GlassPoint Solar and partner Petroleum Development Oman (PDO) say they have reduced costs by 55 per cent in the scale up of a massive desert solar project to produce steam used in thermal enhanced oil recovery (EOR).
GlassPoint’s enclosed trough technology features a unique solar thermal design that takes parabolic trough collectors, or large curved mirrors, and puts them inside an agricultural greenhouse. The mirrors concentrate sunlight on a pipe filled with oilfield-grade water and boils the water directly into steam. The process is typically fuelled by burning natural gas.
The technology is being scaled up from a seven-megawatt (MW) pilot to Miraah, a one-gigawatt solar thermal project under construction on the Oman oilfield. The savings resulted from the use of improved designs, enhanced tooling and increased workforce productivity in deploying its enclosed trough technology.
“The greenhouse serves as protection, foundation and structure in one, enabling major cost and performance advantages compared to exposed solar designs. Most importantly, the zero-wind environment lets us reduce the amount of raw materials used throughout the entire system. Using less material reduces the weight and costs of the solar collectors, and makes the plant easier to install and easier to maintain,” Pete von Behrens, GlassPoint’s chief technology officer, said in a statement.
The companies described the cost saving achievements in a technical paper presented at SolarPACES 2017. The paper, Deploying Enclosed Trough for Thermal EOR at Commercial Scale, details many of the ways GlassPoint has been able to simplify its solar collectors, which are suspended from thin wires from the greenhouse roof.
GlassPoint optimized the equipment and mirror manufacturing process, improving yield in the factory and mirror performance in the field. The mirror material was reduced by 18 per cent to a little over one kilogram per square metre, reducing material costs. They also deployed a new, lighter and stiffer mirror support structure.
The new aluminum space frame design, assembled onsite, is five times stiffer than the previous design and cut aluminum usage by 30 per cent. GlassPoint is also deploying a new drive system, which is used to rotate the mirrors to track the sun, that uses one-third fewer motors, and further reduces installation and maintenance costs.
GlassPoint’s seven MW pilot for PDO has been operating since 2013 and paved the way for Miraah, which began construction in November 2015 at the same oilfield in south Oman. It will generate 1,021 MW of peak thermal energy once complete, making it one of the world’s largest solar plants of any kind.
The California-based company is one of the fastest-growing solar companies in the world with more than one gigawatt of solar oilfield projects under construction, and was recognized by the World Economic Forum as a Technology Pioneer for its role in enabling more economical and sustainable oil production.