Unsettled outlook hangs over CPV

Spain makes a natural test-bed for concentrated photovoltaics (CPV), the solar energy technology that relies on high-efficiency converters.

The Instituto de Sistemas Fotovoltaicos de Concentracion (ISFOC) installation near Puertollano, smack bang in the middle of the country, is there to do just that, hosting a selection of CPV systems built by the emerging leaders of this new sector.

Unfortunately, even in central Spain, it is not always sunny. When the sun doesn t shine, CPV systems produce no energy. On an organized trip to the site in late April as part of the CPV Today event in Toledo, wind turbines on the local hilltops would have made more effective use of the blustery conditions.

The contradictory weather highlighted the paradoxical state that this fledgling industry is in. One paradox inevitably centers on finance. While the ISFOC installations are up and running, the facility s headquarters is still under construction, and only a small amount of data have been collected on live systems.

Until those data look solid, any large-scale private investment appears risky to financiers chastened by the recession. "Now is not the time to go to the financial markets with unproved technology," said Pablo Valera from the investment advisor ASTROM. In the current climate, even the solar industry s darling, First Solar, would have been deemed too risky, he adds.

The irony is that on a large scale and in a sunny climate, CPV has enormous scope to produce solar energy at a very low cost, perhaps as low as $0.10/kWh in a best-case scenario including higher cell efficiencies, cheaper cells and a favorable location.

But until CPV companies can demonstrate low-cost production in volume, "regular" PV based on thin-film or silicon cells looks like a far less risky option. CPV has no long-term track record right now.

Another paradox surrounds the supply of high-efficiency cells, the components that account for a high proportion of the total system cost. Currently, supply is dominated by Boeing s Spectrolab subsidiary and this is keeping cell prices high. Systems firms want to see those prices brought down, either by increased competition or more availability.

The trouble is that without a guaranteed large order, cell makers don t want to risk the substantial investment needed to scale up. In a stalemate situation, systems firms can t place those large orders until they can be guaranteed a supply of low-cost cells. Despite the problems, a remarkable degree of optimism permeates this emerging application. And there are some clear signs that the supply of cells is going to increase, particularly with Spectrolab s investment in a high-volume Veeco E475 MOCVD reactor, the likes of RF Micro Devices beginning to tackle solar-cell manufacturing in collaboration with the National Renewable Energy Laboratory, and III-V foundry companies, including IQE, Kopin and Spire Semiconductor, all taking an interest.

Russ Jones recently joined Spectrolab s senior management team and is heading up the cell maker s terrestrial PV applications business. According to him, the company s investment in capacity will enable it to fabricate cells capable of generating 300 MW of power in 2010, at an average efficiency of 40%.

Beyond that, Jones told CPV Today delegates that Boeing is committed to supporting a much larger expansion, to between 2 and 5 GW of cell production, in the coming years.

All of this sounds like good news for systems companies. Except that Spectrolab s expansion will do nothing to solve the problem of its dominance. As a result, some systems companies have decided to make their own cells; others may turn to foundry companies, although without any very large orders forthcoming, it is difficult for foundries to justify the spending to support production.

Clearly a number of issues must be solved. Key among them will be ISFOC securing the estimated €27 million ($36 million) required to fund the second phase of the project, scheduled to begin in 2010. Standards must be developed, while more effective group action will be crucial to compete with the more powerful PV and thermal solar lobbies.

There is a need for more test-bed projects like ISFOC, to foster CPV technology development to the point where it becomes an attractive investment.

Without that, CPV will remain a cottage industry, reliant on sporadic small-scale deployments in sunny locations with generous subsidies, rather than a serious new application for III-Vs. Gary Conley, the co-founder of systems firm SolFocus, summed it up in a CPV Today panel session: "There is no CPV market; no CPV industry, yet. We have to create it."   

View pdf of article