Since green energy sources do not constantly generate the same amount of energy, electricity production becomes more volatile with the expansion of renewable energies. So-called smart grids, or intelligent power grids, can compensate for these fluctuations and thus ensure a stable grid. The article reveals how smart grid technology achieves this and how the energy transition can be further advanced.
Smart grids are a significant result of Industry 4.0 and energy automation. They represent a combination of generation, consumption and storage. In this process, a central control system balances out power fluctuations in the grid that occur due to fluctuating green electricity.
The individual components of the smart grid are optimally coordinated with each other at all times. To make this work, the smart grid uses modern information and communication technologies as well as decentrally organized energy management systems.
The smart grid is therefore not only an energy network, but also a data network that provides grid operators with information on production and consumption. This means that – unlike in the past – operators know exactly where and when a decentralized producer feeds electricity into the network. This is important – because if the proportion of these distributed generation plants becomes too high, the risk of an unstable network also increases. In this way, optimal network utilization with the integration of renewable energies is much more feasible.
For smart grids to work, all participants in the power grid must be able to communicate their production and consumption. An important role is therefore played by intelligent electricity meters, known as smart meters – which were adopted in Germany back in 2015 as part of the "Digitalization of the Energy Transition" Act. The smart electricity meters have been mandatory in this country since 2017. They record consumption in real time and communicate this to the participants in the smart grid.
Also indispensable are "smart consumers," i.e., devices such as heaters, washing machines or heat storage units that switch on precisely when the grid registers an oversupply of energy.
Within smart grids, the following elements take on different roles:
Control center: This is where all the information – current electricity consumption as well as generation figures and forecasts on a broad database – comes together. With the help of this information, the control center manages the grid and balances out possible supply surpluses or high demand. Interesting developments in the research field of artificial intelligence indicate that smart grids could be controlled by intelligent technologies in the future. This would likely result in a considerable increase in efficiency.
Electricity storage: Corresponding storage technologies offer the possibility of storing surplus electricity. This includes both large-scale storage facilities and private storage units. In this way, electricity that is generated – for example on particularly sunny or windy days – can be temporarily stored and only released when demand exceeds generation. This is where smart meters come into play once again, knowing exactly when the amount of electricity produced is greater than demand and vice versa.
Power plants: The power plants of the future will generate green electricity from renewable sources. This means that large nuclear and coal-fired power plants will be replaced by smaller, but more energy sources. In Germany, these are primarily solar plants and wind turbines. In addition, there are hydroelectric power plants as well as geothermal and biogas plants.
Decentralized generation plants: Households with their own photovoltaic systems, fuel cells or combined heat and power plants could actively participate in electricity trading in the smart grid. Smart meters are also relevant here. It would also be possible to network many small electricity producers with each other in order to flexibly balance out fluctuations in generation. In this way, each producer would have a share in the production of green electricity and thus contribute to environmental protection.
In recent years and in the course of the energy turnaround, the share of renewable energies in electricity generation has been increasing. As a result, more and more energy generated from solar and wind power – including that from distributed generation – is being fed into our power grid.
The problem is that wind and solar plants generate energy more unsteadily than conventional energy sources such as coal-fired or nuclear power plants. This means that – in the case of photovoltaic systems, for example – there is a surplus of electricity during the day, when the sun is shining. At night, on the other hand, no electrical energy is generated.
As our energy demand increases with each passing year, smart grids are a sensible way of balancing out fluctuations. However, for a stable grid to be realized, a dense data network is needed to coordinate the generation, distribution and storage of the energy generated.
Parallel to the power grid, therefore, smart grid also means the emergence of a data network supported by IT and communications technology. Its task is to intelligently monitor and regulate the fluctuating energy supply and the supply of the power network. This should function without gaps and a rapid exchange of industrial spare parts of all networked systems is required.
A smart grid example: As soon as the smart grid recognizes that more energy is currently being produced than is needed, it can selectively throttle the production of individual wind turbines or solar plants. In addition, thanks to the smart meters, the smart grid has the option of reducing surpluses by forcing higher consumption among end users.
The advantage for consumers is that they receive particularly cheap electricity. This is because the price of electricity automatically falls as soon as the supply of energy in the grid exceeds demand. The smart grid therefore optimally matches supply and demand.
Another advantage is that households and small and medium-sized enterprises can also become part of the energy network with their fuel cells, photovoltaic systems or combined heat and power plants and thus actively participate in electricity trading. Solutions in which many small power generators are linked together would also be possible. This would balance out fluctuations in the grid so that each individual generator is jointly responsible for the stability of the grid.
In Germany, but also in Austria and Switzerland, smart grids are already being implemented in model regions. The trials show that even with the software available today, it is possible to regulate electricity production and consumption within the regions. Further investment and research are necessary. However, experts agree that without smart grids, the complete switch to renewable energy sources will not be possible.
Smart grids are seen as a prerequisite for the success of the energy transition. In this context, the smart grid is responsible not only for energy distribution, but above all for communication between energy producers, storage facilities and consumers. For this purpose, the smart grid makes use of information and communication technology, which enables it to balance the fluctuating energy supply in the grid and thus ensure a stable power supply.
