Solar collector sytem from GlassPoint under construction in California for Searles Valley Minerals (a glass container will encompass all the solar collectors) IMAGE © GlassPoint
GlassPoint has secured a partnership to generate its solar steam for Searles Valley Minerals (SVM), a hundred- and fifty-year-old California mining and production firm, one of the largest local employers with over 600 employees.
The mining firm operates the mine and processes the minerals, soda ash, and borate, and has been burning both coal and natural gas for the thermal energy to make the steam needed.
GlassPoint will deploy its trademark huge lightweight concentrated solar collectors in glasshouses, and for the first time will also include thermal energy storage. They expect to be able to generate solar steam for Searles Valley Minerals in about four years, given the predicted permitting and construction time.
750 MW solar system to generate 250 MWt of steam round the clock
“Searles Valley Minerals currently uses about 1.2 million pounds of steam per hour, and we’re committing to provide 700,000 pounds of steam per hour, so we’ll supply roughly 60% or so of their overall demand,” said Randy Palombi, Chief Commercial Officer, Americas at GlassPoint.
“Searles Valley uses a tremendous amount of energy. They have huge thermal and electricity demands, and our system is anticipated to provide significant energy cost savings in addition to CO2 reductions.”
GlassPoint will be putting in a 750 MW solar installation to provide approximately 250 megawatts of thermal energy around the clock. Miraah, their first steam project for Oman’s PDO oil field, had a similar ratio; nearly a gigawatt of solar collected, to generate 350 MWth of steam.
Though the exact size of the planned storage is still in the works, Palombi confirmed that it will be molten salts-based, with approximately 18 hours of storage, and use multiple storage tanks, like Solana in Arizona.
GlassPoint had initially targeted its unique solar steam production for the oil industry, aimed at providing Enhanced Oil Recovery (EOR), a growing market as the easily-extracted oil is depleted. But since restructuring, they have expanded their customer base to many other industries that require thermal energy either as steam or heat.
Two of their recent hires came from the mining industry in California and applied their mining know-how to this market. Typically, mining firms need heat year-round, day and night.
The setup they’ll use to deliver solar steam
They will build the solar ‘field’ inside their proprietary polymer film houses, which enables them to collect solar from much larger parabolic troughs than if they were outdoors like regular Trough CSP. Within the film house, the solar collectors are entirely protected from wind, so they can be much bigger and much lighter (and thus cost less) than if they were outdoors in the wind.
It also costs less to clean film houses than parabolic solar collectors through automated robotic cleaning. So, because they don’t need to design the solar collectors to protect them from wind or dust, they can produce steam at extremely low cost.
“It’s a two-thirds reduction in cost,” noted Palombi. “That’s from the amount of material and structural support that’s needed as well as much lower O&M. Because you’re not exposed directly to wind and other elements that you would be if in a traditional type of trough configuration that was not enclosed. Additionally, there are significant benefits of putting it inside a film house from an O&M perspective.”
Because the solar steam is to be blended with the steam they’re producing from their dual coal and natural gas plants, they will deliver at the same 1400 psi at 900 degrees Fahrenheit that their existing plants deliver.
Together, GlassPoint and Searles Valley Minerals have been working on various scenarios over the last few years: how much to decarbonize. Whether to try to decarbonize 25%, 50%, 75% or even 100% of the energy needs.
So, depending on the size of each configuration considered, they had looked at generating anything from about 100,000 pounds per hour of steam up to 700,000 pounds. Then that drove the size of the solar collecting area needed, and thus how much land was required, which meant they considered various-sized parcels of relatively flat land.
The best option is approximately six miles away
They decided to aim at replacing 60% of the fossil steam, which led to finding enough relatively flat land to site a 750 MW solar field, which resulted in selecting a parcel of land approximately six miles away that is owned by Searles Valley Minerals.
The topography of the land they chose determined that they would need six miles of piping across varied terrain, from undulating forested land to flat muskeg, to deliver the steam from where the solar glasshouses are set up, to where the steam will be used in the mining and refining operations. They got quotes from subcontractors for preheating, post-weld heat treatment, heat tracing, and insulation.
Six miles of pipeline is actually not unusual. Pipelines carrying steam in related industries can be even longer. One Ledor built for Encana is almost forty miles long.
“Long steam pipelines are not ideal, but also not uncommon,” confirmed Marcus Balz, the CTO.
“For nearly all of our large projects, we have to consider large steam pipelines, as often the large areas required are not neighbouring the companies, unfortunately. We take into account the calculated respective losses and the additional Capex, but the effects on both are always below 10%.”
“We have to design to take into account the losses of temperatures and pressures along the way,” added COO David Tickner. “So we export at a higher temperature and pressure to make sure the end result is where the customer needs the output to be.”
Price had to be competitive with fossil energy
GlassPoint has to be able to produce solar steam to Searles Valley at a competitive price with fossil fuels, and compared to its competitors. These minerals are currently produced in one other mine in the US and imported from Turkey.
We’re focused on CO2 reduction and decarbonization, but it has to be at an economic price point that’s competitive.In this case, we are producing solar steam that is at a lower price than their fossil fuel generated steam ” Palombi noted.
We are working on a ling term off-take agreement that will insure a stable cost over the long term. And coal and natural gas prices are pretty volatile, and so giving them that price certainty over 20+ years is really important to them.”
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