1. Definition and principle of solar lighthouse
1.1 Structural composition of solar lighthouse
Solar lighthouse is a new type of lighting equipment driven by solar energy, which is widely used in coastal areas, islands, waterways, parks and other places. Its structure mainly consists of the following parts:
Solar panel: This is the core component of the solar lighthouse, responsible for converting sunlight energy into electrical energy. Solar panels are usually composed of multiple solar cells connected in series or in parallel, which can generate enough electricity to power the lighting system of the lighthouse. At present, the conversion efficiency of common solar panels on the market has reached more than 15%, and some high-end products even reach more than 20%.
Battery pack: The function of the battery pack is to store the electricity generated by the solar panel to provide power for the lighthouse at night or on cloudy days. Common types of batteries include lead-acid batteries, lithium batteries, etc. Lead-acid batteries have a lower cost but a relatively short life; lithium batteries have a higher energy density and a longer service life.
Light source: The light source of the solar lighthouse usually uses LED lights, because LED lights have the advantages of high efficiency and energy saving, long life and high brightness. Compared with traditional light sources, the energy consumption of LED lights is only 1/10 of that of traditional light sources, and the service life can reach more than 50,000 hours.
Light pole and lamp housing: The light pole is used to support solar panels and light sources. It is usually made of high-strength steel or aluminum alloy and has good wind resistance and corrosion resistance. The lamp housing is used to protect the light source and circuit system to prevent rain, dust, etc. from damaging the equipment.
Solar controller: The solar controller is an intelligent management system for solar lighthouses. It can automatically control the charging process of solar panels and the discharging process of batteries to ensure the stable operation of the system. It also has multiple functions such as overcharge protection, over-discharge protection, and short-circuit protection, which effectively extend the service life of the equipment.
Inverter (optional): In some application scenarios that require AC output, solar lighthouses are also equipped with inverters to convert DC power in batteries into AC power to meet the power needs of different devices.
1.2 Principle of solar energy conversion into electrical energy
The working principle of solar lighthouses is based on the photoelectric effect of solar cells. Solar cells are semiconductor devices. When sunlight hits the surface of solar cells, photon energy is absorbed, causing electrons inside the solar cells to jump from the valence band to the conduction band, generating photogenerated carriers (electron-hole pairs). These photogenerated carriers separate under the action of the built-in electric field inside the solar cell to form a current.
Photoelectric conversion process: The photoelectric conversion efficiency of solar cells is an important indicator to measure their performance. At present, the conversion efficiency of monocrystalline silicon solar cells can reach up to 27%, while the conversion efficiency of polycrystalline silicon solar cells is generally around 18%. With the continuous advancement of technology, the conversion efficiency of new solar cells such as perovskite solar cells is also constantly improving, and it is expected to further improve the power generation efficiency of solar lighthouses in the future.
Energy storage and release: During the day, solar panels convert sunlight energy into electrical energy, charge the battery through the solar controller, and store the electrical energy in the form of chemical energy. At night or on cloudy days, the battery begins to discharge, converting chemical energy into electrical energy to provide power for the light source. In this process, the solar controller plays a key control role. It can automatically adjust the current and voltage of charging and discharging according to the battery power and load requirements to ensure the stable operation of the system.
Intelligent control and optimization: Modern solar light towers are also equipped with intelligent control systems that can automatically adjust the brightness and switching time of the light source according to the ambient light intensity, time and user needs. For example, when the ambient light is dim, the system will automatically turn on the light source and adjust the brightness according to actual needs to achieve a balance between energy saving and optimal lighting effects. In addition, the intelligent control system can also realize remote monitoring and fault alarm functions, making it easier for users to manage and maintain the lighthouse.
2. Current application of solar lighthouses in urban landscapes
2.1 Application cases in cities at home and abroad
Solar lighthouses, as a green lighting solution, have been widely used in landscape lighting in many cities at home and abroad. The following are some typical cases:
Foreign cases:
Green lighthouse in Copenhagen, Denmark: This is Denmark's first public building designed in accordance with the concept of carbon neutrality. Although its main function is not a lighthouse in the traditional sense, its design concept and some functions are similar to solar lighthouses. It uses nearly 300 square meters of south-facing roof area to install solar collectors and photovoltaic cells, of which 45 square meters of solar photovoltaic cells are the main energy source of the building, which can meet the needs of lighting, ventilation and maintaining the operation of heat pumps. This way of combining solar energy technology with architectural aesthetics adds a unique landscape to the urban landscape, and also demonstrates the great potential of solar energy in urban buildings.
