Sustainable Greenhouse Heating

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2024: $6,500.00
Projected End Date: 02/15/2026
Grant Recipient: Ethereal Gardens
Region: North Central
State: Wisconsin
Project Coordinator:
Debra Weiss
Ethereal Gardens


No commodities identified


No practices identified

Proposal summary:

Conventional Greenhouse design (the usual hoophouse with metal
"ribs" and plastic covering) is a poor insulator.  They also
do not take advantage of specific heat, ie a particular materials
ability to heat and then retain heat.  Some are better than
others, and anything that is conductive (like metal), has low
specific heat, as does air, yet all commercial greenhouses use
air heating and insulation.  In addition most are heated by
either electrical wood, or some other frankly monumentally
inefficient system.  In additon most farms rely on grid
power which is usually natural gas or coal, greatly contribulting
to greenhouse gases and fuel needs.

Project objectives from proposal:

rough drawing of design

In the last few years a new technology, called thermal batteries,
has emerged to compensate for the bottleneck of energy storage in
most renewable systems.   My proposal in to build a
thermal sand battery in the bottom of my already existing
greenhouse prototype.  This battery is non-toxic and
therefore usuable in organic applications.  It uses the
concept of specific heat by storing excess energy in the form of
thermal energy in a sand filled concrete "sarcophagus".  The
solar/wind will electrocute the sand (like a steel melting
cauldron).  Because sand and stone/concrete have high
specific heat, these batteries are showing thermal retention in
the span of months, meaning they will stay hot, heating any soil
around it to temperatures enabling winter vegetable cultivation,
with my greenhouse to retain heat that rises, further
insulating.  This project will 1) Use off-grid sustainable
power (wind and solar), 2) Greatly reduce heat/energy loss
through insulation and cutting edge physics, 3) enable year round
growing of vegetables even when temperatures are below freezing

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.