Concentrated PV

Pre-fabricated lens panels from companies such as Evonik and LPI mean CPV entrants need not worry about tooling. Are standardised components the way to go for the industry?

THIS ARTICLE HAS BEEN UPDATED

Looking to set up a CPV company? In the past, one of the first things you might have to think about is buying an expensive tooling kit as part of the manufacturing line you would need in order to produce your own modules. That is one item you need not worry about now, though.

The manufacturing companies Light Prescriptions Innovators (LPI) of the US and Evonik of Germany are collaborating to provide off-the-shelf lens panels so you do not have to build your own, theoretically making things cheaper and easier for CPV start-ups.

LPI’s Ventana optical train is billed as a “complete off-the-shelf optics solution for the CPV module manufacturer and integrator” which can “eliminate the design costs, tooling costs and long lead times required to obtain optics.”

Evonik is marketing its optical train as Acrylite, although the two products share technology. The primary optical element in both is produced by Evonik using a Fresnel-Köhler design patented by LPI.

The secondary optical element, meanwhile, is made of glass in LPI’s product, and either LPI glass or Evonik’s Savosil silica glass in Acrylite. Evonik is offering the pre-fabricated product in sets of 10, 50 and 300 panels.

And Peter Marks, new business development manager of Evonik’s Performance Polymers-Acrylic Polymers business line, says it is not aimed at current CPV market leaders such as Amonix or Soitec. “In our way of thinking, they will not change,” he states.

Non-standard designs

“They have very specific reasons for non-standard designs.”

Instead, he hopes to attract the attention of new players seeking to enter the solar market, particularly in regions where the capital costs for PV projects are high, such as in India.

With off-the-shelf products, he says: “Assemblers entering the market do not have to come up with upfront money for tooling. It allows them easy entry into the market because they do not have to do optical designs or pay for tooling. Our product is a one-metre-by-one-metre box.

“The maths is easy. You can go and buy the metal stamping to go with it anywhere.” 

Marks reports there was “a lot of interest” when Evonik launched Acrylite at the CPV-8 conference in Toledo, Spain, last month, and confirms he already has orders for the product, although not in high volumes yet. “We see this as seeding the market,” he points out. 

Elsewhere, there has been a mixed response to the arrival of prefabricated components in the CPV market. Dr Shawn Buckley, founder of Focused Sun, says: “This is a step in the right direction. 

Local integrators

“To be able to get components that are difficult to manufacture from off-the-shelf suppliers could entice local integrators to use this technology.

“Having off-the-shelf components that integrators can buy means that suppliers like Evonik can move into higher volume production than their own sales could justify. Prices drop at high production, making solar cheaper for the consumer.”

That said there is still a question mark over how much value there will be in a standardised optical train for an industry that is still very much defined by a do-it-yourself ethos.

Buckley, for example, favours cutting costs by using cheap single-axis tracking mirrors to reflect light onto standard PV cells. “We like mirrors because we don’t need to transmit sunlight through an acrylic,” he says.

“I always worry about transmitting concentrated sunlight through an organic; the more photons, the faster they’ll degrade the organic.”

Acrylics should not prove a problem to most in CPV, of course. Marks notes that approximately 70% of installations currently use the material, which is half the weight of glass.

Project-specific guarantees

And for peace of mind Evonik offers a 25-year warranty on its Acrylite range, through project-specific guarantees.

But Paul Bellavoine, co-founder, managing director and chief financial officer of the French CPV company Heliotrop, doubts off-the-shelf products can add much value to the market.

To get to the point where a CPV system maker can demonstrate multi-megawatt power plant and manufacturing plant capabilities, he says: “Requires US$50 million to $100 million.

“This is a key reason why out of 200 start-ups who tried to enter the CPV field, only around 20 have emerged publicly, and only one or two will eventually succeed. Therefore, trying to save $50,000 to $100,000 for a CPV start-up is not really the point.” 

He adds: “Understanding and tuning the optical system is a key part of CPV company development, and it cannot be outsourced otherwise you just make me-too modules. PV has shown the limits of me-too companies.”

For Bellavoine, cheap off-the-shelf elements may nevertheless be of use to a small group of CPV users that are not module manufacturers, such as those involved in cell packaging, trackers, module material or design.

Giving such players a prefabricated product could probably help the CPV market. But that does not mean off-the-shelf optical trains are a game changer.