A solar greenhouse is a horticultural facility that does not require heating indoors and can maintain indoor temperature levels solely through solar radiation even during cold seasons, to meet the needs of vegetable crops. It enables the supply of off-season fruits and vegetables in cold northern regions. Due to its excellent lighting, strong heat retention, good insulation, low investment, simple control, and energy-saving features, it is particularly suitable for widespread use in underdeveloped rural areas in our country.

Solar greenhouses not only rely on solar radiation for light and heat during the day, but also utilize the stored heat from the day for nighttime. The front slope with a single slope is covered with thermal insulation during the night, while the east, west, and north sides are enclosed with protective walls.

The basic structure of solar greenhouses includes: walls, front and rear roofs (rear slope), central pillars, pillar footstones, foundation walls, cold-weather trenches, and opaque coverings (insulation). Structural parameters mainly include greenhouse orientation, span, height, angles of the front and rear roofs, horizontal projection lengths of the walls and rear roof, cold-weather trench dimensions, and greenhouse length.

Greenhouse Orientation: The direction of the greenhouse ridge. Solar greenhouses rely solely on the sunny side for light, with the east and west walls and the rear wall being non-transparent. Generally, they are positioned north-south with the length extending east-west, facing due south to maximize light exposure.

2. Greenhouse Span: The distance from the north wall of the greenhouse to the corner of the south-facing transparent roof. It is currently believed that a span of 6 to 8 meters is ideal for a solar greenhouse.

3. Greenhouse Height: The vertical distance from the ridge of the greenhouse to the ground. Generally, it ranges from 2.8 to 3.5 meters.

4. Greenhouse Front and Rear Roof Angles: The front roof angle (front slope angle) refers to the angle between the bottom of the greenhouse front roof and the horizontal plane. It should be between 20.5° to 31.5° or higher during the "Winter Solstice" (the light transmission rate inside the greenhouse). The rear roof angle (rear slope angle) refers to the angle between the greenhouse rear roof and the horizontal line at the top of the rear wall, which is preferable to be 5° to 8° higher than the solar height angle at noon on the local Winter Solstice.

5. Greenhouse Wall and Roof Thickness: The greenhouse walls and rear roof serve both as load-bearing structures and as thermal insulation and heat storage. The thickness ranges from 0.5 to 1.5 meters, tailored to local conditions.

6. Rear Roof Horizontal Projection Length: The longer the rear roof, the better the insulation at night; however, it can cause shading, which may affect crop growth. Calculations suggest that for greenhouse heights between 3 to 3.2 meters, the rear roof horizontal projection length should be around 1.0 to 1.5 meters.

Insulation Ditch Dimensions: The insulation ditch serves to retain heat in winter and insulate against heat in summer. It measures 0.5 to 0.8 meters in depth and 0.3 to 0.5 meters in width, filled with insulating materials such as sawdust, poultry manure, and rice hulls.