Large installations of CPV are not yet common. Until the end of 2009, about 21MW of CPV systems have been reported as set on Sun (Kurtz, 2009; Extance & Marquez, 2010); large part of them (13 MW) are from one HCPV technology of modules based on Fresnel lenses concentrator developed by Amonix Inc. in the last twenty years; the fraction of operational systems with low concentration level (LCPV) is less then 1MW, mainly of Entech Solar products installed in the 90’s. Although at the end of 2009 around 70 vendors of photovoltaic concentrator systems have been found (EPRI, 2009), the CPV is a small niche of the photovoltaic market; indeed, at the end of 2009 already 7 GWp of PV modules have been installed and grid connected around the world. The market of CPV is mainly oriented toward solar farms and large installations, because of the necessity to use Sun-trackers. For this kind of large installations, big investments are required; this is one of the first hurdles for the CPV entry into the market. Indeed, to gather large investments for solar energy production, the demonstration of high reliability and durability of the systems is a fundamental issues, which need time and systems in Sun. Moreover, the high competiveness of the other PV technologies and their levels in industrialization and economies of scale is another high obstacle to face for any new PV product, which must have a price lower than the established technologies.
With the aim to demonstrate the reliability and durability of different CPV technologies the ISFOC project has been set in Spain, for the testing in field of some MWp of photovoltaic concentrator systems. In this experimental solar plant hundreds of kWp of different CPV technologies are continuously monitored and the performances are evaluated.
An important step forward for the commercial feasibility of CPV has been done with the publication of the international standard for the design qualification and type approval for CPV modules and assemblies (IEC62108, 2007). The tests defined in this IEC standard are mainly oriented to demonstrate the durability and reliability of the CPV modules. This recently published text, milestone for the CPV deployment, presents some tests more severe than for standard flat plate modules and takes longer time to be concluded (approximately one year).
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Fig. 16. Installation of CPV systems of Amonix Inc. in Nevada (USA) (www. amonix. com)
Some pioneers companies, the US based Amonix Inc. and the Australian Solar Systems, have set in Sun large installations since the ’90s. However, because of the huge difference between any CPV solution, each technology must proof its reliability independently.
Based also on the durability and reliability of the systems, the Levelized Cost of Energy (LCOE) is a parameter expressed in cents/kWh frequently used to evaluate the economical convenience of a PV solution; this parameter takes into account not just the energy production, but the cost complexities associated with the entire lifetime of a solar plant, from financing through to end of life (Short et al., 2005). The LCOE takes into account installation and commissioning costs, operations and maintenance (O&M), degradation and lifetime, and the output. It calculates the average value of the total energy produced, revalued at the time of calculation based on forward assessments of inflation and costs of financing. Starting considering this parameter, some CPV companies have claimed to can achieve the lowest LCOE in the market, in the order of 10 dollar cents/kWh for the next years ( Nishikawa & Horne, 2008).
An important advantage of the CPV approach is the reduced necessity of capital investments (scalability). Both the thin film industry as well as the Silicon standard module production require high capital investments. By reducing the amount of semiconductor material, the initial investment is also reduced. Although no CPV companies have yet demonstrated it, the relative easiness of scale-up of CPV is logical and could be a significant advantage in a rapidly growing market. Some companies have already declared production capacities of many tens of MWp per year in 2009, with large announced growth for the 2010 (Extance & Marquez, 2010).
Because of any CPV systems is composed of many parts, the economical advantage improves with the cost reduction of any components; it can be achieved with the economy of scale consequence of the rising of the number of installed systems. In order to achieve affordable product prices, some CPV companies are moving toward a sort of vertical integration on the value chain, being often producer of trackers, inverters, components, taking care of the field installations and even approaching the processes for the cells manufacturing. In this path CPV companies are rapidly following the way of the largest standard PV groups; indeed, in standard flat plate industry, some companies specialized in the module production, cells manufacturing, tracking fabrication and system integration are still working without integration. But for the largest groups this process is in progress, from the row material purification up to the final installation, in order to achieve the lowest costs.
Aside the CPV module and system producers, there are many companies working in the development of the components required for the installations; in particular, many companies are focused on the production of solar cells for concentration, on the production of specialized optics and for the fabrication of dedicated trackers (Extance & Marquez, 2010). The CPV is an emerging technology in the photovoltaic sector. The cost of installed kWp is continuously decreasing to try to compete with standard c-Si modules and thin films. The wide range of solutions will lead to the accomplishment of some leaders and to the disappearing of other companies or technical solutions; because of the large amount of investments required for the establishment of a competitive technology, some of these inventions could not found a commercial deployment for financial reasons rather than technological imperfections.
The future of the CPV technologies will be probably defined in the next few years, with the direct comparison of the energy production of the first large solar farms of different photovoltaic technologies in different sites around the world.
