Researchers in Singapore invented a novel device that may help the island nation illuminate its growing underground infrastructure.
As nations like Singapore continue to build sophisticated underground infrastructure, there's growing need for reliable and affordable lighting systems. To meet that demand, a team of researchers at Nanyang Technological University in Singapore created an innovative solution: a smart device that harvests real daylight and transmits it underground.
The device, described in a paper published by the journal Solar Energy, is something like a "smart" magnifying glass. Its main component is an acrylic sphere that sits above ground to absorb and concentrate sunlight. A plastic optical fibre is positioned under the sphere to collect and transport the concentrated sunlight to a desired location up to two stories underground.
To ensure the system collects the maximum amount of sunlight, a GPS device uses motors to move the fibre cable into optimal positions, depending on the position of the sun. This helps save energy, considering the only moving part is the lightweight cable, not the heavier sphere.
But what if it's cloudy? To solve that inevitable problem, the team outfitted the emitting end of the fibre cable with an electrically powered LED bulb that produces artificial light. The researchers said future versions of the device may include a high-efficiency photovoltaic cell that would collect and store energy, meaning it could power the LED bulb during overcast conditions. That would make it a zero-energy device.
Credit: Goela et al.
It's poised to be an efficient system for underground lighting, especially considering the study results showed that the device's luminous efficacy rating was more than double that of commercially available LED bulbs.
"The luminous efficacy of our low-cost device proves that it is well-suited for low-level lighting applications, like car parks, lifts, and underground walkways in dense cities," Dr. Charu Goel, Principal Research Fellow at NTU's The Photonics Institute, said in a press release.
"It is also easily scalable. Since the light capturing capacity of the ball lens is proportional to its size, we can customise the device to a desired output optical power by replacing it with a bigger or smaller ball."
While some of the early prototypes look like complicated snowglobes, future devices would likely be designed to look and function like traditional lamp posts, illuminating streets above ground using electricity.
Credit: Goela et al
This hybrid system could help light the way for Singapore's plans to move more of its infrastructure underground.
As an island nation with a fast-growing population, Singapore has for years been exploring strategies to use subterranean space more efficiently. Singapore has already built underground highways, parking lots, and walkways, and by 2030 the government hopes to expand its subterranean infrastructure, including underground utility plants, roads, and railways.
"Where it is feasible and meaningful, going underground would be the approach to optimise land use and improve the quality of our living environment," reads a report from Singapore's Urban Redevelopment Authority. "In general, the shallow levels of the underground would be used for people-centric activities that require connectivity to above-ground; while the deeper levels would be used for utilities, infrastructure, storage and logistics uses."
Can biomaterials help finally thrust perovskite solar cells to mainstream adoption?
- Perovskite solar cells are an emerging type of solar technology that's more efficient than current photovoltaic technologies, but hasn't yet been adopted due to problems related to cost and stability.
- In a recent study, scientists treated perovskite solar cells with small amounts of capsaicin, finding that the compound improved both stability and efficiency.
- In 2022, a British startup plans to bring perovskite solar cells to market for the first time.
A new study shows that treating perovskite solar cells with capsaicin—the organic compound that makes chili peppers spicy—makes them more efficient.
The study, published in the journal Joule, may help to advance the viability of perovskite solar cells, an emerging type of solar technology that's not yet widely used, but promises to be more efficient and scalable than current photovoltaic technologies.
In the study, a team of scientists from China and Sweden added small amounts of capsaicin (1 percent by weight) to the chemical precursor used to make perovskite solar cells. The team then measured how efficiently the capsaicin-treated cells converted ultraviolet and visible light into electricity, as compared to untreated perovskite solar cells.
The results showed that the treated cells were 21.88 percent efficient, compared to the untreated cells rating of 19.1 percent. The treated cells were also more stable, showing 90 percent of their initial efficiency after 800 hours of storage in ambient air. That's significant, considering one of the main things preventing perovskite solar cells from becoming economically viable is their tendency to degrade relatively quickly in the environment.
Using biomaterials to boost solar technology
The team needs to conduct more research to determine exactly why capsaicin boosts the efficacy and stability of perovskite solar cells, but they hypothesized that the compound increases the density of electrons on the perovskite film due to the way it interacts with lead ions in the solar cell.
