How Hexocover is bringing renewable energy to mining and solving the water shortage
A new technology invented at the University of Arizona is looking to solve the evaporation of water from bodies of water such as mining tailings ponds and reservoirs, while simultaneously generating energy reserves through solar panels.
The invention, called Hexocover, is a hexagonal-shaped modular floating cover made from UV inhibited recyclable plastic. The technology consists of floating hexagonal panels that are arranged to fit individual water surface dimensions, forming a cover over the water.
“Mining activity typically requires a lot of energy,” Ardeth Barnhart, University of Arizona Renewable Energy Network Director said in an issued release. “This technology is a great example of how original ideas that develop the use of solar energy to transform industrial processes can have immediate and transformative effects on water and energy use, create positive environmental impact and provide direct benefits to our economy.”
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Developed by Moe Momayez in the Department of Mining and Geological Engineering at University of Arizona and Nathan Barba, managing partner at RePower Design, Hexocover is the result of their effort to find ways to conserve water in mining tailings (remediation) ponds.
According to our sister publication Mining Global, Hexocover has untapped potential for the industry.
“The new technology will offer a combination of positive environmental impact by minimizing water evaporation, which is costly for mining companies to replace, as well as generating electricity,” wrote the site.
RePower Design worked alongside Tech Launch Arizona, the unit that commercializes inventions that stem from the university’s research, to execute an exclusive license to bring the invention to market.
The license granted RePower Design the sole right to commercialize the technology, which includes the floating panel design as well as the solar panel integration.
The inspiration came from the fact that Tucson, Arizona has an evaporation rate of 109 inches per year, according to Barba, and water in storage facilities and reservoirs always needs replenishment.
"We needed a way to prevent the evaporation of (tailing pond) water, but we needed a system that could move out of the way when the tailings are being released into the ponds," said Barba in a news release. "If we can cover them, we can help with the devastating water shortage problem here in the southwestern U.S. and around the world."
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For the past seven years, Momayez has been investigating the integration of photovoltaic, or PV, panel deployment with mining land reclamation processes, mining-specific environmental effects on PV output efficiency, and geotechnical considerations related to the installation of panels on tailing slopes.
"The PV work on reclaimed mining lands has gained national recognition," Momayez added, "and the idea to control the evaporation of the supernatant water accumulating in the middle of tailing storage facilities was a natural extension of my research and a huge step forward to save water in arid climates worldwide."
"For someone who owns a water reservoir, like a mine or municipality, this invention provides a dual benefit and a dual revenue stream," Barba said.
The future of Hexocover
The mining industry has been historically slow to adopt renewable energy technology, according to a 2013 Navigant Research report, but the report forecasts that renewable energy technologies will supply between 5 percent and 8 percent of the world’s mining industry power consumption by 2022.
Additionally, the technology minimizes the overall environmental impact of operations such as mining.
"Water conservation is a societal imperative, not just in the Southwest, but around the globe," said Doug Hockstad, director of technology transfer at Tech Launch Arizona. "Technologies like this will help save water, especially in arid environments. Since the University of Arizona has such a strong research history in this area, it's exciting to see that research having a social and economic impact."
"I’m most excited about the possibilities of fixing a big problem," Barba concluded. "It’s been interesting to have this original challenge, and then see it develop and get refined and perfected, and now to see it working."
[SOURCE: University of Arizona]
Carbon dioxide removal revenues worth £2bn a year by 2030
Carbon dioxide removal revenues could reach £2bn a year by 2030 in the UK with costs per megatonne totalling up to £400 million, according to the National Infrastructure Commission.
Engineered greenhouse gas removals will become "a major new infrastructure sector" in the coming decades - although costs are uncertain given removal technologies are in their infancy - and revenues could match that of the UK’s water sector by 2050. The Commission’s analysis suggests engineered removals technologies need to have capacity to remove five to ten megatonnes of carbon dioxide no later than 2030, and between 40 and 100 megatonnes by 2050.
