Harbours are a microcosm of the challenges that Europe as a whole will have to face in its energy future. The shift towards renewables puts a strain on the existing electricity system, where demand and supply need to be in balance at all times.

To avoid loss or spill of large amounts of valuable green energy in times of high production, the power and heat sectors can be combined in various ways. This multi-modal energy approach is a driver of sustainability and economic development in both large and small harbours. The techniques are there, what is needed is a smart cooperation.

Harbours form a vital role in the global logistic system and are home to many industrial and commercial enterprises. Correspondingly, they are an important source of economic prosperity, but also face high resource consumption and great environmental challenges. 

In recent years, companies, public bodies and end users are increasingly aiming to improve their ecological balance. At the same time, they demand a reliable and cost-efficient energy supply. In this context, offering a perspective for innovative, sustainable energy solutions becomes a key criterion for harbour regions in the global competition. 

The e-harbours project demonstrated that a successful way to tackle these problems is the creation of smart energy networks, which are able to:

• incorporate an increased amount of renewable energies 
• enable and benefit from increased electric mobility 
• be reliable and stable under all circumstances and - offer a wide range of possibilities to increase energy efficiency and reduce energy costs 

A challenge for energy systems with a large share of intermittent renewable energies, like wind and solar, is the limited storability of electric power. Within e-harbours, several showcases addressed this problem – either on a local scale, or in the context of the entire power system gradually shifting towards renewables. 

Some of the most promising e-harbours showcases succeeded by smartly combining the electricity and heat sectors: Whenever power from renewable sources cannot be fully consumed locally or absorbed by the grid, it can be wise to transform electricity into heat (so-called Power-to-Heat) and temporarily replace the burning of fossil fuels for heat generation.

Such a concept can work profitably both on a local level (as initiated in the Zaanstad showcase) as well as on a large-scale level as demonstrated in Hamburg, where Power-to-Heat can be used to absorb surplus amounts of wind energy in the grid of the German coastal regions. Also, implementation in residential buildings or small businesses is feasible, especially when combined with high-efficiency technology like heat pumps. 

Likewise, combined heat and power production (CHP) plants can be operated in a flexible and more profitable way if heat buffers are added. In the Malmö showcase, the result was that the feed-in storage of industrial excess heat in the district heating grid led to ecological advantages. 

In fact, the combination of heat and power sector resulted the most applicable and transferrable approach in different settings. Since these two sectors of the energy system are historically clearly divided, new partnerships were required, existing views had to be overcome and various practicalities had to be addressed. 

The e-harbours movement enabled others to implement smart and efficient cross-sector energy solutions – by thinking outside the box, forming effective partnerships and learning from the experiences made in the e-harbours project. 

The participation in three large conferences was the major output of the e-harbours movement to achieve its objectives.