Device that measures the power loss due to dirt in photovoltaic cells

A big problem facing solar panels is that the accumulation of dust on them ends up significantly reducing their energy performance. Knowing when it’s worth doing a panel cleaning and when it’s not, would save time and money.

The Polytechnic University of Madrid (UPM) in Spain and the French Atomic Energy Commission (Commissariat à l’énergie atomique et aux énergies alternatives – CEA) have just obtained a joint patent for a device capable of characterizing a substrate in an environment dirty. The co-inventor is Miguel Ángel Muñoz García, a professor in the Department of Agroforestry Engineering at the Higher Technical School of Agricultural, Food and Biosystems Engineering (ETSIAAB).

This patent is the result of a research stay in which Professor Miguel Ángel Muñoz García spent 3 months in 2019 at the French National Institute of Solar Energy (Institut National de l’Énergie Solaire – INES) located in Chambéry, a town in the French Alps. This institution is the equivalent of the Center for Energy, Environmental and Technological Research (CIEMAT) in Spain.

The patented device is capable of measuring dirt continuously, that is, while it is being deposited in the photovoltaic cell. In this way, the fouling process can be measured and how it affects the power that the cell itself is capable of generating. Until now, the cell was dirty in the chamber and then the loss of power was measured. This could cause some dirty particles to fall or become airborne when moving the dirty substrate between the chamber and the measurement station. For this reason, subsequent tests could prove inaccurate or even unusable. With this advance, it is intended to put an end to these inconveniences since it avoids the risk of particle loss, which translates into greater precision of the measurements. To achieve this, it simulates a dirty environment; that is, it creates a dust deposit that serves as a dirt test, in which the natural phenomena of dirt are reproduced, regulating aspects such as temperature and humidity. It is at this time that fouling particles are sprayed onto the substrate, such as a cloud of dust.

Solar panel. (Photo: Bruce Avera Hunter/USGS)

The main novelty is that the measurement equipment has a source that generates a beam of light along the optical axis, as if it were sunlight, so that it allows assessing how the cell loses power while the dust is deposited. on the lens itself. The patented part of the device includes a sliding film that prevents dust from accumulating. This protective film is cleaned as it goes by and allows the lens to be clean at all times.

The main objective is none other than to avoid the loss of power of these photovoltaic cells. Something that occurs more frequently in rural environments, where the power loss can be around 5-10%. Therefore, it is precisely in these areas where this device finds its greatest utility.

Currently, work has resumed on a new, more advanced and automated prototype that was slowed down by the outbreak of the pandemic. (Source: UPM)