GETTING MORE WITH THE SAME SUN

Energy performance India vs. Spain: As the DNI values are similar, how is the energy yield?
February 24, 2011 (CSP Today)

"…With respect to the Global Horizontal Irradiation GHI, which is relevant for Photovoltaic (PV) projects, [India is superior to Spain]…In regard to Direct Normal Irradiation DNI, which is relevant for CSP projects, the annual sum of DNI is almost comparable, with values in the range of 1900-2100 kWh/m2a.

"…[T]wo regions favorable for CSP project locations…Spain, Andalusia…[and] India, Rajasthan…[a] year with an identical annual sum [of 1950 kWh/m2a] for DNI in both locations was used…A standard performance simulation tool for CSP plants was applied…[for an identical] parabolic trough CSP plant with 8 hours of storage…"

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"One would expect at first glance that the annual electricity yield of both plants would be approximately equal…The location in India, compared to the location in Spain, accumulates more hours with moderately high DNI values. While in Spain, only during summer some high DNI values are reached.

"…[T]he CSP-plant at the Indian location can deliver significantly more energy compared to a location in Spain with the same average DNI…[T]he low production during the cold seasons creates the disadvantage in Spain. The Indian production curve also shows the dip in energy production during the monsoon-summer month (Jun-Aug)…"

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"…As a conclusion, one can use as rule of thumb, that energy yield at a location in India could be >20% above a location in Spain with the same average DNI…

"…The performance of a parabolic trough plant is a function mainly of DNI, solar field size, and storage size. The plant configuration requires a project specific optimization to identify the feasible size of the plant (number of loops, capacity of thermal energy storage), which can only be optimized once the DNI is properly evaluated. Further optimization will then review the cost related to the technically optimized concepts."