INTRODUCING THE CHALLENGE
The world is progressing towards adopting more renewable energies, not only because of ethical issues or the tend to care about the environment but also for economical reasons. It’s widely available in the MENA region with a great technical potential. One of these renewables is solar energy.
The performance of solar photovoltaic panels is highly affected by the intensity of solar radiation, as well as other climatic conditions such as ambient temperature, dust, and humidity. Dust, in particular, is one of the solar PV panel’s enemies and has a major negative influence on performance. In this article, we discuss the impact of dust accumulation on solar PV systems.
UNDERSTANDING THE IMPACT
Dust -a term generally applied to minute solid particles with diameters less than 500 µm – is an important factor in the case of solar collectors because of its ability to affect the permittivity at the surface of the solar PV cell. For this reason, we need to focus on dust control as a challenge and look for expected solutions.
An experiment by Hussain, Batra and Pachauri estimated that the reduction in PV systems performance due to dust accumulation is 60%. Other studies calculated a value of 40% and pointed out that the mean value of daily output reduction is 4.4% in the absence of rain.
Controlling dust is a challenge because of its complex optical, biological and electro-chemical properties. In addition, the electrostatic attraction of dust at the surface of the PV module also poses a challenge in developing dust control strategies. Furthermore, dust is not uniformly distributed at the PV module and hence, this impacts the cleaning frequency and the fineness of the glass surface.
The orientation of the solar collector and its impact on the air flow factor is also another parameter that influences the aerodynamics of dust accumulation on the surface a PV module, that must be considered in dust control strategies.
LOOKING FOR A SOLUTION
Hussain, Batra and Pachauri have reviewed dust control strategies in the scientific literature and presented several examples. Their review highlighted that water cleaning with a brush is the most effective cleaning method in terms of results. In dry seasons, the efficiency of this method reaches 97.2% and further increases in rainy seasons.
One method to control dust on the surface is suggested by B. S. Yilbas. The method is to design a “new coating towards dust repelling with enhanced optical transmittance characteristic”. This method will require changing the texture of the surface (the solar panel) and will affect the energy yield of the PV module.
M. Mani and R. Pillai have provided a helpful tool to decide the cleaning frequency of the PV module based on an experimental method considering the climate zone and the conditions for least dust accumulation like tilt angel, and presented recommendations for cleaning.
CRITICAL DISCUSSION ON THE REVIEWED PAPERS
By examining the scientific literature, we found that few studies covered long periods of dust accumulation and several studies were small scale experiments. Our review here was limited in coverage; however, we expect a growing awareness about dust impact on solar energy systems as solar energy applications are spreading in Middle East.
Although all the studies presented solutions and/or recommendations; yet, from a managerial point of view, only few studies provided analytical tools that helps us determine the cleaning frequency and thus control the cost of cleaning the solar panels. So, we think we’re still at the beginning of studying the impact of dust on solar panels and more research has to be done to come up with better solutions.
POTENTIAL FUTURE EVOLUTION
In the future, we expect more experimental research on PV modules with self-cleaning capabilities. Different solutions come every time with more advanced technology. I have seen them in different exhibitions taking place in the UAE.
Taking advantage of nature is a good option but we are always facing instability and difficulty of predicting events of nature. However, it is possible to take advantage of weather conditions to get rid of dust by exploiting the aerodynamics of dust accumulation. The evolution in this method will require studies over a long period of time.
In general, for an emerging technology like solar energy, research, on solving these challenges, will never stop. Awareness through updating our knowledge is required among the professionals and new comers to the renewable energy field.
Interested in reading the complete study? Reach out to Zulfa through her email: [email protected].
Author Bio: Zulfa Rasheed is my name, an electrical engineer who supports clean energy. With a Master of Engineering degree in engineering management from Rochester Institute of Technology (RIT). I glad that I was one of the UNESCO participants in an environmental excursion between Ethiopia and UAE 2015-2016. My recent project was conversion of Ready-Mix concrete plant energy consumption to solar energy. What is this? It’s a contribution to encourage heavy-industry to go solar. I’m interested in Solar PV and ready to support solar initiatives around the world. To increase awareness, to increase willingness for adoption of Solar technology. That’s why I’m here.
- M. Mani and R. Pillai, “Impact of dust on solar photovoltaic (PV) performance: Research status, challenges and recommendations,” Renewable and Sustainable Energy Reviews, vol. 14, (9), pp. 3124-3131, 2010.
- B. S. Yilbas, “Why environmental dust influences solar energy harvesting,” International Journal of Energy Research, vol. 43, (1), pp. 4-8, 2019.
- N. Boddupalli, G. Singh, L. Chandra, B. Bandyopadhyay, “Dealing with dust – Some challenges and solutions for enabling solar energy in desert regions,” Solar Energy, vol. 150, pp. 166-176, 2017.
- A. Hussain, A. Batra and R. Pachauri, “An experimental study on effect of dust on power loss in solar photovoltaic module,” Renewables: Wind, Water, and Solar, vol. 4, (1), pp. 1-13, 2017.
Featured image credits: https://adlbuildingservices.com.au/services/cleaning/solar-panel-cleaning/