Case studies



NAME: Mljet
LOCATION: Croatia - Mediterranean Sea

4244' N and 1731' E

AREA: 100,4 km2
Coastal cliffs, hills

Mediterranean; an average air temperature in January is 8.7 C and in July 24 C


Interconnected to the mainland grid with two undersea cables

Electricity is delivered to the island by two undersea cables. Each cable supplies power to one side of the island. It has been mapped as medium demanded commodity and increase of peak power load and power demand through years has been set to 7%.




Figure 1. Increase of electricity demand and peak load until 2015.





Eighteen different scenarios of energy system development of the Island of Mljet have been modelled and the results are optimized for maximal penetration of renewable energy. Generally, scenarios are divided into two main groups. The first group of scenarios has a limit on hourly penetration of electricity from intermittent sources.




Figure 2. Classification and basic description of calculated scenarios


The limit is set at 30% of hourly system load meaning that in each hour, power system will accept up to 30% of electricity coming from wind or solar. The second group of scenarios do not have the penetration limit on electricity coming from intermittent sources, so if there is enough wind or solar energy, whole power system load will be covered from the renewable sources.

The scenarios are also different according to the installed technology. There are scenarios with only wind turbine installations, solar PV installation and their combination. Further scenarios have installation of hydrogen technologies that include installation of electrolyser, hydrogen storage and fuel cell.