Photovoltaic cells designed to blend in with terracotta roofs

David Eldridge
EUROPEAN PLASTICS NEWS

Published: June 3, 2013 11:15 am ET
Updated: June 3, 2013 11:30 am ET

Image By: Wegalux SpA Wegalux SpA injection molds its Wegalux tiles to integrate seamlessly with Italy's terracotta rooftops

Related to this story

Topics Construction Sustainability Injection Molding
Companies & Associations

The black uniformity of photovoltaic (PV) cells is an increasingly common sight on the rooftops of European buildings. They are a sign of our growing desire for renewable energy, but their appearance has not been welcomed in regions where traditional tiling is valued.

In Italy, which is famous for its terracotta rooftops, Wegaplast SpA has answered the problem with a plastic roof tile with integrated PV cells which is colored to match traditional ceramic tiles.

Wegaplast, based in Toscanella di Dozza, near Bologna, injection molds its Wegalux tile in Luran S, Styrolution's UV-stabilized acrylonitrile styrene acrylate (ASA) copolymer. The Wegalux tile comprises the molded housing and a solar module with two polycrystalline cells. The tile is the same size as a normal tile and can be integrated seamlessly into new or existing roofs.

Ugo Rigon, sales director of Wegaplast's Wegalux division, said: "The PV system can be applied to any sloping or ribbed roof that has Marseille terracotta tiles, which are very common in Italy. Our Wegalux tile is the perfect way to obtain energy from sunlight – even in historical districts and places where it is essential not to obstruct the local scenery."

Styrolution, based in Germany, worked closely with Wegaplast to ensure UV-resistance and weathering performance would enable the tile to withstand the Italian weather. The Luran S grade has high dimensional stability and good resistance to temperature fluctuations.

Luran S grades and their blends with polycarbonate have been impact-modified with acrylic ester rubber, making them suitable for components that are exposed to rain, wind and weather.

Marko Blinzler, product manager, specialties, at Styrolution, said: "As well as being resistant to sunlight, our product also withstands adverse weather conditions, thus offering optimal solutions to even the most demanding architects, designers and builders in terms of surface quality."

The need to meet aesthetic requirements was crucial for Wegaplast.

Rigon said: "Luran S' aesthetic qualities were a decisive factor for us, as Styrolution was able to provide us with the exact shade we needed to make our solar tiles fit in harmoniously with non-PV ones. This pre-colored solution saves us time and costs."

Volker Pieper, Styrolution's business development manager with responsibility for the construction market, said: "The real driver was to integrate a solar cell into the normal design of a house."

He told European Plastics News: "The basic idea was to make the solar cell 'disappear' on the roof, so it does not disturb the aesthetic of Italian villages with black solar cells, but instead it is integrated into the shape and color of existing tiles."

The PV cells are easy to mount on any roof because they are part of the tiles.

A major challenge for outdoor applications is color change over the lifetime of the product's use. ASA has good resistance to yellowing and Styrolution also supplies UV protection packages that are added to Luran S.

For the Wegalux tile, Styrolution conducted xenon tests which simulated 10,000 hours of sunlight exposure. Testing has continued to gather data for longer periods.

The Wegalux plastic tiles will be mounted close to ceramic ones. It is likely that after a large number of years there will be some color deviation as the two materials age in different ways and the shades of terracotta start to vary. But Styrolution does not think this will be significant.

"We believe the color deviation will be acceptable and it will be small enough that you can combine ceramic and plastic on one roof," said Pieper.

He said that after five years of exposure to sunlight, Styrolution expects the tile's color deviation to have a dE value below 5 in the CIELAB color space system. A value above 5 indicates a visible difference in color.

Styrolution is supporting Wegaplast as it develops the second generation of Wegalux tiles, which aim to be more efficient. The first generation already achieves a good performance – producing 1kWp of electric energy requires 10 square meters of Wegalux roofing, equivalent to 128 tiles.

Luran S is targeted at a number of sectors, including automotive exterior parts. In the housing and construction sector, Styrolution is seeking out niche applications. Pieper said the company's targets in the sector are linked to special outdoor applications which are still in development.


Comments

Photovoltaic cells designed to blend in with terracotta roofs

David Eldridge
EUROPEAN PLASTICS NEWS

Published: June 3, 2013 11:15 am ET
Updated: June 3, 2013 11:30 am ET

Post Your Comments


Back to story


More stories

Image

Economic déjà vu: strong spring growth expected after a rough winter

April 15, 2015 2:03 pm ET

The long, harsh winter is finally over, and the first quarter of the calendar is history. So now is an appropriate time to review the emerging trends ...    More

Image

BASF bullish on North American auto market

April 13, 2015 11:44 am ET

The North American performance materials unit of BASF SE expects its 2015 growth to come from the automotive, consumer and industrial markets.    More

Market Reports

Plastics Recycling Trends in North America

This report is a review and analysis of the North American Plastics Recycling Industry, including key trends and statistics based on 2013 performance. We examine market environment factors, regulatory issues, industry challenges, key drivers and emerging trends in post-consumer and post-industrial recycling.

Learn more

Injection Molding Market Analysis & Processor Rankings

Plastics News BUNDLED package contains our in-depth Market Analysis of the Injection Molding segment. You will gain keen insight on current trends and our economic outlook.

As a BONUS this includes PN's updated 2014 database of North American Injection Molders RANKED by sales volume. Sort, merge, mail & prospect by end market, materials processed, region, # of plants and more.

Learn more

Plastics Caps & Closures Market Report

The annual recap of top trends and future outlook for the plastics caps & closures market features interviews with industry thought leaders and Bill Wood’s economic forecast of trends in growing end markets. You will also gain insight on trends in caps design, materials, machinery, molds & tooling and reviews of mergers & acquisitions.

Learn more

Upcoming Plastics News Events

June 2, 2015 - June 3, 2015Plastics Financial Summit - Chicago 2015

September 15, 2015 - September 17, 2015Plastics Caps & Closures - September 2015

More Events