Sustainable Energy for Food Processing

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Introduction

Food processing is the transformation of agricultural products into food, or of one form of food into other forms. Reaching from home cooking to grinding grain and further complex industrial methods, food processing involves a broad variety of processes to produce convenience foods. These require an immense consumption of energy and thus, contribute to a significant percentage (5 to 10 percent) of global greenhouse gas (GHG) emissions. Improving energy efficiency by introducing better technologies and optimizing processing steps along the value chain may help reducing the global warming potential (GWP) of the food industry. Adopting processing technologies that run on renewable energy is one option which further allows reaching independency from fuel price fluctuations and may save financial resources in the long-term and thus, improve producers’ livelihoods.

Interesting approaches that integrate renewable energy in traditional steps of agricultural value chains are listed below. These often include technologies where the original energy input is simply substituted by a renewable energy source , creating access to processing devices in remote areas and reducing greenhouse gas emissions.

Actors & Innovations

The significant effects on income generation and poverty reduction when providing mechanical energy for food processing displays the great potential of sustainable energy systems in rural areas. The following innovations show how the adoption of renewable energy in different processing steps for food production allows substituting traditional energy sources and reducing costs while increasing efficiency. The large variety of approaches reach from aquaculture aeration systems to solar oil presses, having different kinds of effects on local society and economy.

Field Evaluation of a Passive Aeration System for Aquaculture

Aquaculture accounts for a significant percentage of the GDP of many low-income countries. By artificial aeration, the level of dissolved oxygen in the deeper water layers of the fish farm’s ponds can be increased, leading to higher fish yields and enhanced food security. However, using a conventional electrical pump for artificial aeration can become very costly. The University of Toronto and its partners have introduced a passive aeration system that uses solar thermal energy instead. The technology is applied at the bottom of the pond, mixing the water and resulting in higher levels of oxygenation, which improves water quality and yields. Since using solar thermal energy, the system proves much more affordable than traditional ones. Read more…

Solar Agro-Processing Power Stations

The Village Infrastructure Angels (VIA) started the mission of making poverty-alleviating infrastructure affordable to everyone in 2012. As energy plays a key role in agricultural production, especially in processes like milling, introducing solar mills in rural areas through microfinancing programs has increased income and saved manual labour. VIA have deployed different types of solar mills to different countries of the Global South, improving the livelihoods of farmers, especially women, who are often involved in manual processing. Read more…

Solar-Powered Oil Press for Sesame Seeds

This solar-powered oil press allows off-grid oil extraction of sesame seed. Being a counter-seasonal crop that requires little fertilizer or pesticide inputs, sesame grows under harsh weather conditions and can promise higher income when processed appropriately. Designed by the University of Hohenheim, the solar-powered oil press for sesame seed includes a solar panel connected to a control unit which calculates the optimal operational setting dependent on seed moisture content and the current weather conditions, increasing its energetic efficiency. Although the price of the solar-powered unit can reach between € 8,000 and € 13,000, sesame, as a cash crop, allows a payback period of 4 months when the mill is run during the harvest season. Additionally, as a by-product of the oil extraction, the seed cake can be sold as animal fodder. Read more…

Sesame Oil Press Technology (University of Hohenheim).

Case Studies

Implementation of sustainable energy within food processing allowed producers to save time and increase their incomes at once. The following projects show among different value chains how introducing renewable energy improved local production while reducing environmental impact.

Pilot Project “Solar-Powered Sesame Oil Production” in Burkina Faso

With an average yield of 616 kg/ha and 321m837 tons produced in 2015, Burkina Faso is among the top ten sesame producers worldwide. Nevertheless, the country has among the highest electricity prices worldwide, and the lack of infrastructure hinders local farmers from further processing, which leads to exporting most of the sesame grains. As solar energy is abundantly available, a decentralized solar-powered oil production system could open up new opportunities in rural areas at cooperative level. The oil press has been successfully installed in a women’s cooperative in Nouna, Burkina Faso. A training on how to operate the machine has been conducted in collaboration with the University of Hohenheim, Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH and the local partners. Read more…

Tomato Processing with Solar Energy

By adding value to agricultural raw products, these can not only be sold at higher prices, but also acquire new qualities that ease conservation, transportation, and thereby become more marketable. The Tigray Agricultural Marketing Promotion Agency (TAMPA) started in April 2014 in collaboration with the Sustainable Land Management Program (GIZ SLMP) the promotion of micro and small enterprises for tomato processing using renewable energy. The target groups were cooperatives of tomato farmers producing in remote areas without access to electrical power. The processing site can be built by the farmers, as construction material is available onsite or further provided by the GIZ SLM Program. Consisting of a solar reflector for tomato processing, a solar panel, an inverter and acid batteries for further processing steps, the whole project allows packing processed tomatoes in sealed bags. This case study shows how the Ethiopian tomato production of small-scale enterprises can increase its revenues by using a solar processing plant for tomato products. Read more…

Implementing a Productive Use Grant Scheme in Uganda

The GIZ project ‘Electricity Access Impact Maximization’ (E-AIM) in the West Nile region of Uganda mobilized households, social institutions and SMEs for getting connected to electricity. By getting consumers involved, these would benefit from electricity supply and furthermore contribute to the long-term economic viability of the new grid infrastructure. The project encouraged raised general awareness on productive use of electricity (PUE) on the ground and conducted PUE trainings and coaching sessions in twelve trading centres along the new grid lines. By providing a special subsidy to grain mills and maize/rice hullers all over the region, the grant encouraged the usage of very economic but also cost-intensive electric appliances in the highly active local milling sector. Exemplary electric milling showcases aimed stimulating the adoption of electric milling by other millers, which turned in high propagation of the devices despite the difficulties at the beginning. Read more…

Shea Nut Butter Production in Burkina Faso

Within the Solar Food Processing Project, an initiative of the International Solar Energy Society, the project Shea Nut Butter Production aimed applying and demonstrating different solar technologies for the improvement of traditional food processing processes. The project consisted of know-how transfer and trained local personnel, including technical trainings, the target group being local women. The main implemented technologies were solar concentrators and solar box cookers, which could be used for boiling and purifying the shea nuts. The benefits of the solar devices were clear: no smoke, soot or aromas were created that could have affected the quality of the shea nut butter and its oil. Read more…

Publications

Solar Milling: Exploring Market Requirements to Close the Commercial Viability Gap

Many rural off-grid communities rely on diesel-powered milling equipment to process important staple crops. Despite their relatively low upfront costs, diesel mills are expensive to operate, difficult to run, and harmful to the environment. Solar-powered electric mills offer a more reliable and sustainable alternative. This report uses data collected from field testing results of solar mills in East Africa to analyze the market requirements for solar mills and assess their commercial viability. Its findings present opportunities for improving solar milling technologies and recommendations for how to close the commercial viability gap between diesel and solar. Read more ...

Productive Use of Energy in African Micro-Grids: Technical & Business Considerations

With the growing interest in productive use of energy (PUE), this report provides best-practice PU case studies including both technical  as well as the different business models used by the developers in the African context. It is based on the actual customer demographics and load profiles gathered from the PUs activities on micro-grids which are powered by PowerGen Renewable Energy in Tanzania. The chapter on Milling states that electric-mills are preferable to diesel-mills as they are easy to operate and are more reliable. Electric-mills can be be cost-effective if the electricity is less than USD0.32 per kWh. Read more...