REDII Ports Study

Pumped storage

A pumped storage power plant pumps water into a higher holding basin when there is excess electricity in the grid. If electricity is needed in the grid, the water is run downhill through pipes (gravity principle) and then drives a turbine whose kinetic energy is converted back into electricity using the generator principle.

• No reliable statement on costs and function

Water power point absorber

In this technological approach, a float is attached to a lifting metal rod on the edge of a quay or similar to utilize the energy from wave power. The waves lift the float, the movement is transmitted via the lifting rod and converted into electrical energy with the help of a generator.

• Almost constant amount of electricity generated
• can be installed at different quay areas

• Only small amounts of electricity
• Higher maintenance cost
• Placement of the device is important, as optimal wave conditions should prevail

Rooftop PV

There are many possible applications for rooftop photovoltaic systems in the port area. There are countless mounting options available on the market for installing the modules, meaning that in principle any roof surface can be covered with modules.

• very high generation potential

• load-bearing capacity of the various roof structures (statcis) can limit the use
• abrasion caused by (fine) dusty port air

Air-to-water HP

The air-to-water heat pump is the most widely used heat pump technology. It is particularly suitable for use where neither deep boreholes nor surface collectors are possible.

• Advantageous in the area of “Old building”

• Low efficiency compared to water-to-water heat pumps
• Noise level

Solar thermal energy

One way of utilizing the thermal potential of the sun is solar thermal energy. In this technology, glass tubes filled with oil are exposed to solar radiation. The modules are connected to a heating circuit, for example, and transfer the temperature of the oil to the heating water using the heat exchanger principle.

• higher energy yield than solar power
• can also be used as an optimizer for process heat applications

• more expensive than solar power

Biomass boiler

While pellet systems can be up to a few hundred kilowatts in size, biomass systems can be found well into the MW range. Wood chips are often used as fuel.

• Diverse fuel supply (road, rail, ship)
• slightly cheaper than pellets

• High support and maintenance costs
• Not suitable for small systems

PEMFC

The PEMFC is a low-temperature fuel cell and works with a polymer electrolyte. This makes it ideal for supplying heat and electricity to existing buildings, as it can supply the required flow temperatures for heating in the 70-90 °C range. The output of PEM fuel cells is in the range from 2 kW.

• uitable for use in residential buildings and mini combined heat and power systems

• Low system efficiency
• Sensitivity of the cathode to fouling of the fuel gas
• higher maintenance costs

Battery storage

Battery electric storage is one of the classic and technically most advanced variants of electricity storage. The functional principle is based on an electrochemical process. There are currently various types of battery electric storage systems available on the market, of which lithium-ion technology is probably the most widespread.

• Batteries in different performance classes

• Fire hazard
• Expensive technology due to lithium shortage

Water heat storage

The water heat storage tank is basically a very large buffer tank of the type used in conventional heating systems. It consists of a water tank with a capacity of several thousand cubic meters, which is covered with insulating material on the outside. The storage tank is connected to a heat source (e.g. biomass cogeneration plant) and can therefore absorb excess heat. Water heat storage tanks are available in various designs, including with direct heat generators that use surplus renewable electricity to generate heat.

• Temperature can be maintained for a long time thanks to insulation

• Enormous space requirement (area and height)

Flywheel accumulator

Pellet boilers

The fuel is pelletized wood waste (sawdust and damaged wood), which as a standardized product has a consistent quality (consistent calorific value). Due to the combustion process, high temperature levels of up to approx. 90 °C can be achieved in the heating flow.

• variable temperature level (enables gradual refurbishment)
• Fuel costs cheaper compared to fossil fuels

• Political pressure to ban this technology
• higher maintenance requirements

Night storage heater

With a night storage heater, an electricity-powered heating element is used during the day to generate heat, which is stored in a ceramic heat accumulator for the night hours. This technology is particularly useful when there is a surplus of electricity from renewable sources.

