Saarbrücken - Deutschland
Simple, low-cost solutions improve energy efficiencyBackground
The municipality of Saarbrücken identified one of their rented administrative offices as consuming high levels of electrical energy (29.3 kWh/m²/annum). This building is occupied by the Gartenamt, who look after the city’s green spaces. In order to reduce the electrical energy consumption, a survey of the building was undertaken to identify areas where energy could be saved. This survey resulted in the implementation of some simple, low-cost solutions to improving energy efficiency, such as replacing old, energy inefficient refrigerators with fewer highly efficient models and using timers for water heating in staff kitchens. These and other simple measures have resulted in a 25% decrease in electrical energy consumption (now 22 kWh/m²/annum).
Building details |
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| Type of building : |
Administrative building |
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| Year of construction/ Floor area/ Operating hours : |
Built around 1907 and retrofitted between 1950 and 1960/ floor area is 1089 m2 / Operating hours are Monday to Friday, 6am – 6pm. |
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| Heating and cooling / measures installed |
Timers added to electric water heating |
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| Energy/CO2/Water label (before and after improvements if possible) |
A Display® certificate was produced for the building for 2003 :
Energy use 385 kWh/m², label F ;
CO2 emission 51 Kg/m², label D ;
Water use 253 litres/m², label C.
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_ The Display® certificate for 2006 showed a significant reduction in energy consumption. This is due to both the implementation of electrical energy saving measures described in this Shining Example and changes to the heating system, such as improving heating controls and replacing damaged insulation :
Energy use 187 kWh/m², label D ;
CO2 emission 35 Kg/m², label C ;
Water use 247 litres/m², label C.
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Project Description |
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| Aim |
The aim of this project was to reduce the electrical energy consumption of the building by over 30% from 29.3 kWh/m²/annum to less than 20 kWh/m²/annum. |
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| Key points |
The first step in this project was to undertake a detailed survey of the building to see how energy was being used and identify ways to reduce consumption. The survey highlighted several opportunities for saving energy :
- There are many electric hot-water devices for hand-washing in the toilets. As it is not necessary to use hot-water for hand-washing, these devices were disabled.
- Some electric hot-water devices are also present in staff kitchens for washing kitchenware (e.g. coffee cups) and for cleaning the room. Timers have now been attached to these devices to make sure that they are only active during normal working hours, and not during the night or weekends (see photo).
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Timer used for hot-water devices in staff kitchens
- Too many refrigerators were in use in the offices. After discussions with staff it was agreed to reduce the number of refrigerators. Some very old refrigerators with high consumption (up to 450 kWh/annum) were replaced by new, highly efficient refrigerators that only consume 84 kWh/annum (an energy saving of 80%).
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New energy efficient refrigerator
- In some of the inner corridors the electric lights that were active all day (from 6am to 6pm) had a brightness of up to 420 Lux, instead of the standard 100 to 150 Lux. The brightness of the lighting has now been reduced to the standard level.
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| Reason for inclusion as Shining Example |
This Shining Example demonstrates how simple measures with relatively small costs, such as water heating controls and the use of energy efficient appliances, can be used to achieve considerable reductions in electricity consumption (25% in this case). It also demonstrates the importance of discussing any proposed changes to improve energy efficiency with staff who are affected by such proposals. Communication with staff ensures that they understand why the changes are being made and is therefore integral to their acceptance of the changes. This also has the added benefit of raising awareness of energy conservation amongst staff. |
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Costs & Benefits |
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| Costs & funding |
The refrigerators were paid for by the municipality (€350 each), because it is important for employees to have cold drinks, especially during hot days in summer, which are becoming more frequent.
_ The investment for the refrigerators was not large. By replacing every two or three existing refrigerators with only one new model, the refrigerators pay back in around two years. |
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| Benefits |
So far this project has resulted in an electrical energy saving of 25% for this building. In absolute figures this is a drop in consumption from 31,890 kWh to 23,919 kWh (or from 29.3 kWh/m2/annum to 22kWh/m2/annum). This equates to a saving of €1,500 per annum. Energy consumption is expected to decrease even further in the future, because not all of the energy-saving measures were in place during the last period when consumption was measured. CO2 emissions have been reduced by 17 tonnes per annum. |
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Partnership details |
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| Partners & role |
No partnerships were formed for this project, which only involved staff from Stadt Saarbrücken. |
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Recommendations |
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| Achievements |
This project has achieved significant savings in energy costs, electrical energy consumption and CO2 emissions. Monitoring of energy use is ongoing, and further savings are expected now that all of the energy-saving measures have been fully implemented.
_ Another achievement of this project is that it has raised awareness of the need for energy efficiency among staff. Staff were kept informed of the project and their acceptance was sought before the energy saving measures were implemented. |
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| Lessons Learned |
This project can be easily replicated in other buildings, at a very low cost. Undertaking the initial survey to assess a building’s energy consumption can take some time because it is necessary to inspect each office. However, the inspection is easy to do and it can reap significant energy, cost and CO2 savings. |
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Useful info |
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| Publications |
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| Websites |
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| Arrangements to visit |
Contact Jürgen Lottermoser |
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