Justus Wanzala –
Mid-morning at Gaitheri Secondary School in central Kenya’s Murang’a County, and students are busy with their daily routine, as at any other school. But their establishment is different — boasting a better power supply than most rural classrooms. One of its iron-sheet roofs is covered in tiles fitted with energy-producing solar cells — an innovative solar-power technology known as “building-integrated photovoltaics” (BIPV).
The tiles, designed to be laid on roofs during construction, offer an alternative to adding solar panels on top to produce power from the sun’s energy.
Solar tiles are starting to be rolled out in other countries too. Electric car maker Tesla Inc is taking orders for its tiles in Britain and the United States, where the first such roofs have recently been installed.
Tesla has said the product will be pricier than a conventional roof but will look better and ultimately pay for itself through lower electricity costs.
In Kenya, the tiles at Gaitheri school, which has 275 students, were made by Kenyan firm Strauss Energy and paid for with a grant from the United States African Development Foundation.
“They wanted an institution that is away from urban centres and where grid power connectivity is poor,” said teacher Jackson Kamau Kiragu.
The project started in 2016, and has enabled students to improve their performance thanks to more reliable power, which means they can study even after dark.
The solar power is stored in batteries, ensuring a continuous supply at night and on cloudy days.
Kiragu said the BIPV technology has also allowed the school to offer computer lessons.
“We’ve got 18 computers, but power was a challenge before Strauss Energy came on board,” he said.
The school is also connected to the national grid but the power this provides is expensive and suffers from frequent outages, especially in the rainy season.
The solar tiles have reduced the school’s spending on electricity to 1,500 Kenyan shillings (about $14.50) a month, which is largely a fixed charge for access to grid power.
“Irrespective of the weather, we rely on solar power,” said Kiragu.
A large share of Kenya’s population of some 45 million still has no access to electricity, particularly in rural areas, while demand for green energy is growing as the country steps up efforts to curb climate change.
A survey commissioned by Christian Aid and the Pan-African Climate Justice Alliance early this year showed that only about 57 per cent of Kenyans are connected to the grid, indicating huge potential demand for off-grid energy.
The situation has sparked innovations like Strauss Energy’s BIPV technology.
Charity Wanjiku, the company’s chief operations officer, said it was motivated to develop the patented technology because Kenya has abundant sun that is not being fully exploited.
Wanjiku said the technology could help make up a shortfall in hydropower, whose production has declined as drought has hit water levels in rivers and reservoirs.
BIPV can also create jobs, as the tiles must be made and fixed onto roofs by technicians, she added.
While the technology is gaining ground, Wanjiku noted the construction industry in Kenya is rigid when it comes to adopting new technologies. Market penetration is still slow given the technology is new and will require some time to build trust and acceptance among a wider customer base, she added.
But the solar tiles have come onto the market at a time when the country is experiencing a policy shift on utilising solar energy in the construction sector.
In April, Kenya’s Energy Regulatory Commission directed property owners whose buildings use more than 100 litres of hot water per day to install solar water-heating systems.
Wanjiku hopes such policy changes will drive adoption of the solar-tile technology.
“(It) is ideal for estate developers, schools and hospitals,” she said, adding it may still be expensive for individual homes.
The tiles cost between $20 and $250 each, depending on their size.
Research and development is under way to improve the product and bring down costs while enhancing efficiency, Wanjiku said.
Strauss Energy plans to construct a plant with the capacity to produce 10,000 units daily.
Kiragu, meanwhile, is convinced the solar tiles can be a boon to schools. Putting them on even one school building can make a difference in providing cheap, reliable power, he said.
In addition, the tiles are made of clay and durable plastic, so can be used to harvest rainwater for domestic use, he added.
At Gaitheri, the school building was not designed for solar-tile roofing, so the tiles were placed on an existing roof.
They are arranged in batches of 12 comprising a single circuit.
Power from the circuits is channelled into batteries fitted with a charging unit that indicates the amount of power being generated.
The school has 300 tiles, producing a combined 300 kilowatts, and eight batteries with a 25-year lifespan linked to a 48-volt system.
“We usually monitor the two sources — grid and solar (power) —and we have noted that while the grid power shows fluctuation, the solar power is constant,” Kiragu said.
Muddy Ramrakha, board treasurer for the Kenya Green Building Society, said BIPV technology could make a significant contribution to easing dependence on the national grid.
But that will require overcoming a number of challenges, including raising awareness among potential users.
And while photovoltaic equipment is getting cheaper globally, the cost and durability of battery technology will remain a barrier for some time to come, he predicted.
Wider access to finance that promotes the use of green building technologies would help expand the adoption of clean energy innovations like the solar tiles, he added. — Reuters