How can we make old power plants environmentally friendly? - Salla Sallovara, Fortum eNext

We all want to make the world cleaner. We want to breathe fresh air. The only question is how can we make it? Is there any solution for the old power plants? Should we tear them down or modify? Salla Sallovara of Fortum eNext explains what can we do to make old power plant environmentally friendly.