Smart cities: a smart niche for thin film?

The creation of hundreds of smart cities across Asia might sound like a boon for thin-film-based building-integrated PV but experts remain doubtful of the niche’s potential.

The fact that renewable energy integration is frequently cited in relation to...

An upcoming Asian smart-city boom may boost awareness of energy-related issues but is unlikely to create a rush for thin-film-based building-integrated PV (BIPV), experts say.

India is planning to create 100 sustainable cities under a plan unveiled in the new government’s first budget this month. And China already has nearly 200 smart city pilots underway, according to reports.

The fact that renewable energy integration is frequently cited in relation to smart city development might be taken as a sign of a forthcoming uptick in BIPV, a niche traditionally seen as being attractive for thin film because of the technology’s flexibility and aesthetic qualities.

But insiders point out that BIPV has always been high on potential and low on delivery, not just for thin film but also for crystalline-silicon (c-Si) products. Back in 2012, NanoMarkets predicted the global BIPV market would be worth more than USD$5bn by 2015.

Another firm, Transparency Market Research, estimated an 11.4GW market by 2015, with compound annual growth of 56%. This growth does not yet seem to have materialised.

Building-integrated market

“A lot of the thin-film community hoped the building-integrated market globally was going provide a lot of opportunities for them a couple of years back, when module pricing went way down,” says Dr Finlay Colville of analyst firm NPD Solarbuzz.

“Then most of them realised there isn’t really a BIPV market of any note anywhere for them to go after. Any market that is dependent on building-integrated is going to be a really small and really slow-developing market.”

Today, he adds: “There could be some niche advantages for thin-film building integration. But building-integrated anywhere around the world tends to be one-off, customised solutions where the price point is well above any standard building-mount or rooftop application.”

It is far from clear whether the current trend towards smarter cities will change that.

While carbon emissions reduction is certainly a feature of many smart city blueprints, the prime objective of most plans is to improve intellectual and social capital through the application of information and communications technologies, such as wireless networks.

Renewable sources

When it comes to energy, planners are primarily concerned with introducing more efficient systems to reduce consumption, rather than switching to renewable sources.

And in leading smart cities such as Barcelona, Spain, or Songdo, Korea, even though there is a growing use of renewable energy there is a sense that solar power is still typically only present in a few landmark deployments rather than being routinely specified in new construction projects.

Elsewhere, a lack of agreement on what actually constitutes a smart city could allow many authorities to apply the badge to token projects that do not really meet credible criteria for sustainability. The pace and extent of true smart city development is open to question.

For example in India, says says Madhavan Nampoothiri, of RESolve Energy Consultants: “The smart cities announcement is exciting on paper, but will take at least a year or two to really take off because of land acquisition issues and the initiatives of the respective state governments.”

Furthermore, he adds: “Assuming that the smart cities really take off, I am not very bullish about BIPV, given the low energy output in comparison to c-Si.”

However, technologies in the BIPV space are improving for efficiency and cost.

One example is Prism Solar, which focuses on bifacial products where it sees up to 40 per cent more energy than can be produced than compared with the front face of monfacial products.

According to a recent interview conducted by PV Insider acceptance was slow at the outset since bifacial modules have typically been 2 to 3 times the cost of monfacial modules and their backside only had 60 per cent of the STC power of the front side. "However, as our technology has matured, we are now less than two times the cost and our backside power averages 95 per cent of the front side. So the economics have changed in our favor for many of our applications," said Jerry Hughes, Prism Solar’s director of sales and marketing.

Smart city planners

In China, too, there are strong reasons to believe smart city planners will rely on native c-Si products rather than using thin film for renewable energy generation.

With c-Si superpowers such as Yingli Green Energy, Trina Solar and JinkoSolar dominating the PV landscape, it seems highly unlikely architects would resort to more expensive, imported thin film to power their smart city creations.

One company that might swing the balance somewhat, however, is Hanergy.

The Beijing-headquartered power giant is claiming to be ‘the world’s largest thin-film solar power company’ after unveiling plans earlier this year for a 3GW copper indium gallium selenide (CIGS) module manufacturing plant in Hebei Province.

The facility, which will churn out panels based on the manufacturing processes Hanergy acquired from stricken thin-film players MiaSolé and Solibro in 2012, will dwarf First Solar’s 1.8GW capacity. And Hanergy can claim smart city credentials, of sorts.

Electric vehicle charging

In April, it signed a deal to provide PV systems for the Chinese vehicle charging network being built by Tesla, a leading US electric car maker.

“The system uses the CIGS thin-film PV technology, the most advanced in the world,” claimed Hanergy in a press release. “With conversion rates peaking at 20.5%, this technology offers light weight, flexibility, excellent low-light performance and advanced packaging.

“More importantly, no fixed column is required, which significantly reduces the cost.”

But even if Hanergy’s carport initiative remains a far cry from the widespread use of thin film in BIPV, it is encouraging to see the technology being chosen for at least one application that smart city planners could approve of.