Solar Energy in the City: The Path to Greener Rooftop Gardens
The impact of climate change has been evident for decades, and its effects will particularly affect cities in the coming years and decades. Cities already struggle with higher temperatures in "normal" times due to dense construction and minimal vegetation. Added to this are the heat generated by traffic, industry, and households. Overall, this creates conditions for higher temperatures, increased pollutant concentrations, low humidity, and little wind. In some areas, legislative measures have already been taken, such as transitioning to electromobility. Work is also being done on urban greening concepts.
Therefore, the fundamental problems are energy, pollutant emissions, and temperature rise. One way to address these issues is to equip rooftops with green and solar installations.
Introduction to Urban Solar Technology: Potential and Possibilities
To replace fossil energy, solar energy is a crucial and promising contribution. Currently, solar panels in Germany produce about 9% of the total electricity consumption. To highlight the potential of rooftops regarding solar energy, a study by various universities, using artificial intelligence, revealed that the globally available rooftop area of approximately 200,000 square kilometers would be sufficient to meet the world's electricity demand. Sustainable urban development can, therefore, only be envisaged with solar energy. In addition to rooftops, solar solutions can also be installed on balconies and facades. This gives individuals the opportunity to purchase urban solar solutions, contribute to the environment, and simultaneously reduce their energy costs.
Integration of Solar Panels in Rooftop Gardens: Practical Examples and Design Concepts
As mentioned earlier, urban areas face significant challenges. Besides energy, rising temperatures are a central issue. An efficient yet straightforward way to combat rising temperatures is to green the city. In addition to ground-level plantings, rooftop areas are suitable for greening. Moreover, green rooftop gardens can be combined with solar energy. Both methods complement each other excellently, and there are already innovative urban solar projects. This allows efficient use of solar energy in the city, and solar-powered rooftop gardens contribute to sustainable buildings.
Ecological and Social Advantages of Green Roofs with Solar Energy
The German Weather Service, in its "Analysis of the Thermal Effect of Roof Greening through Urban Climate Modeling", published that rooftop greening alone can lower inner-city temperatures by up to 0.8 degrees. This value increases when combined with tree planting and other greenery. The City Marketing Austria advertises that an overall perceived temperature reduction of up to 13 degrees is possible because factors like humidity, wind, and shading come into play, not just the temperature drop.
The consequences of temperature reductions are diverse. For example, humans are most efficient at temperatures between 20 to 22 degrees. According to the IHK Nuremberg, concentration and performance decrease by about 5 percent with each additional degree. High temperatures thus directly impact the efficiency of the economy. To counteract this, air conditioners are usually installed, which, in turn, lead to increased energy demand and higher costs. Solar-powered rooftop gardens would directly counteract this and contribute to sustainable buildings. This is a concrete example of why rooftop greening, combined with solar technology, is a good approach to address existing and future challenges.
In addition to ecological benefits, social benefits are also significant. Pleasant temperatures ensure that people are more likely to connect socially in urban areas. Green environments strengthen social cohesion in urban areas. Evidence for this comes from a study by Dr. Scott Ogletree's team at the University of Edinburgh. The team found that an increase in green spaces in urban areas corresponds to a decrease in the crime rate. In 300 of the 301 examined U.S. cities, there were fewer property crimes, and in 289 of 300 cities, fewer violent crimes.
Challenges and Solutions in Implementing Solar Panels in Urban Areas
Often, the first question revolves around the profitability of a solar installation. This question can usually be answered relatively quickly. If the targeted rooftop area allows for installation and the system is not shaded, it is generally profitable. Profitability, in this context, does not only refer to the direct compensation or the direct usability of the produced electricity but also to the energy saved from fossil fuels, which accelerates climate change and leads to enormous follow-up costs.
Another point concerns the appearance of the city and the integration of solar installations into the prevailing architectural culture. On this topic, many successful case studies from different parts of Europe now document the implementation in urban areas. City planners have the opportunity to benefit from the insights gained from these case studies and adapt them to their areas.
Overall, it should be noted that the combination of solar energy with green roofs offers extraordinary opportunities to improve the quality of life in many areas.