Solar-powered Groundnut Decorticator: Design, Performance and Emission Reductions for Sustainable Agriculture

Abstract

Groundnut (Arachis hypogaea) is a major oilseed crop extensively cultivated in tropical and subtropical regions, with India contributing 17–19% to global production. Shelling, a key post-harvest operation, is traditionally performed using manual or semi-mechanised methods, which are labour-intensive and inefficient for small-scale farmers. Although electric or diesel-powered decorticators improve efficiency but costly, require regular maintenance and are unsuitable for remote, off-grid areas. To address these constraints, a solar-powered groundnut decorticator was developed at Alva’s Institute of Engineering and Technology, Karnataka, integrating renewable energy into areca mechanisation. The study aims to optimise the solar-powered groundnut decortication performance and minimise the kernel loss during shelling. The decorticator design was based on groundnut physical and engineering properties, including roundness (0.76), sphericity (0.72), bulk density (238 kg/m³) and angle of repose (24°), to optimise the feed system and shelling unit. The machine features a cylindrical drum and concave sieve mechanism powered by a 1 HP BLDC prime mover operating between 200–300 rpm, driven by a solar panel–battery hybrid system. It includes a modular frame, a manual feed hopper and dual sieves (10 mm and 8 mm) for effective separation. Performance evaluation at three speeds—100, 200 and 300 rpm—showed maximum shelling efficiency (97.5%) at 300 rpm, but the optimal speed was 200 rpm, achieving 93.75% efficiency, 50 kg/h throughput and minimal kernel damage (7.4%). Germination percentage was highest at this speed, indicating preserved seed viability. With a power requirement of only 350 W, 3–4 hours of battery backup and low maintenance, the machine is ideal for smallholders in rural areas. Its ergonomic design, affordability and portability make it a sustainable alternative to conventional decorticators. The integration of solar power supports energy-efficient farming, reduces post-harvest losses and offers a viable, environment friendly way forward to enhance productivity and rural livelihoods.