What is a climate battery, and is it "geothermal"?
Three different systems get sold as "geothermal greenhouses":
| System | How it moves heat | Heat source | Moving parts | Typical goal |
|---|---|---|---|---|
| Climate battery (earth-tube heat storage) | Fan pushes greenhouse air through perforated pipe buried in the soil under the floor | Mostly stored daytime solar heat, plus some ground heat | One or more fans and a thermostat | Even out day/night swings; cut backup heat |
| Deep earth-tube greenhouse (Nebraska style) | Fan pulls air through tubing in a deep trench | Ground heat at depth | One fan | Keep the house just above freezing with no heater |
| Ground-source heat pump | Fluid loop in boreholes or trenches feeds a compressor | Ground at a near-constant temperature | Compressor, pumps, air handler | Hold a set temperature, heat and cool |
A climate battery is mostly a solar heat battery. On a sunny January afternoon a closed greenhouse runs far warmer than it needs to. The fan pushes that hot air through the tubes and the soil absorbs the heat. At night, cold greenhouse air passes through the warmer soil and picks heat back up. The same loop cools the house in summer.
A ground-source heat pump is the system the Kansas Geological Survey's Public Information Circular 31 covers. KGS notes that soils about 10 ft down hold a "near-constant 50°F to 60°F" year-round, and that Kansas wells and boreholes for these systems must be drilled by a KDHE-licensed water-well contractor, who files a WWC-5 form. KGS also notes Kansas has no shallow hot-water resource for direct heating.
Wichita's numbers: winter load vs. ground temperature
NOAA's 1991–2020 normals for Wichita Eisenhower Airport list 4,592 heating degree days a year at base 65°F. NOAA also publishes the same normals at lower bases, which matters because a greenhouse is not a house. Held at 45°F, a greenhouse only "sees" the cold below 45°F.
| Month | HDD base 65°F | HDD base 55°F | HDD base 45°F |
|---|---|---|---|
| November | 576 | 303 | 107 |
| December | 911 | 603 | 313 |
| January | 986 | 676 | 379 |
| February | 767 | 492 | 250 |
| March | 550 | 278 | 97 |
| Annual | 4,592 | 2,658 | 1,273 |
Source: NOAA NCEI monthly normals and annual normals, station USW00003928. NCEI computes annual and monthly normals separately, so the months do not add exactly to the annual line.
On the other side of the ledger: Wichita's normal annual mean air temperature is 57.0°F (NCEI), and deep soil tends to settle near the local annual mean. That fits the KGS 50–60°F range. So under your greenhouse floor sits a large mass of soil in the mid-50s while January nights average a low of 22.5°F (NCEI). A climate battery exploits that gap, and recharges it with sun.
The Nebraska precedent: citrus near Alliance
The best-documented ground-heated greenhouse on the Plains is Russ Finch's, near Alliance, Nebraska. KCUR and Harvest Public Media covered it in 2016. Here is what that reporting actually says:
- The original greenhouse is about 1,200 square feet and dug roughly four feet into the ground.
- A single fan moves air through perforated plastic tubing in a trench 8 ft deep. Finch: "The only heat source is the earth's heat at 52 degrees at 8-foot deep."
- There are no propane or electric heaters and, in his words, "no backup system for heat."
- The goal is modest: "keep it above 28 degrees in the winter."
- He estimated energy cost at about $1 a day, grows oranges, lemons, figs and grapes, and reported a new greenhouse of the design cost $22,000 to build (2016 figure).
The lesson for Wichita is the setpoint. That system works without a heater because it targets 28°F, not 55°F. Tomatoes in January need more than an earth tube; hardy citrus and winter greens may not.
Honest payback: the arithmetic
Here is the model; rerun it with your own numbers. The full method is in our one-winter heating guide.
Heat loss (BTU per season) = U × A × HDD × 24
Example greenhouse: 12 × 20 ft freestanding, 8 ft sidewalls, gable roof with a 4 ft rise.
- Sidewalls: 2 × 20 × 8 = 320 sq ft
- End walls: 2 × (12 × 8 + ½ × 12 × 4) = 240 sq ft
- Roof: 2 × 20 × 7.21 ft slope = 288 sq ft
- Total surface area A = 848 sq ft
Glazing: 8 mm twin-wall polycarbonate, U = 0.65 BTU/hr·ft²·°F (NGMA suggested coefficient). Setpoint 45°F, so HDD = 1,273.
Q = 0.65 × 848 × 1,273 × 24 = 16.84 million BTU for an average winter.
Now price that heat with natural gas:
- Example input: $12.69 per thousand cubic feet (EIA, Kansas residential natural gas price, January 2026). Replace with your own bill.
- 1 cubic foot = 1,036 BTU (EIA), so $12.69 ÷ 1.036 = $12.25 per million BTU bought.
- At 80% heater efficiency: $12.25 ÷ 0.80 = $15.31 per million BTU delivered.
- 16.84 × $15.31 = about $258 a season.
