EarthTalk®
by Roddy Scheer & Doug Moss
Dear EarthTalk: What is wind repowering and why are environmentalists so bullish on it?
-- H. King, Mesa, AZ
One of the most common forms of clean energy is wind power. People from around the world could recognize a wind farm from just one look. While wind power has been a staple in renewable energy since the idea’s inception, many of the original and old wind turbines have begun to show signs of aging. Wind repowering aims to fix this, by revamping old turbines with more efficient components, or putting in new, state-of-the-art turbines as a whole. These new components and units can reduce noise, more efficiently power a turbine, and a deliver a higher overall energy output.
Denmark, an early adopter of wind repowering, saw a 1.3 GW gain in capacity and a reduction of 109 wind turbines, enabling substantially increased wind energy production with fewer turbines. This promising data prompted a surge in wind repowering projects, and in 2019, 86 percent of wind energy projects there were classified as “repowered.”
These signs of success and scalability showed other countries the benefits of wind repowering. The U.S, with help from large energy corporations like General Electric, has more than 40 active wind repowering sites, with over 2,500 turbines having some type of renovation. This hefty wind repowering advancement is responsible for four gigawatts of energy, or the power for more than 30 million homes.
It’s no secret how fast wind repowering is growing, but upgrades can be made to many different types of renewable energy. Why do eco-advocates support wind repowering so strongly? Wind repowering has energy, financial, aesthetic and technological benefits. Not only does it make units more efficient, it also removes units that might be aesthetically unpleasing, or in less efficient spots than they could be. Wind repowering also increases the lifespan of turbines by as much as 20 years, and reduces the need for maintenance. Repowered turbines are also quieter, sleeker, and produce considerably more energy.
So, while there are many types of repowering efforts for other renewable energy sources, none are as comprehensive or successful as wind repowering. Not only is it a comprehensive option for revamping clean energy, but it does not require the entry costs that just building new wind farms requires.
The only barrier to wind repowering at the moment is legislation. Bills and policies cannot keep up with the demand for it. Readers should call local officials, or urge any nearby wind farms to look at wind repowering. Spreading awareness is the first and most important step.
CONTACTS: Wind Repowering Helps Set the Stage for Energy Transition, https://www.energy.gov/eere/wind/articles/wind-repowering-helps-set-stage-energy-transition; Upgrades and refurbishment for your onshore wind assets, https://www.ge.com/renewableenergy/wind-energy/onshore-wind/services/upgrades-refurbishment; Time to repower your wind energy site? https://www.barr.com/Insights/Insights-Article/ArtMID/1344/ArticleID/536/Time-to-repower-your-wind-energy-site
Dear EarthTalk: Could plain-ol’ beach sand be the next frontier in renewable energy?
-- Paul C., Baltimore, MD
In our ongoing quest for sustainable energy solutions, innovative technologies are necessary to complement renewable sources like solar and wind power. One such potential breakthrough revolves around an unexpected but abundant resource: beach sand.
Sand batteries represent an emerging approach to energy storage, particularly effective in harnessing and retaining energy from intermittent sources like solar and wind. The physical properties of sand, such as its ability to store heat at high temperatures, make it an excellent medium for energy retention. This capacity is being leveraged by innovative technologies to create a more stable and reliable energy supply, as sand can efficiently accumulate and release heat as required??.
The science behind sand batteries involves heating sand to high temperatures using surplus energy generated from renewable sources. This stored heat can then be converted back into energy when needed. This system capitalizes on the thermal properties of sand to create a natural battery that can offer both heating solutions and electricity generation?. As National Renewable Energy Laboratory’s (NREL) Patrick Davenport notes, “Sand and concrete silos with refractory insulation are very inexpensive materials that can lead to low-cost energy storage.” A few key players currently pioneering this technology include Polar Night Energy in Finland, which has implemented a sand battery for residential and commercial heating, and EnergyNest in Norway, which specializes in thermal energy storage using similar principles.
Using sand for energy storage offers multiple benefits: it is abundant, low-cost, eco-friendly, and can store heat for long periods. This makes sand an attractive option for enhancing the stability of renewable energy systems, and providing a reliable energy supply even during times of low sunlight or wind.
