In summer, the average temperature in some areas is 35 °C, but after the installation of photovoltaic power generation system, in the hottest weather, the temperature of the top floor room is about 6 °C lower than the original. The use of photovoltaic power generation not only saves the electricity purchased from the power grid, but also saves the energy consumption of the air conditioner by cooling, achieving double energy-saving effect!
Let’s look at a test
Recently, some people do a series of measured data in hot day
At a high temperature of 35 ° C, at 12 noon, the roof temperature is as high as 68.5 ° C (this temperature is enough for omelettes).
(1) Photovoltaic module surface temperature
Since the photovoltaic module converts solar energy into electrical energy, the temperature of the surface of the photovoltaic module is only 57.5 ° C, which is 11 ° C lower than the roof temperature.
(2) Photovoltaic group backplane surface temperature
Photovoltaic cells generate heat during the conversion of solar energy into electrical energy. At the same time, due to the poor ventilation conditions installed on the roof, the backing temperature of the components will be higher than the surface temperature of the components, reaching 63 ° C, but still better than the roof. The temperature is 5.5 ° C lower.
(3) The temperature of the roof below the photovoltaic module
Below the PV module, the roof temperature without direct sunlight is 48 ° C, which is 20.5 ° C lower than the unobstructed roof temperature!
It can be seen that the photovoltaic module utilizes solar energy and reduces the heating of the roof roof, thereby indirectly reducing the temperature of the top floor room.
The engineer said: "The roof 'cover' on the photovoltaic panel, for the cooling is more obvious, the photovoltaic panel can absorb 80% of the light heat, and this part of the heat is collected on the photovoltaic panel, through the heat to the lower tile On-chip, not sunlight, shines directly on the tiles. In addition, the heat is radiated upwards, so that the heat transmitted to the roof is more limited. Once the solar photovoltaic power station generates electricity, about 20% of the thermal energy on the photovoltaic panels is directly converted into With electrical energy, the heat energy that can be transferred to the roof will be less, and the effect of cooling down on a hot day will be better."
to sum up
“The roof is covered with a layer of photovoltaic panels, and the roof tiles are also protected from the wind and rain. It also has a certain effect on the protection of the roof.” Cooling and “protecting” the roof is only a side effect of photovoltaic panels. The real role of photovoltaic panels is to generate electricity and convert solar energy into electricity.
It is understood that after the photovoltaic panels are installed on the roofs of most of the villages, the photovoltaic project will be officially launched. By then, the village can issue 250,000 kWh of electricity a year, and the villagers will use only 100,000 kWh of electricity a year. Villagers can use electricity for free, and the excess will be converted into economic income in the village.
Roof photovoltaic is a new type of power source with broad prospects, which has the three advantages of permanent, cleanliness and flexibility. Due to its own environmental protection and energy-saving characteristics and support from external state subsidies, it deserves to be the trend of rural cities. I hope you have a roof, don't miss this trend.