
The balcony PV mounting system usually consists of solar panels, micro-inverters, bracket systems, cables and necessary monitoring devices. Its core function is to convert solar energy into direct current through photovoltaic modules under sunlight, and then convert it into alternating current through inverters for household use. The system can be incorporated into the household circuit to drive household appliances, or it can be connected to the power grid to achieve a self-generated and self-used operation mode with surplus power connected to the grid. This process does not rely on traditional coal, natural gas or oil power generation, so it can effectively reduce carbon emissions caused by electricity use.
Currently, the electricity used by most urban households mainly comes from a fossil energy-based power system, including coal-fired power, gas-fired power and some hydropower. Fossil energy emits a lot of carbon dioxide during the power generation process. Taking coal-fired power generation as an example, about 0.9 kg of carbon dioxide is emitted for each kilowatt-hour of electricity generated. If a family uses 10 kilowatt-hours of electricity per day, more than 3 tons of carbon dioxide emissions will be indirectly generated each year from electricity alone. Therefore, changes in the structure of household energy use are of practical significance for overall carbon emission reduction.
Once the balcony PV mounting system is put into operation, it can partially replace fossil energy electricity in household electricity consumption. Taking a common 300W small balcony photovoltaic module as an example, according to the annual average daily power generation of 1.2 kWh in areas with sufficient sunshine, it can generate about 438 kWh of electricity a year. If all this electricity is used for daily household electricity consumption, it is equivalent to reducing carbon dioxide emissions by about 393 kg per year (calculated at 0.9 kg of carbon dioxide per kilowatt-hour). If multiple modules are installed on the balcony, the power generation will increase further, and its substitution effect will be more obvious.
In the grid-connected mode, the balcony photovoltaic system can generate electricity for domestic use first, and the excess electricity will be fed back to the grid. For reducing carbon emissions, the higher the proportion of self-generation and self-use, the more direct the effect of replacing traditional electricity. Especially during the peak period of electricity consumption during the day, the balcony photovoltaic system can power refrigerators, TVs, computers and other equipment, reducing dependence on external electricity. In contrast, if all electricity is fed back to the grid, although it can still generate emission reduction benefits, it is more indirect and depends on the overall energy structure of the grid.
The balcony space of urban residences, especially high-rise apartments, is limited, and the installation area is restricted, so the system power is generally low. But even so, small photovoltaic systems can still provide some green energy supply to a certain extent. For example, electricity is generated during the day for laptops and lighting equipment, and power is supplied by the power grid at night, which can form a "photovoltaic storage complementary" living mode. If combined with household energy-saving measures, such as the use of energy-saving lamps and high-efficiency electrical appliances, the emission reduction effect of the balcony photovoltaic system will be further enhanced.
The carbon emission reduction capacity of the balcony photovoltaic system is closely related to the local solar energy resource conditions. In areas with abundant sunshine resources (such as some cities in the southwest and north China), the system has a higher annual power generation and a higher emission reduction efficiency per unit area; while in rainy and haze-stricken areas, the annual average power generation is limited, and the emission reduction effect will be reduced. But even in cities with average resource conditions, the balcony photovoltaic system can still provide stable power output in clear weather, realize the replacement of some traditional energy power, and thus achieve the effect of continuous carbon reduction.
The carbon emission reduction effect of the balcony photovoltaic system is not limited to electricity substitution. As a promotion carrier for green energy equipment, it can also enhance the awareness and practice of low-carbon living concepts in families. For example, after installing a photovoltaic system, some families will actively adjust the electricity consumption time and concentrate on running high-energy-consuming equipment during the day to improve the utilization rate of photovoltaic power. This behavioral change not only optimizes the energy structure, but also helps the whole society to form a virtuous cycle of green consumption and carbon emission control.
Although the balcony photovoltaic system itself is a clean energy facility, its manufacturing, transportation and installation processes will also generate certain carbon emissions. For example, photovoltaic panels require a certain amount of energy during the production process, so the carbon footprint of the entire life cycle needs to be considered when evaluating the carbon emission reduction effect. However, most studies show that photovoltaic systems can "repay" the carbon emissions generated by the previous manufacturing within 2-3 years after being put into use, and the carbon emissions of the electricity generated thereafter are close to zero, so they are still regarded as an effective carbon reduction tool.
Balcony photovoltaic systems are usually used as part of household energy transformation, forming synergies with energy-saving lamps, smart home appliances, energy storage batteries, and smart power management systems. By optimizing the overall electricity consumption structure, the emission reduction benefits can be further improved. For example, using the electricity stored in photovoltaics during the day to power lighting and mobile devices at night can help achieve time shifting of electricity consumption and reduce the pressure on the public power grid during peak hours. This synergy mechanism provides urban families with more flexible green energy options.
On the whole, balcony PV mounting systems can indeed reduce household carbon emissions to a certain extent by replacing part of traditional electricity and improving household energy efficiency. Although its power generation capacity is limited by the installation area and lighting conditions, it is of practical significance as a path for low-carbon transformation of urban residences. With the advancement of technology and the strengthening of policy support, its application scope and emission reduction capabilities are expected to be further expanded, providing a feasible basis for the promotion of green lifestyles.