Photovoltaic, Energy Storage, DC Distribution and Flexibility: Opening a New Era of Building Energy

Photovoltaic, Energy Storage, DC Distribution and Flexibility: Opening a New Era of Building Energy

On the path of pursuing green and sustainable development, innovation in the energy sector never stops. In recent years, a technology known as "Photovoltaic, Energy Storage, DC Distribution and Flexibility" has gradually come into the spotlight. It is quietly transforming our traditional ways of using building energy, bringing new possibilities for achieving a low-carbon and efficient future life. Today, let's take an in-depth look at the Photovoltaic, Energy Storage, DC Distribution and Flexibility technology.
I. What is Photovoltaic, Energy Storage, DC Distribution and Flexibility?
Photovoltaic, Energy Storage, DC Distribution and Flexibility is the abbreviation for the application of four technologies, namely Photovoltaic, Energy Storage, Direct Current (DC) Distribution, and Flexibility, in the construction field. It is a new type of building energy system, aiming to organically combine photovoltaic power generation, energy storage, DC distribution, and flexible power consumption, so as to achieve efficient, low-carbon, and flexible utilization of building energy.
(1) "Photovoltaic" - Distributed Solar Photovoltaic
As one of the main renewable power sources in the future, solar photovoltaic power generation has enormous potential. Buildings have a huge external surface area, which provides abundant spatial resources for the development of distributed photovoltaics. Nowadays, the photoelectric conversion efficiency of photovoltaic modules is continuously improving. Under laboratory conditions, the highest conversion efficiency has reached 47.1%, and the efficiency of mass-produced crystalline silicon modules easily exceeds 22%. A large number of photovoltaic modules are installed on building rooftops, walls, and other locations, fully absorbing solar energy and converting it into electrical energy, providing a clean energy source for building electricity consumption.
(2) "Energy Storage" - Distributed Energy Storage
The energy storage system plays a crucial regulatory role in the Photovoltaic, Energy Storage, DC Distribution and Flexibility technology. It mainly includes battery energy storage devices such as lithium batteries and lead-acid batteries, and is equipped with a battery management system to monitor the battery's state of charge, temperature, voltage, and other parameters in real-time, ensuring the safe and efficient operation of the batteries. It can store excess electrical energy generated by photovoltaic power generation and continuously supply power to the building when photovoltaic power generation is insufficient, such as at night or on cloudy days, effectively solving the intermittency problem of solar power generation. In the future, with the popularization of electric vehicles, charging piles with bidirectional charging and discharging functions can use electric vehicles as mobile energy storage for buildings, further enriching the forms of energy storage.
(3) "DC Distribution" - Low-Voltage DC Distribution System
Different from the traditional alternating current (AC) distribution system, the DC distribution system has the characteristics of simple form, easy control, and high transmission efficiency. In the Photovoltaic, Energy Storage, DC Distribution and Flexibility system, the DC distribution system directly distributes the direct current generated by photovoltaic power generation or output by the energy storage system to DC electrical devices, reducing the energy loss during the AC/DC conversion process. Moreover, the DC distribution system facilitates the access of distributed power sources (such as photovoltaic power sources) and energy storage systems, greatly improving the flexibility and reliability of the system.
(4) "Flexibility" - Flexible Interaction
"Flexibility" is the ultimate goal of the Photovoltaic, Energy Storage, DC Distribution and Flexibility technology. It aims to transform building electricity consumption from a rigid load to a flexible load. On the one hand, electrical devices can dynamically adjust their output power according to the fluctuations of the DC bus voltage. When it senses that the external power supply is at a peak, the devices automatically reduce their power operation under the premise of ensuring comfort. On the other hand, through the dynamic matching of photovoltaics, energy storage, and load, a friendly interaction with the power grid is achieved. For example, the intelligent lighting system can automatically adjust the brightness according to the light intensity and indoor personnel activities; the air conditioning system can adjust the cooling/heating power according to the indoor and outdoor temperatures and energy supply conditions. The control system uses sensors, communication networks, and intelligent algorithms to monitor and control the energy flow within the building in real-time, achieving flexible control of electrical devices.
