We are using Python to help the National Grid in the UK to balance electricity production and usage. We do this by installing Python powered devices at customers sites that allow us to monitor and set control criteria to automatically turn on and off power consuming and producing devices when there is a mismatch between electricity supply and demand. These devices talk to our Python powered cloud based system using the 3g network, giving us near real-time monitoring of our customers assets. Our entire infrastructure is written in Python, from our billing systems, data analytics systems and customer portal all the way through to our on site industrial system interfaces. In this talk we will be talking about how and why we have used Python, where we have had problems, as well as where in our system we would like to use Python and why we cannot. We will also be talking about what we are going to do next, moving our system from near real time monitoring to near real-time control, using Python for both system modelling and control. We will discuss how we are using Python to creating a system that monitors the balance between electricity supply and demand many times per second and is able to provide a corrective control based on the sum of the output of a dynamic set of our customer sites and the challenges that presents.