In many of our articles we talk about flexibility in the power grid, but what is it actually? What do we mean by this term? Here we give you the answers.
Our everyday lives function so naturally with the help of electricity that we no longer even think about where it actually comes from. It is simply there. It accompanies us from morning to night, even through the night.
But how does electricity actually get to us and how does our power grid work? We would like to explain this briefly before we go into the question of flexibility.
The function of the power grid in general
In Germany, we basically cannot speak of a German power grid alone, since the European power grid is connected across national borders. For us, this means that we can quite conveniently move electricity from A to B, buy and sell electricity, and more easily compensate for fluctuations, but also that the same rules apply to all market participants, and errors in a single location can potentially have an impact throughout Europe. Therefore, it is very important to know and respect the requirements of the power grid. And fortunately, such mishaps happen extremely rarely.
One of the most important metrics in this system is 50 hertz. Hertz indicates the oscillation of the current, that is, its frequency, because our grid is based on alternating current. This means that the current oscillates back and forth between the negative and positive poles. Exactly 50 times per second. This frequency is incredibly important, because even changes of plus or minus 5% can cause the power grid to collapse. For this reason, it is very important to keep the load on the grid, the amount of current, so to speak, and the frequency as stable as possible.
Current challenges for the grid
Now, of course, the question arises as to what flexibility in the power grid is now. So far, everything seems to be working very well. Currently, we are in a situation where more and more renewable energies are being connected to the grid. As a result, the once centralized and constant production by means of a few large power plants is being expanded and slowly replaced by decentralized and volatile, i.e. fluctuating, production by means of many small plants. Of course, we are very pleased about this.
However, this change poses major challenges for the current power grid. As we explained above, the grid must be kept stable despite fluctuating feed-in. At any given time, it has to produce the amount of electricity demanded by consumers. This is due to the lack of ability of the grid to store electricity; it merely transmits electricity from point A to point B. Because of renewables’ dependence on solar and wind, situations can arise where they cannot meet demand, or would even feed in too much. However, since the small plants can be switched on and off more easily and cheaply, this in turn has a positive effect on grid stability.
The importance of flexibility and its role
This is where flexibility comes into play. Flexibility is basically nothing more than shifting the load, i.e. the consumption, in the power grid. Meaning that you as a private individual can, for example, switch off a household appliance, such as your refrigerator, for a short time in certain situations when there is a risk of the load on the grid being too high. This means that you do not need electricity and it does not have to be produced additionally. This works, for example, via smart plugs that do it for you for very small time intervals. On the other hand, you could also charge your electric car at times even when consumption is too low to stabilize the grid. So flexibility is, among other things, the willingness and ability to either reduce, or increase, the demand for electricity in certain situations. This can be provided by a wide variety of stakeholders.
Generally speaking, a system’s flexibility is measured by the extent to which electricity demand or generation can be adjusted to anticipated or unanticipated changes. That is, the system’s ability to respond to these changes to keep the relationship between consumption and generation at an even level, so that consumption matches generation. This happens, for example, by means of the aforementioned load shifting, peak shaving, and curtailment of injection and withdrawal.
Flexibility, then, helps with current challenges by intelligently addressing and responding to the current consumption and production situation in a timely manner. It can even provide an economic benefit to those who provide it.
If you have further questions regarding this topic you are welcome to contact Evyatar Littwitz, Sophia Rohbogner or Gerhard Meindl.
Additionally, we encourage you to read our first post of this series about the topic of Demand Side Management.
For those who understand German, here is a link to an explaining article of the MDR about the German power grid.
Your Es-geht! Team