Information transmission

Ants have a highly efficient way of communicating: they exchange information through scents. Like binary numbers, information is uniquely encoded.

Smart networking to enhance efficiency

Dynamic consumption management

A stable electricity grid is the key element for reliable supply. Storage options, flexibly deployable generation capacities and buffer on the demand side are needed to compensate for the increase in unforeseeable fluctuations in supply and grid instability with the increased use of new renewable energies. Demand-side management requires communicative networking of the various system elements. For this reason, Repower holds 35 per cent in Swisscom Energy Solutions AG: the two companies work together in the area of load management and provide increasingly sought-after system services.

The transmission and distribution grid connects electricity generation and electricity consumption in industry and households. To ensure grid stability, the same amount of electricity must be added as taken away at all times — there always has to be a balance between generation and consumption. This balance is maintained by means of system services. Electricity producers pledge to provide balancing energy to grid operators and increase or decrease their generation capacities temporarily to compensate for fluctuations in the electricity grid.

Fluctuating generation meets inelastic demand

Until now, electricity generation has been geared toward consumption. The base load was covered by central power plants. Peaks in consumer demand were met by electricity from flexible technologies such as storage facilities. The generation landscape will continue to change over the next few years as the electricity generation mix is restructured. Electricity made from new renewable sources like wind, solar or biomass, already account for a significant portion of electricity generation in Europe. In Germany alone, the installed capacity of photovoltaic systems was thirty gigawatts at the end of 2012, a figure that represents the output of thirty large nuclear power plants. Because, however, photovoltaic systems do not supply electricity around the clock, the average generation only corresponds to around four nuclear power plants. But the differences between full generation when conditions are good and almost complete stoppage because the sun isn't shining are enormous. The volatile and decentralised supply of electricity from renewable sources thus creates completely new challenges for system operation.

Until now, it was virtually impossible to influence the consumption curve. How can the necessary balance in the electricity grid be ensured if electricity generation fluctuates and is unpredictable on the one hand and demand is inelastic on the other? One possibility would be disconnecting solar and wind systems from the grid when they generate more energy than needed. However, this approach is anything but efficient because the electricity that the systems could supply would simply be lost. It is therefore better to store the energy generated until it is used. Pumped storage power plants are one proven possibility for temporarily storing large quantities of electricity. However, there would have to be many more systems than exist or are planned today and the transmission grids would need to be massively expanded to be able to accept and temporarily store all of the surplus electricity generated. Which means we need additional solutions: instead of basing generation on consumption as was previously the case, consumption must be successfully managed in the future in such a way that it can adjust to fluctuations in generation.

The electricity system of the future is intelligent

It must be possible for producers, storage facilities and consumers to communicate with one another and be controlled in real-time so that consumption can be oriented more around generation in the future. It requires intelligent networking and coordination of the various components. Information, communication, automation and control technologies are connected to the existing electricity grid. The “smart grid” is based on automatic recording of energy consumption and decentralised supply at the metering points, transmission of this data to a central control station and dynamic control of consumption devices. This means that not only power plants but also now consumers whose electrical devices and heating systems are virtually connected help provide system services.

Real contribution thanks to virtual power plant

This is precisely the idea behind the innovative project that Repower is pursuing together with Swisscom Energy Solutions. Electrical heating systems such as heat pumps, night storage heating and water boilers of a large number of customers are connected to one another to form what is known as a virtual power plant. A single system is created from the many individual installations which can be switched on or off at a moment's notice using dynamic consumption control. Electricity demand is thereby reduced at peak times and shifted to moments of lower consumption. The peak load saved can be sold to the national grid company Swissgrid as a system service.

The project will get underway in the spring of 2013 in the Repower supply region in southeast Switzerland and will be expanded to all of Switzerland if successful. This will enable Repower to make a significant contribution to efficient electricity supply over the long run.