As part of a panel discussion on solar technologies in Croatia held at the Sunny Days conference in Hvar recently, our post-doctoral researcher Ninoslav Holjevac from the Zagreb Faculty of Electrical Engineering and Computing gave a presentation titled ''Solar potential in Croatia in terms of integration into the grid and beyond''.
Holjevac gave an overview of the current situation in Croatia, the development of a system for a better future and solutions for the solar and green transition. "We have reached the point where we must take urgent action. The energy transition is unquestionable. We need it. However, the grid is limited and the one we are currently using was built many years ago; its current capacity is close to being maximized," Holjevac warned. He added that solar energy has not had a dynamic development like wind energy, but this is now certainly changing." All of this together represents a significant increase in demand on the transmission and distribution system. A ‘highway’ must be built which will also enable the integration of large solar panels. We need to take action today in order to overcome problems on time,'' said Holjevac.
He pointed out the significant potential of the Sun in Croatia where there are many locations with 2,500 or more hours of sunshine, noting that we have not yet taken advantage of this: ''There is still a lack of solar panels from Zadar to Dubrovnik; there are too few rooftops solar panels; and there aren't enough solar collectors. There is also a lack of experience needed in order to begin more active project implementation," he said.
Speaking further about problems and opportunities, he noted summer as being a critical period. During peak season, solar panels contribute minimally because the problem with power supply takes place between 9:30 pm and 10:30 pm: “Solar panels are not a solution for grid problems for the period between June to September. Solar energy is great for energy transition as it is inexpensive energy, but we still can’t do without the grid. We need both a grid and solar panels and it is no coincidence that one relies on the other. Batteries and similar technologies help, but to a limited extent. We still can't do without the grid. It will be needed, even with an increase of solar panels on roofs."
He also mentioned the long process of developing the power grid – a 400 kV project lasts 10 years. He stressed that there is an enormous number of requests for connection and the system must keep up with these requests. "The development of the power grid is essential for the continuation of the green transition and the rise of large solar panels. Solar panels will contribute to the problem but will also resolve the problem. I am convinced that from a technical standpoint, things will be solvable. These are all opportunities. They are also in agro solars while the significant pilot project ‘Slavonia’ is unused. Certain surfaces can also benefit from floating solars and, additionally, solar panels are not affected by polluted surfaces. Also, there is opportunity in hydrogen, which is one of the pillars of the energy transition,'' Holjevac listed all the potentials of solar panels.
Finally, he concluded that the development of the system, primarily a 400 kV grid, is needed for further integration of a significant share of solar panels, as well as optimal use of the current capacity and opportunities provided by solutions that are lower in capital and less time intensive. Among other things, changes in the current system, the legislation and the rules are necessary. "We need to develop a dialogue among all stakeholders and move towards a green and sunny future," Holjevac said.