A New Vision for Warm Winters: Documentary of the 2022 Rural Solar Clean Heating Project in Yongjing, Linxia

In northwest China’s rural areas, winter heating has long faced a "triple predicament": severe coal pollution, high costs, and safety risks. Yongjing County, in Linxia Hui Autonomous Prefecture on the Yellow River’s upper reaches, endures cold winters with temperatures as low as -15℃. Traditionally, villagers relied on scattered coal burning—failing to keep rooms warm, emitting harmful smoke, endangering health, and worsening regional ecology. To solve this, Yongjing launched its 2022 Rural Winter Solar Clean Heating Project, leveraging 2,500+ annual sunshine hours. Covering 413 households with internal circulation self-draining solar collectors, it paved an "eco-friendly, efficient, economical" path for rural clean heating.

I. Project Background: Fixing Rural Heating’s "Triple Predicament"

Yongjing’s rural winter heating suffered from pollution, inefficiency, and high costs. Pollutant-wise, households burned 2-3 tons of coal yearly, filling villages with smog, pushing PM2.5 beyond standards, and raising respiratory diseases. Efficiency-wise, coal stoves kept rooms at 10-15℃ (below 8℃ at night), risking cold-related issues for the elderly and children. Cost-wise, coal at 1,200 yuan/ton cost families 2,400-3,600 yuan/year—15%-20% of their income.

Yet Yongjing has strong solar potential: located at the Qinghai-Tibet/Loess Plateau transition (1,500-2,800m altitude), it has clear air, intense solar radiation, and sunny winter days. The local government made "solar clean heating" a key livelihood project, using subsidies, tech screening, and pilots to create a "zero-pollution, low-cost, high-comfort" solution. The 2022 first phase covered 413 households in 12 villages across 6 towns (e.g., Liujiasi, Yanguoxia).

II. Technical Solution: Internal Circulation Self-Draining Collectors

Considering Yongjing’s harsh winters, simple rural houses, and limited household operation skills, the team chose internal circulation self-draining solar collectors after comparisons. Unlike traditional models, they offer "strong frost resistance, easy use, high efficiency"—ideal for rural heating.

Technically, they use "natural circulation + automatic drainage": daytime, collectors absorb sunlight, heat antifreeze (heat transfer medium), and send heat to a storage tank via natural flow; night, medium drains to the tank, preventing freezing/cracking. No manual operation is needed, lowering use barriers.

For 50-60㎡ rural houses, each system has: 100 collector tubes (0.2㎡/tube, total 20㎡), 400L insulated storage tank (thermal conductivity ≤0.03W/(m·K)), 2KW water-electric dual-purpose fan, and supporting parts. Tubes are serially installed on south-facing roofs; the tank stores heat for night use; the fan blows hot air indoors, switching to electric heating on cloudy days. An intelligent thermostat (default 18℃) starts the fan below 16℃ and stops it above 20℃, avoiding waste.

III. Project Implementation: 413 Households’ "Warm Shift"

From August-October 2022, the team installed and commissioned equipment in phases. Tech staff surveyed each house to set collector angles at 35° (matching Yongjing’s latitude for max efficiency), trained households on thermostat use and surface cleaning, and finished all 413 systems by late October.

In November 2022, with snow and -5℃ temperatures, systems launched. Wang Jianguo, a Luochuan Village villager, said: "Coal left rooms freezing; now it’s warm day and night—no more adding coal or cleaning cinders."

Monitoring showed: with 6+ hours of daily sunshine, systems kept rooms at 18±2℃; fans ran 8 hours/day, 85% powered by solar (electric only for short cloudy periods). Winter (Nov-Mar) electricity costs were 300-500 yuan—80% lower than coal. Unselected households asked to join later.

Environmentally, PM2.5 in 12 villages dropped 40% vs. previous winters; smog days decreased. Xiaoci Village’s Party Secretary Yang Ming noted: "No more coal smell—air is cleaner."

IV. Project Value: Livelihood-Ecology "Dual Win"

The project solved heating issues for 413 households and set a model.

For livelihoods: stable 18±2℃ reduced cold-related illnesses; lower costs freed funds for education/healthcare. Luochuan’s Li Guilan said: "Coal cost 3,000 yuan; solar only 400—saved money for my grandson’s needs."

For ecology: 413 households cut 1,032.5 tons of coal use, reducing 2,787 tons of CO₂ and 8.26 tons of SO₂. Solar, as renewable energy, avoided mining/transport damage.

For industry: local tech staff were trained in installation/ maintenance; standardized systems offered "replicable" experience for other northwest rural areas.

Yongjing’s 2022 project used tech to fix rural heating pain points, delivered policy warmth, and created "warm, clean, economical" winters. Now a rural energy transition benchmark, it will expand to more households, boosting ecologically livable villages.