1. What is a distributed PV system?
Distributed photovoltaic power generation system refers to the use of PV modules, the solar energy directly into the user side of the grid power generation system. This system is located near the user and is used by local power generation. It can be connected to the grid with a voltage level of 10 kV and below, and the total installed capacity of a single point of connection (380V) does not exceed 6MW. The total installed capacity Not more than 8 kilowatts.
2. Distributed photovoltaic power generation system applications and installation methods?
Distributed photovoltaic power generation system can be installed in any place with sunlight, including: the ground, the top of the building, side elevations, balconies, which in schools, hospitals, shopping malls, villas, houses, factories, Carport, bus stop at the top of the most widely used; installation of concrete, color steel plate and tile-type three types.
3. How to estimate the installed capacity and the generating capacity of the distributed PV system?
Distributed photovoltaic power generation systems can be installed on the roof and the ground; for the ground power plants and cement roof, the installation of 50-70 watts per square meter of components; for color steel roof and sloping roofs can be installed per square meter 80-100 Tile assembly. Distributed photovoltaic power generation system per watt per year between 0.8-1.6 degrees in power generation, Hebei Province, 1.2 kWh.
4. Distributed photovoltaic power generation system components and the role of the main components?
Distributed photovoltaic grid-connected system consists of solar modules, grid-connected inverters, converters, AC-DC power distribution cabinets, photovoltaic racks and other products.
1). Solar cell components: it is a photovoltaic system in the core components, its role is to convert solar energy into electricity.
2). Grid-connected inverter: A device that converts direct current into alternating current. As the PV module converts the electrical energy to DC, and the actual use of the vast majority of the load is AC load, so the need for this device will be converted to alternating current DC for load use.
5. State subsidies for distributed photovoltaic power generation?
August 30, 2013, the National Development and Reform Commission issued the "price leverage on the role of promoting the healthy development of photovoltaic industry, the notice" to improve the photovoltaic power generation price policy. Distributed PV power generation projects in accordance with the implementation of the policy of subsidy in accordance with the price of electricity, distributed photovoltaic power generation system will be subsidized for each country 0.42 yuan by the State Grid on behalf of the monthly repayment.
6. How to calculate the subsidy income of distributed PV power generation?
The subsidy income of the distributed PV power generation owners is divided into three parts: 1. State subsidy; 2. Electricity expense offset by spontaneous use; 3. Desulphurization coal purchase price.
Distributed photovoltaic power generation system into the grid is divided into all the spontaneous self-use (all the power generation to supply their own load), spontaneous self-use more than electricity Internet access (priority to their own load, excess power into the national grid), all online Power generation, all incorporated into the national grid) three.
Depending on the grid-connected model, the benefits are calculated as follows:
1). Subsidy income for spontaneous use is: (local electricity price + distributed photovoltaic power generation subsidies) × all power generation;
2) Spontaneous self - use subsidies for the Internet access benefits: (spontaneous use of the proportion of local electricity price + distributed PV subsidies + Internet ratio of the proportion of desulfurized coal × acquisition of electricity) × all the electricity;
3. All subsidies for the Internet access: (distributed photovoltaic power generation state subsidies + coal desulfurization acquisition price) × all the electricity.
7. PV grid-connected system voltage and how to choose?
China's grid voltage level is divided into (in kV): 0.23 (corresponding to the actual demand of 220V), 0.4 (corresponding to the actual demand of 380V), 0.69 (corresponding to the actual demand of 660V), 1,3,6,10,35 , 66,110,220,500. Among them, 0.23-1kV is called low voltage, 3-35kV is medium voltage, 35-110kV is high voltage, and 110kV is higher than UHV. In general, PV grid-connected system is often selected when the user low-voltage side of the grid, that is, the grid point voltage of 220V or 380V; large-scale power plants generally choose medium voltage or high voltage grid, this approach requires additional boost device To the photovoltaic power generated by the increase to the grid voltage.
8. What information should be provided for enterprise users to apply for grid connection?
The following information is required for enterprise users to apply for grid connection:
Original and photocopy of legal representative 's ID card.
2). Enterprise legal person business license, land certificate, real estate license and other items legitimacy support documents.
The government department in charge of investment agrees with the approval of the preparatory work of the project (need to approve the project).
4) Information about the preliminary work of the project.
9. What information should be provided for individual users to apply for grid connection?
The following information is required for individual users to apply for grid connection:
1). Original ID card and a copy of the manager
2). Personal account of this, land certificates, real estate license and other items to support the legitimacy of the document
3). The government investment department agrees to carry out the preliminary work approval of the project (need to approve the project)
4) Information about the preliminary work of the project.
10. What are the advantages of distributed PV systems?
1). Green energy, energy saving and environmental protection.
