Solar parking lot: Solar carports and solar parking lot systems - the sustainable type of photovoltaics on asphalt surfaces

Asphalt surfaces are common in many cities and provide a large area that can be used for the installation of solar carports and solar parking systems. This type of photovoltaics is particularly sustainable because it is installed on existing areas and does not take up any new areas. At the same time, shading helps prevent cities from overheating, as overheated streets are one of the biggest climate problems in urbanization. In addition, solar carports and solar parking systems can help reduce environmental impact through emission-free electricity generation.

The problem of overheating cities is a big and serious problem, but most people don't know what to do about it. Urban planning is a key factor in combating the overheating of urban environments. According to climate researcher Dr. Ebi Krypton “79% of global CO2 emissions are directly or indirectly attributable to urban activities.” This high percentage of blame for greenhouse gas emissions illustrates how much pressure our cities are under as population densities increase. Unfortunately, many modern architects and urban planners tend to accept heat as an unavoidable element in their designs. But there is hope - if we get excited about and implement climate-adapted architectural solutions, this can help limit global warming to 1.5°C to 2°C.

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• Green Smart City: Green infrastructure and emission-free power supply

Smart City: Green infrastructure and power supply – Image: Xpert.Digital / studiostoks|Shutterstock.com

A study by 'De Lorean Power' from Switzerland found that employees' parking behavior ideally corresponds to the amount of solar power generated. The daily mileage of the electric vehicle can be covered in almost any weather and the excess can be fed into the grid. The annual solar power generation in the parking lot corresponds to the vehicle's energy needs. Solar parking spaces have the greatest potential for generating electricity of all infrastructure areas. There are approximately 2 parking spaces available for each registered car in Switzerland. In available regions, it can generate over 10 terawatt hours of solar power per year (15% of current electricity consumption). “It is astonishing how few pilot plants there are,” say the authors of the study. In addition, such a roof protects the car from the elements and reduces the heat of the car in summer.

According to an evaluation by the Federal Statistical Office (FSO), Switzerland has at least 5 million above-ground parking spaces (6,400 hectares) with around 4.7 million registered cars. These parking areas were recorded using a digital process that only recognizes larger adjacent areas and not individual parking spaces. Traffic experts therefore expect 8 to 10 million parking spaces. That's about 2 per car.

According to the other study “Solar power generation for infrastructure facilities and conversion areas”, above-ground or open parking areas have the greatest PV potential of all infrastructure areas. These areas can provide up to 10 terawatt hours (TWh) of PV electricity per year. This means that the total electricity production in Switzerland is 65.5 TWh.

The average parking area is 12.5 square meters (2.5 meters x 5 meters). This is also the area that a solar roof must have. The energy yield of a PV system depends on many factors, including solar radiation, component efficiency and module orientation. In Thurgau, with 1 kW of installed PV power, around 1000 kWh of electricity can be generated per year (1000 kWh per 1 kWp).

Depending on the PV modules used, 1 kWp requires an installed capacity of 4 to 8 square meters. In this study, 5 m2 per kWp are calculated. This means that a 12.5 m2 parking space with 2.5 kWp output can be installed, which generates 2,500 kWh of solar power per year. The average Swiss household consumption is around 4,500 kWh/year (excluding heating, ventilation and electric vehicles).

The modular structure of a carport system is advantageous and allows you to adapt the roof to almost any parking space, thus ensuring continued good utilization of the parking space and ensuring expandability.

Using bifacial modules, the carport can be made transparent. This is visually very interesting and leads to higher solar yields, as corresponding PV modules can also use light coming from below and thus deliver 10-20% additional yield. Bifacial technology is currently not used much because it is not necessarily cost-effective due to higher module prices. However, it is assumed that this technology will become established in the next few years.

In our 4+2+ modular and scalable solar carport system, where partially transparent and bifacial modules are used, these points apply and are now also a price alternative :

Solar roofing variants specifically for vehicles – Image: Xpert.Digital

More about it here:

• Numbers, data, facts: solar carport, carport with solar roof, roofing variants in comparison and model parking space with electricity yield

Limitless: Modular and scalable solar carport system for cars and trucks

Limitless: Modular and scalable solar carport system for cars and trucks

Technical data: Modular and scalable solar carport system for cars and trucks

Technical data: Modular and scalable solar carport system for cars and trucks

The advantages at a glance:

