand how the stimulation works.

Clark is optimistic. “No pill yet developed can produce these sorts of effects safely and reliably,” he says. “Helping people is the ultimate goal of all of our research, and it’s encouraging to see that progress is being made.”

 

Related News

View more

Sub-Saharan Africa has a huge electricity problem - but with challenge comes opportunity

Sub-Saharan Africa Energy Access faces critical deficits; SDG7, clean energy finance, off-grid solar, and microgrids drive electrification for health, education, and economy amid World Bank and IEA efforts to expand reliable, affordable power.

 

Key Points

Reliable, affordable power in sub-Saharan Africa via renewables, off-grid solar, and SDG7-led electrification.

✅ SDG7 targets universal, modern energy access by 2030

✅ Off-grid solar and microgrids boost rural electrification

✅ Health, education, and business depend on reliable power

 

Sub-Saharan Africa has an electricity problem. While the world as a whole has made great strides when it comes to providing access to electricity and moving toward universal electricity access worldwide (the world average is now 90 per cent with access, up from 83 per cent in 2010), southern and western African states still lag far behind.

According to Tracking SDG7: The Energy Progress Report, produced by a consortium of organisations including the World Bank, the International Energy Agency and the World Health Organization, 759 million people were without electricity in 2019 and threequarters of them were based in sub-Saharan Africa. At just seven per cent, South Sudan had the lowest access figures; Chad, Burundi and Malawi were only marginally higher. What’s more, due to a combination of factors, the situation is getting worse. In total, the region’s access deficit increased from 556 million people in 2010 to 570 million people in 2019.

These days, being without electricity has an impact on every sphere of life. The Covid-19 pandemic only served to put this into sharper relief. Intermittent electricity meant vaccination doses that rely on cold storage were impossible to deliver and, as more than 70 per cent of the health facilities in sub-Saharan Africa have no access to reliable electricity, the problem was vast. But even without a global pandemic, having no power stymies opportunity in every field, from education to economics.

French photojournalist Pascal Maitre, who has spent much of his career writing about sub-Saharan Africa, wanted to document the problems faced by people in areas with no electricity. He thought particularly carefully about the location for his project. ‘First, I was thinking I could take images in the Democratic Republic of the Congo,’ he says. ‘But then I thought that if you chose a place that has war, it’s logical that electricity won’t really work. So, instead, I wanted to find a place that is quite stable. I decided to go to Benin, where they have a democracy. It is a good example of a country that’s not in really bad shape but where they still have this problem. Also, I didn’t want to go to a place that is very remote, where it is normal not to have good service. So I decided to go to a place around 50 kilometres from the capital that you can get to by road.’

Maitre visited several villages in the region, as well as making trips to Chad and Senegal, and encountered the full range of limitations engendered by the power shortage. From teachers struggling to conduct lessons in the dark to midwives forced to work with only the weak light from a phone, the situation was clearly unacceptable. ‘People were very, very, very upset,’ he says. ‘I conducted a lot of interviews in different villages and lack of electricity touches education, economy, business, security and also emigration, because people have to move to big cities or maybe to Europe to get jobs.’

Where once the situation might have been accepted as the norm, people today are fully aware of the ways in which they are held back by the lack of power. As Maitre remembers: ‘A guy said to me one day, “Do you think it is normal that last time my wife delivered a baby, the midwife had to hold her phone between her teeth in order to see what she was doing?” You feel very frustrated.’ He adds that the fact that most people now have mobile phones only highlights the hardship. ‘Before, maybe it was not so frustrating. But now, most of these people have cellphones. The cellphone company puts antennae everywhere so the phones work, but people cannot recharge their phones. They have to go to the market, where someone will come with a generator to recharge.’

Governments and global organisations are very aware of the problem across the world as a whole. Sustainable Development Goal 7 (SDG7) – one of the 17 goals set out in 2015 by the United Nations General Assembly – was designed to ensure universal access to affordable, reliable, sustainable and modern energy by 2030, underscoring the push for clean, affordable and sustainable electricity for all by 2030. As part of this goal, international financial flows to developing countries in support of clean energy reached US$17 billion in 2018. As a result, some areas have seen huge improvement. According to the Energy Progress Report, in Latin America and the Caribbean, and in Eastern and South-Eastern Asia, the advance of electrification has been enough to approach universal access. By 2019, in Western Asia and North Africa, and Central and South Asia, 94 and 95 per cent of the population respectively had access to electricity.

But these statistics only serve to emphasise just how bad the situation is in sub-Saharan Africa, where electricity systems are unlikely to go green this decade according to several analyses. As the report states: ‘While renewable energy has demonstrated remarkable resilience during the pandemic, the unfortunate fact is that gains in energy access throughout Africa are being reversed: the number of people lacking access to electricity is set to increase in 2020, making basic electricity services unaffordable for up to 30 million people who had previously enjoyed access.’

The small silver lining is that if the situation is dealt with properly, the region could build a renewable-energy system from the ground up, rather than having to undergo the costly and complex transitions underway in developed countries. In rural areas, small-scale or off-grid renewable systems (mostly solar) are expected to play an important role, as highlighted by a recent IRENA report on decarbonisation, in increasing access. In fact, solar panels are already used in many areas. In 2019, 105 million people had access to off-grid solar solutions, up from 85 million in 2016, and almost half lived in sub-Saharan Africa, with 17 million in Kenya and eight million in Ethiopia.

Rachel Kyte is currently serving as the 14th dean of the Fletcher School at Tufts University in the USA, but her CV is long. She was previously CEO of the UN-affiliated Sustainable Energy for All (SeforALL), as well as the World Bank Group vice president and special envoy for climate change, leading the run-up to the Paris Agreement. According to her, a focus on renewables is absolutely essential, both for wider efforts to tackle climate change, with some advocating a fossil fuel lockdown to drive a climate revolution, but also for the people of sub-Saharan Africa. ‘The fossil fuel industry has said it will just extend the centralised fossil-fuel power systems that we have today to reach these people,’ she says.

 

Related News

View more

Turning thermal energy into electricity

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.

 

Related News

View more

Sign Up for Electricity Forum’s Newsletter

Stay informed with our FREE Newsletter — get the latest news, breakthrough technologies, and expert insights, delivered straight to your inbox.

Electricity Today T&D Magazine Subscribe for FREE

Stay informed with the latest T&D policies and technologies.
  • Timely insights from industry experts
  • Practical solutions T&D engineers
  • Free access to every issue

Download the 2025 Electrical Training Catalog

Explore 50+ live, expert-led electrical training courses –

  • Interactive
  • Flexible
  • CEU-cerified