Thin-film solar can grow in high-value markets like aerospace and building materials, NREL study says

Energize Weekly, November 21, 2018

Silicon solar cells account for 95 percent of the global market, but there are potentially multi-billion dollar markets for flexible, thin-film cells, according to an analysis by researchers at the federal National Renewable Energy Laboratory (NREL).

“Multiple markets are emerging for renewable, low-cost power generation including aerospace and unmanned aerial vehicles (UAV), portable charging, micro-integrated products, and vehicle-and building-integrated power,” according to the NREL analysis, which was published in the journal, Nature Energy.

“These markets are underserved by the rigid Si [silicon] modules that dominate the utility, commercial and residential PV [photovoltaic] markets today,” the study said.

While more expensive, there is an opportunity for flexible, thin-film because value in these markets go beyond “the standard cost, efficiency and reliability triad that dominates large, grid-tied markets,” the NREL researchers aid. “Flexibility and portability offer two additional value propositions.”

For example, while the cost of silicon photovoltaic modules was 27 cents a watt in June, flexible solar cells for aerospace run $100 a watt, and flexible solar cells for portable charging systems can fetch $4 a watt, according to the analysis.

“Conventional rigid PV manufacturers minimize costs with a one-size-fits-all solution for large, grid-tied markets in permanent static installations,” the study said. “The high-value markets in aerospace, person-portable and vehicle-integrated products critically value flexibility and/or specific power (the power-to-weight ratio).”

The analysis identifies five areas where these thin-film technologies can grow their markets:

• Aerospace, which has the “highest price point,” with high specific power requirements for satellites and unmanned aerial vehicles. The present-day market is estimated at 5 megawatts (MW) a year.
• Vehicle Integration, which would add solar charging to cars, trucks and buses. While the potential market is large with 2020 global estimated sales at 100 million vehicles, the value proposition “remains challenging … because each product needs to be customized and integrated differently,” the study said.
• Microscale PV-integrated products, such as solar lanterns and home-charging systems. “These markets are particularly robust owing to declining PV, battery and LED prices, especially in Asia and Africa with payback periods from 3–11 months. In 2015, US$200 million was spent on about 11 million solar lanterns or chargers,” the study said. 
• Portable charging, which is estimated to already be a 3-MW-a-year market for recreational use and a 1-MW military market. “Note that the potential market size would shift upwards if the global military market followed U.S. trends,” according to the study. 
• Building Integrated PV (BIPV), which adds solar cells to building materials for roofs, walls and windows. This market is already projected to reach $9 billion in 2019, according to BIPV Technology and Markets.

“Each of these nascent markets approaches or exceeds gigawatt-scale cumulative potential in the next decade with projected prices exceeding $1 a watt,” the study said.

Three thin-film technologies have reached gigawatt-scale annual production: amorphous thin-film silicon (Si), cadmium telluride (CdTE) and copper indium gallium diselenide (CIGS). These substances are applied to metal, glass and potential plastic substrates to make solar cells.

Still, major investment will be needed to boost production and bring down costs. For example, to reach manufacturing costs of $1 a watt, investments of $2 billion would be needed for CdTE, $400 million for CIGS, and $155 billion would be needed for Si.

“To put this in perspective, the cumulative cost of products that the Si PV industry has sold until now is only around US$300 billion,” the researchers said.

“While a handful of thin-film companies are successfully competing at utility scale, market entrants may require experience in alternative markets before expanding to utility scale,” the NREL study said. “This concept is often discussed in the PV community, but potential markets and their requirements are difficult to determine.”