San Diego will be the Meeting Place for Solar Technolgy Experts on February 2-3 at the 2nd Concentrated Photovoltaic Summit

San Diego, CA (PRWEB) November 25, 2009

“Modularity is indeed a big factor in CPV's favour”

Interview with University of Nevada Las Vegas’ Robert Boehm - speaker at the 2nd Concentrated Photovoltaic Summit US, February 2-3 2010

Given the recent and limited field experience with CPV systems, it is almost impossible to define the minimum requirements that the products must fulfil regarding performance reliability and safety.

It is obvious that if CPV is trying to compete against conventional photovoltaics, it should have, at least, the same requirements as conventional PV. For instance, reliability and durability offered by CPV systems must be at least as high. It is difficult to gather information about reliability and durability experiences in CPV systems, as most of them are still in a prototype phase; so, the field experience is limited. Those difficulties get worse because the companies involved in concentrating photovoltaics are reluctant to share their achievements and difficulties due to market strategies and research confidentiality, as highlighted by CPV Today in its report, Achieving Grid Parity, released earlier this year.

There is a premium cost on CPV, but the differential in cost is becoming smaller, says Robert Boehm, Professor of Mechanical Engineering and Director of the Energy Research Centre, University of Nevada Las Vegas.

Both the increased efficiency of cells generally, their efficiency increase with concentration, and the ability to access more sunlight in a day are helping narrow this cost, according to Boehm, who is scheduled to speak at CPV Today’s 2nd CPV Summit US, to be held in San Diego (December 2-3) this year. While some thin film technologies are becoming increasingly cost competitive in the field generally, these require quite a larger footprint for the same generation. In some markets this will not be a negative aspect for thin film, but in some it may be quite critical, added Boehm.

Boehm spoke to CPV Today about the possibility of cost reduction in case of CPV and other technologies such as thin-film and CSP. Excerpts:

CPV Today: CPV cost reduction roadmap forecasts that the initial investment will drop down to 2500 €/kWp in the short run upon the assumption of a rapidly increasing manufacturing volume together with a learning factor of 15% (Nishikawa and Horne, 2008). The EU Photovoltaic Technology Platform agrees on this figure and envisages that this dramatic decrease will take place by 2010. What do you make of such projections?

Robert Boehm: This trend is a definite reality. It has certainly been the case that CPV manufacturers have been developing their systems one or two units at a time. I also know that many are moving toward modern manufacturing techniques with the use of robotic elements and other approaches that will significantly decrease their cost of manufacture.

CPV Today: The cost per kWp of thin-film modules is lower than those of conventional wafer-based silicon modules and CPV systems. Additionally, their appearance makes them attractive to many people and especially suitable for the built environment. However, less efficiency (as it is the case for thin-film) means more module area, entailing more costs in supporting structures, wiring, concrete and the like. This is why, in the end, the LEC of flat-plate thin-film may be considered equal to that of static c-Si. What kind of support do you think CPV industry needs at this stage to compete?

Robert Boehm: I think that as CPV is developing the characteristic of less expensive manufacturing costs, as well as decreased cost of installation... this is quite positive. Market stimulation with the use of RPS and tax incentives will move the industry considerably along this pathway to lower costs. With the potential of developing higher and higher efficiency cells, the HCPV approaches will become overall much less expensive. Also to be noted is the development of low concentration systems which show their own good characteristics.

CPV Today: Would it be right to say that only scale and large scale power plants are key success drivers for CPV?

Robert Boehm: That is my feeling generally. However, roof-mounted, low concentration PV systems will find a good application on large flat roofed buildings. These can probably be installed either during building construction or as a retrofit without the need to modify the basic building design.

CPV Today: What do you make of advantages of CPV over CSP? For instance, CPV displays a higher degree of modularity than CSP. This means that it is easier to gradually expand the capacity of a CPV plant than it is in the case of CSP. Also, do you think there is more scope for cost reductions in CPV than in CSP?

Robert Boehm: The modularity is indeed a big factor in CPV's favour. Also the greatly enhanced efficiency benefits (with promise of potential improvements of this aspect) of HCPV over CSP is another factor. The one CSP technology that is closest competitor to CPV is the dish Stirling approach on both accounts. However, this technique brings with it a potential enhanced requirement for maintenance efforts. Of course, some CSP technologies give short term solutions to energy storage not available to either the dish Stirling or CPV approach. Minimising the use of water may also be a factor in some decisions between CSP and CPV. Even if water is required only for cleaning, the higher efficiency of many of the CPV approaches will require less water per unit of output.

CPV Today: Initial investment costs are currently higher in CPV installations if compared with parabolic trough CSP technology. CPV has a higher sensitivity to clouds. The lack of clear radiation affects more negatively in CPV than in CSP performance. How do you think CSP scores over CPV?

Robert Boehm: Yes, CPV does suffer more severe transient effects compared to trough technology. The latter has the inherent stability of long fluid transit times that offer some ability to smooth short transients. Trough plants offer the possibility of more easily incorporated longer-term storage. These are two big issues facing CPV in that head-to-head comparison. However, with costs of CPV coming down and performance increasing, CPV will compete well on other bases.

Boehm is scheduled to speak at CPV Today’s 2nd CPV Summit US, to be held in San Diego (February 2-3 2010).

For more info, click here:

http://www.cpvtoday.com/usa/agenda.shtml

or contact:

Heidi Hafes
Events Director
New Solar Today
T:(+ 44) 0207 375 7206

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