• Flexible and modular (scalable) design
• Clearance height for cars from 2.66 m (expandable to 4.5 m or more for trucks)
• Parking space depth for cars up to 6.1 m, opposite possible up to 12.5 m.
  The depth depends on the dimensions of the solar modules used
• Solar carport system is optimally designed for partially transparent solar modules
  12% / 40% light transmission (!) - With certified approval for overhead installation
• Optionally with powerful LED lighting, dimmable and with motion control
• Can also be used for parking stands with inclined positioning
• No hidden costs regarding foundations
  Use of point foundations (cheapest variant, no complex excavation of the ground for concrete slabs etc. necessary for statics) or installation with floor slabs, depending on the existing ground conditions/asphalting

Further sources:

• Ground foundation cost factor for solar carports
• Solar carports where there is no longer a standard - the optimal solution for every challenge with solar roofing for open parking spaces
• Solar carport systems: Which is the better and/or cheaper option?
• The solar carport strategy for open parking spaces
• The modular solar carport system for all applications and cases

Truck solar carport system

Due to the fact that the 4+2+ column technology is the most flexible solution (both technically and in terms of price) for a parking space roofing system, it can also be easily expanded and used for larger vehicles such as trucks with appropriate modifications.

The increasing overheating of cities is a global problem. In recent years, the temperature in urban areas worldwide has increased by an average of 0.5 to 1 degree Celsius. This warming is primarily due to the absorption of sunlight by asphalt and other dark surfaces.

Scientists agree that this urban heat island effect is the result of global warming. However, temperature differences between urban and rural areas can also be influenced by other factors such as vegetation, wind and construction.

The effect is particularly noticeable in large cities, as this is where most people live and most cars drive. The heat is kicked up by the cars and rises into the air. It is then thrown back by the high-rise buildings and gets stuck in the urban canyons.

The problem of overheating in cities is twofold: on the one hand, the direct absorption of sunlight by asphalt and other dark surfaces and, on the other hand, the heat being stirred up by traffic.

A possible solution to the problem of overheating in cities is the installation of solar carports and solar parking systems. These systems can reduce both the absorption of sunlight and the dispersion of heat.

Solar carports are covered parking spaces that are equipped with photovoltaic modules. These modules convert the incident sunlight into electrical energy. At the same time, the heat from sunlight is dissipated and not passed on to the surroundings. This can reduce the temperature under the carport by up to 10 degrees Celsius.

Installing solar carports and solar parking systems is an effective way to reduce overheating in cities. However, these systems not only offer a solution to the problem of overheating, but can also be used to generate renewable energy.

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• Impact of urbanization: Urban heat island (UHI) – avoided through solar roofing while generating electricity

An urban heat island is an urban or metropolitan area that is significantly warmer than surrounding rural areas due to human activity. The temperature difference is usually greater at night than during the day and is most noticeable when winds are light. UHI is particularly noticeable in summer and winter. The main cause of the UHI effect is the change in the land surface. A study has shown that heat islands can be influenced by proximity to different types of land cover, such that proximity to barren land causes urban soil to warm, while proximity to vegetation makes it cooler. The waste heat generated by energy use is another factor. As a population center grows, its area increases and the average temperature increases. The term heat island is also used; it can be used for any area that is relatively hotter than the surrounding area, but generally refers to areas disturbed by humans.

Monthly rainfall is greater in the lee of cities, partly due to the UHI. Increasing heat in urban centers lengthens growing seasons and reduces the occurrence of weak tornadoes. The UHI worsens air quality by increasing the production of pollutants such as ozone, and it worsens water quality as warmer water flows into the region's rivers and strains their ecosystems.

Not all cities have a pronounced urban heat island, and the characteristics of the heat island depend heavily on the background climate of the area in which the city is located. The urban heat island effect can be reduced by green roofs, passive daytime radiative cooling, and the use of light-colored surfaces in urban areas that reflect more sunlight and absorb less heat. Urbanization has exacerbated the impacts of climate change in cities.

The phenomenon was first studied and described by Luke Howard in the 1810s, although he was not the one who named the phenomenon. Research into the urban atmosphere continued in the nineteenth century. Between the 1920s and 1940s, researchers in Europe, Mexico, India, Japan, and the United States sought new methods of understanding the phenomenon in the emerging field of local climatology, or microscale meteorology. In 1929, Albert Peppler used the term “urban heat island”, which is considered the first example of an urban heat island. Between 1990 and 2000, approximately 30 studies were published annually; By 2010 this number had risen to 100, and by 2015 there were already more than 300.

More about it here:

• Impact of urbanization: Urban heat island (UHI) – avoided through solar roofing while generating electricity