03.04.2018 | Intelligent grids and their importance in Switzerland
Smart grid, the "intelligent grid", stands for a package of IT technologies that can make the power grid more reliable, more flexible, more efficient and more economical. Smart grids will also play a key role for absorbing the growing, but irregular proportion of renewable energies (photovoltaic/wind).
What does the capacity of the Swiss power grid have to do with the Energy Strategy 2050?A great deal! Today, power grids with centralised power generation dominate the domestic landscape. The base load electricity generated in large-scale power plants (nuclear energy and hydropower) is fed into the high-voltage grid and routed to the end user over branched medium and low-voltage grids. More flexible power plants (storage, pumped storage) produce when demand is high and reduce or stop production when power consumption is low. As a result, the produced electricity volume always corresponds to the power consumed. If this balance is disrupted, grid imbalances or power failures can occur.
This production and consumption structure will change owing to Energy Strategy 2050. More and more power will be generated decentrally in wind power plants or photovoltaic systems. This presents great challenges for the existing grid infrastructure. If we stay with the current system, an expensive, strong expansion of the grids would be necessary.
However, there are also more flexible, less costly solutions: "If needed, intelligent grids can increase their capacities to react to increasing and decreasing feed-in volumes from renewable energies," explains Pascal Previdoli, Deputy Director at the Swiss Federal Office of Energy (SFOE). If we cleverly control transformers, production and consumption we can make additional efficiency gains possible. Devices, electric vehicles and houses interact with each other and become smart applications, smart homes and talk to the smart grid. Smart metering - intelligent measurement devices in homes - deliver important information for consumers and grid operators." (see box below)
See how a smart grid functions here:
So-called smart meters enable fully automatic recording, processing and invoicing of consumer energy demand. CKW is also active in this area, for example, as a service provider for self-consumption collectives that produce their own power with solar plants. CKW installs the intelligent electricity meters, automatically records the energy data of the renters and produces the exact ancillary cost statement for each party. The renter can monitor power consumption by means of an app and, in doing so, identify power guzzlers. Smart meters are the first step to smart households characterised through energy efficiency.
However, extensive studies present rather sobering results on the use of intelligent power meters to save electricity. Average savings range at only two per cent of household power consumption. CKW has made similar experiences. "Smart technologies require smart users," says Verena Tiefenbeck at the ETH Zurich (go to her blog here). She believes that the social sciences could help here and enable people to recognise and realise savings potentials.
As stated in Swiss Energy Scope by the ETH Lausanne (EPFL), the power grid of the future will have to be able to carry out new tasks:
The Swiss power grid comprises 250,000 kilometres of lines in the medium and low-voltage grids, as well as 6800 kilometres in the extra-high voltage grid (380 and 220 kilo-volts), some four million connected users and nearly 100,000 decentralised production facilities. Advanced technologies are needed to collect and manage millions of data records on grid conditions in real-time. Information is processed decentrally or centrally by means of algorithms. The national grid company Swissgrid describes the process as follows: The intelligent power grid creates a "symbiosis with modern information and communications technologies." The sum of these technologies is called smart grid.
You will find more information on this topic in the white paper "Smart Grid Vol. 2" by the association Smart Grid Schweiz, of which the Axpo subsidiary CKW is also a member.
The costs of modernising the Swiss power grid are estimated at 20 to 30 billion francs over a time span of 20 to 30 years, e.g. about 1 billion francs per year. These expenditures will continue to be financed by consumers through their electricity bill. This would represent a price increase of 1 to 2 cents per kWh.
Based on industry data, the ETH Lausanne estimates the proportion for smart grid technologies to make the grid "intelligent" at 5 to 8 billion francs.