After seven years of research, development and demonstration work, Energinet.dk has now completed the world’s biggest full-scale test with the establishment of an intelligent power system, called a smart grid. The project has attracted considerable international attention, and a final report has now been published documenting the technology and the work behind the smart grid trial. The report can be downloaded from the Energinet.dk website.
- Our development work can be compared with that which preceded the introduction of autopilots in aeroplanes. When the autopilot was invented and pilots made the switch from manual flying to relinquishing control to an autopilot, many tests were conducted before people had sufficient faith that the plane would not crash. You could say that we have developed and tested the autopilot which, together with many other new technologies, will be used in the green and intelligent power systems of the future, says Per Lund, Chief Engineer at Energinet.dk.
Denmark a display window for the world
Denmark is world-leading at integrating uncontrollable wind in the power system. In 2011, wind power accounted for 28% of electricity consumption. Denmark’s biggest renewable energy resources are wind and biomass. Together with biomass and solar energy, wind will therefore be one of the key resources in transforming energy systems over the next 40 years to realise the political vision that renewable energy meets total Danish energy consumption in 2050. But how is it possible to control a power system with hundreds of thousands of wildly fluctuating power generation units? And what happens to all the energy when the wind is blowing so hard that we have more energy than we need? The key to realising this political vision in 2050 is the development of the intelligent power system, or smart grid.
Energinet.dk has spent the past seven years developing the so-called cell controller, which will be a key part of the technology behind tomorrow’s intelligent power system, the smart grid. The cell controller can best be described as the brain behind an intelligent power system.
Trial in southern Jutland
The cell controller trial was conducted around the town of Holdsted in southern Jutland in close cooperation with SE (formerly Syd Energi). Across a 1,000 square kilometre area with 28,000 households, businesses and institutions, five CHP units, 47 large wind turbines and 12 substations between the 60 kV and 10 kV grids, the technology behind an intelligent power system has now been tested. As the brain in the intelligent power system, the cell controller controlled the CHP units, the wind turbines and the substations as one integrated, intelligent power system during optimised, normal operations. In addition, it was demonstrated that, in an emergency situation, the area could function as an island, independently of the rest of the Danish power system. Here, the numerous production and consumer units in the area were disconnected from the existing control system and instead connected in an independent, virtual power plant through state-of-the-art computer systems.
- The test was observed by a number of international researchers as it is the world’s biggest complete prototype of a smart grid with a newly developed and advanced control, regulation and monitoring system, the so-called cell controller, says Per Lund.
- It has been a lengthy and complex process, during which we have learned a lot from the mistakes and fortunately few technical breakdowns which have occurred during the development process. Now we have a technology which works, concludes Per Lund.
Facts on full-scale test
There are approx. 28,000 electricity consumers in the test area, with a peak load of approx. 55 MW. The nominal production capacity from the five CHP units and 47 wind turbines is approx. 70 MW, with each category responsible for approx. 50%. The local area therefore has a nominal wind power share of 50%. As a result, when the wind is blowing strongly, the area is a net exporter of electricity.
The final full-scale test of the cell controller concept took place in October and November 2010 and in May and June 2011 around Holsted in southern Jutland between Billund and Esbjerg.