Experiments with Geobacter Sediment Batteries

As part of my ongoing research and work about the recording and transformation of energy, I have been recently building a test-series of portable microbial fuel cells or sediment batteries.

The Geobacter is a biological organism that exists in water sediment and has recently been discovered to both recycle industrial wastewater (petroleum-based pollutants and heavy metals in groundwater and sediment) and generate electrons as a byproduct. Using equal amounts of water and sediment, a 5-gallon plastic container and 2 custom graphite electrodes can create simple and portable batteries. The harnessed energy from one battery is enough to power an LED or very low voltage/amperage device for several days.

My goal for this ongoing project is to take water and sediment samples from sites of urban renewal (Chicago, Brooklyn, etc) and develop the battery for a variety of artistic uses.  I would also like to answer a few questions. What would I power with these batteries? How would I exhibit this work?