1. Power Energy Conservation Technology Measures Energy conservation, emission reduction, and pollution reduction are tasks for the whole society during the "Eleventh Five-Year Plan" period and important factors in building a harmonious society. The national "Eleventh Five-Year Plan" proposed a 20% reduction in energy consumption per unit of GDP by 2010, a very challenging task. According to calculations by the Shanghai Power Company, line loss accounts for 97.05% of the company's total energy consumption; followed by building energy consumption and water consumption, accounting for 1.43%. Therefore, the power grid company's energy conservation and emission reduction measures focus on optimizing dispatch, reducing overall line losses, electricity consumption-side management, and building energy conservation. 1.1 Reducing Power Generation Energy Consumption 1.1.1 Optimizing Dispatch Mode "Adjusting power generation dispatch rules and implementing energy-saving, environmentally friendly, and economical dispatch." The National Development and Reform Commission and other departments have issued relevant notices requiring priority consideration of renewable energy and low-energy-consumption units in power generation dispatch. To this end, power companies should expedite the development of new dispatch plans, using energy conservation, environmental protection, and economic efficiency as standards to determine the generation sequence and timing of various generating units. Priority should be given to dispatching low-energy-consuming units, or dispatching directly according to energy consumption standards, incentivizing power generation companies to reduce energy consumption and decrease the generation of high-energy-consuming units. The economic indicators of a power grid's generation side mainly depend on two factors: the level and condition of all installed equipment and the average load factor. Given a fixed average load factor, the primary means of improving the overall economic efficiency of the power grid is to increase the average load factor (including both its value and quality); a secondary means is to optimize the load distribution among operating units given a fixed average load factor. Taking the Shanghai power grid as an example, if a "large-scale replacement of small-scale" policy is adopted, the energy-saving potential is much smaller compared to the East China power grid. However, if the policy is in place and there is sufficient technical support, combined with a series of measures such as load distribution at power sources, reasonable scheduling and shutdown of generating units within plants, two-shift operation, and optimized load distribution within plants, the average coal consumption for power supply across the entire grid can be reduced by 4g/(kW•h), saving 257,600 tons of standard coal in 2006. 1.1.2 Renewable Energy Power Generation In my country, new energy and renewable energy refer to wind energy, solar energy, small hydropower, ocean energy, geothermal energy, hydrogen energy, and biomass energy, excluding conventional energy and large-scale hydropower. The development and utilization of renewable energy is an important means to achieve "energy conservation, consumption reduction, environmental protection, and efficiency improvement." According to relevant national energy development plans, during the "Eleventh Five-Year Plan" period, my country will vigorously develop wind power and appropriately develop solar photovoltaic power generation and distributed energy systems. When large-scale development and utilization of renewable energy sources such as wind and solar power are carried out, the grid connection of renewable energy power generation and the impact between renewable energy sources and the power grid must be addressed. On the one hand, in addition to prioritizing the purchase of wind power, power grid companies should also undertake the obligation of power grid construction and power transmission, requiring substantial capital investment; therefore, government policy support is crucial. On the other hand, due to the intermittent and random characteristics of wind and solar power, large-scale integration into regional power grids will have an increasingly significant impact on the structural design, operation and dispatching methods, reactive power compensation measures, and power quality of the regional power grid. Power grid companies must adopt appropriate technical and management measures. 1.2 Technology to reduce comprehensive line loss 1.2.1 Optimization of power grid planning Urban power grids can reduce line loss through reasonable power grid planning. Under the premise of constructing a distribution network that meets the N-1 criterion and the distribution network in key areas meeting the N-1 criterion under maintenance conditions, Shanghai power grid comprehensively considers the load density, energy saving and loss reduction and power receiving channels of external power sources in the near and long term. From the perspective of coordinated development of various voltage levels, it constructs high-voltage distribution networks according to local conditions and vigorously develops 110kV grid and 110kV direct-to-10kV power supply. Construct a distribution network that is energy-saving, low-consumption and meets environmental protection requirements. The development of Shanghai city determines that the development of cable network is the main focus in the central urban area, and the substations are small and compact, and attention is paid to coordination with the environment. In order to reduce line loss and improve voltage quality, Shanghai power grid adopts medium-voltage distribution network extension into residential areas, compresses the range of low-voltage distribution network, and deploys more points for close-range power supply. At the same time, low-loss and low-noise equipment is adopted. 