The Commission states technologies fit into two categories: extracting carbon dioxide directly out of the air; and bioenergy with carbon capture technology – processing biomass to recapture carbon dioxide absorbed as the fuel grew. In both cases, the captured CO2 is then stored permanently out of the atmosphere, typically under the seabed.
The report sets out how the engineered removal and storage of carbon dioxide offers the most realistic way to mitigate the final slice of emissions expected to remain by the 2040s from sources that don’t currently have a decarbonisation solution, like aviation and agriculture.
It stresses that the potential of these technologies is “not an excuse to delay necessary action elsewhere” and cannot replace efforts to reduce emissions from sectors like road transport or power, where removals would be a more expensive alternative.
The critical role these technologies will play in meeting climate targets means government must rapidly kick start the sector so that it becomes viable by the 2030s, according to the report, which was commissioned by government in November 2020.
Early movement by the UK to develop the expertise and capacity in greenhouse gas removal technologies could create a comparative advantage, with the prospect of other countries needing to procure the knowledge and skills the UK develops.
The Commission recommends that government should support the development of this new sector in the short term with policies that drive delivery of these technologies and create demand through obligations on polluting industries, which will over time enable a competitive market to develop. Robust independent regulation must also be put in place from the start to help build public and investor confidence.
While the burden of these costs could be shared by different parts of industries required to pay for removals or in part shared with government, the report acknowledges that, over the longer term, the aim should be to have polluting sectors pay for removals they need to reach carbon targets.
Polluting industries are likely to pass a proportion of the costs onto consumers. While those with bigger household expenditures will pay more than those on lower incomes, the report underlines that government will need to identify ways of protecting vulnerable consumers and to decide where in relevant industry supply chains the costs should fall.
Chair of the National Infrastructure Commission, Sir John Armitt, said taking steps to clean our air is something we’re going to have to get used to, just as we already manage our wastewater and household refuse.
"While engineered removals will not be everyone’s favourite device in the toolkit, they are there for the hardest jobs. And in the overall project of mitigating our impact on the planet for the sake of generations to come, we need every tool we can find," he said.
“But to get close to having the sector operating where and when we need it to, the government needs to get ahead of the game now. The adaptive approach to market building we recommend will create the best environment for emerging technologies to develop quickly and show their worth, avoiding the need for government to pick winners. We know from the dramatic fall in the cost of renewables that this approach works and we must apply the lessons learned to this novel, but necessary, technology.”
The Intergovernmental Panel on Climate Change and International Energy Agency estimate a global capacity for engineered removals of 2,000 to 16,000 megatonnes of carbon dioxide each year by 2050 will be needed in order to meet global reduction targets.
Yesterday Summit Carbon Solutions received "a strategic investment" from John Deere to advance a major CCUS project (click here). The project will accelerate decarbonisation efforts across the agriculture industry by enabling the production of low carbon ethanol, resulting in the production of more sustainable food, feed, and fuel. Summit Carbon Solutions has partnered with 31 biorefineries across the Midwest United States to capture and permanently sequester their CO2 emissions.
Cory Reed, President, Agriculture & Turf Division of John Deere, said: "Carbon neutral ethanol would have a positive impact on the environment and bolster the long-term sustainability of the agriculture industry. The work Summit Carbon Solutions is doing will be critical in delivering on these goals."
McKinsey highlights a number of CCUS methods which can drive CO2 to net zero:
- Today’s leader: Enhanced oil recovery Among CO2 uses by industry, enhanced oil recovery leads the field. It accounts for around 90 percent of all CO2 usage today
- Cementing in CO2 for the ages New processes could lock up CO2 permanently in concrete, “storing” CO2 in buildings, sidewalks, or anywhere else concrete is used
- Carbon neutral fuel for jets Technically, CO2 could be used to create virtually any type of fuel. Through a chemical reaction, CO2 captured from industry can be combined with hydrogen to create synthetic gasoline, jet fuel, and diesel
- Capturing CO2 from ambient air - anywhere Direct air capture (DAC) could push CO2 emissions into negative territory in a big way
- The biomass-energy cycle: CO2 neutral or even negative Bioenergy with carbon capture and storage relies on nature to remove CO2 from the atmosphere for use elsewhere