Energy insufficiency is obstructing the socio-economic and industrial improvement of Bangladesh. Renewable energy contributes about 560 Megawatt (MW) of the total electricity production of 20,430 MW, which can be a sustainable solution to the demand-supply crisis. This paper, summarises the current energy situation of Bangladesh and examines the available renewable energy resources and their future prospect. It has been revealed that Bangladesh is heavily (62%) relying on natural gas although government has already taken steps to generate electricity from renewable energy sources. Current policies and legislations related to generation of renewable energy in Bangladesh have been discussed explicitly. Finally, some suggestions have been made to tackle the ongoing energy crisis in the country, in addition to the renewable energy.Abbreviations: GDP: Gross domestic product; RNPP: Rooppur Nuclear Power Plant; Tcf: Trillion cubic feet; IDCOL: Infrastructure development company limited; BPDB: Bangladesh Power Development Board: GS: Grameen Shakti; BWDB: Bangladesh Water Development Board: USD: United States Dollar; IPP: Independent power producer: BCAS: Bangladesh center for advanced studies; NWPGCL: North West Power Generation Company Limited: BCSIR: Bangladesh Council of Scientific and Industrial Research; EGCB: Electricity Generation Company of Bangladesh: WRA: Wind Resource Assessment; REB: Rural Electrification Board: BRAC: Bangladesh Rural Advancement Committee; kW: Kilowatt: PJ: Petajoules; MW: Megawatt: IFRAD: Institute for fuel research and Development; GWh: Gigawatt hours: ICS: Improved Cooking Stoves; MWh: Megawatt hours: DoE: Department of Environment; TWh: Trillion-watt hour: DLS: Department of Livestock Services; RPCL: Rural Power Company Limited: mmcfd: million cubic feet per day; APSCL: Ashugang Power Station Company Limited: BSCIC: Bangladesh Small & Cottage Industries Corporation (BSCIC); GOB: Government of Bangladesh: BADC: Bangladesh Agricultural Development Corporation; SREDA: Sustainable and Renewable Energy Development Authority: DIDA: Danish International Development Agency; LGED: Local Government Engineering Directorate: BAU: Bangladesh Agricultural University; NGO: Non-Governmental Organization: HBRI: Housing & Building Research Institute; IRENA: International Renewable energy Agency: : BARD: Bangladesh Academy for Rural Development; ETP: Electronic Traffic Pricing: BCCD: Bangladesh Commission for Christian Development; PV: Photovoltaic: BRRI: Bangladesh Rice Research Institute; SHS: Solar Home Systems: NDBMP: National Domestic Biogas and Manure Program; TOE: Tonne of oil equivalent: K/km: Kelvin/kilometer; LEAP: Long range Energy Alternative Planning

Waste in the food supply chain is estimated to be about 30–40% of the total food production, which aggravates the world hunger and increases waste management burden and environmental impact. Despite the dire food scarcity, majority of this food waste takes place in developing countries because of the lack of appropriate and affordable preservation techniques. Traditional open sun drying is the most popular food-reservation technique to the local farmers due to near-zero capital cost and cheap labor cost. However, this method is highly energy intensive, unhygienic, and time demanding. The high energy consumption resulting from uncontrolled simultaneous heat, mass, and momentum transfer processes in traditional drying systems highlights the necessity of pursuing sustainability in drying process targeting reduced energy consumption, environmental and social impacts. This paper presents a comprehensive review on the sustainable food drying technologies based on renewable energy sources, with emphasis on the developing countries. It was observed that the integration of thermal energy storage with heat pump makes the integrated drying system more efficient, and dries food with better quality. Likewise, advanced integrated drying systems, such as, solar with microwave, and heat pump with microwave make the drying process more cost and quality competent. Finally, impact of resource distribution and governmental incentives for renewable energy use in sustainable drying is discussed.