Aug 25, 2015

How Hexocover is bringing renewable energy to mining and solving the water shortage

Renewable Energy
4 min
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 pond...

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.”

RELATED TOPIC: The importance of solar and wind energy in mining

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.

Designing Hexocover

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."

RELATED TOPIC: Chilean mines are turning to renewable energy

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.

RELATED TOPIC: California may turn to Mexico for renewables to meet clean energy goals

"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."

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[SOURCE: University of Arizona]

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Apr 23, 2021

Drax advances biomass strategy with Pinnacle acquisition

Dominic Ellis
2 min
Drax is advancing biomass following Pinnacle acquisition it reported in a trading update

Drax' recently completed acquisition of Pinnacle more than doubles its sustainable biomass production capacity and significantly reduces its cost of production, it reported in a trading update.

The Group’s enlarged supply chain will have access to 4.9 million tonnes of operational capacity from 2022. Of this total, 2.9 million tonnes are available for Drax’s self-supply requirements in 2022, which will rise to 3.4 million tonnes in 2027.

The £424 million acquisition of the Canadian biomass pellet producer supports Drax' ambition to be carbon negative by 2030, using bioenergy with carbon capture and storage (BECCS) and will make a "significant contribution" in the UK cutting emissions by 78% by 2035 (click here).

Drax CEO Will Gardiner said its Q1 performance had been "robust", supported by the sale of Drax Generation Enterprise, which holds four CCGT power stations, to VPI Generation.

This summer Drax will undertake maintenance on its CfD(2) biomass unit, including a high-pressure turbine upgrade to reduce maintenance costs and improve thermal efficiency, contributing to lower generation costs for Drax Power Station.

In March, Drax secured Capacity Market agreements for its hydro and pumped storage assets worth around £10 million for delivery October 2024-September 2025.

The limitations on BECCS are not technology but supply, with every gigatonne of CO2 stored per year requiring approximately 30-40 million hectares of BECCS feedstock, according to the Global CCS Institute. Nonetheless, BECCS should be seen as an essential complement to the required, wide-scale deployment of CCS to meet climate change targets, it concludes.

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