Johann Gerdenitsch, department of environmental planning and Solar Appointee of the City of Fuerth

Introduction

The increased request for suitable PV-installations, demands that municipalities have a differentiated knowledge about usable potential. Based on concrete examples of the roofing landscape of the city of Fuerth, this lecture will present methods for recording this potential. The results give a very varied picture of the different building users (eg., residential buildings, commercial industrial buildings, agricultural and public buildings) and roofing forms that are suitable for solar energy purposes. Examples of cooperation possibilities and initiatives as to how this potential can be mobilized via different means of public relations will then be outlined.

Inventory of solar energy installations and capacities

At the end of 2003 Fuerth counted 170 solar — thermal collection installations with a total collection surface of 1482 m2. Almost all of these are single installations with an average collection surface of 9m2 on one-family houses and they mainly support the heating-sytems used for the warming of domestic water.

At the beginning of 2004 a total of 111 photovoltaic-installations had been installed on Fuerth’s roofs with a total production of 1611 KWp.

Around 84 installations with a production of approx. 182 KWp are installed on private residential buildings (predominately one-family houses.)

10 PV installations with a production of about 270 KWp are on municipal buildings, 8 thereof being on municipal schools with a share of approx. 250 KWp.

Particularly in 2003/2004, farmers installed installations on agriculturally used buildings (approx. 116 installations) with a total production of around 160 KWp.

A large PV-facility constructed on the former waste disposal site in Atzenhof started operation in Dec. 2003 with a total production of 1MWp.

The waste site has been operated as a waste management plant for almost 50 years and is a consciously planned and officially approved constructional facility of the city of Fuerth.

Thus, it cannot be compared to the open space (undeveloped area) facilities in matters concerning the Renewable Energy Law and its full scope of supply (and service) should be detailed in the appraisal by the National Solar Association.

The total municipal portion of the PV-installations in the city of Fuerth accounts for 1270 KWp (79%) which is not a negligible amount.

A 10-fold increase in the solar electricity production was able to be made from 2001 to 2004.

Fig.: Development of PV-installations in the urban area of Fuerth

The roofage potential for solar energy installations

The evaluation of an inventory that was in large, made on the basis of aerial photographs, brought the following results;

From a total of approx. 22 600 buildings in the urban area, over 5000 (22 %) are suitable for using for solar energy. [34]

picture: existing solar installations and the roofage potential in the village
structured suburb of Unterfarrnbach in the city of Fuerth

The approx. 5000 PV-suitable buildings in the urban area have a surface potential of approx. 800,000 m2 that is usable for solar energy.

On approx. 4600 buildings with slanting roofs (i. e. 92 %) there is a PV suitable surface of approx. 600 000 m2 available and 200,000 m2 on approx. 400 buildings (i. e. 8%) with flat roofs.

The flat roof potential prevails particularly in commercial / industrial areas but also partially on public buildings.