Schlumberger Energy Institute Solar | Page 5

The 4 main sub-technologies of CSP Distinguished by the technology and way they focus the sun’s rays 01. Linear Fresnel l l l l l l Reduced land-use requirements Low cost Direct steam generation possible Low optical efficiency Lowest solar-to-electricity efficiency LFRs use long rows of flat or slightly curved mirrors to reflect the sun’s rays onto a downward-facing linear, fixed receiver. l Thanks to the high position of the receiver, collectors can be installed closer to each other, reducing the land-use footprint and cost. Fixed Receiver remains stationary and mechanically independent. 02. Solar Tower l l l l l l Reduced water requirements High flexibility Direct steam generation possible More challenging scalability Less standardization Solar towers - aka central receiver systems - are made of a field of heliostats (i.e. devices the track the sun from a stationary point), surrounding a central receiver atop a built structure. l Heliostats can vary greatly in size. 5 | slb.com