Africa is one of the world’s sunniest continents - making it a great place for solar energy! But the extreme heat can degrade the widely used photovoltaic panels. Researchers in Ghana have found a sturdy alternative.
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00:00Scratches and cracks on a solar panel from extreme heat stress.
00:05Technician Emmanuel Rozak is responsible for the photovoltaic system at a lodge in Tamale, northern Ghana.
00:12Here, the air temperature can rise about 40 degrees Celsius and the solar panels often heat up to 70 degrees in the sun.
00:20The extreme heat eventually causes a significant drop in their performance.
00:25When it was new, it was generating more power.
00:28But now that it has been cracked and then it has used for some time, the power is not sufficient enough like first.
00:41Ghana wants solar energy to make up 10% of its electricity supply by 2030.
00:48But heat stress can cut the panels' output by up to a quarter and cause them to fail earlier.
00:55Further south, in Ghana's second-largest city, Kumasi, solar energy researchers are looking for a remedy at the Kwame Nkrumah University of Science and Technology.
01:05Electrical engineer Syed Abdul Ganiu is researching ways to combat the loss of performance caused by heat stress
01:14by using a newer type of solar panel that is still largely unknown in Africa.
01:21A photovoltaic thermal collector, or PVT collector, generates electricity like conventional solar panels.
01:28But at the same time, it transfers excess heat into a system of water-filled tubes, thus cooling the module.
01:36And this heat is passed onto the water and the water can be collected from the other side.
01:41So as the water flows through it, it absorbs the heat from the panel, cooling the cells and giving it a better efficiency compared to the PV system.
01:51Put simply, PVT systems perform better for longer.
01:55We used a simulation software to simulate the output of this over 25 years.
02:01And during that period, we realized that the degradation rate over the 25 years of the PVT was predicted to be around 12.3% as against 15% for the solar PV,
02:14which means that this is likely to degrade slower than the PV system.
02:21It may not sound like a big difference, but it adds up over the expected 20-year lifetime of a solar model.
02:30In a hot climate like Ghana's, which is getting hotter every year due to climate change, the long-term effects can be striking.
02:39PVT collectors can cost about twice as much as a conventional solar panel.
02:46But they make better use of the sun's energy because they produce more electricity and hot water at the same time,
02:54making them suitable for places that need a lot of hot water, for example in industry, hospitals and hotels.
03:05Like this 82-room hotel in Tamale, which still gets its energy from the national grid,
03:12the hotel manager believes switching to PVT could significantly reduce energy costs.
03:17If we take off hot water and all those stuff, then our bills would have been considerably low.
03:28To quantify it, I would say at least 40% of our bills would have been down.
03:35PVT collectors could offer a promising alternative that could help Ghana to meet its ambitious solar targets,
03:42especially as people become more aware of the particular problems of heat stress for solar panels.