Sand battery technology is currently being tested and used in various projects worldwide, not only demonstrating the viability of sand as an energy storage solution but highlighting its potential scalability and integration into existing energy infrastructures.
Despite the potential, challenges that include technical, economic and logistical hurdles that be addressed. Developing and deploying sand battery technology on a large scale requires significant research and development efforts. Additionally, the role of government and private investment is crucial in overcoming barriers and driving forward the innovation needed for widespread adoption??.
Sand batteries are a promising solution for renewable energy storage, potentially revolutionizing how we store and utilize energy from renewable sources. Their ability to provide a stable, reliable energy supply could be a game-changer for the renewable sector.
CONTACTS: Can sand be used to create energy on demand?, https://www.asce.org/publications-and-news/civil-engineering-source/civil-engineering-magazine/article/2023/03/can-sand-be-used-to-create-energy-on-demand; Using Hot Sand To Store Energy, https://cleantechnica.com/2021/08/31/using-hot-sand-to-store-energy/.
Dear EarthTalk: We used to hear a lot about algae's potential as a renewable source of biofuels. Is it still being cultivated and processed accordingly? – P.K., Richmond, VA
In recent years, algae has emerged as a potential renewable and less pollutive energy resource. Some species have high levels of fat, carbohydrates and proteins that can produce up to 30 times more energy than other biofuels. And algae, unlike corn and soy-based biofuels, can thrive well in a variety of environments (including otherwise unusable waste or brackish water). Combined, the high-energy content and abundance of algae make it a promising alternative to current fuel sources.
Some companies, including the low-carbon energy research organization, Decerna, experimented with algae, hoping it could be produced at an industrial level. They cultivated it in artificial light, feeding it a mixture of glycerol, yeast and various chemicals. They then extracted the functional fats and converted them into biodiesel. The researchers calculated the energy required during each stage of the process and the carbon emissions produced from burning the resulting biodiesel. They concluded that the production process required more energy than the final product generates, and that total emissions produced during the production and combustion phases of the algae surpassed those of traditional petroleum diesel.
It was also learned that the extraction of the algae’s biomolecules may involve the use of harsh chemicals or solvent, and that the growth of algae may also require chemicals like fertilizers and pesticides, which can have adverse effects on aquatic ecosystems if they get into surrounding water bodies through runoff, or if they accumulate in the algae biomass. Mechanical procedures require fewer chemicals but are less effective at separating the diverse array of materials within the algae. Also, cultivation of algae on a large scale uses large amounts of electricity as it often relies on artificial lighting to ensure optimal and controlled growth conditions. Moreover, the space required to grow and process algae on a commercial scale can also be a significant environmental concern. Large-scale algae cultivation facilities often occupy substantial land areas or require dedicated infrastructure such as ponds, bioreactors or photobioreactors.
Despite the promise that algae holds, there is a clear need for technological advancements across the entire supply chain. Techniques for seaweed cultivation, harvesting and transportation must be made more efficient. Several laboratories, such as the National Renewable Energy Laboratory and the Las Alamos National Laboratory, have been cultivating and manipulating particular strains of algae to genetically maximize the production of fuel biomolecules and other bioproducts. Additionally, improvements in pre-treatment methods, co-digestion processes, and the development of eco-friendly extraction techniques are essential. Furthermore, advancements in fuel conversion technologies are necessary to ensure that the algae is economically viable and able to be implemented into the current infrastructure. With these changes, perhaps we will see the rise of algae-based biofuels in the future.
CONTACTS: Algae for global sustainability? https://www.sciencedirect.com/science/article/pii/S006522962100015X; The use of algae for environmental sustainability: trends and future prospects, https://pubmed.ncbi.nlm.nih.gov/35332453/; Developing algae as a sustainable food source, https://www.frontiersin.org/articles/10.3389/fnut.2022.1029841/full; Role of microalgae in achieving sustainable development goals and circular economy, https://www.sciencedirect.com/science/article/pii/S0048969722057886.
