Spectrolab, a wholly owned subsidiary of Boeing (NYSE:BA), has started the mass production of its newest terrestrial solar cell, the C3MJ+. With an average conversion efficiency of 39.2 percent, C3MJ+ will be the industry’s highest-efficient cell. These (updated triple-junction) devices have an average conversion efficiency of 39.2% at a 500-sun concentration.
This year has seen the first grid-connected CPV installations on a megawatt-scale, and with companies such as Amonix investing in volume CPV system manufacturing facilities, it is likely that 2011 will witness significant market growth for the technology as its reliability is proved out.
CPV relies on multi-junction cells produced by the likes of Spectrolab, its US rival Emcore, and the German company Azur Space. While the individual cells are expensive to produce, the fact that they can handle concentration ratios in excess of 500 suns, and perform better in hot conditions than conventional PV materials, means that they are already able to produce relatively low-cost electricity in the most suitable conditions.
Russ Jones, the director of CPV Business Development of Boeing’s Spectrolab said that, “These more efficient cells are drawing interest from a number of current and potential customers. Last year we set a new world record for efficiency with a test cell that peaked at 41.6 percent. We now have entered production with essentially this same technology and plan to deliver the first of these 39.2 percent efficiency cells in January.”
That is an improvement of 0.7% on its existing “C3MJ” cells (the product nomenclature reflects the three junctions within the cell’s structure, which enable it to capture much more of the solar spectrum than conventional silicon or thin-film cells).
The design of the C3MJ+ cells is said to be similar to that of the record-breaking 41.6% device that Spectrolab announced in 2009. That lattice-matched cell showed its maximum efficiency at a concentration of 364 suns, slightly below the typical concentrating photovoltaics (CPV) industry standard of 500 suns.
Since then Spectrolab’s world record has been broken by Spire Semiconductor, which revealed just last month that it had produced a 42.3% efficient cell, which also delivered 42.2% at 500 suns.
However, for commercial purposes what actually matters is performance of the average cell in production and not just a record-breaking headline and Spectrolab’s move into volume production is good news for CPV system builders, as it would mean into higher energy production and lower cost per unit of energy generated.
“These more efficient cells are drawing interest from a number of current and potential customers,” said Russ Jones, director of business development at Spectrolab. “Given the news cells’ close similarity to our existing production cells, we believe that our current C3MJ customers will be able to easily upgrade for more efficiency.” Spectrolab reports that it expected most customers to adopt the new cell rapidly, while a new 40%-efficient cell (C4MJ) will be launched next year. "We have seen a substantial increase in demand in 2010 as compared to 2009," the company said. " We expect to deliver about 30 MW of CPV cells in 2010 and as previously stated we expect demand to be as high at 100MW in 2011” Jones added.
As far back as 2006 Spectrolab was achieving conversion efficiencies of over 40 percent in the lab with its high-efficiency multi-junction concentrator solar cells and it reached a peak of 41.6 percent with a test cell last year, setting a new world record. The company’s newest terrestrial concentrator photovoltaic (CPV) cell, called the C3MJ+, uses essentially the same technology as its record breaking test cell and follows on from its C3MJ solar cell in production since mid-2009 which boasts a conversion efficiency of 38.5 percent. The C3MJ+ solar cells
Spectrolab claims the title of the world’s leading supplier of solar cells for satellites with its cells supplying power to around 60 percent of satellites currently in orbit, as well as the International Space Station. Boeing hopes to transfer that success to the terrestrial solar cell market with the new high-efficiency solar cells that are expected to be available from January. It is expected Spectrolab will achieve a 40 percent average production efficiency for terrestrial solar cells in 2011.