Advantages of solar greenhouses

Advantages of solar greenhouses
1. Absorb more sunlight energy. The front slope angle of traditional solar greenhouses is generally set according to the local winter sunlight irradiation angle. Try to keep the shed surface perpendicular to the light to the greatest extent and fully absorb sunlight energy. It can reflect that the maximum absorption of sunlight energy is at noon. Morning and afternoon are not very important.
2. Good heat preservation effect and high energy storage. The heat preservation of the solar greenhouse is divided into two parts: thatch straw curtain quilt heat preservation and wall heat preservation. At night, the thatch and straw curtains and quilts slow down the speed of energy loss through heat conduction and heat radiation in the shed, achieving the purpose of double insulation. There are walls on the east, west and north sides. It can not only block the invasion of cold air from the east, west, and north sides, but also achieve the function of storing energy, and can also store straw curtains and act as a manual operation platform. Thick walls are used to keep the cold air from the east, west, and north sides basically impenetrable, and thatch curtains and quilts are used to keep warm at night. The lowest temperature is about 10°C higher than the lowest outdoor temperature, and the ratio of the frozen area of ​​the shed to the effective area of ​​the shed is 1.23:1. Most areas can survive winter production, and heating facilities can be added in the shed in cold regions, and production can also survive winter.

3. Simple film covering, suitable for small-area operation. It is covered by traditional shed film, and the operation is simple. It only needs to be tightened around the middle and pressed with a film line in the middle. There are walls on three sides, and the cold air on the east, west and north sides is basically impenetrable. No matter how large the area is, its freezing damage is only on the shed surface and the south side. The frozen area per unit area is basically the same as the length of cold air intrusion from the surrounding ground, which is very suitable for small area operation.

(2) Disadvantages of solar greenhouses
1. High investment cost. The cost of a solar greenhouse per mu (effectively used area) is generally 50,000-80,000 yuan.
2. High investment in heat preservation. On average, shed film, laminating line, straw curtain or quilt and straw curtain rope are 5,000-6,000 yuan per mu. If you use electric roller blinds, you need to invest about 10,000-20,000 yuan per mu.
3. The use cost is high. The loss of shed film per mu of greenhouse is about 1000-1500 yuan per year, the loss of straw curtains or quilts is 1500-2500 yuan, the labor cost of uncovering straw curtains or quilts is 2000-3000 yuan, and the depreciation of fixed assets is 2500-4000 yuan, (according to 20-year use calculation) the bank interest of invested funds is 5000-8000 yuan (calculated at 10% annual interest), and the total fixed cost is 12000-17000 yuan, which means that the annual net income per mu reaches 12000-17000 yuan to be equal.