II. Application Scenarios of Photovoltaic, Energy Storage, DC Distribution and Flexibility
(1) Residential Buildings
For household users, the application of the Photovoltaic, Energy Storage, DC Distribution and Flexibility system in residential buildings is expected to achieve self-sufficiency and efficient utilization of household energy. Rooftop photovoltaic power generation can meet part or even all of the household's electricity needs, and the energy storage system plays a role when photovoltaic power generation is insufficient at night or on cloudy days. The DC distribution system can support DC electrical devices such as DC TVs and DC refrigerators, reducing energy conversion losses. With the help of flexible power consumption control, smart devices in the home can automatically adjust their working modes according to factors such as electricity prices and photovoltaic power generation. For example, when photovoltaic power generation is sufficient, they give priority to using photovoltaic power and store the excess power in the energy storage system, thereby reducing household electricity costs.
(2) Commercial Buildings
Large commercial buildings, such as shopping malls and office buildings, have great potential for applying the Photovoltaic, Energy Storage, DC Distribution and Flexibility system. Their large rooftop and facade areas can accommodate a large number of photovoltaic modules, generating considerable electrical energy. The energy storage system can balance the intermittency of photovoltaic power generation and the volatility of electricity consumption in commercial buildings (where there are obvious peaks and valleys in electricity consumption during business hours). The DC distribution system provides more efficient power supply for DC electronic devices in commercial buildings, such as computers and electronic displays. Flexible power consumption control can dynamically adjust the power consumption of devices such as lighting, air conditioning, and elevators according to factors such as the number of people in the building and business hours, achieving refined energy management and energy savings.
(3) Industrial Buildings
In industrial production, the Photovoltaic, Energy Storage, DC Distribution and Flexibility system can provide power support for some electrical devices. The energy storage system can provide emergency power for key devices when there are power outages or voltage fluctuations in the power grid, ensuring the continuity of production. Through flexible power consumption control, devices such as motors and lighting in industrial buildings can be optimized and adjusted according to production plans and energy supply conditions, reducing the energy consumption and production costs of industrial buildings.
III. Advantages and Significance of Photovoltaic, Energy Storage, DC Distribution and Flexibility
(1) Significantly Improved Energy Efficiency
The Photovoltaic, Energy Storage, DC Distribution and Flexibility system reduces the energy losses in the multiple AC/DC conversion processes of the traditional system. The DC distribution system and flexible power consumption technology can better match the energy supply and demand within the building, significantly improving the building's energy utilization efficiency. Studies have shown that compared with traditional building energy systems, the Photovoltaic, Energy Storage, DC Distribution and Flexibility system can increase the comprehensive energy utilization efficiency of buildings by 10% - 20%.
(2) Contributing to the Realization of Low-Carbon and Environmental Protection Goals
By fully utilizing solar photovoltaic power generation in buildings, the dependence of buildings on electricity from the traditional power grid is greatly reduced, thereby reducing carbon emissions. Especially throughout the entire life cycle of a building, the Photovoltaic, Energy Storage, DC Distribution and Flexibility system can significantly reduce the greenhouse gas emissions generated by building electricity consumption, strongly promoting the achievement of carbon emission reduction goals in the construction industry. At the same time, the flexible power consumption technology can flexibly adjust the building's energy consumption according to factors such as energy prices and weather conditions, improving the flexibility and adaptability of the building energy system.
(3) Promoting the Deep Integration of Buildings and the Energy System
The Photovoltaic, Energy Storage, DC Distribution and Flexibility system promotes the transformation of buildings from being mere energy consumers to energy producers and managers. Buildings can not only meet their own electricity needs but also feed excess electrical energy back to the power grid when there is a surplus, realizing two-way interaction between buildings and the energy system and laying a foundation for building a more intelligent and efficient energy system.
Nowadays, Shennongjia has completed the construction of Hubei's first "Photovoltaic, Energy Storage, DC Distribution and Flexibility" green building demonstration power supply station, and Wenzhou has successfully applied the first "Photovoltaic, Energy Storage, DC Distribution and Flexibility" system. These practical cases fully demonstrate the feasibility and superiority of the Photovoltaic, Energy Storage, DC Distribution and Flexibility technology and have accumulated valuable experience for its wider promotion and application. As an important pillar for the development of zero-carbon energy, the Photovoltaic, Energy Storage, DC Distribution and Flexibility technology is painting a beautiful blueprint for future green building energy with its unique advantages. It is believed that in the near future, with the continuous maturation of the technology and further cost reduction, Photovoltaic, Energy Storage, DC Distribution and Flexibility will be applied in more buildings, creating a more low-carbon, comfortable, and intelligent living environment for us. Let's look forward to the energy revolution brought by the Photovoltaic, Energy Storage, DC Distribution and Flexibility technology together!