Dust is a natural material derived from the degradation of materials such as rock, soil, and organic substances. The generation of dust is often accelerated by human activity such as land clearing, development, earthworks, mining, agriculture and traffic. Dust affects many processes, and depending on the components in the dust, can cause severe health and operational issues. As we are slowly witnessing the transition of energy dependence from fossil fuels to renewable energy, dust will still continue to pose as an issue.

IMPACT OF DUST ON SOLAR POWER GENERATION

Photovoltaic (PV) cells operate by absorbing photons (particles of light). The electrons are then separated from their atom and are captured. The movement of these electrons across a wire results in electricity, to power our homes or heat the coil that boils water etc. However, electricity generation from PV cells like all machines and systems – they absorb energy at a certain rate depending on a number of different factors. These factors include the intensity of light, the position of the PV cell, chromatic aberration (atmospheric interference) and condition of the glass of the PV cell.

It is logical to understand if it’s a cloudy day, the clouds absorb and reflect the sun’s rays and reduce the number of photons that the PV cell can absorb. The same goes for the direction. If the PV cell is facing North, and the sun rises in the East, the quantity of sunlight will not be optimal. We are, to a degree, able to make adjustments to increase photon absorption, such as placing the PV cell on a guidance system that moves the PV cell relative to the rotation of the earth (meaning where ever the sun is facing, the PV cell is facing the suns direction). However, in other cases, such as the weather, we cannot adjust.

There are a number of circumstances where PV absorption can be minimised, which are due to environmental factors. Through the concept of entropy and the destructive forces of our nature, PV cells are bound to get dirty. The system is outside, which means it is exposed to intense sunlight, heavy rain, dust events, dirt from wind, pollen, debris and bird faeces, all of which can block the sun. In particular, dust can affect solar panels by providing a film over the PV cell which directly affects the permittivity of the technology. If this dust comes into contact with water through rain, it can create a muddy coat over the PV glass (the severity of the dust is dependent on the angel of PV cell array). The physical barrier between the sun and the PV cell will drastically decrease the cells ability to absorb energy. If the dust cover is severe, the rate of photon absorption by the PV cell can drop by 60%, and in some cases up to 85%. The major challenge to this issue is due to dust’s electrostatic attraction, which makes it difficult to develop effective dust control strategies.

At the moment there are a number of short term solutions, such as physical cleaning, and introducing a new coating to enhance dust repellent (however this is difficult without affecting the energy yield of the PV cell). It is recommended that if physical cleaning is the method of choice, that it is done approximately once per month. There have even been speculative studies that involved using the lotus leaf, which has specific self-cleaning properties that utilise microscopic forces and mechanisms that can be optimised to remove dust from solar panels (however this is in its early research). Other solutions include water blasting, by utilising trucks or tractors, however, this is costly, and is not deemed a long-term solution. However, GRT developed solutions to stop dust at the source which is not only a long-term solution but also a cost-effective one.

GRT-dust-control-solar-panel
GRT:Enviro Binder used in solar farms to control erosion and dust

IMPACT OF DUST ON WIND POWER GENERATION

As mentioned before, dust is everywhere, in the environment it is impossible to remove it completely out of the equation. Yes, there are certain mitigation techniques and measures that can be implemented, however, dust is and has been, a long term issue for all construction, mining and energy industries. The impact of dust does not only affect solar, but there have also been numerous studies undertaken on the impact of dust on wind turbines. Wind turbines operate by wind pushing on the curvature of the turbine’s blades to force it to rotate on an axis that drives the turbine in the body of the wind generator. Once the electricity has been produced, the turbine transports this electricity into large battery systems, which are then distributed to the community or plant.

One of the most critical components of the wind turbine is the large rotating blades, as they have direct contact with the wind. If they do not function effectively, the whole system falls apart. Even though these larges structures are located almost over 100m into the air, over time they too become dirty and develop a film or accumulation of dust on the surface. When the winds are low, birds can use them to sit on, and their droppings can affect the texture of the blades. Studies found that the roughness of a turbines blade impacts the way it interacts with the wind and is directly related to the quantity of electricity that is capable of producing. The turbines are not able to effectively utilise the winds power to efficiently move the blades if the texture of the blades are rough from dust, bird droppings or debris. If this is coupled with an increase of the drag force of the airfoil, the rates of power generation significantly drop. Subsequent studies also confirmed these findings but also found evidence of a decrease in lift force of the blades, which directly affects the power output of the turbine. The lift force affects the initial capability of the turbine to initiate rotation. In severe cases, the dust has altogether stopped the turbines, due to the increased mass that resulted from dust accumulation. This has forced energy companies to close turbines for maintenance and safety concerns, which decreases production rates.

