By Heba Hashem
Concentrated Solar Heat (CSH) systems are yielding big energy savings for industries, cutting their fuel consumption and meeting a substantial amount of their heat demand.
Solar-process heat technologies enable temperatures of up to 400°C today, potentially fulfilling almost half of the heat demand in the world’s industrial sector, according to a report by the International Renewable Energy Agency (IRENA).
For medium-temperature process heat applications (100°C to 400°C) such as distillation (chemical industry), nitrate melting (mining), dyeing (textile), sterilization (pharmaceutical), and pasteurization (dairy industry), the main technology used is solar concentrators. These include parabolic dishes, parabolic troughs, linear Fresnel collectors, and some advanced flat-plate collector designs.
“We have much higher heat consumption in industry than electricity, so companies will save increasing energy costs on their heat demand side in the future. Using solar heat also increases a company’s competitiveness by guaranteeing stable energy prices in the long run,” said Bärbel Epp, Managing Director at Solrico, a research agency focusing on the solar heating and cooling sector.
In Spain, industries that are burning diesel and Liquefied Petroleum Gas (LPG) are benefiting the most from CSH systems, with payback periods below five years, according to Diego Crespo Mencía, Project Engineer at Protermosolar (Spanish Solar Thermal Electric Power Industry Association).
In countries like Mexico and India, CSH plants for industrial processes are being refinanced in just three to five years, which makes these projects commercially viable investments.
“The more expensive the fossil fuel is, the shorter the payback period. Additionally, if an industry installs a CSH facility today and it’s running 20 years from now, the IRR on this investment could be as high as 20% [the average lifetime of a solar thermal system]”, Mencía noted.
Despite these demonstrated benefits, CSH systems are still new to many countries. Among the biggest bottlenecks are the lack of familiarity with the technology and the low oil and gas prices in some markets. Around 40% of industrial energy consumption is covered by natural gas and around 41% by petroleum, according to IRENA.
“Industries are not aware that CSH technology exists and that it’s a solution that can replace fossil fuels in thermal processes,” Crespo said.
Today, Mexico and India have the largest number of solar process heat systems in operational plants, and region-wise, Europe has the largest number of plants.
“India is a policy-driven solar market supported by international organizations, and one-third of the investment cost [of a CSH system] is subsidized by the state. In Mexico, the market is driven by professional suppliers and cost-effective parabolic trough collectors that can beat the energy prices of fossil-fuel oil boilers,” Epp explained.
One of the important CSH plants can be found in Chile, a 10 MWth parabolic trough collector that was installed in 2012 at a copper mine in the Atacama Desert. Developed by Spain’s Abengoa for Minera El Tesoro, the solar thermal plant supplies steam at 250°C, substituting as much as 55% of the diesel fuel used in copper extraction.
Worldwide, more than 500 industrial manufacturers are using solar heat in their facilities, mostly in food & beverage, followed by machinery and textiles, research by Solar Payback found.
In countries where solar irradiation and fuel prices are high, such as a Jordan and Morocco, CSH is a highly promising avenue for industry.
RAM Pharma, a Jordan-based pharmaceuticals producer, capitalized on this opportunity in 2015 by installing a CSH system to generate process steam for drying, sterilization and fermenting.
Developed by Germany’s Industrial Solar, the Fresnel-based plant supplies steam at 160°C and has reduced the factory’s diesel consumption by 42%, according to Mahmoud Al Najami, General Manager of RAM Pharma, who was quoted in the Solar Heat for Industry brochure.
Elsewhere in the MENA region, fossil fuel subsidies have long impaired the cost-competitiveness of solar energy.
However, countries like Egypt, Morocco, Oman and Saudi Arabia are gradually phasing out energy subsidies. At the same time, the increasing costs and volatility of fossil fuel prices are improving the viability of CSH systems.
“The removal of energy subsidies will be one of the best drivers for CSH systems because it immediately makes the industry aware,” Epp highlighted.
“Even an announcement which might be delayed is considered a threat because industries plan for the long term. This should also open doors for turnkey suppliers of CSH systems.”