Biomaterials like capsaicin could someday make perovskite solar cells economically viable, but the techniques still need to be improved.
"In the future, green and sustainable forest-based biomaterial additive technology will be a clear trend in non-toxic lead-free perovskite materials," Qinye Bao, a senior author of the study from East China Normal University, said in a statement. "We hope this will eventually yield a fully green perovskite solar cell for a clean energy source."
The recent study isn't the first time scientists have used biomaterials to boost the performance of perovskite solar cells: Caffeine and the protein bacteriorhodopsin (bR) have also shown benefits. The main appeal of biomaterials is that they're abundant in the environment, so they're relatively cheap and easy to obtain compared to synthetic materials.
The future of perovskite solar cells
Since perovskite absorbers were first used in solar cells in 2006, efficiency rates have climbed from just 3 percent to over 25 percent. Research also suggests that pairing perovskite solar cells with silicon could boost efficiency levels to nearly 30 percent.
Joe Berry, a senior scientist at the U.S. National Renewable Energy Laboratory, said:
"The potential impact for perovskite solar cells is basically transformational," he said, adding that the long term goal is to cut manufacturing costs and make them ubiquitous. "That is to say, you can put them everywhere. You can literally paint them on the side of a building and everything then become something that can produce electricity and power."
In 2022, the U.K.-based startup Oxford PV plans to become the first company to bring perovskite solar cells to market (though the cells would also include silicon). If such companies can demonstrate that perovskite solar cells, or hybrid approaches, can produce cheap electricity and won't break down over years of use, it could nudge industries and utilities to start adopting solar at a quicker pace.
Researchers from Harvard receive permission for a test that may help cool Earth and fight global warming.
- Swedish space agency allows Harvard researchers to test a stratospheric balloon next year.
- The balloon may eventually be used to release particles into the atmosphere to reflect sunlight.
- The goal would be to cool Earth and fight back against global warming but the approach has critics.
Harvard University researchers were given permission by the Swedish Space Corporation to carry out a test next year that may lead to releasing artificial particles into the air to partially block out the sun. This approach could potentially reduce global warming and cool our planet, but has raised geoengineering concerns among environmentalists.
The Harvard test would involve a balloon being flown about 20km (12 miles) above the Arctic town of Kiruna in Sweden next June. The balloon's gondola would be packed with 600 kg of scientific equipment and the purpose of that flight would be to try all of it out, especially the communications gear. If the test is successful, it may lead to another test in the fall of 2021 or in spring of 2022. At that point, a small amount (up to 2kg) of the non-toxic calcium carbonate would be released into the atmosphere, reported Alister Doyle of the Thomson Reuters Foundation. The goal of dispersing what is essentially chalk would be to see if these particles could reflect the sunlight and thus reduce the Sun's harmful effects.
Supporters of solar engineering think technological solutions may be found to counter rising temperatures but their ideas have also faced pushback, admitted David Keith, who takes part in the project and has professorships in both applied physics and public policy at Harvard.
"There are very many real concerns" about the risks of climate change and solar geoengineering, said Keith," adding "Understanding them requires a range of activities including experiments."
Finding the right "dose" for solar geoengineering
The opponents of the idea see pitfalls in climate engineering and artifical sunshade projects. There are too many risks and unpredictable domino effects. Attempting to mitigate the effects of global warming through geoengineering obscures the necessity of moving away from fossil fuels and carbon-based economies, argue the critics.
Environmental policy expert Lili Fuhr of the Heinrich Böll Foundation in Germany described the Harvard test as "crossing an important political red line" and thinks the small experiment will lead to larger and more dangerous ones. She believes the plan may be in violation of a UN moratorium on geoengineering, which is non-binding.
SCoPEx: Stratospheric Controlled Perturbation Experiment
The leaders of the Harvard project, dubbed the Stratospheric Controlled Perturbation Experiment (SCoPEx), downplayed any concerns and explained that they are complying with all regulations . The conspiracy-minded will be happy to find out that while not only 300 or so stratospheric balloons were launched around the globe in 2019, among the backers of SCoPEx is none other than the Microsoft founder Bill Gates.