Dear EarthTalk: What are the environmental/climate benefits (or drawbacks) of the Inflation Reduction Act? -- David Montague, via email
The Inflation Reduction Act (IRA), a bill passed by the Biden Administration in 2022 to bolster the U.S. economy, was especially notable for its unprecedented investments in clean energy and climate health. Setting $369 billion aside for climate investments, the IRA incentivizes citizens to implement and invest in renewable energy by increasing tax benefits to homes with installed solar panels and battery storage equipment, and by giving substantial funding to clean energy companies. The bill’s efforts were predicted to bring $3 trillion into renewable energy, open up 170,000 new jobs within the industry, and increase the sales of electric vehicles.
Climate analysts initially projected that America’s greenhouse gas emissions would be cut roughly 40 percent below 2005 levels by 2030 due to the IRA’s funding of clean energy, with an average of 46 to 79 gigawatts of carbon-free energy predicted to be added to America’s electrical grid annually. The IRA puts additional priority on making clean energy more affordable for disadvantaged communities and lower-income households by increasing tax benefits for specific areas and families to start establishing clean energy within their communities. Implementing clean energy in disadvantaged communities may assist in mitigating the harmful air pollution in those areas, and in reducing their carbon footprints.
Despite its environmental benefits, the IRA has still allowed the fossil fuel industry to thrive and even expand. The bill was only approved by the U.S. Senate after the Biden Administration agreed to sell a $200 million lease for oil and gas companies to develop a large plot of land in the Gulf of Mexico, as many senators are investing partners with those companies. In a recent USA Today article on the IRA, reporters Matthew Brown and Michael Phillis stated that “the bill prohibit[s] leasing of federal lands and waters for renewable energy unless the government has offered at least 2 million acres of public land and 60 million acres in federal waters for oil and gas leasing during the prior year.” Clean energy improvements notwithstanding, fossil fuels will continue to burn and communities will continue to suffer from environmental hazards if specific legislation to discourage oil and gas development is not passed.
As of now, fossil fuels are reaching record levels of development and usage in the U.S., while only 32 gigawatts of carbon-free energy, a trifling amount in the scheme of things, have been added to the grid per year due to project delays, supply issues and the resistance of local communities. Many supporters of the bill argue that it was right to secure energy security for the American economy and its citizens via fossil fuels, since the clean energy industry is still developing a greater capacity for energy output. However, it could just as easily be argued that discouraging the continued development of oil and gas could have accelerated the clean energy industry’s projects and growth. The IRA is undeniably an economic bill first, and an environmental bill second. But while environmentalists may have their issues with the final outcome, let’s remember that the IRA is still the single largest climate bill ever passed in U.S. history.
CONTACTS: How the IRA of 2022 Can Lower Your Energy Bills, www.solar.com/learn/inflation-reduction-act; How the IRA’s Tax Incentives Are Ensuring All Americans Benefit from the Growth of the Clean Energy Economy, home.treasury.gov/news/press-releases/jy1830; The IRA's surprise winner, the U.S. oil and gas industry, https://www.usatoday.com/story/news/nation/2022/08/18/climate-change-inflation-reduction-act-oil-gas/7837956001/.
Dear EarthTalk: Have wildlife crossings become more common in North America, and are they effective at reducing wildlife kills and improving conservation efforts overall? – T.R., Detroit, MI
In recent years, North America has seen a notable increase in the implementation of wildlife crossings, reflecting a growing recognition of their importance in reducing wildlife fatalities from vehicle collisions and enhancing conservation efforts. These structures, ranging from underpasses to overbridges, are becoming more prevalent as part of a concerted effort to address the environmental impacts of roads.
The significance of these crossings is underscored by projects like one in Southern California designed largely to protect mountain lions. This project, among others, demonstrates a shift towards integrating wildlife conservation into public infrastructure planning??. Similarly, the Federal Highway Administration has incorporated wildlife crossings into its programs, emphasizing safety for both animals and motorists??.
