The increasing integration of distributed and renewable energy sources into the electrical power network presents challenges for the operation and management of the network. New techniques are required to ensure the effective management of the balance between supply and demand, and the proper maintenance of voltage stability and power quality in the network. A new energy management system, designed specifically for the management of smart grids, is described, and its operation in conjunction with energy storage systems is explored. Large scale demonstration systems have been implemented in order to study and prove the new techniques, the configurations and results of which are recorded. The experience gained from the demonstration systems will result in improvements to the new techniques and consequent benefits for the future management of electrical networks.