While the approaches to dealing with it remain varied and debated, global warming has been linked to a variety of increasingly more severe weather effects, from heat waves to stronger hurricanes and catastrophic flooding, as well as the worsening spread of illnesses, greater pollution, economic inequality, and the accelerating extinction of wildlife. And in a sign that things aren't magically going to get better, the Intergovernmental Panel on Climate Change (IPCC), comprised of over 1,300 scientists from the United States and other countries, predicts the temperatures around the world will rise by 2.5 to 10 degrees Fahrenheit over the next century, bringing all matter of new calamity. Despite this being a global problem, countries that prepare and adapt accordingly will fare the best in the coming years.
- The International Energy Agency is an intergovernmental organization that advises member nations on issues related to energy and the environment.
- In its annual report, the IEA reported that the cost of solar is dropping more rapidly than previously thought, providing some parts of the world with historically cheap electricity.
- The IEA predicted that, over the next decade, renewables will meet 80 percent of global electricity demand growth, while the demand for oil will peak.
Electricity from solar energy is the cheapest it's ever been, thanks largely to technological improvements and policies that reduce the risk of investing in renewable energy.
That's one of the key takeaways from the World Energy Outlook 2020 report, which is published annually by the International Energy Agency (IEA), an intergovernmental organization that advises member nations on energy security, economic development and environmental protection.
"I see solar becoming the new king of the world's electricity markets," Dr. Fatih Birol, the IEA Executive Director, said in a statement. "Based on today's policy settings, it is on track to set new records for deployment every year after 2022."
The World Energy Outlook 2020 is out! It shows how the Covid crisis has brought deep disruption & uncertainty to t… https://t.co/if9yt1mHZc— Fatih Birol (@Fatih Birol)1602561688.0
The IEA's 2020 report notes that the COVID-19 pandemic has made it hard to predict the future of global energy demand, but it laid out several scenarios of what may happen over the next few years. In the main scenario, the international community is projected to generate 43 percent more solar power than the IEA had predicted in 2018.
That increase, as Carbon Brief first reported, is partly due to new analyses showing the cost of solar power to be 20 to 50 percent cheaper than the IEA thought in 2018.
Globally, the average cost of electricity from large-scale solar photovoltaic projects has dropped by magnitudes over the past decade, from 38 cents per kilowatt-hour in 2010 to 6.8 cents per kilowatt-hour in 2019, according to the International Renewable Energy Agency.
"Solar PV is now consistently cheaper than new coal- or gas-fired power plants in most countries, and solar projects now offer some of the lowest cost electricity ever seen," the IEA wrote in a press release. "In the [main scenario], renewables meet 80% of global electricity demand growth over the next decade. Hydropower remains the largest renewable source, but solar is the main source of growth, followed by onshore and offshore wind."
Solar energy and other renewables also pose a major threat to coal. The IEA report notes that the COVID-19 pandemic has catalyzed a "structural fall in global coal demand," and that renewables and "cheap natural gas and coal phase-out policies, means that coal demand in advanced economies drops by almost half to 2030."
What's more, India, the world's second-largest coal producer, is projected to build 86 percent less new coal power capacity than the IEA predicted in 2019.
Here's a remarkable detail buried in @IEA #WEO20 India will build 86% less new coal power capacity than expected l… https://t.co/oBKGtDRzpT— Simon Evans (@Simon Evans)1602756526.0
While it's relatively easy to predict the near-term rise of solar and fall of coal, the future of oil remains more uncertain. The report notes that, without additional policy pushes, it's too soon to predict a rapid decline in oil demand and production. Yet, some industry experts do expect to see oil demand level out, if not rapidly decline, over the next decade.
"The era of global oil demand growth will come to an end in the next decade," Dr Birol said in a press release. "Based on today's policy settings, a global economic rebound would soon push oil demand back to pre-crisis levels."
One scenario in the report describes a pathway that would see the global community achieve net-zero CO2 emissions by 2050 and limit global warming to 1.5 degrees Celsius, which is the target of the United Nations Framework Convention on Climate Change.