• No piping required
• low installation costs

• low economic efficiency, if mains power has to be used

Solar carports

Open spaces such as parking lots generally offer great potential for generating solar power. As the areas must of course provide space for vehicles and maneuvering, solar carports are a means of setting up the photovoltaic system decoupled from the ground. This allows the area to be used for both parking and energy generation.

• Output per area is increased
• Carport offers protection for vehicles

• High investment costs (3 times higher than normal rooftop PV systems)
• higher construction costs
• increased risk of damage and therefore frequent maintenance

Facade PV

Industrial buildings in particular often have large, straight facade surfaces with few openings for windows, doors or gates. Facade photovoltaics are particularly suitable for surfaces such as these. It is possible to install glass modules with special wall brackets as a curtain wall - whereby the space in between can then also be used to insulate the building.

• Important for production halls & silos
• Ultra Thin modules can be used on facades, which prevents static problems

• higher assembly costs, as the use of large scaffolding or elevator platforms is often necessary
• Lower efficiency due to vertical installation
• Risk of vandalism

Small Wind Turbine

Like their larger counterparts, small wind turbines are systems that generate electricity by using the kinetic energy of the wind.

• High variety of possible installation locations
• No lengthy approval procedures are to be expected

• No long-term reports yet on durability & actual amount of electricity produced

Ice storage tanks

Ice storage tanks are used where heat is supplied by a heat pump. The ice storage tank uses the thermal energy during the phase transition from water to ice and vice versa. This technology is particularly useful where a low temperature level is required for heating purposes.

Mini biogas plant

The principle of biogas production is based on a fermentation process in which the energetic base material is mixed with water and bacterial cultures. The enzyme cleavage of the base material by bacterial cultures produces methane. This can either be converted into electricity in a CHP unit or fed into the local gas grid as biogas after processing.

• Use of food waste or human faeces as base material
• small plant size

• High additional costs for the treatment of the gas
• Daily personnel costs for filling & emptying the plant
• Biogas yield is at a comparatively low level

Solar foil

Solar foil is an ultra-thin and particularly flexible solar module. With almost the same generation capacity and life expectancy, this technology weighs 30-50% less than other glass modules.

• can be used on roofs with insufficient statics
• increases PV potential

• uncertainty with regard to Durability & actual power yield (as new on the market)
• abrasion due to dusty air could damage substrate material

Power2H2 - Electrolyzers

Surplus electricity is used to produce green hydrogen via an electrolyzer. This can then be used for electricity generation as well as for heat generation or combined heat and power generation.

• Low costs

• requires expensive grid electricity lack of generation
• difficulties under licensing law

Gravity storage

A variation of the pumped storage power plant is the so-called gravity storage. Here, weights (e.g. concrete blocks, pressed metal scrap, non-recyclable components from wind turbines, etc.) are pulled up by a winch when there is a surplus of electricity in the grid and lowered when there is a shortage of electricity. When lowered, the cable to which the weight is attached is unwound and electricity is generated using the generator principle. Gravity storage systems can be erected in the form of a crane or inside a building. The output is in the MW range.

• Low investment price

• Probably increased maintenance effort
• A lot of space is required for the system
• High weight
• likely high costs

Waste water HP

Another usable environmental energy is the residual heat from waste water. The principle works in the same way as a water-to-water heat pump. The difference is the heat exchanger, which is installed in the volume flow of a wastewater pipe or sewer. Waste water has an average annual temperature of approx. 11°C and, if the volume flow is constant, offers a high proportion of usable heat energy.

• Relatively high efficiency

• complex installation
• Increased maintenance effort on the heat exchanger side

PAFC

Compared to other fuel cells, the PAFC works with phosphoric acid as the electrolyte and is well suited for combined heat and power generation in the industrial sector (without high temperature requirements). In this type of fuel cell, electricity and heat generation is based on the splitting of hydrogen into its components water and oxygen.

