Transmission constraints are increasingly shaping how renewable projects progress in Southeast Europe, with market activity split between developers that have secured grid access and those that have not. The shift comes as solar-panel and battery costs fall, while transmission capacity is treated as a more valuable development input. In this context, connection agreements and the timing of grid studies are central to project development.
Montenegro connection agreement for Velestovo solar-plus-storage
Montenegro’s CGES signed a connection agreement with Nu Energy for the planned Velestovo solar project near Cetinje. The project targets up to 60 MWp of solar capacity combined with a 50 MW/100 MWh battery. Total investment is estimated at about €50 million.
The connection agreement does not complete development or financing on its own. It instead removes uncertainty over whether the electricity system can physically accept the project’s output. This distinction is relevant because it affects how quickly projects can move from early stages toward commercially usable arrangements.
Serbia delays grid studies for variable renewable projects
In Serbia, regulations changed in May for a large group of new variable renewable projects already in the queue. Connection studies for those projects will not be processed until a window from Sept. 1 to Dec. 31, 2029. The change replaces an earlier timetable that had envisaged processing in 2026.
The Renewable Energy Sources of Serbia association said the update effectively halts early development for affected projects because a grid study is required before connection. Projects with advanced connection rights, or those treated differently under the rules, are positioned more favorably as a result.
A two-tier market based on transmission rights
The regulatory shift contributes to what is described as a two-tier market for renewables development. A developer may have land, wind measurements, environmental studies, a turbine supplier and potential lenders but still lack a commercially usable project without a firm connection route. Conversely, established transmission access can increase project value even before construction begins.
Banks and investors are expected to adjust their focus accordingly as financing and acquisitions depend more on grid agreement maturity. Investors buying pipelines are likely to differentiate between nominal megawatts under development and megawatts with secured connection rights. In Serbia, the delay until late 2029 may leave projects with advanced grid positions facing a scarcity premium.
Slovenia expands funding for grid and smart-grid investment
Other countries are responding through investment measures rather than restrictions on development timelines. In August, Slovenia increased funding available from its Modernisation Fund programme for transmission and distribution projects to about €58.66 million. A separate programme provided €69 million for smart-grid investment through 2030.
The measures aim partly to improve network capability to integrate renewable generation, storage, electric vehicles and other new loads. The policy direction also reflects differences in construction cycles across technologies used in power systems.
Construction cycle mismatch: generation versus grid buildout
Solar plants can be developed and built relatively quickly once permits and land are secured. Batteries can be deployed even faster than both solar generation and transmission infrastructure. Major transmission substations and high-voltage lines can take many years due to system studies, planning approvals, land acquisition, environmental procedures and complex construction.
This timing gap can allow renewable development to proceed ahead of the infrastructure needed for connection. Storage partially changes the equation by reducing export peaks, providing balancing and shifting renewable generation into more valuable hours under some regulatory models. However, storage still requires a connection capable of importing and exporting electricity.
Velestovo highlights equipment availability versus grid limitations
The Velestovo case illustrates the contrast between equipment procurement and grid constraints described across the region . Its solar modules and batteries can eventually be sourced from a competitive international equipment market. Its connection to Montenegro’s high-voltage system cannot be treated the same way.
As renewable capacity continues expanding across Southeast Europe, grid access is increasingly treated as one of the region’s most valuable energy assets.
