Photovoltaics International Papers

Thin-film solar cells based on chalcopyrite semiconductor Cu(In,Ga) (S,Se)2 compound (hereafter called CIGS or CIGSeS irrespective of the exact composition) have continuously drawn interest because of their progressively increasing high photovoltaic conversion efficiencies and the merits of long-term performance stability, high energy yield, low cost production potentials and other advantages for industrial manufacturing and application of solar.

The drive towards better Si utilization (g/Wp) has been an obsession in the Si PV industry over the last few decades as one of the key aspects in making photovoltaic energy production competitive. With the cost of Si still making up a third of the final Si solar module cost, there is continued interest in reducing the cost of Si by producing thinner wafers and reducing kerf losses.

Combined R&D expenditures of 12 major PV module manufacturers in 2016, tracked since 2007, decline by approximately 4.4% in 2016 to US$519.3 million, compared to US$542.9 million in 2015. As 2015 expenditures were a new record high, 2016 becomes the second highest year of spending and 2014 the third highest. All three years highlight total combined annual R&D expenditures above US$500 million.

Since the first demonstration by Sanyo in the 90s of crystalline silicon heterojunction (SHJ) solar cells with already promising energy conversion efficiencies above 18%, this device architecture has experienced an extraordinary history of development, embodying outstanding scientific findings and efficiency records.

During 2017, the PV industry is forecast to produce and ship close to 100GW of solar modules, reaching this key milestone well ahead of all market forecasts previously projected. Furthermore, the explosive growth of solar PV shows no sign of abating, despite the constant threats and barriers imposed by on-going trade import restrictions.

LONGi, Jolywood and many other large PV manufacturers claim that bifacial mono c-Si technology is the future. Since 2015, bifacial PV installations have been entering multi- MW installation levels, and are expected to enter multi-GW levels in 2018.

Modern single metallization lines using flatbed screen printing (FSP) can realize a maximum output of approximately 2,000 wafers/h. For several reasons, achieving a significant further increase in throughput of the FSP process is technically challenging.

To guarantee the long-term competitiveness of the PV industry, the cost of PV power generation ($/kWh) must be continuously reduced. Such reduction can be achieved in two ways: 1) by improving PV module performance (efficiency, annual energy yield, reliability); 2) by reducing manufacturing costs ($/Wp).

It’s always nice when someone tells you directly that you can’t do something to set out and prove them wrong. Photovoltaics International, its sister title PV-Tech.org and their publisher Solar Media were told in the early phases of planning the inaugural PV CellTech conference, that pulling together a string of CTOs and R&D heads from the some of the biggest firms in the cell processing supply chain would not be possible. Following the event’s second outing in March 2017, we have now done it twice.

The first appearance of a shingled solar cell interconnection pattern (see Fig. 1) dates back to 1956 with a US patent filed by Dickson [1] for Hoffman Electronics Corporation, which is just two years after the first publication of a silicon solar cell by Chapin et al. [2]. In the years that followed, further patents were filed containing concepts of shingling solar cells serving various module designs and applications – for example, Nielsen [3] for Nokia Bell Labs, Myer [4] for Hughes Aircraft Company, Baron [5] for Trw Inc, Gochermann and Soll [6] for Daimler-Benz Aerospace AG, Yang et al.