University of Vermont

Snowy Day

Compost Power Project Heating Up

by Katharan M Blofson, Clean Energy Fund Education & Outreach Graduate Assistant


The Compost Power project underway at Slade Hall is heating up!

On 11/9 and 11/10, students joined the Compost Power Network's Gaelen Brown in a hands-on Compost Power construction workshop, learning about and installing the Jean Pain compost mound system adjacent to the existing Slade greenhouse.  The Compost Power Network, based in Waitsfield, VT, advocates for and educates about compost heat recovery, and is working to pilot and test Jean Pain method compost heat recovery systems for space and hot water heating.  

Slade's system will capture the heat generated by decomposition, and direct it to warm the greenhouse soil using radiant tubing.  The Clean Energy Fund funded this project with a grant of $15,000, in the interest of supporting student initiative and involvement in renewable energy and food systems research questions around season extension and cold climate agriculture.  

In the weeks leading up to the workshop, students and UVM Physical Plant staff worked to repair and paint the greenhouse, in preparation for installing the garden beds. PPD carpenters also rebuilt the south-facing greenhouse wall.  

The Jean Pain mound is on the north side of the greenhouse.

The Compost Power! workshop started with a presentation on composting and the Jean Pain compost heat recovery method, and then workshop participants got right down to work.  Students piled hay bales into a 16' circle that would eventually be taller than most of them.  

Perforated drainage pipes in the bottom of the Jean Pain mound facilitate airflow in the lower portion of the mound.  


Students bringing in the woodchips that are the decomposition fodder for the Jean Pain mound by wheelbarrow.


An excavator joined in to make their work a little bit easier, filling the oversized hay bale "container" with woodchips!


Students installing the radiant tubing in the Jean Pain mound.

Heat is released as the woodchips begin to decompose, and transferred to cool water in radiant tubing inside the pile, warming it through heat exchange.  This warm water is then directed to the garden beds in the greenhouse, transferring significant amounts of heat to the soil.  The Compost Power project will test Jean Pain principles of compost heat recovery, and attempt to answer the questions: How much heat can a mound of a certain size produce?  How much garden bed area will that heat? Is this method practical for season extension and year-round production of greenhouse crops?   

Now that students have returned soil to the greenhouse after helping to repair it, the vegetable seedlings that they started in the fall are awaiting transplanting in the UVM Greenhouse--to their new home in the Slade Greenhouse's compost-warmed soil!