Solar barns in tobacco: Sustainable TZ future

IN Tanzania, tobacco farming supports hundreds of thousands of rural households and places the country among the world’s top ten producers.

Yet behind this economic contribution lies a costly and destructive practice: curing tobacco leaves with firewood. This method has accelerated deforestation, raised production costs, and exposed farmers to serious health risks from prolonged smoke inhalation.

A new technology known as the solar barn is emerging as a potential solution. By using solar energy instead of firewood, gas, or grid electricity, solar barns promise cleaner production, lower costs, healthier farmers, and reduced pressure on forests, while strengthening Tanzania’s competitiveness in the global tobacco market.

What is a solar barn? A solar barn, technically called a solar curing barn, is a specially designed structure that cures harvested tobacco leaves using sunlight. Leaves are hung inside a barn with a transparent plastic or clear iron-sheet roof, similar to a greenhouse.

Sunlight heats the interior, drying the leaves gradually. Ventilation openings regulate airflow to prevent rotting, while some barns use solar-powered fans and panels to control temperature and humidity.

The goal is simple: cure tobacco efficiently without burning wood. Tobacco’s economic importance Tobacco is produced globally at about 6.7 million tonnes annually. China leads with nearly 40 percent of world production, followed by India, Brazil, and the United States.

Tanzania ranks among the top ten producers, contributing about 1.6 percent of global output. Domestically, tobacco remains a major cash crop grown in more than ten regions with suitable soil and climate. Tabora leads national production, followed by regions such as Shinyanga, Kigoma, Katavi, and Ruvuma.

The crop supports rural incomes, government revenue, and foreign exchange earnings. In May 2025, while presenting the Ministry of Agriculture’s budget for the 2025/2026 financial year, former Minister Hussein Bashe requested parliamentary approval of TZS 1.242 trillion. Agriculture employs more than 60 percent of Tanzania’s population and has shown steady growth, rising from 2.6 percent in 2021 to 4.2 percent in 2023, with projections of 5 percent by 2025.

Agricultural exports reached USD 3.54 billion in 2023/2024. Within this broader agricultural expansion, tobacco curing methods are drawing renewed scrutiny for their environmental and health impacts.

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A long history, new challenges Tobacco farming in Tanzania dates back to the colonial era, when German and British administrations introduced it as an export crop. After independence in 1961, the government expanded production through smallholder schemes, extension services, and cooperative marketing systems.

Today, tobacco remains one of Tanzania’s leading cash crops. The Tanzania Tobacco Board (TTB) has emphasized quality improvement, compliance with international standards, and environmental conservation, including tree-planting initiatives to offset curing-related deforestation.

Despite these efforts, the Tanzania Tobacco Research Institute (TORITA) reports that curing is still almost entirely dependent on firewood and logs—methods that are environmentally unsustainable and hazardous to health. The cost of firewood curing In Tabora Region, Tanzania’s tobacco heartland, the impact of firewood curing is clear. Farmers report rising costs, declining forests, and health problems caused by smoke exposure.

Rashid Abdalla, a tobacco farmer and Vice Chairperson of Itundu AMCOS in Urambo District, said most farmers have only heard about solar barns but have no hands-on experience.

“Affordable solar barns would reduce costs, protect forests, and improve our health,” he said, noting that many farmers suffer eye irritation from smoke. Another farmer, Selemani, detailed the financial burden.

A single trip of firewood costs between TZS 300,000 and 350,000. Curing one acre of tobacco requires three trips, totaling up to TZS 1,050,000 per season.

“Solar barns could change everything,” he said, urging the government and TORITA to speed up implementation so farmers can adopt the technology in the next season.

John Jeremia, who farms three acres, said he harvests five to six curing cycles per acre each season. Tobacco income pays for his children’s education, food, and healthcare. He called for reliable solar equipment and political support to ensure the technology succeeds.

Other farmers welcomed the idea but raised concerns. Eric Andrea questioned whether solar barns would work effectively during prolonged rainy seasons. John Kapongo stressed the need for government-led education through cooperatives and demonstration projects to build farmer confidence.

Research and innovation TORITA has been researching alternative curing fuels for years. Senior Researcher Elimboto Muna said the institute has tested sawdust, coal, and solar energy, with promising results.

“Our trials show that solar curing preserves key tobacco quality attributes,” he said.

In collaboration with the Nelson Mandela African Institution of Science and Technology (NM-AIST), TORITA is constructing a large solar barn in Tabora. Expected to be completed within two to three months, it will serve as a national demonstration and training center. The new barn is designed to reduce curing time from seven days to just two or three. It will use bamboo poles and can cure one acre of tobacco per cycle.

According to TORITA, curing one batch of tobacco using firewood requires about 19 cubic meters of wood, weighing up to 520 kilograms. Solar barns could eliminate most of this demand without compromising quality. Forests under pressure Tobacco curing is a significant contributor to Tanzania’s deforestation crisis. The country loses more than 400,000 hectares of forest annually, largely due to firewood and charcoal use.

A 2019 National State of the Environment Report estimated annual forest loss at over 469,000 hectares, with 16 percent of land already degraded. In Uyui District, Forest Officer Majaliwa Magunda said the Forest Act (revised in 2023) governs illegal logging and penalties.

Authorities encourage tobacco farmers to plant at least 500 trees per acre for curing, but enforcement remains difficult due to illegal harvesting in protected reserves. To curb forest loss, the government has also banned firewood and charcoal use in institutions feeding more than 100 people daily since January 2024, and more than 300 people from January 2025.

Health risks of smoke exposure The health consequences of firewood use are severe. Experts estimate that cooking with firewood for one hour is equivalent to smoking 300 cigarettes. Around 33,000 Tanzanians die each year from exposure to dirty cooking fuels, including firewood and charcoal.

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Respiratory specialist Dr Elisha Osati has warned that smoke releases toxic chemicals such as carbon monoxide, increasing the risk of lung, heart, and eye diseases. Nationally, only 16 percent of Tanzanians use clean cooking energy.

The Ministry of Energy aims to raise clean cooking energy use to 80 percent by 2034 as part of broader efforts to protect public health and the environment. Market pressures and sustainability According to Innocent Tibesigwa, Manager of Milambo Cooperative Union, global oversupply of fluecured tobacco—following renewed production in Brazil and Argentina—has affected demand.

Tanzania produced about 55 million kilograms recently. He urged farmers to focus on environmental conservation, occupational safety, and Good Agricultural Practices to remain competitive.

From an engineering perspective, Adrian Edwin of ELICO Foundation Tanzania said solar-powered drying systems already operate yearround in sectors such as fish processing, even during rainy seasons. He believes similar designs could be adapted for tobacco curing.

A practical solution, not a dream Globally, the economic burden of tobacco-related diseases exceeds USD 1.4 trillion annually. Meanwhile, more than three million people die each year from exposure to fire and solid fuels used for cooking. Deforestation linked to firewood use worsens climate change, reduces water availability, and degrades fertile land. Against this backdrop, solar barns offer a practical, scalable solution.

They can cut production costs, protect forests, improve farmer health, and enhance tobacco quality for domestic and international markets. The objective of this story is to show that solar barns are not a distant innovation but a realistic response to urgent environmental, health, and economic challenges.

With Tabora as a testing ground, and research led by TORITA, Tanzania has an opportunity to transform tobacco curing—saving forests, safeguarding farmers, and securing the future of one of its most important cash crops.