Solar lighthouse on Hawaii Island, USA: In 1978, the United States installed the world's first solar lighthouse on Hawaii Island, marking the official birth of the solar lighthouse industry. The emergence of this lighthouse not only solved the lighting problem in remote areas of the local area, but also provided valuable experience for the subsequent development of solar lighthouses. Today, some solar lighthouses on the island of Hawaii are still in use. While providing lighting, they have also become a unique local landscape, attracting tourists' attention.
Domestic cases:
Solar lighthouses during the 2008 Beijing Olympics: Beijing installed solar lighthouses at multiple scenic spots and venues to provide lighting for the Olympic venues. These solar lighthouses not only met the lighting needs during the Olympics, but also demonstrated China's technical strength and innovative spirit in the field of green lighting. While improving the quality of urban landscapes, they also conveyed to the world China's determination to actively advocate green and environmentally friendly concepts.
Intelligent solar street light system in a large manufacturing plant: The plant launched a project to fully upgrade the traditional street light system to an intelligent solar street light system in early 2023. After the transformation, the plant lighting system saves more than 60% of electricity bills annually, which is equivalent to reducing carbon emissions by about 200 tons. At the same time, the uniform and soft lighting effect significantly improved the night working environment, improved employee satisfaction, and improved the overall safety level of the plant. The successful implementation of this project not only won a good social reputation for the company, but also became a model case for green lighting transformation in industrial areas.
2.2 Application scenarios (streets, parks, squares, etc.)
The application scenarios of solar lighthouses in urban landscapes are rich and varied, mainly including the following:
Street lighting:
Energy-saving and environmental protection advantages: The application of solar lighthouses in street lighting can effectively reduce the city's dependence on traditional electricity resources. Compared with traditional street lights, solar street lights absorb solar energy through solar panels during the day and convert it into electrical energy for storage, and then use the stored electrical energy for lighting at night. This way of using renewable energy not only reduces carbon emissions, but also reduces the city's energy costs.
Intelligent control function: Modern solar lighthouses are equipped with intelligent control systems that can automatically adjust the brightness according to the ambient light intensity. It automatically turns on and adjusts to the appropriate brightness when the light is dark, and automatically reduces the brightness or turns off when the light is sufficient, achieving a balance between energy saving and lighting effects. In addition, the intelligent control system can also realize remote monitoring and fault alarm functions, which is convenient for urban management departments to manage and maintain street lights.
Park lighting:
Improve landscape effect: The application of solar lighthouses in parks not only provides lighting functions, but also integrates with the natural landscape of the park. Its unique shape and soft light add a romantic and tranquil atmosphere to the park. For example, some solar lighthouses in parks use bionic design, imitating the forms of plants or animals in nature, and complementing the surrounding natural environment.
Create a safe environment: In the park's trails, squares and other areas, solar lighthouses can provide sufficient lighting to ensure the safety of tourists. Especially at night or in bad weather, bright lights can prevent tourists from getting lost or having accidents.
Square lighting:
Meet the needs of large-scale events: The square is an important place for holding various large-scale events in the city, and the solar lighthouse can provide bright and stable lighting for the square. In some festivals or cultural performances, the solar lighthouse can achieve a variety of changes in lighting through an intelligent control system to create a different atmosphere.
Enhance the image of the city: The application of solar lighthouses in the square not only meets the lighting needs, but also enhances the overall image of the city. Its modern design and environmental protection concept demonstrate the city's sense of technology and pursuit of sustainable development.
3. The visual impact of solar lighthouses on urban landscapes
3.1 The integration of the shape of the lighthouse and the urban style
The shape design of the solar lighthouse plays an important role in integrating with the urban style. Its unique appearance not only adds a beautiful landscape to the city, but also forms a harmonious and unified whole with the surrounding environment.
Modern minimalist style: Many solar lighthouses adopt a modern and simple design style, mainly with simple lines and geometric shapes. This design style is in line with the architectural style of modern cities. For example, the green lighthouse of Nanjing Zhongdan Ecological City has a simple and generous appearance design, which echoes the surrounding modern buildings. This style of lighthouse is widely used in urban streets, squares and other places, injecting a sense of modernity and technology into the urban landscape.
Bionic design: Some solar lighthouses adopt bionic design, imitating the forms of plants or animals in nature, so that they can better integrate with the natural environment. In natural landscape areas such as parks, lighthouses of this design can complement the surrounding natural elements. For example, the solar lighthouses in some parks imitate the form of trees, with their light poles like tree trunks, and lamps distributed on the light poles like leaves, which are integrated with the surrounding natural landscape. This design is not only beautiful, but also reduces the abruptness of the natural environment and enhances the overall landscape effect of the park.
