We eliminated fossil fuels from our 1866 brick home in rural Wisconsin—here’s exactly what we installed, what it cost, and what we learned.
What We Built
Our 1866 brick home in rural Wisconsin is now a zero-emissions home. Here’s what that actually means:
- 25.2 kW solar array (56 panels) producing ~21 MWh per year
- Geothermal heat pump replacing oil furnace and wood pellet backup
- Two electric vehicles replacing gasoline (35,000 miles/year combined)
- L2 EV charger in the garage
- Net metering with the grid (summer surplus offsets winter deficit)
The result: Zero direct fossil fuel consumption for heating, cooling, or transportation.
The System, Piece by Piece
Solar: 25.2 kW Array
What we installed:
- 56 VSUN Solar 450W MONO-Perc Bi-Facial panels
- 56 Enphase IQ8A microinverters
- Enphase IQ Envoy monitoring system
- Grid-tied system with net metering
- Unirac SolarMount Pro Series racking on standing seam metal roof (no penetrations)
Performance (2025 actual):
- Annual production: 21.3 MWh
- Summer output: 2.6 MWh/month average (May-Aug), peak days ~130 kWh
- Winter output: 0.7 MWh/month average (Dec-Feb), some days near zero
- Solar covers: 60% of annual household energy needs (35.7 MWh consumed)
Why it works in Wisconsin:
- Net metering means summer surplus credits offset winter deficit at full retail rate ($0.142/kWh)
- Cold temperatures actually improve solar panel efficiency (solar cells are semiconductors that work better cold—they just have fewer daylight hours to work with)
- Snow slides off standing seam metal roof naturally (panels self-clear)
- Even in winter, we get productive days when sun reflects off snow
Cost (2024):
- Gross: $72,707.00 (includes transformer upgrade)
- Federal tax credit (30%): -$21,812.10
- Focus on Energy rebate: -$500
- Net cost: $50,394.90
- Grid connected: August 13, 2024
Geothermal: Ground-Source Heat Pump
Equipment status during January 2026 cold snap (-18°F lows, -22°F wind chill). Note: Aux Elect Heat is OFF—the geothermal system maintained comfort without backup heat.
What we installed:
- WaterFurnace 7 Series variable-speed geothermal heat pump (Model: NVV048D101CTL0KN)
- Vertical closed-loop field: 7 bore holes at 150 feet deep (1,050 total feet)
- IntelliZone2 zoning controller (multi-zone temperature control)
- Electric resistance backup for extreme cold
- Second circulation pump added after first winter ($1,077.50) to address capacity gap
- Replaced oil furnace and wood pellet stove
- Installed by Flock’s Heating & Air Conditioning (Cashton, WI - flocksheating.com)
Performance:
- Heating: Keeps 2,820 sq ft house comfortable even at -18°F (wind chill to -22°F)
- Cooling: Yes—better than the heat exchange AC that came with the house (which was at the end of its life)
- Efficiency: Variable-speed system adjusts to demand (more efficient than standard on/off cycling)
- Backup heat: Electric assist available for extreme cold, but with 2-pump system, aux heat stayed OFF during January 2026 cold snap (-18°F lows for 4 consecutive days)
Why it works in Wisconsin winters:
- Ground temperature 6 feet down stays constant year-round (~50°F in Wisconsin)
- Heat pump extracts heat from ground even when air is -20°F
- WaterFurnace 7 Series uses variable-speed compressor (adjusts output to match demand rather than cycling on/off—more efficient and more comfortable)
- Electric backup ensures comfort during extreme cold snaps
- No combustion = no carbon monoxide risk, no flue, no fuel delivery
Cost (2023):
- Gross: $58,898.00 (initial installation, June 2023)
- Federal tax credit (30%): -$17,669.40
- Net cost: $41,228.60
Note: We added a second circulation pump in 2025 ($1,077.50) to address a capacity gap during extreme cold—see lessons learned below.
Replaced:
- Oil furnace: $2,300/year in fuel costs
- Wood pellets: $450/year in fuel costs
- Total heating savings: $2,750/year (minus $450 geo maintenance = $2,300 net)
Ongoing costs:
- Annual maintenance: $450/year
Electric Vehicles: Two EVs, Zero Gas Stations
What we drive:
- Toyota BZ4X ($53,000)
- Ford Mustang Mach-E ($52,000)
- Combined annual mileage: 35,000 miles
- 95%+ charged at home (we use public charging about once every other month)
Charging:
- L2 charger installed in garage (240V, 10 kW output)
- Solar offsets charging costs (summer surplus, winter grid)
- Typical range added: ~27 miles/hour (winter) to ~40 miles/hour (summer)
- Cost per mile: ~$0.03-0.05 (electricity) vs. ~$0.10 (gasoline equivalent)
Performance in rural Wisconsin:
- Longest regular trip: 260 miles round-trip to Minneapolis airport (~6x/year). One L3 charging stop in warmer months; two stops total in winter.
