Advancing efficiency and scale in CPV arrays

In 2011, Amonix installed over 35 MW of CPV arrays across the U.S Southwest. In order to meet the competitive price targets of these projects, improvements have been made across the power path, from optics to cell. Modules fielded in 2011 produced over 20% more power than those fielded in 2009. The recent deployments provide feedback that enables ongoing optimization for field conditions. The ratio of currents generated by each of the sub-cells in the III–V multijunction is monitored and compared to prediction. An understanding of the balance in sub-cell currents leads to re-tuning of the epitaxial structure for higher energy yield. Losses in the optical path, including the effect of gridline width, have been reduced substantially. High production cell efficiencies, combined with significant improvements in the optical path, have led to peak DC module efficiencies that exceed 34% under operating conditions. A record module rating of 33.5% outdoor operating efficiency has been confirmed by NREL.