Burgess COMMENTARY

Peter Burgess

CPV specialists say failure and progress go hand in hand

All industries experience some level of failure, management or technical. Therefore, any failures in CPV should not overshadow the entire sector. But the sector has some tough critics. We look to Amonix, Solar Junction and NREL to assess the situation.

It is vital for any burgeoning solar technology to define failure and performance related issues. However, instances involving the breaking down of any component of the CPV module; and any inability to perform its primary designed function or disparity in module power beyond standard percentage owing to module alignment or irradiance variation should be reasons for concern.

Failure, as Vahan Garboushian, CEO and founder at Amonix says, is defined as total field failure that cannot be fixed in the field. He says this has happened in the past with particular CPV designs having a fundamental flaw.

“Performance is a contractual issue resulting from overselling the potential of CPV in the past. Both “failure” and “performance” issues are avoided by CPV companies with mature designs based on lots of field experience,” points out Garboushian.

Failure and progress – go hand in hand

Anyone who thinks that the failure of a company is merit for the dismissal of an entire industry is short sighted, emphasises Garboushian.

“Failure is a part of progress. If you’re not failing, you’re not learning. I welcome anyone to show me a 30-year old Si solar panel still working today,” challenges Garboushian.

Importantly, he adds that the industry will continue to step up its credibility by highlighting its success stories – the reliability, efficiency and operating costs of systems in the field. He says an example of success is the Cogentrix Alamosa 40MW DC plant with 504 Amonix 60KW systems. It has been in operation for the last two years with “excellent reliability and steady performance with no degradation”, he says.

One failure – how fatal can it be?

So how critical can one failure be at this juncture for an entity and the entire sector?

According to Jeff Allen, VP- business development at Solar Junction, this is a genuine concern particularly for larger installations. He says for smaller companies/ installations field failures may not be reported thereby the impact to financing, EPC and deployment may be minimal.

Matthew Muller, CPV performance testing and IEC CPV standards development, Engineer IV NREL, National Center for Photovoltaics, says it is clear that if a MW scale CPV field failed in large numbers, this would be damaging to the industry. Design qualification standards help to prevent this type of problem, but of course this is still possible. Alternately, a multi-year data set demonstrating cost effective power production from a large CPV system enhances credibility and improves funding opportunities for additional installation of CPV systems, says Muller.

He also added that he is “not aware of ‘failure’ issues on a large scale that could be considered a problem”.

“Any technology will have manufacturing defects or other reasons that lead to a small number of failures. As far as I am aware, CPV companies that have achieved scale have instituted quality similar to other industries,” says Muller.

“CPV performs well with efficiencies much higher than standard PV. CPV performance can be complicated to measure using standardised methods. The CPV industry is working to complete a draft IEC standard, 62670-3 titled Concentrator Photovoltaic Performance Testing. This document, when complete, will be very useful to the industry and to customers as it will provide clear methods for measuring and comparing CPV performance,” he says.

Root cause

Because of the potential of CPV, several dozen new companies started out and tried to enter the market with a premature product, lacking field verification and testing.

Garboushian agrees with this and says this alone with some hasty poor designs has resulted in poor reliability and a black eye for the entire sector.

“Amonix has always relied on a minimum of two years of field testing before commercially launching a product as it is evidenced by its outstanding reliability record of the 40 MW Alamosa plant. With the proper design no degradation or ground shorts should happen,” he says. “This is why the IEC process exists. All products should be tested to industry agreed standards to add confidence to the performance of the product long term.”

Reasons for optimism

The CPV industry can plan for some of failure-related concerns. Initiatives for early detection should be leveraged from other mature industries harnessing concepts of weather sensors including DNI meters, onboard system telemetry sensors (such as the inverters, modules) to detect power variations possibly indicative of system related power production issues and during the earliest phases so that local support can rapidly resolve issues identified.

“Companies, such as Soitec Solar and Solar Systems, are doing effective jobs of monitoring their deployments,” says Allen.

Individual failures, as Garboushian says,are a healthy indication of a maturing market. “Right now there are two dozen or more CPV companies formed to chase the CPV market. Why so many? The economics of CPV pen out very competitively, as anyone that digs into CPV economics will come to understand. That attracts many entrants,” he says.

Links: [1] http://news.pv-insider.com/users/ritesh-gupta