• Dynamic behavior (power controllability)
• robust construction

• comparatively lower power density
• frequent replacement of the anode & cathode, due to the phosphoric acid

Floating PV

Floating PV is ideal for unused water areas in the harbor. It consists of a flexible aluminum frame and the actual PV system. The wave-going system can be positioned outside the harbor in direct weather conditions.

• Little or unused water areas can be used to generate electricity
• Combination with point absorbers or small wind turbines possible
• Higher system efficiency, as water cools the system

• Difficult accessibility
• frequent need for cleaning

Water-to-water HP

This technology uses the medium of water, or the environmental energy it contains, to generate heat. A refrigerant is fed in a closed circuit past a heat exchanger connected to a water circuit, then absorbs the temperature level of the water, is fed to a compressor and compressed there, the temperature level rises with increasing pressure. The compressed refrigerant is fed back past a heat exchanger that is connected to the heating system and releases the heat. This is followed by an expansion valve, which allows the refrigerant to expand and return to its original state, further reducing the temperature.

• Low volume of water required for use
• Water is more stable against fluctuations

• required antifreeze is a potential risk of environmental damage
• clogging of the heat exchanger can cause lower efficiency

Wind Turbine

A wind turbine generates energy from the air flow. The wind drives the turbine's rotor blades, which transmit their rotation via the downstream gearbox to a generator, which then produces the electricity.

• Significantly higher yields compared to small-scale solutions

• Challenges under licensing law, especially with regard to noise quotas

CH generation

In combined heat and power generation, a fuel is fed to an engine which is connected to a generator. Combustion produces heat that can be used for heating or process purposes. In addition, electricity is generated by the built-in generator.

• Can be used if there is a steady supply of renewable fuel and high heat consumption

• requires constantly high heat consumption for economic efficiency

Vertical Wind Turbine

In a vertical wind turbine, the rotor blades are arranged vertically around their own axis.

• Wind direction not relevant
• No need to track the system
• Lower noise and vibration emissions

• lower generation capacity due to lower efficiency

Wind kite

With this technology, a cable winch stationed on the ground with a built-in generator is used to raise a fabric kite into the air and bring it back down to the ground. Repeating the process creates a constant flow of electricity.

• Small system size
• minimized shadow impact
• minimized noise emissions

• Longevity of the materials not investigated
• Potential disadvantages in approval law issues

Pavegen

The idea behind Pavegen is a floor that converts the weight of footsteps into electricity using the piezo effect. With this technology, the force of a mass applied to the floor (e.g. the steps of a person) is transferred to a flexible substrate, which deforms and thus generates a voltage. Although the amount of electricity generated is very small, it could be increased by a large number of steps, for example when boarding a ferry.

• High installation costs

Solar roof tiles

Solar roof tiles are made of fired ceramic into which PV modules have been incorporated or are themselves PV modules made of conventional materials.

• can also be used in the case of listed buildings or other building regulations & thus enable self-generation of electricity

• approx. 25 % less output per m2 than conventional solar modules
• approx. twice the investment price per kilowatt peak compared to conventional modules

Solar sun sail

For a solar sun sail, either a fabric is covered with thin photovoltaic film or a mesh of assembled mini photovoltaic modules is used.

• susceptible to wind
• low energy yield

Solar fence

A solar fence is a vertically elevated PV module that can take on the function of a fence as a row.

• not more expensive than rooftop PV

• Risk of damage due to wind
• High degree of soiling under port-specific environmental conditions
• Risk of damage due to vandalism or hitting the modules

Solar paving

The solar paving consists of PV modules that either have the dimensions of paving or standard PV modules. For installation, the pavement of the parking areas is cut and removed, then the paving is produced in accordance with standards and the modules are laid on top.

• Maximum load of 8 t
• High investment costs
• Risk of damage to the system due to heavy vehicles driving over it
• Risk of flooding
• High degree of contamination under port-specific environmental conditions