Africa’s land is diverse with large parts of its land being either desert, arid or semi-arid, windy and with no access to the national electricity grids hence a potential market for off-grid and isolated solar PV systems.
However, most these desert, arid and semi-arid regions, which for example in Eastern Africa make up more than 80% of the total land area, though being suitable for the development of solar PV technologies, are also known to be harsh environments with potential to impact on the sustainability of installed solar PV equipment and their performance.
In addition, to these dry regions, East Africa has other areas considered to have harsh conditions for solar PV systems such as pollution, found near industrial premises. There are also areas with extremely high salt, such as those near the sea, that can cause corrosive effects on the equipment.
“The most prominent harsh climatic conditions someone has to take into account when planning and building a solar PV plant in East include local wind conditions, close proximity to the sea, and industrial urban areas,” said Prof Izael Pereira Da Silva, the Acting Deputy Vice Chancellor Research and Innovation at the Nairobi-based Strathmore University.
The university owns and operates the Strathmore Energy Research Centre (SERC), a research centre within the University that does quality research, technical training as well as consultancy services in the renewable energy sector in East Africa.
The importance of mounting and power electronics
The centre has been picked by German manufacturer of solar mounting systems and PV module fasteners Schletter GmbH and also German manufacturer of solar inverters SMA Solar Technology to train solar PV consumers, suppliers and installers on their equipment.
“It is important to take into account local wind conditions when developing the structural design of the mounting structure (close to the sea are predominantly stronger winds, up to 54m/s),” said Da Silva.
“Insufficient structural strength will result in modules becoming lose, hence a big risk to personnel and down time of the plant,”
Prof Da Silva said most of the suitable but harsh environments in East Africa are those close to the sea and which “because of their high salt content in the air require right materials to be chosen for solar mounting.”
“Degradation of a protective zinc layer on steel (pre or hot dip galvanized) will be reduced in severe marine condition of up to 30 micron/year, meaning even a protective layer of 90 micron will be used up within three years,” he said.
He recommends the use of aluminum-made solar mounting equipment in such harsh conditions.
Prof Da Silva said the solar PV systems mounted near industrial areas in urban regions are subjected to harsh conditions “because of the corrosive effect on solar PV plants and mounting structure during the minimum life span of 20 years.”
He explained that solar panels are either mounted onto the roof or on open space but whichever way is used “wind force, corrosion and soil condition need to be taken into account, to arrive at the right structural design and choice of material.”
“It also becomes important to use module clamps which are certified by the module provider as this is important in terms of bankability and insurance claims.”
Off-grid market operators and companies should adapt to harsh environments in their drive to ramp up capacity in such areas by “using proven concept suppliers of inverters, modules and mounting structures and also training of service providers.”
East African countries such as Somalia, Ethiopia, Sudan, South Sudan, Uganda, Tanzania and Kenya have large swathes of land prone to high temperatures and increased but unpredictable UV irradiation, which is known to accelerate degradation of polymers for PV cell packaging.
In countries such as northern Kenya, Ethiopia and Somalia, large areas experience abrasive airborne dust that could collect on solar PV module faces leading to loss of power translating into low earnings for the commercials PV systems operators.
The dry areas are synonymous with prolonged dry periods when the temperatures soar to an all high and dust covers the atmosphere most of the time, a recipe for stalling solar PV systems especially where cleaning of the PV equipment and modules is a new phenomenon and if done, it is rare and far between.
The importance of O&M
Apart from considering the right structural design and choice of material for the solar PV systems mounting in these harsh environments, operations and maintenance (O&M) is also important.
With the acute water scarcity in Eastern Africa’s dry regions, the cleaning of solar PV modules remains a major challenge but which experts say is necessary if the equipment’s performance is to be optimized.
Low-quality systems in the market
While it is important to light up these off-grid areas, a serious challenge is the presense of poor quality solar PV systems in the market that have little capacity to withstand the challenging environments.
In Tanzania, for example, Lighting Africa, which is part of the World Bank Group, says the country’s energy sector regulatory bodies have “limited ability to effectively enforce standards.”
Lighting Africa says in a previous report in Tanzania solar PV segment that although the country has regulations for enforcing standards on the quality of solar systems, there have been challenges in implementing the rules and where attempts have been made, they remain “unsystematic and the evidence is clear from the proliferation of sub-standard electronic products all over the country.”
Written by Shem Oirere, a freelance writer based in Nairobi, who specializes in renewable energy.