Introduction

At the moment street lighting in the City of Graz has approx. 24,000 lamps plus special illumination, such as on the Hauptplatz or over the Mursteg. These lamps are directly controlled by approx. 1,400 switch boards. The  electricity costs (incl. energy fee and VAT) amount to about Euro 1.17 million a year. Many lighting installations are from the 1960’s and are up to 40 years old. Big energy saving opportunities are offered by the use of up-to-date technologies – new highly efficient lighting equipment, new lamps with mirror technology and light regulation as well as control adjusted to the needs (reduction of power consumption over night). However, the funds required for putting all this into action have been missing up to now.

Objectives and target audience

The objective of the programme “Green Light Graz” is to modernize all the street lighting in Graz wherever there are opportunities of saving money and to open up the opportunities of saving energy. The implementation of the programme “Green Light Graz” enables the City of Graz to profit in various respects:

• saving costs in terms of energy and renewal;
• ! immediately relieving the budget by implementing the Thermo profit Model;
• ! improving “quality of lighting” in the City of Graz – creating a more modern cityscape!
• ! implementing the objectives and targets of KEK Graz (KEK – Kommunales Energiekonzept – Municipal Energy Plan): increasing energy efficiency and saving energy, reducing CO2 emissions;
• immediately holistically opening up the efficiency potentials instead of taking long-term isolated measures that fail to yield equivalent success at saving.

Financial Resources and Partners involved

Order value: 1.804,174 € (gross).
In the course of this project, all the project costs (engineering, investment, management, controlling, etc.) are pre-financed and re-financed by the City of Graz paying a monthly contracting rate (energy cost budget). This means no investment costs accrue to the City of Graz.

Process

In 2005, the Pilot Project “Green Light Graz I” (modernizing street lighting along the main traffic route Wienerstraße – Gürtel and other main streets) was started. 718 lamps in main streets were renewed and provided with state-of-the art technologies and control engineering.

• diecast aluminium lamp with the System of Protection IP66;
• no need for tools when opening and thus ease of replacing the lighting equipment;
• highly efficient reflector with a facet look;
• glass vessel made of safety glass;
• switching and reducing control for reducing power consumption over night.

The Graz Energy Agency has taken over the whole project handling for contract management as an overall package by order of the City of Graz. As for technical implementation and financing, the Graz Energy Agency co-operates with Energy Graz. Together these two organizations guarantee the calculated energy savings.
Maintenance and servicing, operation, troubleshooting and elimination of defects, etc., continue to be conducted by Energy Graz within the existing contract. The energy delivery contracts remain unaffected by this agreement.
The Graz Energy Agency presents an annual report to the City of Graz. This report states the savings and evaluates implementation.
The Thermoprofit Implementation Model
In the course of this project, all the project costs (engineering, investment, management, controlling, etc.) are pre-financed and re-financed by the City of Graz paying a monthly contracting rate (energy cost budget). This means no investment costs accrue to the City of Graz.
Furthermore, the financing model has been designed as to make sure that the City of Graz is given a share in the savings achieved from the beginning. This makes a direct contribution to relieving the budget. After the end of the term, the complete savings will be for the benefit of the City of Graz!
The nominal contractual period amounts to 15 years.
The monthly contracting rate remains the same throughout the term. The financing model is based on a variable rate of interest, the monthly contracting rate remaining constant and the term being adjusted adequately.

Results

The energy savings
Lighting hours: 4161 hours
Power consumption before the measures: 905,766 kWh
Energy savings – guaranteed: 524,000 kWh (- 58 %)
Energy savings, actual: 533,100 kWh (- 59 %)
Savings of energy costs: 67,200,- €/year
This means the guaranteed savings are even exceeded. The additional savings to the amount of € 2,000.- are for the benefit of the City of Graz.
The cost savings
Thanks to the Thermoprofit Model, the budget is immediately relieved by approx. € 30,000.- a year. After 15 years, the full saving to the amount of at least € 67,200.- is for the profit of the City of Graz.

Critical Success Factors / Challenges

It is true savings to a similar amount as at the first project can no longer be achieved. Nevertheless, the use of up-to-date technologies still offers significant economic energy saving opportunities.
An estimate made by the Graz Energy Agency and Energy Graz shows that economic saving measures might be taken at about 15,000 light points. In addition to the use of efficient lamp and control technologies, such innovative measures as LED technology and solar lamps can be integrated.
As for the considered light points, there is a saving potential of about 20%. This results in energy cost savings of approx. Euro 120,000.- a year for the City of Graz.
Even in this case implementation using a Thermoprofit Model could take place in such a way that the City of Graz can immediately profit from the savings and the budget is thus relieved.