Flexible Solar Cells

Thin film solar cells have long been regarded as the ultimate future of photovoltaic solar energy technology for one major reason: their lower materials utilization should result in lower manufacturing cost in very high volume production. This expectation, coupled with a temporary interruption that began about four years ago in the supply of the basic polysilicon feedstock used to make silicon solar cells, stimulated large-scale investments worldwide in various thin film solar cell technologies. Thin film solar panels are now available that are made from amorphous silicon (α-Si), copper indium gallium diselenide (CIGS); copper indium diselenide (CIS), cadmium telluride (CdTe) and even silicon itself.

While thin film solar cells did make some market penetration during that time they failed to capture a significant market share compared to traditional silicon solar cells. The two primary reasons for this failure are 1) thin film solar cells have not achieved sufficiently high efficiencies to be attractive in the market; and 2) the manufacturing equipment required is typically very specialized and much more expensive than the equipment required to make silicon solar cells. Industry observers typically use a rule of thumb factor of two times the cost of setting up a silicon solar cell fabrication line.

It is this combination of high capital cost and low efficiency that Natcore's LPD technology addresses. The nanostructured, thin film, flexible solar cell under development at Natcore is made using our patented LPD technology. Both the fabrication process and the cell structure are exclusive to Natcore. The near term module efficiency using this technology will be equivalent to commercial silicon modules at 15% to 16%, and the longer term improvements will raise the efficiency to 20% or more.

A roll of flexible film cells will reduce the cost of making a solar panel and the time required to install a commercial solar array by at least 60%.

Even more importantly, the capital expenditure required to make the cells will be one-tenth of that required to make even a standard silicon solar cell (and therefore one-twentieth the capital expenditure of today's thin film solar cells). This stunning reduction in cost is made possible by the fact that Natcore's cell can be manufactured using existing, under-utilized (or no longer used) photographic film manufacturing equipment. All Natcore needs to do (and is in the process of doing) is develop the three deposition systems needed for the different cell layers (absorber layer, window layer and top contact layer) and insert them into the existing roll-to-roll lines at any of several factories around the world. Preliminary engineering studies have demonstrated that the entire investment needed for a 150 MW/yr cell production rate is in the range from $40 million to $50 million.

Natcore is hard at work to demonstrate the desired cell performance at the large scale needed to move into roll-to-roll manufacturing. The company is working on teaming relationships with major U.S. film manufacturers to accelerate its progress from development to commercialization. Once ready for sale, Natcore's flexible film solar cell array technology will cause a paradigm shift in the market by exceeding the DOE-established price levels needed to achieve grid parity for the price of solar generated electricity.