Solar Paints, Films and Coatings - Turning the Dream into Reality
The problem with conventional solar cells and panels based on silicon is that the manufacturing process is costly and time-consuming, despite recent advances.
Various companies are hiring rooftops and developing joint ventures to benefit from feed-in tariffs offered throughout the world.
But what if you could buy roof panels with solar cells already installed and use cheap films and paints to generate solar power.
Several major research projects have been turning this dream into reality.
A team from the University of Melbourne Australia has used nano technology to make tiny solar cells that can be suspended in liquid, such as ink or paint. This suspension can then applied to a surface such as glass or plastics or metals.
Paints, Films and Coatings for Solar Future
The coatings could be integrated into the manufacturing process when the building materials are being made. You may be able to buy solar windows, solar roof and external cladding panels that can be added to new buildings or the coatings or paints could be retrofitted to old buildings.
The microscopic solar films will be made of tiny nano-crystals which have a diameter of just a few millionths of a millimetre.
There are huge savings in terms of the cost of expensive materials used to make the cells. The nano-cells will require less than 1% of the materials needed to make conventional solar cell panels.
This means that the new coating could be 20-30% cheaper for the same power output.
Dysol - Dye Based Solar films
Dysol, an Australian-based company, has been a leader in this field for many years using unconvential dye based solar capture techniques to produce films and coatings on building components.
They are about to turn their research into reality. Dysol has contracts with the giant Tata Steel company to develop various building components, such as roofing panels, claddings and steel girders with solar panels embedded in the surface.
The products should be available in two years time. In the near future, the entire outer surface of new buildings could be generating electricity.
The reduced cost will be revolutionise alternate energy, shifting it from expensive add-ons to mainstream building components that are used everywhere and become mainstream.
Solar Array Coatings produced using and Ink-Jet Printer
Researchers at Oregon State University have developed a similar approach using an ink-jet printer to make coatings and films for solar cells.
The team used what is known as chalcopyrite (or CIG) - a substance composed of a mixture of copper, two rare earth elements indium and gallium, and also selenium.
The CIG compound has a higher solar efficiency than silicon, that is currently used to make solar panels. The compound can be applied as a special ink using a common inkjet printer module to generate a thin film.
So far, the team has been able to make solar cells with an efficiency of 5% and this can be increased to about 12% or more with further research. This process is much cheaper than conventional methods for making solar cells using silicon crystals, and there is no waste.
CIGS is already used to produce solar cells but the manufacturing methods are complex, expensive and require high-tech machines and processes involving expensive vacuum systems and toxic chemicals.
While these cells have efficiencies of 15-18%, the cells made using ink-jet processes could be much cheaper, and this more than offsets the lower efficiency (5-12%).
Good, Cheap, Efficient - Choose Two
This concept is a version of the conventional Project Triangle concept used in engineering and project management - Fast, Good and Cheap, - where you can only pick two of the options.
- Fast relates to the time taken to make the product,
- Good is the products quality, and
- Cheap is the cost of building and also designing the product.
The triangle concept stresses that all three properties are interrelated. It is impossible to optimise all three simultaneously as one will always have an negative affect on the other:.
- A fast design to a very high standard - will not be cheap.
- A fast cheap design - will not be of high quality.
- A high quality design optimised for low cost - will take a long time to develop.
For solar cells the three terms are Good, Cheap, Efficient.
Much of the conventional research has been focused on making solar cells more and more efficient.
The best silicon based cells that we put on house roofs have an efficiency of 20 - 25%.
But the manufacturing costs and materials costs of these cells are very high.
When space is limited you want the cells to be as efficient as possible.
This also means that you want to place the cells in an ideal location in relation to the suns orientation and perhaps install tacking devices.
Because the cells are so expensive you need work hard at making them as efficient as possible.
However the new approaches sacrifice efficiency for reduced cost.
It you can coat an entire roof or the entire outer surface of a building with a solar film or coating very cheaply then the sheer size counteracts for the low efficiency.
Solar paints, films and coatings are about to become a reality and will foster in an era when solar power generation will be common place and a part of everyday life.
© 2011 Dr. John Anderson