Access to electricity is essential for humanity to develop. Nowadays, 600 million people in sub-Saharan Africa (SSA) have no access to energy services, most of them living in rural areas. However, this region has an outstanding solar potential that could unlock cheap power generation through solar power systems. This raises the question of how rural communities in Africa could avail the benefits of renewable energy systems to gain access to electricity and develop sustainable and productive activities around while facing low purchase power, high interest rates, and high investment costs. The concept of decentralized energy-water-food system proposes a solution: it enables renewable energy access with biomass and solar energy for the private power of the local community, provides secure water supply and year-round irrigation, and increases their livelihood through the profitability of farming and generation of jobs. The concept is applied to a case study in rural Ghana and the least-cost design is obtained. An economic feasibility analysis is carried out on the evaluation of profitability and the total financial value generated for the main stakeholders. The results portrait the economic advantages of the proposed concept design--a hybrid solar-biogas system--to deliver affordable electricity, water, and food supply.