Integration of cultural elements: In some cities or regions with historical and cultural heritage, the design of solar lighthouses will integrate local cultural elements to make it a part of the city culture. For example, in some ancient towns or historical and cultural blocks, solar lighthouses may adopt traditional architectural styles or decorative elements, such as Chinese-style lampshades, carvings, etc., to echo the surrounding historical buildings. This design not only enhances the cultural atmosphere of the city, but also enhances the citizens' sense of identity with the city culture.
3.2 The improvement of lighting effects on urban night scenes
The lighting effect of solar lighthouses plays a significant role in improving the city's night scenes. Its unique lighting design and intelligent control system add brilliance to the city's night scenes.
Energy-saving and environmentally friendly light sources: Solar lighthouses usually use LED lights as light sources. This light source has the advantages of high efficiency and energy saving, long life, and high brightness. Compared with traditional light sources, the energy consumption of LED lights is only 1/10 of that of traditional light sources, and the service life can reach more than 50,000 hours. This energy-saving and environmentally friendly light source not only reduces energy consumption, but also reduces carbon emissions, which meets the requirements of sustainable development of cities.
Intelligent lighting control: Modern solar light towers are equipped with intelligent control systems that can automatically adjust the brightness and switching time of the light source according to the ambient light intensity, time and user needs. For example, when the ambient light is dim, the system will automatically turn on the light source and adjust the brightness according to actual needs to achieve a balance between energy saving and optimal lighting effects. In addition, the intelligent control system can also realize remote monitoring and fault alarm functions, which is convenient for urban management departments to manage and maintain street lights.
Create a unique night view atmosphere: The lighting design of the solar light tower can be adjusted according to different scenes and needs to create a unique night view atmosphere. In parks, squares and other places, solar light towers can create a romantic, peaceful or warm atmosphere through the color, brightness and changes of lights. For example, in festivals or literary performances, solar light towers can achieve multiple changes in lights through intelligent control systems to create different atmospheres. This unique night view not only enhances the beauty of the city, but also attracts more tourists and citizens, and promotes the development of the city's night economy.
Improve urban safety and functionality: Solar light towers provide bright lighting for the city at night, improving the city's night safety and functionality. In streets, parks, squares and other places, bright lights can prevent accidents between pedestrians and vehicles and ensure the safety of citizens. At the same time, good lighting conditions also facilitate citizens' night travel and activities, and improve the quality of life in the city.
4. The positive impact of solar lighthouses on the urban environment
4.1 Energy conservation and emission reduction and sustainable development
As a clean energy device, the wide application of solar lighthouses in cities has a significant driving effect on energy conservation and emission reduction and sustainable development.
Significant energy conservation and emission reduction effect: Solar lighthouses do not consume traditional fossil energy during operation and do not produce greenhouse gas emissions such as carbon dioxide. Taking a medium-sized city as an example, if all traditional street lights are replaced with solar lighthouses, about thousands of tons of carbon dioxide emissions can be reduced each year. In addition, the energy consumption of solar lighthouses mainly comes from solar energy. The use of this renewable energy greatly reduces the city's dependence on traditional electricity and saves a lot of energy resources.
Helping urban sustainable development: The use of solar lighthouses is in line with the concept of sustainable urban development and helps cities achieve energy conservation and emission reduction goals. With the global attention and response to climate change, more and more cities are incorporating solar lighthouses into urban planning and construction to reduce carbon footprints and improve the city's environmental quality and ecological benefits. For example, the solar lighthouse projects in some cities not only provide lighting for the city, but also become an important symbol of sustainable urban development, demonstrating the city's active exploration of green energy applications.
4.2 Reduce the urban heat island effect
The urban heat island effect is an important environmental problem facing modern cities, and the application of solar lighthouses can alleviate this phenomenon to a certain extent.
Reduce heat emissions: Traditional street lamps generate a lot of heat during operation, which will aggravate the urban heat island effect. Solar lighthouses use LED lights as light sources, which have high luminous efficiency and generate less heat. Compared with traditional street lamps, solar lighthouses significantly reduce heat emissions to the surrounding environment when operating at night, which helps to reduce the nighttime temperature in the city.
Improve the microclimate environment: The layout and design of solar lighthouses can have a positive impact on the urban microclimate. Reasonably distributed solar lighthouses can provide soft lighting at night while reducing heat radiation to the ground. This helps to regulate the temperature and humidity in local areas, improve the microclimate environment of the city, and create a more comfortable living and working environment for citizens.