NOVELTY - A friendly domestic biomass or bio-waste treating and biogas generating system comprises a bioreactor with: (i) a lower reaction chamber for generation of biogas; (ii) a flexible biogas holding assembly encapsulated by a cap; (iii) an internal baffle which ensures retention of reaction mixture inside the bioreactor 0 thus ensuring complete degradation and stabilization of the reaction mixture, and producing more effective biogas; (iv) photovoltaic cells or modules may or may not be mounted onto the superficial portion of the cap of the flexible membrane.    USE - The system is useful for harnessing and utilizing anaerobic digestion technology for producing renewable fuel in the form of biogas generation and solar energy for charging batteries or operating electronic devices (claimed).    ADVANTAGE - The invention provides friendly, portable, stackable, easy to assemble, durable, light weight, easy to transport biogas reactor which meets the rural and urban areas needs of energy from renewable sources and/or waste management; eliminates the construction work, cost and time for installing the bioreactor as compared to the traditional biogas systems; maintains constant pressure and flow rate of biogas by applying dead weight over the gas storage flexible unit; provides durable, modular, light-weight, anticorrosive, user-friendly and an ultra violet stable reactor for biomethanation; provides a bioreactor which is easy to transport since the components are stackable and can be transported in multiple numbers conveniently; reduces or eliminates external moving parts involved for biomethanation in the bioreactor; reduces the capital cost of small capacity biomethanation plants; mounts photo-voltaic cells/modules as renewable source of energy on the bioreactor to generate electricity; generates energy in the form of biogas and electricity from a single system by incorporating solar modules with the bio-energy solution; utilizes biogas as cooking fuel, bio-manure as organic means for soil enrichment and solar electricity for charging lanterns as well as other portable electronic appliances as like but not restricted to mobile charger and laptop computing devices; produces by addition of colorants and/or pigments an evidently visible flame, which is otherwise colorless and undetectable in daylight; and provides powers needs for both domestic as well as commercial applications, by integration of multiple bioreactors in series.    DETAILED DESCRIPTION - A friendly domestic biomass or bio-waste treating and biogas generating system comprises a bioreactor with: (i) a lower reaction chamber for generation of biogas; (ii) a flexible biogas holding assembly encapsulated by a cap; (iii) an internal baffle which ensures retention of reaction mixture inside the bioreactor thus ensuring complete degradation and stabilization of the reaction mixture, and producing more effective biogas; (iv) photovoltaic cells or modules may or may not be mounted onto the superficial portion of the cap of the flexible membrane, where a compartment is externally provided adjoining the cap of the biogas collecting assembly for charging electronic devices via the photo voltaic module.