Many communities could generate enough renewable energy to answer the needs of the entire local population. These are the findings of a research project called ERNEUERBAR KOMM! In fact, solar energy and wind power alone would often be enough to answer the needs of all private households. It would only require solar panels on ten percent of all available rooftops and five percent of unused land, combined with just half of the locations suitable for wind turbines. This analysis of renewable energy potential was carried out by Prof. Dr. Martina Klärle, head of the Weikersheim-based Steinbeis Transfer Center for Geoinformation and Land Management. To make her holistic assessment of land use, Klärle looked at core geodata and used geographic information systems (GIS). Her Steinbeis Center helps local authorities make practical use of ERNEUERBAR KOMM! findings.
Thanks to a 2008 research project called SUN-AREA, it was finally possible to automatically calculate the solar energy potential of rooftops. Once SUN-AREA was complete, Prof. Dr. Martina Klärle and her colleagues embarked on a project called ERNEUERBAR KOMM! Its aim: to create a renewable energy analysis that would calculate the potential of all forms of renewable energy – quickly, efficiently and precisely – based on existing geodata. Calculations would be made by individual community or rural district.
The system provides implementation guidelines, highlighting the potential to use different forms of energy in the community. A Web-based tool calculates and plots the energy potential by area. Users in the community can then calculate the potential of renewable energy in their area using an ondemand Internet platform. ERNEUERBAR KOMM! also features an online calculator developed using game-based learning techniques to encourage local authorities to use the tool.
A regional association in the Rhine-Main area around Frankfurt was selected to take part in a pilot project to estimate the potential of a local area, which encompassed 75 communities. Holistic evaluations of potential are currently taking place in the city of Worms, the Black Forest central region (Energy Region 2010), the Main-Tauber district, and a variety of other communities in the states of Baden-Württemberg and Bavaria. The ERNEUERBAR KOMM! project can be implemented in all communities throughout Germany.
To define the precise energy potential of an area, the ERNEUERBAR KOMM! system uses a geographic information system (GIS). This draws on official geodata and statistics held by the local communities, so it also includes information on the population, how land is used, exclusion areas, wind speeds, radiation levels, rooftops and natural drops in flowing water. The baseline data needed to carry out the evaluation is generally quite thorough, so there is no need to carry out special searches. To analyze and refine data, existing planning guidelines are used. For example, exclusion areas are calculated by looking at designated conservation zones and rules relating to permitted distances (of installations like wind turbines) laid down under local bylaws. The calculations can be carried out by individual community. The figures show exactly how many rooftops or how much land in a community can be used to generate electricity through solar power, wind energy, biomass and hydroelectric power. They also show how much electricity this would generate and the percentage of private household demand this would cover.
The ERNEUERBAR KOMM! analysis is based on available land or open areas. The formulae used to make the calculations can be applied to all types of renewable energy to determine the relationship between the amount of electricity generated and the area needed to do this. What this means for users of the Web-based calculator is that the system will show, for example, that 100 hectares of designated farming land is suitable for biomass energy production. At the click of a button, the user can then select 10 hectares of this area and view the amount of energy this relates to. This allows users to see immediately how much land is being used for the chosen renewable energy in relation to the amount of energy produced. The database also ties in local population figures and electricity use per inhabitant to calculate how many households can be supplied with power from the areas selected.
Overall, the calculations do more than just show theoretical potential in technical terms. Mayors, local councils or citizens can actually use the online calculator to pull together their own energy package factored up by “utilization level.” This allows users to select the proportion of potential energy to be provided by wind, solar, biomass or hydroelectric power. The Internet platform uses an interactive design to allow the system to calculate, on demand, the proportion of energy requirements that can be covered and plot this on a bar chart. It is easy to view and compare the yield of each energy form. For example, users can select 40 percent of rooftops suitable for solar energy and see that this would cover the electricity requirements of 50 percent of private households. Or the system would show users that biomass would be needed from 200 hectares of agricultural land to supply 4000 inhabitants with electricity, or use a single wind turbine.
Settings can be made for each type of energy in a separate window which shows how many of the available areas are technically compatible, or for wind power, the possible number of turbines. Users of the online calculator then factor in the proportion of these that should be utilized (the utilization level).
Who the key players will be in the emerging era of renewable energy is still not cast in stone. But it is clear that the authorities at all levels will play a central role in moving energy policy forward. ERNEUERBAR KOMM! now provides them with a hands-on tool to support them on their journey.
Prof. Dr. Martina Klärle
Steinbeis Transfer Center Geoinformation and Land Management Weikersheim
su1072@stw.de