Technically, solar heat could replace 100% of the fuel used in alumina refinery

As industries worldwide look for ways to reduce emissions without compromising competitiveness, the future of industrial heat is becoming a critical question. In this exclusive interview for Mine to Market, Rod highlighted how solar steam could transform energy-intensive alumina refining by replacing fossil-fuel-dependent heat with a more resilient and lower-carbon alternative. He shared insights into the economic case for solar heat, the role of CBAM in accelerating decarbonisation, the challenges of scaling adoption, and why access to clean industrial energy could become a key differentiator for alumina producers.

Rod MacGregor is the founding CEO of GlassPoint, established in 2009. With over three decades of experience, he has built and led technology-driven companies across the United States, Europe, China and the Middle East. Throughout his career, he has worked with leading global organisations across the energy and technology sectors, including Royal Dutch Shell, AT&T, Intel and Volkswagen.

AL Circle: The Bayer process remains heavily dependent on high-temperature process heat, which is still largely supplied by natural gas, coal or fuel oil in many regions. What is the strongest economic argument for replacing fossil-fuel-based steam with solar steam?

Rod MacGregor: The direct economic benefits of using solar heat fall into four categories: (a) in many locations solar heat is simply the lowest cost option, in addition, (b) because the price of solar steam is fixed, it buffers refineries from fuel price volatility, and (c) in locations like the GCC, where gas supply is limited, it allows customers to expand production without additional gas allocation, and finally, (d) it provides energy security by delivering heat without reliance on imported fuel that can be disrupted by geopolitical shocks.

However, the indirect economic benefits can be equally compelling. Because the platform is decarbonised by design, it reduces exposure to carbon taxes like the European Union’s Carbon Border Adjustment Mechanism (CBAM), delivering meaningful savings when exporting to Europe. 

Solar heat also helps refineries be responsive to the increasing demand for low-carbon products, where customer buying behaviour is increasingly influenced by the carbon intensity of the alumina.   

AL Circle: Recent geopolitical disruptions around the Strait of Hormuz have once again exposed the vulnerability of fossil-fuel-dependent industries to global energy supply shocks. For alumina refineries located in energy-importing regions, how can solar steam reduce exposure to fuel price volatility and supply-chain disruption?

Rod MacGregor: Sunshine is free, abundant and available locally everywhere on the planet. It’s like having an on-site gas well that can’t be turned off. By adopting solar heat, refineries are essentially localising their energy supply, decoupling their economics from both the availability and price of fuel, providing a new layer of operational resilience. 

With CBAM entering its definitive phase from January 1, 2026, aluminium and alumina exporters to the European Union are under mounting pressure to reduce embedded emissions. What commercial risks could producers face if they continue relying on high-emission thermal energy without credible decarbonisation measures?

Clearly, the refineries with the lowest-cost decarbonisation strategy will be the winners.  Refineries with a lower carbon intensity will pay less in CBAM compliance and hence command more pricing power and better margins. Since the cost of carbon under the European Trading System (ETS) is projected to rise, the competitive advantage of low-carbon producers will only rise over time.

This effect is amplified for refineries in sunny locations where the cost of low-carbon solar heat is less than the cost of burning fuel. It’s a powerful combination of lower operating cost, lower compliance cost, and customer preference. 

It is important to realise that this is not just a European problem. The UK is considering its own version of CBAM, California has a carbon cap & trade system, and Australia has its own carbon pricing mechanism. Refineries that ignore decarbonisation risk being marginalised to a shrinking set of geographic markets.    

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AL Circle: How much traction has GlassPoint seen in the adoption of solar steam for the Bayer process so far? What, according to you, could be the potential factors for still a slower adoption of the system: capital cost, refinery integration, land availability, customer risk appetite or lack of policy support?

Rod MacGregor: GlassPoint started in the oil and gas industry, helping major operators in California and the GCC produce heavy oil more economically. We only recently started in the alumina refinery market with our announcement with Ma’aden for a 1.5 GW system for their alumina refinery at Ras-al-Khair in Saudi Arabia, which will be the largest solar industrial heat project in the world, eclipsing the previous largest project, also built by GlassPoint for PDO in Oman.

Our experience with building large-scale industrial heat projects has helped us remove many of the barriers to adoption. For example, we provide heat-as-a-service so that refinery customers do not have to deploy their own capital. Instead, they enter into long-term heat supply agreements, providing them with price certainty and energy security.

GlassPoint’s business model effectively derisks adoption of solar heat. The refinery only pays for heat when it is delivered, so if no heat is delivered, they don’t pay. This combination of no up-front investment and no execution risk makes the proposition effectively risk-free. To ease refinery integration, we typically supply steam at the same temperature, pressure and quality as the existing boilers so that no change to the refinery itself is required.

One hurdle that will always exist is that any solar facility requires land. However, even there GlassPoint has an inbuilt advantage, as we convert 66 per cent of sunshine into useful heat at the refinery, making it the most energy-dense platform in the market, requiring one-sixth the amount of land of a system built from traditional solar (PV) panels.

AL Circle: Can solar steam fully replace fossil-fuel-based steam in the Bayer process, or should it be seen as a hybrid solution? What percentage of a refinery’s thermal energy demand can realistically be met through solar steam under current technology and operating conditions?

Rod MacGregor: Technically, solar heat could replace 100 per cent of the fuel used in a refinery.  However, the economic sweet spot is between 65-85 per cent depending on location and latitude. The remaining 15-35 per cent is provided by burning fuel or in some cases by electrification.

Read the complete interview here