Two factors are influencing the use of photovoltaic-driven solar power today. While the market is primarily driven by government policy, feed-in tariffs, the use of PV at the utility scale, and the expansion of the “smart-grid,” there are also great advances being made on the technology side that enable PV to be increasingly competitive with conventional power sources.
Crystalline silicon and thin film technology continue to see significant improvements in efficiency, made possible by advances in manufacturing process technology and the use of new materials. Efficiency gains are also being made through advances in balance-of-system components, such as inverters.
This issue highlights several of these types of advances. Our cover story, “Towards grid parity: advances in c-Si PV manufacturing technology,” describes how the solar industry has achieved a 7% year over year reduction in costs. Most of this reduction stems from improvements in manufacturing, including increased automation, high productivity cell processing, and yield improvement with more effective use of metrology. Techniques to increase cell efficiency are also helping reduce the cost/Watt. For crystalline-silicon PV, these include selective emitters, double-printed contacts, an all back-contact structure and anti-reflective coatings.
“Increasing cell efficiency and optimizing productivity using wide-area metrology” highlights the three-way scaling challenges of thin film PV technology: scaling of cells from lab size to full panel size; scaling of production from R&D and pilot lines to mass volume production; and scaling of quality and reliability engineering. All are critical to reducing cost/Watt.
“Improving materials applications for solar device manufacturing” notes that current economic conditions have forced many fabs to simultaneously practice process improvement while “pushing product.” Slight adjustments, however, can yield a substantial costs savings through reductions in raw material use, process footprint and waste generation.
As impressive as these efficiency gains and cost reductions can be, it’s important to note that PV panels are only about half of the cost equation. Solar system installation costs include balance-of-system (BOS) components, labor and the inverters, as noted in “Inverter technology drives lower solar costs.”