Walipini Greenhouse
Walipini Greenhouse
Walipini Greenhouse an underground greenhouse utilising the earth's natural insulation abilities and utilising passive solar heating.
Imagine cultivating fresh produce throughout the year, even amidst the frost-laden winters of northern climates, without relying on external heating sources. This vision becomes a reality with the Walipini greenhouse—a subterranean structure that utilises the Earth's natural insulation and solar energy to create a stable, warm environment for plants.
What is a Walipini Greenhouse?
A Walipini, meaning "place of warmth" in Aymara, is an underground greenhouse that utilises the earth's natural insulation and passive solar heating to create a stable, year-round growing environment.
Originating from the high plains of Bolivia, the term "Walipini" translates to "place of warmth" in the Aymara language. Developed in the 1990s by the Benson Agriculture and Food Institute, this innovative greenhouse design was crafted to provide local farmers with a low-cost, sustainable solution for year-round cultivation in challenging climates.
It is gaining popularity among sustainable farmers and permaculture enthusiasts worldwide.
Underground Greenhouses
While the modern Walipini was formalised in Bolivia, the concept of subterranean greenhouses has historical precedents. In Victorian-era Britain, "pineapple pits" were used to cultivate exotic fruits. Similarly, in pre-revolutionary Russia, underground greenhouses enabled the growth of citrus fruits in frigid climates.
Understanding the Walipini: Design and Functionality
A Walipini greenhouse is essentially an earth-sheltered cold frame. It involves excavating a pit, typically 6 to 8 feet deep, and covering it with a transparent roof made of materials like polyethylene sheeting or polycarbonate panels. The structure is strategically oriented—south-facing in the Northern Hemisphere—to maximise solar gain
Walipini Key Features:
Thermal Mass: The surrounding earth acts as a thermal battery, absorbing heat during the day and releasing it at night, maintaining a relatively stable internal temperature.
Passive Solar Heating: The angled roof captures sunlight, warming the interior space without the need for external energy sources.
Protection from Elements: Being underground shields the greenhouse from harsh winds and temperature fluctuations.
Geothermal Warmth: Nature's Heating System
One of the Walipini's most remarkable attributes is its ability to harness geothermal warmth. At depths of around 6 feet, the Earth's temperature remains relatively constant, approximately 52°F (11°C), even during freezing external conditions. This natural insulation ensures that the greenhouse maintains a conducive environment for plant growth year-round.
Benefits of a Walipini Greenhouse
Year-Round Food Production
By harnessing geothermal heat and solar energy, Walipinis maintain a consistent internal temperature, allowing for continuous cultivation even in colder climates.
Energy Efficiency
The earth-sheltered design reduces the need for external heating, lowering energy costs and environmental impact.
Cost-Effective Construction
Utilising natural materials and requiring minimal structural components, Walipini greenhouses can be built with a modest budget.
Protection from Harsh Weather
Being underground shields crops from wind, hail, and extreme temperature fluctuations.
Key Considerations and Common Challenges
Site Selection and Sunlight Exposure
Proper orientation (typically north-south) and ensuring adequate sunlight penetration are crucial. In higher latitudes, low winter sun angles can limit effectiveness
Water Drainage and Moisture Control
Effective drainage systems are essential to prevent water accumulation, which can lead to root diseases and structural issues.
Structural Integrity and Retaining Walls
Depending on soil type, additional support structures like cinder blocks or angled walls may be necessary to prevent collapse.
Ventilation and Air Circulation
Incorporating vents and possibly fans ensures air movement, preventing mold growth and regulating humidity.
How to build a walipini greenhouse
- Planning and Design
Determine size based on crop needs.
Design for optimal sun exposure. - Excavation
Dig to a depth of 2 / 2.5m or 6-8 feet, ensuring sloped walls for stability. - Drainage Installation
Lay gravel and install drainage pipes to manage water flow. - Wall Construction
Use rammed earth, earthbags, gambion, straw bales, water barrels or other materials suitable for your soil type that will build sturdy walls. Always useful to have some thermal mass to hold heat in the underground greenhouse. - Roof Framing and Glazing
Construct a sloped roof frame and cover with transparent materials like polyethylene or polycarbonate panels. - Ventilation Setup
Incorporate vents or windows to facilitate air circulation and prevent humidity buildup.
The Walipini greenhouse
The Walipini greenhouse stands as a testament to innovative, sustainable agriculture offering a sustainable solution for year-round cultivation. By leveraging the Earth's natural resources, it offers an eco-friendly solution for year-round cultivation, aligning seamlessly with principles of permaculture and regenerative growing.
Whether you're a seasoned farmer or a gardening enthusiast, the Walipini presents an opportunity to deepen your connection with the land and grow food in harmony with nature. It’s more than just a greenhouse—it's a philosophy rooted in resilience, self-reliance, and stewardship of the earth.
Frequently Asked Questions
Q: Can I build a Walipini in a high water table area?
A: It's challenging due to potential flooding. Raised beds or alternative greenhouse designs might be more suitable.
Q: What crops are best suited for Walipini greenhouses?
A: Leafy greens, root vegetables, and herbs thrive, especially in cooler months.
Q: Do I need additional heating during winter?
A: In extremely cold regions, supplemental heating may be necessary, but the design significantly reduces this need.
Q: Can I build a Walipini in a region with heavy snowfall?
A: Yes, but it's essential to design the roof with a steep angle to prevent snow accumulation and ensure structural integrity.
