A vibrant team of researchers and engineers is nudging Malta toward the frontline in solar energy innovation.

The University of Malta’s Institute for Sustainable Energy based in Marsaxlokk now boasts a world-class solar research lab. Led by Prof. Luciano Mule’ Stagno, the laboratory is tucked demurely to one side of the bay in renovated ex-military barracks, converted to house over 40 pieces of cutting edge equipment.

Research has started at the lab to find ways of improving efficiency in solar energy systems and making them cheaper. The benefits are not just for Malta but for the entire world as nations wean themselves off fossil fuels.

Efficiency in solar panels has been inching higher worldwide as competing manufacturers try to outdo each other. Even small improvements can give one supplier an edge over rival firms with any gain multiplied as production of solar panels runs into the millions.

As a PhD student at Missouri’s University of Science and Technology in 1991, Prof. Mule Stagno studied defects in silicon, used for the production of photovoltaics. Working with the pioneering firm MEMC, (now SunEdison), he continued research on silicon wafers for integrated circuits/solar cells and is the author of nine patents held by the company.

Returning to Malta with a solid background as a solar research scientist after working in the United States, Asia and Europe, Prof. Mule Stagno first took the initiative to apply for European Regional Development funding for the laboratory in 2010. 

The application to research ways of improving solar panels was made in response to a call for projects related to climate change. But the Maltese government had already applied under the same scheme for several projects of national priority. The bid for funds to equip a solar research lab had to wait until a second try under the next call.

The grant for €4.2 million finally came through but getting the solar research lab up and running within barely 18 months was a tight deadline to meet.

By 2015 all the equipment had been procured for the study of defects in semiconductors and other solar materials. The fully equipped laboratory now has the ability to build its own solar thin films and basic solar cells for testing.

There are few solar materials research laboratories in the world which surpass it...

The main object of study is to detect miniscule defects in the silicon ‘wafers’, used for production of solar panels. Impurities such as undesirable atoms of another material (carbon or oxygen) can lower the performance of integrated circuits.

Silicon is grown industrially as a crystal. Defects so small that they are at the atomic level can lower efficiency of silicon cells. Problems may appear early in the growing stage of the silicon crystal. Worst affected are high end solar cells. In semiconductor devices, the smaller the chip, the more a defect in materials is likely to be problematic.

A long term goal for the ISE laboratory is to eliminate these problems for industry while keeping costs down.

Emerging photovoltaics

There are many different types of thin films for making PV cells. None has yet beaten silicon for low cost, durability and efficiency.

Solar energy is already becoming cheaper than fossil fuels in desert countries like Mexico, Chile and the Emirates, where sunshine is plentiful and land is massively cheap. It is every solar researcher’s dream to develop new materials which could lower the cost factor by two, or even four times. Then solar energy would become the obvious choice for all without the need for incentives.

Researchers are working steadily toward the day when lower costs and raised efficiency could push the payback time for PV panels to within six months.

The Marsaxlokk laboratory now has the equipment to study and make thin films. The solar research lab is looking at new materials with an aim to developing the next generation of solar cells.

Microscopic analysis of salt drying on panel surfaces carried out by student Laura Gretowska.Microscopic analysis of salt drying on panel surfaces carried out by student Laura Gretowska.

Perovskites (discovered by a Russian named Perovski) have been around for a long time but their photovoltaic properties were not discovered until about six years ago. Among other tools, a plasma chamber has been built at the lab to prepare perovskite samples. From a cost of around €100 to make a conventional solar panel, the use of perovskites could bring it down to just a few euros. However there are still some problems with this organo-metallic material as it degrades too readily. Coming up with a way to make perovskites both more stable and more efficient could revolutionise the solar industry.

Several of these versatile tools have raised interest in university and top industry circles for testing of all kinds of samples and not only those related to solar panels.

Two systems engineers, a lab officer, an electrical engineer and another specialising in materials and mechanical engineering make up the permanent lab staff along with two academics.

Apart from the Maltese contingent, a number of foreign students will be working at the laboratory this summer as part of their Masters degree.     

Outside, on the extensive grounds, a solar tracker follows the sun across the sky, imitating a sunflower. A small black box containing a shade-detecting sensor allows the solar panels mounted on the tracker to follow the sun throughout the day for maximum output, generating an average 8 kWh.

The software which keeps the tracker locked onto the sun’s path was designed by two French engineering students. Plans are already in the pipeline for a second solar tracking model. 

The laboratory caters for a full research cycle on solar materials and systems. There are few solar materials research laboratories in the world which surpass it... “maybe only two or three”, according to Prof. Mule Stagno. This is truly an achievement of which Malta can count itself proud.

Another half a million euros in funding from the University of Malta has made it possible to set up several other research projects related to renewable energy.

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