I believe that the answer would be heat. In reactions that are exothermic, heat energy is released from the energy stored in the chemical bonds of the reactants.
I do not think that electrochemical reactions necessarily "release" electricity they merely transform chemical energy into electric energy.
Answer: What are the potential pitfalls of using diseased cells as the foundation for all stem cell research? Do you think this situation should be changed? What additional research or evolutionary concepts support your perspective?