Research consistently shows the effectiveness of these structures. Jennifer S. Holland of the Pew Trusts highlights the sheer number of reports of roadkill incidents, with “drivers hit[ting] 1 to 2 million animals each year,” and reports of significant decreases in road kills in areas with wildlife crossings, which also support animal migration patterns?. The economic rationale is also strong: In regions like Banff, Alberta, the initial costs of wildlife crossings are often offset lowered expenses related to wildlife collisions?.
Beyond the immediate benefits of reducing kills, wildlife crossings play a key role in maintaining ecological connectivity, essential for the survival and health of many species. In Banff National Park, a series of crossings allows wildlife such as grizzly bears and elk to safely navigate across busy highways.
Community engagement and educational programs have helped raise awareness about the benefits of wildlife crossings, promoting broader public support and involvement, vital for securing funding and political support for new projects?. Moreover, international examples of successful wildlife crossings provide valuable lessons and inspiration. In Costa Rica, crossing designs that cater specifically to the needs of jaguars demonstrate the global applicability and adaptability of crossing technologies??.
The U.S. has recognized the importance of these initiatives and is supporting them through federal funding programs, with Lauren Sforza of The Hill writing, “$110 million in grants will be awarded to 19 wildlife crossing projects across 17 states”. This national support is instrumental in expanding wildlife crossings across the country, highlighting a commitment to biodiversity and road safety?.
The proliferation of wildlife crossings in North America is a positive development that not only mitigates wildlife-vehicle collisions but also significantly contributes to biodiversity conservation. The continued expansion and improvement of these crossings are vital. As such, these structures represent a critical intersection of road safety, animal welfare and environmental stewardship.
CONTACTS: Wildlife Crossings Can Protect Migrating Animals, https://www.pewtrusts.org/en/trust/archive/spring-2020/wildlife-crossings-can-protect-migrating-animals.
Dear EarthTalk: Why are conventional toothpaste tubes not eco-friendly? What better alternatives are out there? -- Jackie V., Pittsburgh, PA
The impact of conventional toothpaste tubes is significant and largely negative. Typically made from non-biodegradable plastic and aluminum, they present significant challenges in recycling processes. The mixed material composition requires complex, costly separation techniques, making recycling inefficient and often nonviable. According to Forbes, some 1.5 billion toothpastes tubes are discarded each year.
The production and disposal of these tubes involves substantial energy use and emissions. From the extraction and processing of raw materials to manufacturing and eventual disposal, the lifecycle of conventional toothpaste tubes is energy-intensive and ecologically damaging. After use, they are typically “discarded at a facility and will end up in the landfill” says Julie Smith of Aspire Colorado.
In response to these issues, there has been a rise in eco-friendly alternatives. Zero-waste toothpastes, which eschew traditional tubes, are becoming increasingly popular. These typically come in tablet or powder form and are packaged in biodegradable or recyclable materials. Toothpaste tablets are especially sustainable as they also reduce water usage, relying instead on saliva of water.
Other innovative solutions include toothpastes packaged in metal tubes, which are easier to recycle than plastic ones, and brands that use plant-based container materials. These efforts reflect growing consumer demand for sustainable products, reflecting a broader trend towards environmental responsibility.
Several brands have been leading the way in this shift towards sustainability. David’s Natural Toothpaste offer toothpaste is packaged in metal tubes, and The Humble Co. uses plant-based materials for their biodegradable tubes. Both options present a significant reduction in waste compared to traditional plastic tubes. These products not only help to reduce environmental impacts and also cater to health-conscious consumer by avoiding harmful chemicals often found in conventional toothpastes.
However, transitioning to these eco-friendly alternatives is not without its challenges. Makers face significant hurdles in altering established production lines, sourcing materials that meet quality and safety standards and potentially incurring higher costs. Consumers may also be hesitant to switch to new formats, such as tablets or powders, or may be skeptic about their efficacy. Additionally, the initial cost of these alternatives can be higher, which may deter widespread adoption.
Regulation and industry standards play a crucial role in facilitating this transition. Governments can promote the use of sustainable packaging by implementing policies that encourage recycling, reduce the use of non-recyclable materials or provide incentives for companies to develop greener products. Specific regulations that mandate the use of recyclable materials in packaging can drive innovation in the industry, leading to more sustainable options becoming available and economically viable.