1.2.2 Energy saving of power transformers (1) Transformer energy saving transformation. There are many transformers with large capacity, and the total loss cannot be ignored. Therefore, reducing transformer losses is an essential energy-saving measure. If an amorphous alloy core transformer is used, it has the characteristics of low noise and low loss. Its no-load loss is only one-fifth of that of conventional products, and it is fully sealed and maintenance-free, with extremely low operating costs. The S11 system is currently the low-loss transformer that is being promoted and applied. Its no-load loss is about 75% lower than that of the S9 series, and its load loss is equal to that of the S9 series transformer. Therefore, low-loss transformers should be promoted and used in the construction of power transmission and distribution projects. (2) Economic operation of transformers. Economic operation of transformers refers to minimizing the power loss of transformers by selecting the best operating mode and adjusting the load under the condition of transmitting the same amount of electricity. Economic operation of transformers does not require investment. As long as the scientific management of power supply and consumption is strengthened, the purpose of saving electricity and improving the power factor can be achieved. Each transformer has no-load loss and short-circuit loss of active power, and no-load consumption and rated load consumption of reactive power. The capacity, voltage level, and core material of transformers are different, so the above parameters are different. Therefore, economic operation of transformers means selecting transformers with good parameters and operating transformers with the best combination of parameters. Selecting transformer parameters and optimizing transformer operation can begin with analyzing the load characteristics of transformer active power loss and loss rate. 1.2.3 Optimization of Reactive Power Configuration in the Power Grid A large amount of reactive current in the power grid will lead to increased line losses, reduced transformer utilization, and voltage drops for users. Reactive power compensation is one of the important measures to reduce line losses using technical means, achieving a reasonable distribution of reactive power while rationally allocating active power. The purpose of reactive power optimization is to reduce the active power loss of the network by adjusting the distribution of reactive power flow and maintaining the best voltage level. Reactive power optimization compensation generally includes optimal compensation for reactive loads in substations, optimal compensation for distribution lines, and optimal compensation for the low-voltage side of distribution transformers. According to the power loss formula, when the active power and voltage transmitted by the line or transformer remain constant, line loss is inversely proportional to the square of the power factor. The lower the power factor, the more reactive power the power grid requires, and the greater the line loss. Therefore, installing reactive power compensation devices at the receiving end can reduce the reactive power loss of the load, improve the power factor, and increase the active power output of electrical equipment. With the development of power electronics technology, pilot applications of active power filters (Active Power Filters) and static synchronous parallel compensators (STATCOMs) should be actively carried out. 1.3 Electricity Demand-Side Management Technology Implementing electricity demand-side management can bring direct economic and social benefits. Effective technical means are the foundation for implementing demand-side management. Researching and mastering energy efficiency technologies and load management technologies, and adopting advanced technologies to improve end-user electricity efficiency, plays a guaranteeing role in achieving the goals of electricity demand-side management. 1.3.1 Changing User Electricity Consumption Patterns This mainly refers to load shaping management technology, including peak shaving, valley filling, and peak shifting/valley filling. Based on the load characteristics of the power system, user electricity demand is reduced, transferred, or increased during off-peak periods in a certain way to change the temporal distribution of electricity demand, reduce daily or seasonal peak loads, improve system reliability and economy, reduce new installed capacity, save power construction investment, and lower expected power supply costs. This mainly involves using cold and heat storage technologies, energy substitution operation technologies, changing operating procedures, and adjusting shift systems among end-users. 1.3.2 Improving end-user electricity efficiency mainly involves selecting high-efficiency electrical equipment, implementing energy-saving operation, adopting energy substitution, realizing waste energy and heat recovery, applying high-efficiency energy-saving materials, rationally scheduling operations, and changing consumption behavior. Promoting high-efficiency energy-saving refrigerators, air conditioners, televisions, washing machines, computers, and other household and office appliances reduces standby power consumption. Implementing energy efficiency standards and labeling regulates the energy-saving product market. Guiding enterprises to adopt reactive power compensation, intelligent control technology, variable frequency speed regulation, and high-efficiency transformers and motors, etc., is beneficial for peak shaving and valley filling of the power grid, optimizing power grid operation, improving energy consumption structure, reducing environmental pollution, and improving end-user electricity utilization. 