Development on Borkum

Borkum’s ambitious energy agenda

The island of Borkum has a yearly consumption of 30.6 GWh of electricity and 130 GWh of heat. Approximately 50% of the electricity is purchased on the electricity market and is transported to the island by the submarine cable: The share of self-produced renewable electricity in the overall electricity mix accounts for 38.7%. Borkum has set itself the ambitious goal to be carbon neutral by 2030. Currently, nearly 60% of the island’s energy supply is covered by renewable energy sources. In comparison, only around 38% of the energy in Germany as a whole is produced from renewable energies.


The energy supply in Borkum is guaranteed by Stadtwerke Borkum (NBG), the public utility company, water authority and the only electricity distributor in the island. Two wind turbines of 1.8 MW each, a 1.4 MW solar PV park and 0.27 MW of distributed PV installations feed renewable electricity into the grid. Borkum is not yet energy self-sufficient. Indeed, electricity is also imported from the German mainland through an undersea cable. The heating demand is provided by a gas CHP plant and individual gas boilers. 5 charging stations for electric vehicles are installed on the island.


Borkum involved in various EU projects focussing on innovative energy technologies

Borkum participated via NBG in the NETfficient project focussing on the validation of several types of local storage technologies in combination with PV through extensive prototype testing. Borkum is also involved in the Interreg project H2Watt which assesses the potential of hydrogen and promotes knowledge transfer within the North Sea.


Partner NBG will oversee the technical demonstration activities on Borkum

All technical solutions (see Technologies for further information) developed by project partners are tested in real environment on Borkum. The technical activities are overseen by NBG, the local energy supplier and DSO, which will engage with the citizens by organising information events and overview the planning and implementation of technical tasks. At the core of NBG’s technical mission is the installation of a seawater heat pump system which distributes heat to 100 housing units. The activities carried out in Borkum pave the way for the replication of results to Fellow islands and other EU islands.

Existing 1.4 MW Solar PV farm

Existing 3.6 MW Onshore wind turbines

MW/LV transformer substation

H2-based storage system: electroliser + H2 tank +PEM fuel cell battery pack

1MW Ultracapacitor + 1 MWh Li-ion Battery pack

Seawater district heating network + heat storage

EV charging station

Power inverter

Building RESS-based system: 20 kW roofmounted PV + 70 kWh Li-ion battery pack + Smart meter

Home RESS-based system: 4kW roof-mounted PV + 8 kWh battery pack + Smart meter

Smart IT platform




Project background

Following concerns of the population regarding air quality due to a new coal fired power plant on the Dutch coast, Borkum started on a path towards renewable energy many years ago. Yet the challenges associated with the intermittent nature of power supplied by such renewable sources currently remain: Consumption peaks cannot be met by solar and wind energy and expensive grid electricity needs to be bought in. Vice versa, peak generation leads to energy exports at unfavourable conditions. A logical step to tackle this challenge is to investigate energy storage, which was indeed the research objective of the previous Horizon 2020 NETfficient project coordinated by partner AYESA.

The NETfficient project:

  • Begun in 2015 and finished by the end of 2018.
  • Validated several types of local storage technologies in combination with photovoltaic production in the electricity grid of Borkum, increasing their readiness levels through extensive prototype testing
  • Deployed distributed photovoltaic installations adding up to 279 kWp and a power-to-heat aquarium installation

To a greater or lesser extent, geographical islands today are facing several challenges posed by the objective of achieving zero-emission energy systems. Within this framework, the overall goal of the ISLANDER project is to make substantial progress towards a fully decarbonised, smart geographical island which will pave the way to other European Follower islands towards a zero-emissions energy system.

ISLANDER will run for 4 years, ending in September 2024. The project is coordinated by Spanish partner AYESA and consists of a total of 11 organisations from 7 European countries. It has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 957669. The European Commission is co-funding the project with nearly€ 7 million.

ISLANDER in a nutshell

ISLANDER paves the way for the decarbonization of EU islands’ energy systems by demonstrating smart grid solutions combining renewable energy production with storage technologies in real-life settings. Starting with the Pilot island of Borkum, the project aims at replicating these solutions to 4 Follower Islands. The objectives of ISLANDER are as follows:


  • The development of an advanced smart IT platform using latest mathematical optimisation techniques, and which will flexibly manage Distributed Energy Resources (DER) coupled with Hybrid Energy Storage (HES) while also incorporating Demand Response (DR) and Local Power Balancing (LPB). This will provide a powerful approach to make the most of the renewable generation, to interconnect the electrical and heat grids, and to enhance the stability of the island’s power network.


  • The development of an improved multi-scale forecasting methodology relying on comprehensive modelling of demand and supply and on the recent advances of machine learning, in order to deliver high-accuracy forecasting data at the multiple levels required by the optimisation algorithms running the smart IT platform.


  • The development of a methodology for the large-scale design of optimal distributed DER+HES systems which, in combination with the planned smart IT platform, will optimise investment and operation costs to reach and even, surpass cost parity with fossil fuel energy sources in the island.


  • The facilitation of the creation of an energy community on Borkum, that empower local citizens to support and participate in Borkum’s energy transition.


  • The replication of the ISLANDER results to the Follower islands and the associated archipelagos: the Scottish island of Orkney, the Greek islands of Skopelos and Lefkada, and the Croatian island of Cres.

Demonstration of smart grid solutions in operational environment on Borkum island

Project duration: 4 years from October 2020 – September 2024

7 EU countries represented by 11 organisations: research centres, SMEs, and large enterprises

About € 8,3M total budget, co-funded with € 7M by the European Commission

4 Followers Islands: Cres (Croatia), Lefkada and Skopelos (Greece), Orkney (UK)