CONTACTS: Oral Care Companies Finally Tackle Packaging Waste, https://www.forbes.com/sites/beamcmonagle/2021/04/24/oral-care-companies-finally-tackle-packaging-waste/?sh=4c2465505ae1; Carbon Footprint of Toothpaste Tubes https://www.aspirecolo.com/post/carbon-footprint-of-toothpaste-tubes
Dear EarthTalk: What percentage of U.S. currency today is actually in dollars and coins versus digital? Would it be good for the planet if we ditched bills and coins completely? – P.L., via email
As the digital transformation of our economy accelerates, it is vital to examine not just the economic ramifications but the environmental impacts associated with both physical and digital currencies.
The physical form of U.S. currency, specifically coins and banknotes, makes up a significant portion of the total currency in circulation today. As of the end of 2020, there was approximately $2.04 trillion worth of U.S. currency in circulation. This amount represented about 50.3 billion individual notes, spanning various denominations from $1 to $100 bills??, and the balance coins. In contrast, a substantial portion of the central bank's money supply is in digital form. As of late 2021, digital balances at the Federal Reserve amounted to $4.18 trillion, compared to $2.21 trillion in circulating cash??.
The production of physical currency, including coins and bills, involves resource-intensive processes. Mining for metals like zinc and copper is necessary for coin production, while the creation of banknotes often requires paper, which is linked to deforestation and other environmental issues. For example, it now costs more to produce a penny than its face value, underscoring the inefficiency and environmental cost of producing physical currency. As highlighted by Kathiann Kowalski of Science News Explore, "the metals then go to a factory, where copper coats each side of a thicker zinc layer"?, illustrating the complex and energy-intensive processes involved in minting coins.
Conversely, digital currencies eliminate the need for physical materials used in coins and banknotes. However, the operation of these technologies predominantly depends on electricity generated from fossil fuels, contributing to greenhouse gas emissions and other environmental impacts. The shift toward digital currency systems like Bitcoin has highlighted concerns regarding their sustainability due to the high energy consumption of blockchain technologies and mining processes??.
When comparing the environmental impacts of physical and digital currencies, it's apparent that both systems entail significant environmental costs. Physical currencies require extensive raw materials and energy for production and transportation, contributing to pollution and resource depletion. On the other hand, digital currencies, while reducing physical waste, increase the demand for energy, potentially exacerbating carbon emissions unless powered by renewable energy sources.
This all suggests a need for both policy intervention and technological innovation. Policies could encourage the adoption of more sustainable practices in currency production, such as using recycled materials for banknotes or improving the energy efficiency of minting processes. Similarly, innovations in digital currency technologies could help reduce their energy consumption, making them a more sustainable option in the long run.
CONTACTS: Money and Payments: The U.S. Dollar in the Age of Digital Transformation, https://www.federalreserve.gov/publications/january-2022-cbdc.htm; How we choose to pay has hidden costs for the planet, https://www.snexplores.org/article/money-currency-plastic-paper-cash-credit-environmental-cost.
Dear EarthTalk: How are the world’s rhino populations faring these days? – A.K., Montreal, Quebec
The rhinoceros, famous for its impressive size and striking horns, is one of the biggest land mammals in the world. Once widespread, the species has now become a symbol of catastrophic population decline within conservation discourse. But with more media attention and therefore increased conservation efforts, the situation of rhino populations around the world might be looking up.
There are five different species of rhinos across Asia and Africa: Sumatran, Javan, Black, Greater one-horned and White rhino. Species count is varied, with numbers ranging between 34-47 (Sumatran rhino) and 16,803 (White rhino). Still, all species have significantly declined throughout the 20th century. In 1900, an estimated 500,000 rhinoceros existed. By 1970, this dropped to 70,000, by 2022 to 27,000. All five rhino species are now considered endangered and two have less than 100 individuals in the wild.
