Solar thermal energy, Hydrogen economy, Radiation

Experiment Three

Investigating the effect of temperature on the output of the polycrystalline cell

In this experiment, I investigated the effect of the temperature of the cell on its output. Temperature affects semiconductors in a way that it affects no other material: they are semiconductors because at room temperature there is sufficient energy to thermally excite some of the electrons, thus giving them a slight charge-carrying capacity and making them semi-conductors. The important thing about this is that doping the semiconductor with atoms that have more or less outer-shell electrons will increase or decrease the number of electrons available to carry charge significantly and have a huge effect on the conductivity of the semiconductor. Another important result of this is that their conductivity varies with temperature. I therefore predict that they will perform better at higher temperatures. I have not tried the other two cells due to the time-consuming nature of the experiment, and I would expect the results to be the same for all cells anyway.

Experiment Four

Investigating the effect of the angle of incidence on the relative power output of the polycrystalline silicon cell

The nature of the experiment meant that the light was reaching the cell at different angles on different regions of the cell. In a real situation, the light reaching the cell would consist of parallel sunlight, diffuse light scattered by the particles in the atmosphere, and reflected light from the surroundings. This led to an interest in investigating the effect of this, other than mathematical, on the power output of the cell. Also, as I was carrying out the investigation, I realised that if the angle affected the utilisation of the light, this could have an even larger effect on my results than the dispersion of light and consequent uneven distribution over the surface of the cells. This could mean that, not only were the smaller cells getting more intense light, but...
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