Linear Fresnel Reflector

Linear Fresnel reflector (LFR) also based on solar collector rows or loops. However, in this case, the parabolic shape is achieved by almost flat linear facets. The radiation is reflected and concentrated onto fixed linear receivers mounted over the mirrors, combined or not with secondary concentrators. One of the advantages of this technology is its simplicity and the possibility to use low cost components. Direct saturated steam systems with fixed absorber tubes have been operated at an early stage of use of LFR technology. This technology eliminates the need for HTF and heat exchangers. Increasing the efficiency depends on superheating the steam. Superheated steam up to 500°C has been demonstrated at pilot plant scale and first large commercial superheated LFR plants have begun recently their operation.


Since the steam is the working fluid, LFR technology is usually fitted with steam storage system. Molten salt storage system can be also implemented. Furthermore, PCM storage systems are currently demonstrated at pilot plant scale.


There are almost more than 200MW LFR plants in operation or under construction. After a first pilot scale application in Australia, a few new pilot plants have been tested in Spain and in the United States. In 2012, the first commercial 30-MW Puerto-Errado 2 plant began its operation in Spain. France has already implemented two linear Fresnel pilot plants and is currently building two new commercial plants with this technology of 9 and 12 MW respectively, named Llo and Alba Nova 1 plants constructed respectively by CNIM and SOLAR EUROMED. In Australia, there are two plants running with this technology of 6 and 9.3 MW respectively. There is also one 44-MW plant under construction at Kogan Creek. In India, Reliance has completed and connected to the grid in November 2014 at Dhursar in Rajasthan a 125MW CLFR plant designed and constructed by AREVA Solar.


Compared to other technologies, the investment costs per square meter of collector field using linear Fresnel technology tend to be lower because of the simpler solar field construction, and the use of direct steam generation promises relatively high conversion efficiency and a simpler thermal cycle design. The Fresnel design uses less expensive reflector materials and absorber components. It has lower optical performance and thermal output but this is offset by lower investment and operation and maintenance costs. The Fresnel system also provides a semi-shaded space below, which may be particularly useful in desert climates for agriculture. Acting like a large, segmented blind it could shade crops, pasture and water sheds to protect them from excessive evaporation and provide shelter from the cold desert sky at night. Many improvements in the absorber tubes and the geometry are under development. Some of those ongoing improvement efforts relate to the shape and the disposition of mirrors to accommodate some of the peculiarities of this technology.


Therefore LFR offers high thermal performance and low cost, as well as various cost competitive thermal energy storage solutions. Hence, LFR is becoming one of the CSP technologies capable to achieve very low LCOE costs.


In addition to electricity generation, linear Fresnel technology is also quite useful for direct thermal applications, such as cooling or industrial process heat applications. Very low cost LFR collectors are providing 200-300°C steam solutions at competitive cost for process heat application such as desalination, food processing and pharmaceutical industries. Low cost LFR collectors are providing 250°-500°C steam solutions at very competitive cost to hybrid CSP – fuel fired combined cycle or Enhanced Oil Recovery applications.

Case Study: Dhursar – the world’s largest CSP project based on Compact Linear Fresnel Reflector (CLFR) technology

Reliance Power’s the first 125 MW of the 250 MW CSP project, located at Jaisalmer District, (Rajasthan, India), has been successfully connected to the grid in November 2014. It is the largest CSP plant in Asia and also the world’s largest CSP project based on Compact Linear Fresnel Reflector (CLFR) technology.
Rajasthan Sun Technique Energy, a wholly owned subsidiary of Reliance Power, was awarded to build a 250 MW CSP project in April 2012. The innovative CFLR Technology for the project is provided by Areva Solar – the US subsidiary of the AREVA SA of France, which is simple in design, having minimal environmental spill, lesser land requirement and is more efficient than other solar thermal technologies available.
The concentrated solar power plant is part of the first phase of the ambitious Indian program, the Jawaharlal Nehru National Solar Mission, which aims to set up 22,000 MW of solar power capacity by 2022. Of the 250 MW capacity, the first 125 MW of the project can generate up to 280 GWh of electricity every year. When completed, the 250 MW CSP project will result in the avoidance of nearly 557,000 metrics tons of CO2 emissions per year for the 25-year life of the project, compared to a similar sized coal-fired power generation plant. At peak, this creates 500 construction jobs and 40 O&M positions.

Source: AVREA Solar

Case study: Puerto Errado 2

Puerto Errado 2 (PE2), the 30MW solar thermal power station built by Novatec Solar using liner Fresnel solar energy facility, has been completed and is in operation since August 2012 in Murcia, Spain. The technology uses direct steam generation and, unlike other solar thermal technologies, does not require heat exchangers and oil-filled absorber tube networks for heat transfer. Instead, this highly economical and proven concept utilizes compact almost flat glass mirrors, with a mirror surface of 302,000m2. The uniquely efficient solar boiler produces superheated steam directly at a temperature of up to 500 degrees Celsius and a pressure of 100 bar.
PE2’s 30MW electrical output is generated exclusively by solar power and produces approximately 50 million kW hours of electricity per year. Annually, this equates to a reduction of carbon dioxide emissions of over 16,000 metric tonnes and enough clean energy to power 15,000 Spanish households.
PE2 is the third commercial installation based on this technology. A 1.4 MW plant has been delivering power to the Spanish high voltage grid since 2009. In May 2012, Novatec completed a 9.3 MW plant at the 2,000 MW Liddell coal-fired power plant in New South Wales, Australia – integrating CSP technology with conventional coal-fired power generation for the first time ever.

Source: Novatec solar and ABB