2). Spontaneous use, the nearest access, local consumption satisfied.
3). User-side low-voltage grid, power loss is small.
4). Easy to install, easy to operate.
5). The efficient use of idle roof resources, to create additional revenue.
6). An investment, long-term gains.
11. Distribution of photovoltaic grid-connected system of power generation method of estimation?
To estimate the amount of electricity generated by distributed PV systems, it is necessary to know the system installed capacity, local effective sunshine time, and system efficiency. For example, 1000W PV grid-connected system, assuming an effective sunshine time of 5 hours, photovoltaic grid-connected system efficiency is about 80%, so the system daily power generation capacity = system installed capacity × local effective sunshine hours × system efficiency = 1000 × 5 × 0.8 = 4000Wh, 4 degrees of electricity.
12. Briefly the working principle of distributed PV system?
During the day, the PV module receives the light energy into electric energy. The DC power is converted into alternating current through the PV inverter, and then through the AC distribution box, the electric energy can be supplied to the electric lamp, TV (working state), air conditioning and other loads. Distributed to the grid (meter) to sell electricity; night, distributed photovoltaic system to stop working, the user can download the grid power supply load to use.
13. Brief description of the application of distributed photovoltaic power generation project six processes?
1). The project owner to fill in the form by the grid companies to help, but the owner is best to clearly understand what they need to fill in the content, while residents apply for owners also need to provide my ID card and a copy of the account, the real estate certificate; Good to the power grid business consulting in advance, to understand clearly.
2). If the owner's project occupies the community public space, the applicant and his unit also need to provide all residents of the written signature (including all participants of the signature, phone number, ID number) and the residential property, The Commission agreed that the proof, and by their neighborhood communities seal.
3). When the access plan prepared by the grid enterprise is completed, the project owner should inform the grid enterprise as to whether it can accept it as soon as possible. Otherwise, it may affect the progress of the construction.
4). Before the construction of the project, the owners need to prepare the appropriate size of the photovoltaic panels, preferably unified specifications, the same power, according to the project capacity to match matching inverter, inverter to the measuring device connecting wires, Of the cement pier, triangle bracket and other infrastructure, and grid enterprises will provide free measurement device.
In construction, the project owner in the construction process, the quality of construction equipment, the relevant parameters and other indicators must be implemented in accordance with the access plan, there is any doubt should communicate with the grid in a timely manner to prevent the need to rework phenomenon, so as not to waste manpower , Material and time.
6) The project owner may request the power grid enterprise to assist in completing the application form for completing the application for commissioning inspection and acceptance.
14. How is the mounting orientation of the PV array determined?
The PV array should be installed in the south direction (the northern hemisphere) in order to receive the maximum amount of radiation throughout the year.
15. What is the effect of load on PV arrays and buildings when installing a distributed PV system?
From the point of view of safety and stability, the influence of permanent load, wind load, snow load and temperature load on PV array and buildings should be considered in the design to ensure sufficient strength and rigidity of the PV module, bracket and matrix base. Extreme climate damage. Before the installation of the distributed system, the load capacity of the building should be surveyed, calculated and checked, and a reasonable installation and construction scheme should be designed under the precondition of ensuring the building to meet the load.
16. Will distributed PV affect power quality?
Voltage, frequency and waveform. The main AC / DC conversion components of the system are inverters, and the inverters can be put into use only after passing the power quality test. The output power of the photovoltaic power generation system can be incorporated into the power grid after passing the national power grid acceptance test. So the distributed photovoltaic system will not affect the power quality.
17. What information does the design engineer need to provide when designing the system according to customer requirements?
When designing the system, the information to be provided by the customer includes the installation site, roof type, roof structure drawing, roof surface condition, building surroundings, building construction year, access voltage level, average monthly electricity demand, roof photo, meter box Photos and more. Of course, the more detailed the information provided, the more conducive to more rational and reasonable design. If necessary, the customer is required to assist the design engineer to complete the site visit.
18. What is the concept of components?
PV modules (also known as solar panels) is a number of single-cell string connected in parallel and tightly encapsulated, solar power generation system is the core part of the solar power generation system is the most important part. Its role is to convert solar energy into electricity.
19. What is the concept of inverter?
Inverter is the DC power (battery, battery) into alternating current (usually 220V, 50Hz sine wave), the inverter bridge, control logic and filter circuit is the core of photovoltaic systems equipment.
20. What is the concept of photovoltaic support?
Solar PV racks are special supports for solar PV systems in order to place, install and fix the solar modules. General materials are aluminum, stainless steel. PV bracket product sub-ground support system, flat roof support system, adjustable angle roof support system, inclined roof bracket system, column bracket system.