In the context of increasingly serious global warming, renewable energy sources have become a sustainable development solution chosen by many countries, organizations and individuals for the global future. In particular, rooftop solar power systems are considered one of the solar power systems widely used in many provinces and cities in Vietnam. So what is rooftop solar power, what are the benefits of using this power system? Let's GREEN IN Find out through the article below!
1. What is rooftop solar?
Pursuant to Clause 5, Article 3 of Decision 13/2020/QD-TTg, the concept of rooftop solar power is explained as follows: “Rooftop solar power system is a solar power system with photovoltaic panels installed on the roof of a construction work and has a capacity of no more than 01 MW, directly or indirectly connected to the power grid with a voltage level of 35 kV or lower of the Electricity Buyer.”
2. Some rooftop solar power models
Currently, rooftop solar power models are divided into three popular installation models including:
2.1. Independent rooftop solar power system
The way this type of solar battery works is that after absorbing light to convert it into electricity, the generated electricity will be stored in the battery for use when needed. This independent rooftop solar power system is commonly applied in some areas with difficult terrain such as islands and mountainous areas that have difficulty installing the national grid system.
2.2. Grid-connected rooftop solar power system
The grid-connected rooftop solar power system is the most commonly used in Vietnam today with the following mechanism: the direct current after being generated from solar panels will be converted into alternating current by using an inverter. Electricity will be supplied to consuming devices. If the amount of electricity produced exceeds the demand, the excess will be transmitted to the national grid and recorded through the electricity meter.
2.3. Hybrid rooftop solar power system
This is a combination of two models of independent solar power and grid-connected solar power. Electricity generated from solar panels will be prioritized to fully charge the battery. Then, the electricity will be converted into alternating current to supply the devices in use. If the device does not use up all the electricity, the surplus will continue to be sent to the national grid.
3. Components of rooftop solar power
A rooftop solar power system will include the following components: solar panels, inverters, batteries and solar chargers. Each part has a different role to play in order to provide the most efficient operation for the rooftop solar power system:
3.1. Solar panels
The main component of a solar panel is pure silicon. In addition, a large number of photodiodes acting as light sensors will be coated on the surface of the panel to collect and convert solar energy into electricity, thereby providing energy to operate the entire system.
3.2. Inverter power converter
Plays a role in converting the direct current produced from the DC of solar panels into alternating current to help operate household electrical appliances.
3.3. Solar charging
The main task of solar charging is to ensure that the transfer of energy from solar panels to the battery system takes place effectively, thereby contributing to improving the performance and prolonging the life of both the battery and the system.
3.4. Battery storage system
Since solar power is not produced continuously due to limited lighting time, batteries are used to store this energy source. When the grid is lost or the solar power system does not generate electricity, the storage battery will provide electricity to maintain the operation of consuming devices, replacing the power from the grid.
4. Operating principle of rooftop solar power system
Sunlight will be absorbed by the solar panel system and converted into direct current. Through the inverter, this current will be converted to alternating current to operate household electrical appliances. The priority order for using solar power is the first consuming loads, if there is a shortage of electricity, the grid will compensate and vice versa, if there is excess electricity, it will be pushed out to the grid.
5. Advantages of using rooftop solar power systems
- Take advantage of empty spaces such as roofs and terraces to produce electricity for daily activities.
- Helps save electricity, reduce the burden of monthly electricity bills, and can even recover capital by selling excess electricity back to EVN after 4-6 years of use.
- Contribute to protecting natural resources and the environment because solar panels are classified as infinite renewable energy.
- Help businesses move towards sustainable development and build a "green" brand.
6. Common questions when installing rooftop solar power?
6.1. Does rooftop solar affect the electrical system in the house?
Solar power systems are usually installed on the roof of a house or factory and connected directly to the national grid after the electricity meter (or after the factory's transformer station). This means that if the factory consumes 500kW of electricity per hour and the rooftop solar power system produces enough 500kW, the entire electricity demand will be met without having to buy from EVN.
If the system produces 600kW per hour, the surplus of 100kW will be sold back to EVN. Conversely, if it only produces 400kW per hour, the plant will buy an additional 100kW from EVN to meet demand. This entire process is fully automated. The system not only helps reduce electricity bills by providing on-site power, but also ensures a stable power flow and optimizes energy efficiency.
6.2. Is rooftop solar really safe?
Rooftop solar power must strictly comply with electrical safety standards and regulations. The installation and construction process must also be carried out by experienced units, possessing a quality control system and safety, health and environment (QHSE), from which, users can be completely assured of the safety level of this rooftop solar power system.
6.3. Cost of installing a rooftop solar power system and payback period?
Depending on the type of equipment and installed capacity, the cost of rooftop solar power systems will vary. As for the payback period, it can be about 5 - 7 years according to current household electricity prices.
7. Conclusion
The above article has helped you learn about rooftop solar power systems. Hopefully our information will be of some help to you. Don't forget to follow the next articles at GREEN IN for more updated information!