PRE-PACKAGED BIG SUN

Modular, scaleable CSP technology poised to grab marketshare? Modular CSP technology can achieve high operating temperatures and efficiency, while, scaleablity makes them easier – and quicker – to get into the ground than large-scale CSP plants.
Andrew Williams, 17 February 2011 (CSP Today)

"…[M]odular, scalable CSP technology has become an increasingly viable option for CSP plant developers – but how does the technology compare to large-scale approaches, particularly in terms of efficiency, optimal temperature range, ease of installation, and economies of scale?

"California-based CSP company eSolar has employed modular technology at its Sierra Generating Station in Lancaster, California – with a similar plant also under construction in India with partner ACME. Its modular power tower technology uses factory-built heliostats, receivers and towers that are shipped to site and easily deployed, enabling rapid plant commissioning. Plants can also be designed to meet customer requirements without the risk, and significant re-occurring engineering, associated with non-modular designs…"

click to enlarge

"Ease of scale-up is also a key advantage for Arizona-based Stirling Energy Systems (SES), which can deploy its SunCatcher Stirling Dish technology in small-scale 50MW power plants as well as in large-scale plants up to 1000MW…60 SunCatcher units are already used at the Maricopa Solarsite in Peoria, Arizona, a 1.5 MW Dish Stirling plant delivering power under a 10-year agreement with Salt River Project (SRP)…

"The overall efficiency of modular technology used by eSolar is equivalent to large-scale power towers of the same type (i.e. thermodynamic steam cycle) – but…are less susceptible to single points of failure…Dish Stirling modular technology offers the highest solar-to-electric conversion performance of any CSP system, with an average ‘sun-to-grid’ efficiency range of 24-28% (31.25% peak)…The 440°C operating temperature range of eSolar’s solar steam receivers was chosen to match…common boiler tube materials and…commercial steam turbines…[T]he modular dish Stirling technology employed by SES has achieved even higher operating temperatures…"

click to enlarge

"A big advantage of eSolar’s modular heliostat design is that the heliostat field can be constructed very simply. Once the ground is prepared and the materials on site, each one can be built in a few weeks. The towers, shop-built monopoles similar to those used in wind turbines, are shipped to site, lifted in sections with a crane and bolted together. The receiver is also factory-built and shipped to site…Dish Stirling technology is also easy to assemble and erect on site…[and usually] doesn’t need a foundation…

"At this stage, projected market share depends on a range of variable factors, such as further CSP technology developments (including storage, hybridization and cost reduction), as well as changes in government incentives, investment market trends, fossil fuel prices and CO2 emission policies. However, since projects that utilise modular technologies are generally easier to execute, project developers are likely to look increasingly favourably on modularity in the future."