Southeast Europe faces a wide range of political and economic challenges, not least in the energy arena.

Infrastructure quality in the region varies widely, and the emphasis on coal and hydropower to the exclusion of other renewables sets the area apart from the rest of Europe. But plans are in place that could turn the region into a budding energy storage market -- helping it improve the grid network and making it more energy-secure.

"Energy storage can play a major role in contributing to the energy security of the region," said Gabriela Cretu, an electricity and renewable energy expert at the European Union-backed Energy Community policy group.

Gjergji Simaku, head of Renewables and Energy Efficiency at the Albanian Ministry of Energy and Industry, says that the top driver of that country’s deployment of renewable energy is domestic energy security, followed by sustainable development.

The potential for the development of solar and wind in the region is high, according to Igor Kuzle, a professor at the University of Zagreb in Croatia, who spoke at a recent workshop on the future of energy storage in Southeastern Europe.

According to Kuzle's figures, Croatia has a current installed wind energy capacity of 330 megawatts, but plans to develop 1,200 megawatts by 2020 and 2,000 megawatts by 2030. Serbia could have as much as 1,300 megawatts, but it remains untapped due to the country’s tariff system and the limitations of its grid. Nevertheless, with fossil fuels currently enjoying massive -- and probably unsustainable -- subsidies in the region, the case for renewables will become more pressing.

All states in the region are obliged to increase the percentage of renewables in the mix by 2020, due to a directive from the European Union. Even countries such as Serbia and other parts of the former Yugoslavia not in the EU have signed up to binding targets, based on the notion that meeting the goals will help bring them into the community at a later date.

So what threatens energy security in the region? Despite the relative proximity of the Ukraine, the current crisis there will have minimal impact on Southeast Europe -- at least when it comes to energy. The Ukrainian grid is asynchronous with those in Europe, so it has never provided electricity to the region. In addition, its main energy export of natural gas is not used for generation in Southeast Europe.

Threats are more of the homegrown variety. The region relies on relatively dirty lignite coal to generate around half its energy.

Much of the generation infrastructure is old and even dangerous, dating back to the Cold War era. It is also a sparsely populated area, which also has many islands. As a result, there are a significant number of communities that are off the main national grid and highly dependent on diesel deliveries to run small local generators.

The area is also prone to drought and flooding. Drought affects hydro generation, and floods have a big impact on thermal generation, inundating the region’s coal mines that supply much of the fuel.

Energy storage is used in limited amounts by taking advantage of lower-priced electricity for urban dwellings in Zagreb, Belgrade, and other large cities. There is also potential for combinations of renewables and battery storage for off-the-grid communities, including the far-off prospect of vehicle-to-grid systems as electric vehicles become more popular in Croatia and Greece.

But it’s pumped hydro energy storage (PHES) that currently dominates in the region. The technology offers the greatest potential for growth due to the hydro resources available.

Alpine topography and heavy rainfall make the region ideal for hydropower. Heavy investment during the Cold War has allowed Southeast Europe to get half its energy from hydro. 

As a result, “Southeastern Europe still presents good opportunities for the development of hydropower plants,” according to Dietmar Reiner of Verbund, a company which operates and owns over 130 hydro power plants, plus a similar number of wind parks.

For the same reasons, Goran Krajačić, an energy researcher from the University of Zagreb, believes that PHES has similar potential. He cites a 2013 study by Gimeno-Gutierez and Lacal that identified 13 possible sites in his own country of Croatia, with a combined total capacity of 60 gigawatt-hours. However, he admits that environmental constraints would effectively disqualify half.

In an interview with Greentech Media, Krajačić also highlighted a planned 3-gigawatt project that Serbia intends to build on the Danube river. “This will make a big impact on the energy mix,” he commented.

Verbund operates a plant in Albania, where nearly 100 percent of the country’s electricity currently comes from hydro. Until recently, Albania was a net exporter of electricity, but it now faces a shortfall in production and is in search of new ways to meet demand.

One solution to this shortfall could come from upgrading some of its old hydro assets that had been given over to irrigation, converting them into pumped hydro energy storage plants, in order to ensure any extra energy generated is captured for later use. Once optimized, their daily cycles could satisfy part of the peak demand, help reduce import costs, and improve the country’s energy security.

Slovenia recently commissioned a new PHES plant, which is now operational. Specifically built to keep costs to a minimum, the Avče plant used an existing natural lake for the lower reservoir, so engineers only had to excavate the upper reservoir. The result is 180-megawatt station, fully operational for the relatively cheap sum of €180 million ($200 million).

On the subject of funding, Krajačić notes that subsidies for generation are the norm in the region. As he also points out, substantial government support has been the driver of renewables. If you’re going to subsidize renewables, you might as well subsidize storage too, he argues.

Various funds are available from the European Union, but the big money will come from individual member nations such as Germany, which usually expect their companies to be hired to develop projects. Krajačić also said that considerable investment in the area was coming from China, including for the 3-gigawatt planned PHES project in Serbia.

Croatian power utility HEP is considering the construction of four new PHES projects with a total capacity exceeding 1,400 megawatts, and there are some potential private initiatives currently being considered, according to Krajačić.

Bulgaria and Greece have notable PHES schemes already operating. Bulgaria has the largest project in the region: the 788-megawatt Chaira Hydro Power Plant, which provides time shift, frequency regulation, and voltage support services. Additionally, there’s a 104-megawatt facility in the same complex and another 160-megawatt plant in Devin province.

Greece also has two facilities -- the Sfikia Pumped Hydro Power Station, rated at 315 megawatts, and Thisavros Hydro Power Plant, with 384 megawatts. Including Slovenia’s contribution of 185 megawatts, this brings the total to just under 2 gigawatts for the entire region.

Some analysts say the region could build a 100% renewable grid by 2050 with the installation of 100 gigawatts of pumped hydro storage. Clearly, the region still has a ways to go.

Off land, countries encounter more challenges to energy distribution -- and different opportunities for the energy storage market. Greece has between 1,200 and 6,000 islands, depending on the counting method used. Many are inhabited, and these island communities are dependent on non-interconnected systems, which are essentially microgrids.

Unlike other countries in the region, there is a noticeable penetration of non-hydro renewable energy in Greece, including on islands such as Kythnos where wind power provides up to 60 percent of the local energy needs, with a small solar PV contribution, backed by diesel.

Stathis Tselepis of the Greek Centre for Renewable Energy Sources and Saving surveyed the current island grid systems and found that of 30 non-interconnected islands, with peak demand ranging from less than 10 megawatts to over 100 megawatts, thermal energy generation represented 1,721 megawatts of capacity and renewables represented 446 megawatts of capacity.

Given current incentives from the Greek government for island renewables, the need for both smarter grids -- and more storage -- is clear. Tselepis believes that energy storage will become increasingly necessary for grid balancing and other ancillary services. He and other energy experts from the region point to the success of El Hierro in the Canary Islands as proof that an island community can run on 100 percent renewable energy.

Croatia also has its own populated islands, and the whole region has isolated communities that are off the grid and would benefit from a self-contained smart grid system, with renewables and storage.

Although the need for storage in Southeast Europe is strong, investment is a challenge. Attracting private money to this part of the world has never been easy.

Jasmina Trhulj, an energy market expert with the Energy Community Secretariat, sees “political interference, unstable legal and regulatory frameworks, a lack of well-functioning national and regional electricity markets, and currently low energy prices" as the primary obstacles to developing the storage market.