Kaixo, classifier of photoelectric cells

Currently there is great talk of renewable energies and, amongst these solar energy is highly important. In order to harness and utilise this form of energy there are many technologies available of which one is solar panels. These panels are made up of photoelectric cells (the 80-100 little square units in any one panel).

Photoelectric cells are classified according to the power they produce, given that total power production of any panel can be limited by just one photoelectric cell of lower power production. Why is this? Because this cell has a maximum current and does not allow the transmission of more. The total current – and power – of the panel is thus limited.

From prototypes to machines

In the 90’s, in response to a request from the Isofoton company, the Bilbao Institute of Microelectronic Technology, TiM, proposed the development of an advanced system for the measurement of photoelectric cells. This photoelectric cell classifier was named Kaixo (“Hello” in the Basque language).

The initial proposal was shortly transformed into a prototype. But this prototype, although carrying out measurements correctly, was not completely automated.

But, in 1998, given the then development of renewable energies, many companies underwent considerable growth, Isofoton amongst them. So much so that today Isofoton is the first in Europe and seventh worldwide in the manufacture of photoelectric cells. That same year, Isofoton commissioned TiM a second prototype.

That second prototype had to be more automated and more precise than the first. To this end, light and temperature stability had to be far more strictly controlled. Also, the second prototype had to be suited to the industrial world, so that maintenance operations could be efficiently carried out and the classifier easily inserted on the photoelectric cell production line, in a more automated manner.

6 or 7 machines of the new prototype have been made. These machines measure the 60,000 photoelectric cells which Isofoton manufacture daily. Moreover, these measurements can be carried out while the cells are being manufactured, without interruption to the production line. Thus, if a defective cell is produced, the process by which the defect arises can be identified. Before the existence of the prototypes, all measurements were carried out manually, automation meaning much better precision in measurement and a significant saving in time.

Better solar panels

Currently there are a number of research projects under way which are targeting the increase in power produced by each cell. This is because to meet the energy needs of a family home, solar panels of about 20-30 m2 are required. If the power potential of the cells can be increased, the size of the panels could be reduced. This is important considering that the greater the surface area of the panels, the greater the cost (more cells are needed, more wiring, more glass, etc.).

For the immediate future TIM will continue to carry out research to enhance and optimise manufacturing processes, to obtain more efficient cells and a more automated industry.

Notes

Project director:
Juan Carlos Jimeno eta Victor Martinez
Research team:
J.C. Jimeno, V. Martinez, R. Gutierrez, F. Recart, G. Bueno, F. Hernando, Mª J. Saenz, Mª V. Rodriguez, C. Ikaran, S. Uriarte
Faculty:
Technological Institute of Microelectronics

Contact :
Garazi Andonegi
Elhuyar Fundazioa
garazi@elhuyar.com
(+34) 943363040