Skip to main content

News feed

BME researchers could solve the nationwide solar panel issue at once

2025. 01. 20.
Solar panel installation

The first article in our TechFlow series on current BME research shows that the solution is right there in the devices, which would only need to be coordinated using the method developed by the Faculty of Electrical Engineering and Informatics.

Anyone who has had household solar panels installed recently, or even just thought about it, must have faced the issue that in certain residential areas it is not possible to install more panels, at least not to feed power into the public grid. This is because the voltage issues caused by the increasing number of solar panels required their expansion to be restricted even though the use of renewable energy would be obviously desirable for climate protection and energy saving reasons.

This dilemma has been solved by researchers of the Smart Power Lab at the Department of Electric Power Engineering of the Faculty of Electrical Engineering and Information Technology. They have developed a solution that is relatively quick to deploy and does not cost much. Their article on this innovation has been recently published in the journal Electrotechnika.

Density barrier

“The motivation for us was that because of the current regulations, it is no longer possible to install more solar panels in many places. And this is for a reason: simulations indicate that above a certain solar panel density, higher voltages can actually build up that could damage electrical equipment. Therefore, we tried to find a solution, not so much from a researcher’s but from an engineer’s point of view, that would overcome this problem without the need for expensive infrastructural developments”, told us Dániel Divényi, Associate Professor and Deputy Head of the laboratory.

Divényi Dániel

So their goal was to create a system which everyone could participate in and benefit from. They started from the fact that more than 90 percent of solar panels have inverters capable of regulating their output depending on the voltage measured locally. And an algorithm can tell you which device at a given municipality or in a street, depending on its distance from the transformer supplying the public grid, should have this control feature switched on.

Feszültségproblémák

Moreover, you don’t need to install a large-scale communication system and implement central optimisation and operations management; all this can be done in a decentralised manner. “Such a system has essentially been in place in Hungary for voltage regulation since the introduction of cooperative electricity systems. Actually, this is where we got the idea from.

The cost of using this feature is minimal compared to replacing the local transformer or wiring,” 

explained Dániel Divényi.

In a street or a municipality where the situation is critical, it would be sufficient to carry out a network calculation only once a year, and to register the number and locations of equipment. Such data would allow to identify which solar panel needs what control parameter to be set. The experts can then calculate the individual settings and “everything works autonomously from then on until many more solar panels are installed or the grid operator makes significant changes to the grid”.

Napelemek

If this system is not introduced, either the restrictions will have to be maintained until the planned power grid extensions are completed, or the solar panels will always be switched off at the houses furthest away from the transformer, where over-voltage occurs the most frequently, but obviously this latter cannot work in the long run as it would be unfair to certain users.

Elvesztett energia

According to Dániel Divényi, the method developed in VIK’s laboratory does not conflict with any legislation, nor does it require any special authorisation procedure, and is certainly in line with EU directives that encourage market flexibility. The researchers have already had discussions with service providers and presented the idea to the relevant ministry, and so far the feedback has been positive. It is also worth putting the proposed solution to the test as soon as possible, because as time goes by, more and more homes will have electric cars and household energy storage devices, which will also put a strain on the grid.

“It will be possible to employ this new function for these new devices as well, because even though the operation is slightly different, but the logic could be the same: 

whoever participates in voltage regulation contributes to the efficient operation of the electricity system, and the system will reward it in return,” 

the expert noted.

The researchers in the laboratory are now working on a solution for use cases where the transformer’s circuit has several junctions or the loads on the specific phases are different. “Such cases complicate the calculation, but the concept still works. We need to start a pilot project to validate the concept, and we are already in discussion with an operator that is open to testing our solution.”

The question arises whether there is a similar system at work abroad whose experience could be used at home. Dániel Divényi said that so far they have not found any such foreign example, which may be explained by the fact that Hungary has a relatively large number of household solar panels, and also that power grids abroad are built to a higher capacity than here.

pg
fotó: Pixabay/Pexels