Declines are often human-caused. Poaching for rhino horn remains the greatest threat, since rhino horns are often falsely considered aphrodisiacs or luxury goods. According to Save the Rhino International, 9,415 African rhinos have died due to poaching in the last decade. Another threat to rhinoceros is habitat loss, occurring due to the conversion of land for human settlement, agriculture or logging. Rapid human population growth and urban expansion have led to over 17 countries losing their entire rhinoceros populations. A newer threat to rhino populations is climate change. According to Timothy Randhir from the University of Massachusetts, “Rhinos need really unique [climate] conditions.” Increased precipitation and longer monsoon periods in Asia as well as rising temperatures in Africa already negatively affect the survival chances of rhinos and will continue to do so in the future.
Recently, the number of rhino individuals has been rising across species. According to the International Union for Conservation of Nature’s (IUCN) African Rhino Specialist Group, the global rhino population increased from 26,272 in 2021 to about 27,000 in 2022. Black and Greater one-horned rhinoceros numbers have been steadily increasing over the past two decades. Sub-species like the Southern White rhinoceros have shown an impressive recovery. In 1900, there were only 20 individuals left. Numbers have continuously been rising since, with now over 16,800 Southern White rhinos existing.
Improvements have not come about through a reduction in threats, but through improved protection. While there has been a marked decline in poaching from the 2010s, it is now on the rise again. Some 561 rhinos died due to poaching in 2022, more than in 2021 (501) and 2020 (503). Due to persistent threats, very few rhinos survive outside of national parks and reserves. Through conservation in protected sanctuaries, species like the Black rhino have increased by nearly five percent in only one year. But Michael Knight, chair of the IUCN rhino group, warns: “It is imperative to further consolidate and build on this positive development and not drop our guard.” Some species, like the Javan and Sumatran rhino, remain in decline. The Northern White rhino has only two individuals remaining, and both are female.
CONTACTS: IUCN SSC African Rhino Specialist Group, https://iucn.org/our-union/commissions/group/iucn-ssc-african-rhino-specialist-group; Save the Rhino International, https://www.savetherhino.org/.
Dear EarthTalk: What have been the most dramatic effects of global warming on Africa and what do longer-term climate projections foretell for Africa’s future? -- William C., Raleigh, NC
Global warming has already had profound impacts on Africa, which is already grappling with many environmental and socio-economic challenges. The most dramatic effects observed so far include increased temperatures, changes in precipitation patterns, and a rise in extreme weather events—all of which have far-reaching consequences for the environment, agriculture and human livelihoods.
Temperatures across Africa have risen significantly in recent decades, with some regions experiencing increases twice the global average rate. This exacerbates existing problems, particularly in arid and semi-arid regions. Prolonged heat waves and severe droughts have become more frequent, threatening water supplies and agricultural productivity.
Changes in precipitation are another significant impact. Some regions have seen decreased rainfall, while others face more intense and erratic rainfall. The Sahel, a semi-arid region south of the Sahara Desert, has experienced both prolonged droughts and intense rainfall, leading to flash floods. These shifts disrupt farming practices, erode soils and reduce crop yields, exacerbating hunger and poverty.
Extreme weather events ever more frequent and severe. Southern Africa, particularly Mozambique, has faced devastating cyclones like Idai in 2019, which caused extensive damage, and displaced or killed thousands. Flooding destroys homes and crops and facilitates waterborne diseases.
Long-term climate projections for Africa paint a grim picture. By the end of the 21st century, average temperatures are expected to increase, leading to more severe heatwaves and droughts. Water scarcity will intensify, particularly in North and Southern Africa, where river flow and groundwater recharge rates are projected to decline. Agriculture, which employs a large portion of the population, faces dire challenges. Staple crops such as maize, sorghum and millet are expected to see reduced yields, a productivity decline that threatens food security and could increase dependence on food imports, straining economies further.
