Voltio investigates the localisation, design, and integration of bio-electrochemical systems. These devices utilise an emergent technology capable of generating clean, sustainable electricity by tapping into nature’s metabolic and photosynthetic mechanisms. Microorganisms such as cyanobacteria and microalgae adhere to a substrate that acts as an anode, and a biochemical reaction triggers an electron flow towards a cathode, generating a current. In this project, plant microbial fuel cells and photomicrobial fuel cells, or biophotovoltaics, were explored from scientific and design perspectives. These explorations proposed and visualised a variety of devices and evaluated contexts where this technology could have a positive impact, including off-grid energy systems, emergency aid, and educational tools. An array of device iterations is presented to demonstrate the versatility of the technology and illustrate pragmatic visual speculations for its implementation via localised interventions into the built environment. Scientists and designers should work together to facilitate a smooth, large scale integration of this technology that could positively impact many communities and aspects of society.