The idea of developing solar cooling and heating greenhouses
If we want to change the status quo of rural heating, we must first revitalize the rural economy, and facility agriculture will surely take the lead
With an area of 41,000 square kilometers and a population of 17.4 million, the Netherlands is located between 51-54 degrees north latitude and is a typical high-latitude country. The average annual temperature ranges from 5 °C to 13 °C, with an average of 13 °C during the day and an average of 5 °C at night. The annual solar radiation is 3700 MJ/m2, and the sunshine time is 1480 hours.
The land of bullets, which has so few natural resources, is the world's second largest exporter of vegetables, with 86% of the country's vegetables produced for export. Facility agriculture has been developed in the Netherlands for more than 100 years, and its glass greenhouses account for a quarter of the world's total area. In the 1970s, the production of Dutch tomatoes (Xihong Market) reached 80 kg/m2, and the current shouguang level is 20 kg/m2. Dutch vegetables basically do not use chemical pesticides and elongation agents, how we grow them, everyone understands.
Wageningen University in the Netherlands, one of the three major agricultural universities in the world
The development of Dutch agriculture is inseparable from its centuries-old economic leadership, so it is not feasible to completely copy it domestically. First of all, we do not have a strong economic foundation as a backing, and secondly, the continent is vast, most of the areas are rich in light resources, the development of facility agriculture, much better than the Netherlands conditions, take parts of the Loess Plateau region for comparison:
The average annual temperature of Huining is 3 °C to 16 °C, the average daytime average is 16 °C, and the night average is 3 °C;
The average annual temperature of Tongwei is between 2 °C and 15 °C, the average daytime is 15 °C, and the average night is 2 °C;
The average annual temperature in Gangu is between 6 °C and 17 °C. The average daytime is 17 °C, and the night average is 6 °C;
It can be concluded that through the energy of the New Year, the light, cooling and heat resources of the Loess Plateau region are better than those of the Netherlands.
The average annual rainfall in the Netherlands is between 750 mm and 800 mm, and the Loess Plateau area is basically located on the high side of the 400 mm and other precipitation lines, and the water vapor loss control and rain collection facilities are three-pronged through full energy management of greenhouses, full closure control of water vapor losses and rain collection facilities. Half of the land collects hot and cold resources, and half of the land is used to grow fruits and vegetables with high requirements on hot and cold.
It can be concluded that with 7 times the land area of the Loess Plateau as the Netherlands, as long as 2/7 of it is developed, the high-yield and high-quality Dutch agriculture will be copied to the Loess Plateau.
The collected rainwater, the agricultural greenhouses can not be used up, can be to the slope of the large, not suitable for development and utilization of the area of water, increase the density of vegetation, improve the climate, increase forest carbon sinks; can also develop ecological fisheries at the bottom of the ditch.
Conclusion 3: Combining solar energy collection, soil heat storage, rain collection facilities, and greenhouses can realize the loess plateau into a livable place with beautiful mountains and rivers and developed high-quality agriculture.
Yellow River Jizi Bay
The amount of solar radiation
In recent years, in order to improve air quality, rural areas on the mainland have begun to implement "coal to electricity" and "coal to gas" on a large scale, but the feedback effect is very unsatisfactory. First of all, after the coal reform, most of the people can't afford to use it, and can only choose to resist hard. Secondly, the peasants' enthusiasm for coal reform is not high, and the state has invested a lot of financial resources and is not pleased. Now the countryside, basically have become hollow villages, most of the rural people usually live in the city, the countryside is left with some old people, children, children and grandchildren will only come back for a few days when the New Year, some even do not come back, winter let parents go to the city to spend the winter, so then to the rural house above the investment, it feels not worth it.
At present, several clean heating methods are not satisfactory, either the initial installation cost is high (solar energy), or the use cost is high (air energy, gas). Rural people's income is limited and unstable, so even if the state is willing to install air heating and gas heating for free to farmers, there are few who really dare to use it, due to the instability of the expected income, most rural people are very frugal, heating is the improvement of the quality of life, people can only talk about the improvement of the quality of life in the case of higher and stable incomes. At present, rural people have a big thing to do, that is, to buy a house in the city, because there is no place to earn money in the countryside, the education of children and women, marriage has become a problem, relying on the current way of farming, it is good not to starve to death.
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The video was filmed in Huining, Gansu Province, and as far as the eye can see, it is all dry land, the kind that relies on the sky to eat. How can such a barren land keep the footsteps of the people? Where to start with the revitalization of rural areas? The poverty of Huining stems from drought, and less rainfall is only one of them, mainly because the evaporation is too large. If agriculture is to be developed in this area, facility agriculture must be considered. If we can build greenhouses on these floors, will it reduce evaporation? Can greenhouse rain collection technology solve the problem of greenhouse water use? The use of solar energy to collect heat and cooling, the use of soil heat storage, cold storage, can not solve the greenhouse cold, heat source problems? If these problems are solved, will farmers still have to go out to work? Rural economy has developed, peasant incomes have increased, is it still difficult to clean and heat up in rural areas?
The premise of the large-area application of solar collector and cooling is that the manufacturing cost of solar collector and collector is greatly reduced. At present, we have a technology, if large-scale manufacturing, the price of unit area materials is expected to be pressed to 10 yuan / square meter (collector lighting area), as for the effect, only practice can know, the reason why the video of Huining is played, is because we want to find suitable land in this place, to carry out our experiments.