Shirin Kriklava - Stiftung Altes Neuland Frankfurt

Frankfurt's bridges require around 140 GWh/a of electricity - electricity consumption from hot water, heat pumps and autonomous driving included!

Of the 140 GWh of electricity per year, about 53 GWh/a are used by Bridge households with about 35,000 Bridge residents. Around 22 GWh/a are consumed by businesses such as restaurants, educational institutions, etc.. Of the remaining 65 GWh/a, 58 GWh/a are used by bridge traffic, and 7 GWh/a are consumed by bridge infrastructure such as elevators, street lighting, control technology, pumps, etc.

Content: Composition of the electricity demand on the Frankfurt bridges

The 35,000 Bridge residents consume about 1,500 KWh/a per capita in their households -including heat pumps for space heating and cooling- or a total of about 53 GWh per year, because only the most modern technology and extremely energy-saving appliances are installed in Bridge homes.

A total of 22 GWh/a is required for 275,000 m2 of non-residential building space, and restaurants, sports facilities, educational institutions, and more must also be equipped with energy-saving devices and also sensor technology from the start, so that everything is controlled on a demand basis and only comes on when it is used.

With 14 hours of travel time per day all year round, the 400 bridge vehicles consume 58 GWh/a of drive energy (plus around 2 GWh for control technology). The comparatively low power consumption of approx. 85 kWh/100 km for electric-powered vehicles and approx. 230 kWh/100 km for H2 -powered vehicles is due to the lightweight construction of the bridge vehicles and the smooth operation of the autonomous traffic.

The largest electricity consumers on the Frankfurt bridges are the buildings with a total of 75 GWh/a, followed by the e-vehicles with 58 GWh/a

The residential buildings on the bridges are comparatively economical in electricity consumption

1.15 million square meters of building space are being created on the Frankfurt bridges, 875,000 m2 of which is residential space, the rest is a colorful mix of areas for education, culture, sports, medical professions, gastronomy or ecologically valuable supermarkets and stores.

The 35,000 inhabitants of Frankfurt's bridges require around 53 GWh/a for lighting, household appliances, etc. and hot water as well as heat pumps. Compared to Frankfurt, this is economical, as the 750,000 inhabitants of Frankfurt's households consume 900 GWh/a, and this despite the fact that only a small proportion of these households have heat pumps - most buildings in Frankfurt still have gas heating. If they were all heated with heat pumps like the bridge households, the electricity demand would be significantly higher.

The fact that the electrically driven heat pumps of the bridge buildings do not significantly increase the electricity consumption of the bridge households is primarily due to the coupling with geothermal energy, solar thermal energy and waste heat from data centers, which increases the COP (Coefficient Of Performance) of the heat pumps: The electricity consumption of heat pumps for space heating and cooling for all buildings is only 17.8 GWh/yr.

The household of the future operates with optimized power consumption

In keeping with the trend toward smaller households, over half of bridge housing units are 2- to 3-person households.

According to Stromspiegel, electricity consumption per person in a low-electricity-consuming optimized two-person apartment (with hot water provided by electricity, as is also planned on the bridges, but without a heat pump) is currently still around 1,800 kWh/yr.

When calculating the electricity demand of the 35,000 bridge residents, it must be taken into account that they live in buildings with different sizes or numbers of floors

The total electricity demand for the residential buildings on the bridges (excluding heat pumps) is about 38 GWh/a. With 35,000 bridge residents, the average electricity consumption per person is accordingly around 1,100 kWh/a.

Non-residential buildings consume slightly more electricity on average than private households

An electricity consumption blended value can be calculated for the 275,000 m2 of mixed color "non-residential" space:

Weighting the industry-specific electricity consumption per square meter by the square meter share of each industry on the bridges, we arrive at an average (optimized) electricity consumption of around 80 kWh/m2 a, including heat pump electricity consumption, which is used to provide heating and cooling.

For the non-residential areas on the bridges, this results in a total electricity consumption of approximately 22 GWh/a.

Culinary and education take up the largest share of space on Frankfurt bridges

The specific electricity demand changes according to the type of use: gastronomy is the main electricity consumer in the non-residential buildings on the bridges

Other infrastructure such as street lighting, controls, pumps, elevators, etc. consume comparatively little electricity, totaling 7 GWh/a

The bridge infrastructure consumes approx. 7 GWh/a - automation and control are the main electricity consumers, followed by lighting on and under the bridges.

As part of the four- to five-year preliminary planning phase for the Frankfurt bridges, electricity consumption must be planned in detail in all areas

Example: Lighting design 200 m section Kennedyallee between railroad bridges and Paul-Ehrlich-Straße

The vehicles on the bridges transport around 40 million passengers per year - and consume 58 GWh of electricity p.a. to do so: Of these, 200 are e-vehicles and 200 are hydrogen vehicles.

The 400 vehicles on the bridges travel 14 hours a day at an average speed of 17.8 km/h. Each vehicle covers an average of 250 km per day.

The large bridge vehicles for multi-passenger transport run on hydrogen, while the smaller ones are pure e-cars.

According to the current state of development for both types of propulsion, the energy consumption for electricity-powered vehicles is 15 kWh/100 km and for hydrogen-powered vehicles 60 kWh/100 km: Both vehicle types are planned in lightweight construction, which means that their consumption is lower than that of current commercial (bus) models with alternative forms of propulsion.

The bridges generate around 417 GWh of electricity per year - but the bridges themselves and their vehicles consume only 140 GWh/a of this. The remaining surplus of around 190 GWh is used to supply vehicles on roads along the bridges.

127 GWh/a will be provided for electricity-powered vehicles along the bridges, and additional energy will be put into the production of 64 GWh/a of hydrogen for H2 -powered vehicles along the bridges.

Profis zu dem Thema

Leibniz Forschungszentrum Energie 2050 - ETH Zürich - Institute of Energy and Process Engineering - The World Sustainable Energy Institute - California Center for Sustainable Communities at UCLA - National Renewable Energy Laboratory - National Institute of Advanced Industrial Science and Technology - Energy Research Institute at NTU - Asean Center for Energy

Conclusion: The electricity demand on the bridges is already optimized during the construction of the quarter

Residential buildings, like non-residential buildings, are equipped with energy-efficient appliances and sensor technology for targeted appliance use. At 75 GWh/a, they consume about half of the electricity on the bridges.

The second-largest consumers are the hydrogen and electricity-powered vehicles on the bridges: they are very energy-efficient due to their light weight and optimized, low-brake routing, and require a total of 58 GWh/a.

At 7 GWh/a, bridge infrastructure consumes the smallest share of the total bridge electricity consumption of 140 GWh/a.

Electricity demand on the Frankfurt bridges

Heating and cooling requirements of the bridges

Photovoltaics as quarter power

Near-surface geothermal energy

The energy infrastructure of the future

The bridge world

Sustainability through technology

The Co2 balance of bridges