Kansas Gas Service's gas commodity charge resets monthly under its cost-of-gas tariff, so this number moves. The EIA figure is an all-in average that includes delivery and fixed charges.
So the most a climate battery could save on this greenhouse is about $258 a year on gas, and only if it replaced the heater entirely. Simple payback = added cost ÷ annual savings. Published figures give a range. Ceres Greenhouse Solutions puts its residential ground-to-air heat systems for greenhouses under 1,000 sq ft at $2,000–$5,000 (Ceres, page updated Oct 2026). Atmos Greenhouse puts climate-battery costs at about $7.14 per sq ft of greenhouse for excavation, tubing and fans, not counting labor or electrical work, based on March 2026 material prices (Atmos). That is about $1,700 for this 240 sq ft house before labor. The table uses three added costs across that range, with labor included. Plug in your own quote.
| Added cost of climate battery (assumption) | Replaces 100% of gas heat ($258/yr) | Replaces 50% ($129/yr) |
|---|---|---|
| $3,000 | 11.6 years | 23.3 years |
| $6,000 | 23.3 years | 46.5 years |
| $10,000 | 38.8 years | 77.5 years |
At a 55°F setpoint (2,658 HDD) the same greenhouse needs 35.2 million BTU, about $538 a year on gas, which halves those paybacks. On propane or electric resistance heat, the savings per year are roughly two to three times larger. That is the honest picture: on Kansas gas, a climate battery is a comfort and resilience upgrade, not a fuel investment.
When a ground-coupled greenhouse makes sense in Wichita
Build one when the value is not only on the gas bill:
- No gas line at the site. If the alternative is propane or resistance heat, the savings column grows fast. See the fuel comparison in the heating guide.
- Summer cooling. Wichita greenhouses overheat from spring through fall. The same tubes pull heat and humidity out of the air during the day.
- Steady nights. Stored heat smooths the swing that stresses plants on clear, cold nights.
- Pairing with passive solar or a dug-in floor. A climate battery works best with an insulated north wall and good south glass. See our passive solar and earth-sheltered builds.
Design decisions a Wichita build forces
Soil and water table. County soil surveys (NRCS Soil Data Access) show well-drained Blanket, Nalim and Shellabarger soils across much of the county and heavy shrink-swell clays (Irwin, Tabler, Rosehill) to the east and south. In the Arkansas River valley, Canadian–Waldeck soils can carry a seasonal water table about 2–3 ft down. Buried air tubes need to stay above groundwater and drain their condensate. We check the site before we set tube depth. Excavation is scoped per site.
Glazing. The battery can only store heat the glazing lets in and keeps. Twin-wall polycarbonate cuts conducted heat loss about 42% versus single glass (0.65 vs. 1.13 U-value). Compare options on our glazing page.
Below-grade air. Sedgwick County radon tests averaged 3.6 pCi/L in 2010 data, and 30.9% came in at or above 4 (KDHE 2014 profile). Use sealed, joined tubing and test the air if you plan to spend long hours inside.
Footings and permits. Our 12 × 20 example is 240 sq ft, over Wichita's 200 sq ft building-permit exemption and under the unincorporated county's 400 sq ft line. Check yours in the permit guide, and see foundations for frost depth.
Not ready to talk yet? Start with our guide to heating a greenhouse for one Wichita winter, which runs the same model across glazing, setpoint and fuel.
Frequently asked questions
Does a geothermal greenhouse work in Kansas?
Yes, within limits. Kansas has no shallow hot-water resource, per the Kansas Geological Survey, but soil about 10 ft down holds 50–60°F year-round. That is enough to keep a greenhouse above freezing or to store daytime solar heat. It is not enough on its own to hold a summer-crop setpoint through January.
How much does a climate battery save on heating in Wichita?
It depends on setpoint, glazing and fuel. For a 12 × 20 twin-wall greenhouse at 45°F, the whole season's heat is about 16.84 million BTU, roughly $258 at the January 2026 EIA Kansas residential gas price. The battery can only save part or all of that number. We do not quote a guaranteed savings percentage.
Is a climate battery the same as a ground-source heat pump?
No. A climate battery is a fan moving greenhouse air through buried pipe. A ground-source heat pump uses a compressor and a fluid loop, and in Kansas its boreholes must be drilled by a KDHE-licensed water-well contractor. The heat pump holds a setpoint; the climate battery softens swings.
Can I grow citrus in a Wichita greenhouse without a heater?
The Nebraska example aims to keep the house above 28°F with ground heat alone and grows oranges and lemons. That is a deliberate low setpoint. For a Wichita build we would plan backup heat for the coldest nights rather than promise none is needed.
Get a quote
Tell us your footprint, the setpoint you want, and whether you have gas at the site. We will design the glazing, tube layout and backup heat together, and show you the heat-loss math for your plan. Our core service area is Sedgwick County and towns within about 30 miles of Wichita; outer-county projects are case by case.