1.4 Building and Substation Energy Conservation Although the building energy consumption of office buildings and substations generally accounts for a small proportion of the total energy consumption of power companies, air conditioning and lighting account for a large share of commercial electricity consumption in the whole society. Therefore, as energy supply enterprises, power grid companies should set an example in energy conservation, establish a good image for the power industry, and promote social energy conservation through demonstration effects. 1.4.1 Energy-saving technology of building envelope Energy-saving technology of building envelope refers to improving the thermal performance of building envelope to isolate outdoor heat from entering the room in summer and prevent indoor heat from leaking out to the outside in winter, so that the indoor temperature of the building is as close as possible to the comfort temperature, thereby reducing the load of auxiliary equipment (such as heating and cooling equipment) to achieve a reasonable and comfortable room temperature, and ultimately achieving the purpose of energy saving. Energy-saving technology of building envelope is divided into wall energy-saving technology, window energy-saving technology, roof energy-saving technology, shading system, ecological greening, etc. 1.4.2 Energy saving of electrical equipment (1) Optimization of electrical layout and wiring. In terms of electrical equipment layout, try to place equipment that needs heat dissipation in well-ventilated places to minimize mechanical ventilation and reduce energy consumption in the building; take heat insulation measures for the partition walls between equipment rooms that generate a lot of heat, such as transformer rooms, and equipment rooms that need to be equipped with air conditioning. (2) Select environmentally friendly and energy-saving equipment. a. Transformers are the main energy-consuming equipment, and reducing transformer losses is the key to energy saving in substations. b. Make full use of natural lighting, especially in stairwells and corridors for personnel inspection and equipment transportation; all lighting sources should use light-emitting diodes. c. Select fans and air conditioning equipment equipped with frequency converters, that is, adopt intelligent products that can automatically start and stop according to environmental conditions, that is, only start when the equipment is running or when handling accidents, so as to save electricity. d. Use temperature and humidity controllers to automatically turn on the heaters in the switch cabinet when the ambient temperature and humidity do not meet the operating requirements. 1.4.3 Air conditioning energy saving technology Air conditioning energy saving refers to the use of advanced technology or reasonable methods to control indoor temperature and humidity in air conditioning systems and equipment to achieve the purpose of saving energy consumption. Air conditioning energy saving technology can be carried out from several aspects: reducing the air conditioning cooling load, improving the efficiency of the cold air distribution system, improving the efficiency of the refrigeration system, adopting cold storage systems, and utilizing phase change energy storage materials, etc. 1.4.4 Lighting energy saving (1) Utilize natural lighting. Make the most of natural lighting, especially in stairwells and corridors where personnel patrol and equipment transportation should use natural lighting as much as possible. (2) Select high-efficiency and energy-saving electric light sources. The energy saving of light sources mainly depends on their luminous efficiency. The selection of lighting sources should be based on the needs of the place of use, as well as the color rendering index, lifespan, dimming performance, and ignition characteristics of the light source. The principle is to actively select new generation energy-saving light sources according to different needs, such as replacing incandescent lamps with electronic energy-saving lamps, and replacing high-pressure mercury lamps with high-pressure sodium lamps and metal halide lamps. (3) Use high-efficiency lamps with high luminous flux maintenance. A lamp is a device that redistributes the light emitted by a light source. The energy-saving index of a lamp is the light output ratio (LOR) (lamp efficiency). Selecting high-quality, high-efficiency lamps with high luminous flux maintenance is of great significance for lighting energy saving. (4) Use advanced control systems and strategies. The energy-saving potential of using advanced control systems and strategies is based on two aspects: a. Usually, the grid voltage is higher than the standard voltage at night, causing the lamps to operate at overpower, which not only exceeds the brightness standard, but also shortens the lamp life. b. Since lighting demand (especially street lighting) decreases sharply after 23:00, the brightness level can be appropriately reduced (to meet the brightness requirements and specifications of lighting standards). By appropriately stabilizing and regulating the voltage of the street light circuits, more energy can be saved, while extending the lifespan of the lamps. 2. Conclusion This paper mainly elaborates on technologies for reducing power generation energy consumption, reducing overall line losses, power consumption-side management, and energy conservation in substation buildings. Considering the characteristics of power companies, areas with significant energy-saving potential can be analyzed, focusing on reducing line losses, economic dispatch, improving overall energy utilization efficiency, green lighting, distributed energy supply, energy conversion, and building energy conservation.