THREAD: The @IEA now has an aggressive 1.5°C scenario, reaching net-zero by 2050. It builds on the Sustainable Dev… https://t.co/Fjc86yHX3Q— Glen Peters (@Glen Peters)1602749021.0
To hit that ambitious goal, renewables would have to meet roughly 75 percent of global electricity demand in 2030, compared to 40 percent today, and electric vehicles would have to account for 50 percent of all passenger cars sold worldwide by 2030.
On the individual level, behavioral changes would also play a key role in this scenario. The report notes that up one-third of cuts to CO2 emissions would come from individuals doing things like:
- Working from home more often
- Line-drying laundry
- Driving more slowly
- Reducing use of air conditioning
- Flying less
Sweden tops the ranking for the third year in a row.
What does COVID-19 mean for the energy transition? While lockdowns have caused a temporary fall in CO2 emissions, the pandemic risks derailing recent progress in addressing the world's energy challenges.
The current state of the sector is described in the World Economic Forum's Energy Transition Index 2020. It benchmarks the energy systems of 115 economies, highlighting the leading players in the race to net-zero emissions, as well as those with work to do.
With pressure to get idle economies back to “normal", the short-term shift to a more sustainable energy sector could be in doubt. But the current crisis also presents an opportunity to rethink how our energy needs are met, and consider the long-term impact on the planet.
The past decade has seen rapid transformations as countries move towards clean energy generation, supply and consumption. Coal-fired power plants have been retired, as reliance on natural gas and emissions-free renewable energy sources increases. Incremental gains have been made from carbon pricing initiatives.
Since 2015, 94 of 115 countries have improved their combined score on the Energy Translation Index (ETI), which analyzes each country's readiness to adopt clean energy using three criteria: energy access and security; environmental sustainability; and economic development and growth.
But the degree of change and the timetable for reaching net-zero emissions differ greatly between countries, and taken as a whole, today's advances are insufficient to meet the climate targets set by the Paris Agreement.
WEF Fostering Effective Energy Transition 2020 edition
The 10 countries most prepared for the energy transition
Sweden tops the overall ETI ranking for the third consecutive year as the country most ready to transition to clean energy, followed by Switzerland and Finland. There has been little change in the top 10 since the last report, which demonstrates the energy stability of these developed nations, although the gap with the lowest-ranked countries is closing.
Top-ranked countries share a reduced reliance on imported energy, lower energy subsidies and a strong political commitment to transforming their energy sector to meet climate targets.
The UK and France are the only two G20 economies in the top 10 however, which is otherwise made up of smaller nations.
Powerful shocks Outside the top 10, progress has been modest in Germany. Ranked 20th, the country has committed to phasing out coal-fired power plants and moving industrial output to cleaner fuels such as hydrogen, but making energy services affordable remains a struggle.
Kevin Frayer/Getty Images
China currently has the world's largest solar PV capacity
China, ranked 78th, has made strong advances in controlling CO2 emissions by switching to electric vehicles and investing heavily in solar and wind energy - it currently has the world's largest solar PV and onshore wind capacity. Alongside China, countries including Argentina, India and Italy have shown consistent strong improvements every year. Gains over time have also been recorded by Bangladesh, Bulgaria, Kenya and Oman, among others.
But high energy-consuming countries including the US, Canada and Brazil show little, if any, progress towards an energy transition.
In the US (ranked 32nd), moves to establish a more sustainable energy sector have been hampered by policy decisions. Neighbouring Canada grapples with the conflicting demands of a growing economy and the need to decarbonize the energy sector.
The COVID-19 pandemic serves as a reminder of the impact of external shocks on the global economy. As climate change increases the likelihood of weather extremes such as floods, droughts and violent storms, the need for more sustainable energy practices is intensified.
Policy-makers need to develop a robust framework for energy transition at local, national and international levels, capable of guarding against such shocks.
"The coronavirus pandemic offers an opportunity to consider unorthodox intervention in the energy markets, and global collaboration to support a recovery that accelerates the energy transition once the acute crisis subsides," says Roberto Bocca, Head of Energy & Materials at the World Economic Forum.
"This giant reset grants us the option to launch aggressive, forward-thinking and long-term strategies leading to a diversified, secure and reliable energy system that will ultimately support the future growth of the world economy in a sustainable and equitable way."