Due to the costly maintenance issues, studies were further conducted to track the origin of the dust. Results indicated that the majority of the dust was sourced from untreated gravel roads throughout the area. These large turbine structures are usually found in highland or isolated areas away from large cities. Many of these locations aren’t highly populated, and in some regions still rely on gravel roads. There is a technology currently on the market that is capable of reducing the quantity of dust suspended from gravel roads.

Are environmental regulations, health and safety concerns or potential profit loss a concern right now?

Stopping the Problem at the Source – GRT Dust Control

Global Road Technology has produced some of the most innovative solutions that directly reduce dust suspension on unsealed roads and broad-scale open areas. These technologies have been applied and proven in these specific renewable industries, but also across the oil and gas, mining, civil, and rural industries. GRT’s technology can be applied across the fields in most circumstances that involve dust control.

As we can see even as the energy dependency shifts from coal to renewable, untreated dust will continue to be a burden. However, with technology such as those developed by Global Road Technology, the impact of dust and erosion can be managed cost-effectively and efficiently.

To close the article, a profile of three of the key products developed with particular application into the renewables sector is included below:

1. GRT: Enviro-Binder

Material Type: Environmentally friendly liquid polymer

Application: Applied to exposed soil for water and wind erosion. From open batters to areas of concentrated water flow such as V drains (road ditches).

Other uses include: preload embankment protection, stockpile and bunds, and catch banks.

Mechanics: The product binds with soil and as a result forms a complex interconnected structure with granular surface particles.

Length of effect: Guaranteed to work up to 6 months once applied, but has performed up to 24 months.

Other features include: Waterproof, can be used in environmentally sensitive areas, minimal environmental impact, versatile product and can be utilised for multiple circumstances.

For more information – Visit GRT: Enviro-Binder

2. GRT: Wet-Loc

Material Type: non-drying, long-lasting, totally waterless and non-setting, synthetic fluid.
Application: Site access roads and laydown areas.

Other industry uses include: underground mining roads, areas of heavy damaging traffic such as tracked machinery routes, and race tracks (speedways and even horse and camel tracks).

Mechanics: adsorbs into soil particles preventing them from becoming airborne.
Length of effect: Up to 12 months

Other features include: UV Ray resistance, water/storm resistant, non-hazardous, biodegradable, self-healing, and robust.

For more information – Visit GRT: Wet-Loc 

3. GRT: Soil- Loc

Material Type: Long Chain Polymer Technology

Application: protects large open areas in the resource sector, civil construction and land development from wind and rain erosion.

Mechanics: Diluted in water and added with agitation or into flow water. This GRT product acts as a protective layer on top of resources or stockpiles, to protect it from erosion. In high seasonal wind or storm events, over 50-100mm of materials can be eroded from the surface causing degradation and transportation of unwanted dust and contaminants. GRT Soil-Loc minimises the loss from such events.

Length of effect: Dependent on the intensity and frequency of events.

Other features include: non-corrosive, non-flammable, non-volatile, water-resistant, and allows topsoils to still absorb moisture from irrigation or rain without removing the soil.

For more information – Visit GRT: Soil-Loc 

 

For more information on Global Road Technology products please visit: https://globalroadtechnology.com/

References:
https://cleanenergy4africa.wordpress.com/2020/01/20/solar-energy-and-dust-control/
https://www.soilsolutions.com/a-study-on-the-real-effect-dust-has-on-wind-power-efficiency/
https://www.lenntech.com/abstracts/1671/effect-of-dust-on-the-performance-of-wind-turbines.html
https://www.energymatters.com.au/panels-modules/cleaning-solar-panels/
https://www.solarquotes.com.au/blog/solar-panel-cleaning/
https://energyinformative.org/solar-panel-cleaning/
https://www.sciencedirect.com/science/article/pii/S1876610214007425
https://www.energymatters.com.au/renewable-news/solar-panels-cleaning/