Coastal areas are at risk, too, from rising sea levels. Cities like Lagos, Nigeria and Alexandria, Egypt are particularly vulnerable to coastal erosion and flooding. Mangrove ecosystems, vital for coastal protection and fisheries, are also threatened by sea level rise and changing salinity patterns. Biodiversity loss is another critical concern. Many of Africa’s unique ecosystems, such as the Congo Basin rainforests and the savannas, could be drastically altered. Species that cannot adapt to rapidly changing conditions face extinction, disrupting ecological balances and affecting livelihoods dependent on natural resources.
“Africa is responsible for less than 10 percent of global greenhouse gas emissions,” says the World Meteorological Organization’s Secretary-General Petteri Taalas. “But it is the continent which is the least able to cope with the negative impacts of climate change.” Promoting resilient infrastructure, sustainable agriculture and regional cooperation are crucial to a sustainable future for its people.
CONTACTS: Global warming: severe consequences for Africa, https://www.un.org/africarenewal/magazine/december-2018-march-2019/global-warming-severe-consequences-africa; Africa suffers disproportionately from climate change, https://wmo.int/media/news/africa-suffers-disproportionately-from-climate-change.
Dear EarthTalk: How feasible is creating orbiting solar plants that can beam energy down to Earth? If it’s possible, when can we expect to see such tech implemented? – P.R., via email
In the 1941 short story Reason, science fiction author Isaac Asimov introduces a space station that produces energy by sending microwave beams to the planets. This concept is closer to reality as international space programs and research labs test the technology necessary to bring it to life. Traditional solar technologies convert sunlight into usable energy here on Earth. However, their use is limited to daytime hours and restricted by weather and geography. The idea of an orbiting solar plant bypasses these restrictions, allowing energy harvesting above the clouds.
There are different designs, but the principles are similar: A large satellite transforms solar power into electricity using photovoltaic cells made of material that generates voltage and electric current when exposed to light. The power is then beamed down to earth by microwaves (or lasers) to dedicated receiving stations that turn the energy back into electricity to get fed into the local grid.
Entities such as the European Space Agency (ESA), Space Solar (a start-up in the UK), and the California Institute of Technology are investing working on launching this type of project. Besides the obvious benefit of having all sun, all the time, orbiting solar plants have various other benefits. There are no dangerous byproducts as there are for other energy production methods: no fly ash from coal or radioactive waste from nuclear power. The entirely renewable—it will not run out in the age of humanity—so it is harmless could help limit the impacts of climate change if adopted on a global scale.
So why don’t we already have these power-generating stations orbiting in space? There are still challenges to overcome. The cost is prohibitive, the structure would need to be about 2,000 metric tons, roughly equivalent to the weight of 286 male African elephants and need to be a mile and a quarter in diameter, with a little over a half-mile-long transmitter. Another challenge is engineering, particularly the parts used for such power-beaming structures. Given the difficulty of reaching the satellites for maintenance and repairs, it is suggested that parts must withstand at least 15 years in space. Additionally, there’s a need to improve the efficiency of current wireless power transmission to ensure that all the energy can be collected down to Earth.
There are some significant drawbacks, too. Solar plants orbiting closer to Earth would transmit energy more easily, but light pollution would be difficult for humans and both flora and fauna to cope with. Research also suggests that exposure to artificial light at night can increase health issues in humans, including obesity, depression, diabetes and more.
Whether Asimov’s proposal from nearly a century ago will be implemented remains to be seen. The ESA has recently sought ideas to make it more feasible. “The potential of this concept to contribute to long-term sustainable energy is very high,” says ESA Engineer Advenit Makaya. For the time being, you can invest in solar power on Earth and keep your eyes on the sky as the technology advances and costs drop.
CONTACTS: Space-Based Solar Power Overview, https://www.esa.int/Enabling_Support/Space_Engineering_Technology/SOLARIS/Space-Based_Solar_Power_overview; NASA study: clean, space-based solar power beaming is possible, https://spacenews.com/nasa-study-clean-space-based-solar-power-beaming-possible/.
EarthTalk® is produced by Roddy Scheer & Doug Moss for the 501(c)3 nonprofit EarthTalk. See more at https://emagazine.com. To donate, visit https://earthtalk.org. www.earthtalk.orgb Send questions to: question@earthtalk.org questions@earthtalk.org .
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