A complete analysis of key technical issues in solar power generation

9 Cost Analysis of Off-Grid Photovoltaic Power Generation System

　　Investment cost and operation cost constitute the main cost of off-grid photovoltaic power generation system. However, it should be noted that an off-grid photovoltaic power generation project, especially an off-grid photovoltaic power generation project in rural areas of remote areas, creates additional value for the whole society, which is not simply the sum of the local values.

　　The external factors include: benefiting the environment, improving health, safety and education, reducing urban migration, promoting national unity, social stability and technological progress. The value of these benefits is more based on social and environmental benefits than economic analysis.

　　It is important for off-grid photovoltaic power generation system project builders to submit various cost descriptions related to the project. The costs can be divided into the following five parts:

　　(1) Initial investment (cost of equipment, infrastructure and installation);

　　(2) Set the replacement cost (set and installation);

　　(3) Operation and maintenance costs (wages and consumable material costs);

　　(4) Energy service fees (inspection and maintenance service fees of the owner or energy service company);

　　(5) Recycling and disassembly costs.

　　The system cost statement submitted to the power station operator should include at least the following four;

　　(1) Annual cash flow;

　　(2) The total cost of the power plant life cycle;

　　(3) Calculated power generation cost;

　　(4) Annual operation, maintenance and replacement costs.

　　According to statistics, of the more than 90 off-grid photovoltaic projects built in my country from 1998 to 2008, about %% were domestic government investment or international government aid projects.

　　10 Acceptance Contents of Photovoltaic Power Generation System

　　The acceptance of photovoltaic power generation system mainly includes the following 7 parts:

　　(1) Array base

　　Concrete foundation and anchor bolt specifications

　　·Base position

　　· Overhead square platform sets the size of each platform and the specifications of the bearing components

　　(2) Array rack part

　　Firmness of installation

　　·Tilt angle of the rack

　　Adjustable rack tilt adjustment range

　　(3) Solar cell array

　　· Wiring of each sub-array

　　Maximum output power of each sub-array

　　· Binding and fixing status of component connection lines and array output cables

　　(4) Power feeder section

　　Feeder line route

　　Insulation resistance between lines or between lines and ground

　　·Sealing condition of threading pipe opening

　　Cable end treatment

　　Connection between power feeder and control cabinet

　　(5) Control cabinet part

　　Installation location and firmness of installation

　　External wiring

　　Power-on test

　　(6) Battery part

　　· Open-type batteries shall comply with the manufacturer's instructions or the technical specifications for the construction and acceptance of communication power equipment installation projects.

　　Sealed battery box processing

　　·Battery capacity

　　(7) System protection part

　　· Location and grounding resistance of the grounding system

　　·Connection method of each component of lightning protection grounding device

　　Location and height of lightning rods

　　·Establish earthquake-resistant protection for each battery

　　11 Solar Photovoltaic Buildings - Integrated Principles

　　(1) The penetration of ecologically driven design concepts into conventional architectural design: The building itself should have an aesthetic form, and the integration of the PV system and the building makes the building's appearance more attractive. The use of PV panels in buildings not only makes good use of solar energy and greatly saves the building's energy use, but also enriches the building's facade design and facade aesthetics. BIPV design should be based on the basic principle of not damaging or affecting the building's effect, structural safety, function and service life. Any BIPV design that damages and adversely affects the building itself is an unqualified design.

　　(2) The integration of traditional building structures and modern photovoltaic engineering technologies and concepts; the introduction of building integrated design methods and the development of solar energy and building integrated technologies. Building integrated design refers to the integration of solar energy application technology into the entire process of building design to achieve the requirements of beautiful, practical and economical building design. BIPV is first and foremost a building. It is an architect's work of art. The key to its success is the appearance of the building. From the beginning of the design of the building, all the contents contained in the solar energy system should be designed as an indispensable design element of the building. The various components of the solar energy system should be cleverly integrated into the building as an integrated design, so that the solar energy system becomes an integral part of the building composition and achieves a perfect combination with the building.

　　(3) Pay attention to different architectural features and people's living habits; appropriate proportion and scale: The proportion and scale of the PV panels must be consistent with the overall proportion and scale of the building and the function of the building, which will determine the grid size and form of the PV panels. The color and texture of the PV panels must be harmonious with the rest of the building and unified with the overall style of the building. For example, on a historical building, PV panel integrated tiles may be more suitable than large-scale PV panels. In a high-tech building, industrialized PV panels can better reflect the character of the building.

　　(4) The organic combination of thermal insulation enclosure structure technology and natural ventilation, lighting and shading technology; exquisite detail design: it does not only refer to the waterproof structure of the PV roof, but more attention should be paid to the specific detail design. The PV board should be well integrated from a simple building technology product into architectural design and architectural art.

　　(5) Photovoltaic systems and buildings are two independent systems. There are many aspects involved in combining the two systems. To develop an integrated photovoltaic and building system, photovoltaic manufacturers cannot do it independently. They must work closely with relevant aspects such as building materials, architectural design, and construction, and work together to succeed.

　　(6) Balance between the initial investment of the building and the investment in the photovoltaic project during its life cycle; comprehensively consider the building operation cost and its external costs. Building operation is reflected in various activities throughout the life cycle of the building, such as planning, construction, use, renovation, and demolition. Building energy-saving technology, solar energy technology, and ecological building technology have an important impact on building operation. Not only should we pay attention to the initial investment in the building, but also to the later operation and cost expenditure of the building. Not only should we meet the housing needs of the people, but we should also pay attention to the energy consumption expenditure of housing use. In addition, the increase in external environmental costs such as carbon dioxide emissions should also be considered.

　　12 Planning first is the key to the integration of solar photovoltaic buildings

　　Solving the integration of solar energy and buildings, and solving the coordination and unification of building design and solar energy construction are not technically difficult problems. The real difficulty lies in the interests of developers and the public's awareness of energy conservation. This urgently requires government departments to take the lead in planning foresight and standardization. It is recommended that the government construction administrative department should propose or stipulate the rigid requirements of "simultaneous design, simultaneous construction, and simultaneous completion" of housing construction and solar energy construction. Therefore, in the face of the increasingly severe energy situation, the introduction of relevant specifications or mandatory standards for energy-saving buildings should probably take the lead. On the basis of the policy guidance and incentive mechanism of governments at all levels, we should improve the level of vocational training and public education, strengthen product (system) testing and certification and building access system, improve specifications and standards and related technical regulations, give full play to the enthusiasm of all levels from enterprises to owners, and jointly promote the orderly and healthy development of solar photovoltaic buildings.