- Winter range impact: ~30-35% reduction in cold weather (efficiency drops from 3.9-4.2 mi/kWh in summer to 2.7 mi/kWh in winter)
- Public charging: Rarely needed—we use A Better Route Planner (ABRP) for trips over 2 hours. Has worked every time.
Cost:
- Total vehicle cost: $105,000 (BZ4X $53K + Mach-E $52K)
- Extended warranties not included (similar to ICE vehicle costs)
- Federal EV rebates: $7,500 (Mach-E only; BZ4X not eligible—manufactured in Japan)
- Net EV premium: ~$10,500 ($18K premium over gas equivalents minus $7,500 rebate)
Replaced:
- Gasoline: ~1,400 gallons/year @ ~$3.10/gallon = ~$4,340/year avoided
How It All Works Together
This isn’t three separate systems—it’s one integrated zero-emissions home.
In summer:
- Solar panels produce ~85 kWh/day average (May-Aug)
- House uses electricity for cooling, appliances, and EV charging
- Surplus production (11.5 MWh exported in 2025) flows to grid, earning credits at retail rate
- Geothermal cooling runs efficiently
- EVs charge during daylight or overnight
In winter:
- Solar panels produce ~23 kWh/day average (Dec-Feb)—some days near zero
- Geothermal heating draws significantly from grid
- EVs charge overnight using grid power
- Summer credit surplus offsets winter grid consumption
- Net metering balances annual energy use
The result (2025 actual):
- Annual solar production: 21.3 MWh
- Annual home + EV consumption: 35.7 MWh
- Solar covers 60% of total annual energy needs
- Net grid import: 14.4 MWh/year (winter deficit after summer surplus credits)
- Annual grid cost: ~$2,045/year (14.4 MWh × $0.142/kWh) plus connection fees
What We Learned (The Honest Part)
What Worked Better Than Expected
Solar in suboptimal locations still works. We maximized installed capacity by putting panels even in suboptimal locations on the roof. Our thinking: we likely would not revisit or enhance the capacity ever again, plus the solar tax credits were available “now.” We did not know what tomorrow would look like for incentives. The panels in suboptimal spots still produce—just less than ideal orientation. No regrets on maximizing while we could.
Geothermal keeps up once heat leaks are addressed. After fixing one major issue (see below), the geothermal system keeps the house comfortable even during extreme cold.
EVs work fine in rural areas. Range anxiety is overblown. We charge at home 95%+ of the time, and for longer trips, A Better Route Planner has never failed us. Winter range loss is real (30-35%), but manageable with planning.
Net metering makes the math work. Without 1:1 retail rate credits, the economics would be much worse. Wisconsin’s net metering policy is a key enabler.
What Was Harder Than Expected
Heat leaks challenged the HVAC system. We had a garage door entry to our basement that leaked a lot of heat and cooling. The heat leakage challenged the HVAC to keep up when temperatures went below 20°F. Once we addressed that issue by replacing the garage door with a patio door in the same opening, the HVAC could keep up. Lesson learned: Make sure you have major heat leaks addressed to allow your systems to work at their best. A geothermal system sized for your home still needs a reasonably sealed envelope to perform well.
System sizing at the edge of capacity. Our house was at the upper end of what the single-pump system could handle. During the first winter (2023-24), the system could not maintain temperature during a cold week. We added a second circulation pump for $1,077.50, and the difference has been dramatic—the 2-pump system has maintained 65°F or higher throughout the cold periods of winter 2024-25 and 2025-26, including a January 2026 stretch with lows of -18°F for four consecutive days. Lesson learned: When a house is at the upper range of a system’s capacity, consider sizing up. Real-world performance in extreme conditions matters more than theoretical specs.
Coordinating multiple vendors takes project management. Geothermal, solar, electrical upgrades, and roof work all had to be sequenced correctly. Having PM experience helped—this could overwhelm someone without it.
What We’d Do Differently
Address envelope issues first. If we were doing it again, we would have replaced the leaky garage door entry before the geothermal installation—not after discovering the HVAC struggled to keep up. Seal the envelope, then size and install the heating system.
Still maximize solar capacity. We would still install panels in suboptimal locations. The marginal production from those panels still adds up over 25 years, and we captured the tax credits when they were available.
Size up the geothermal if you’re borderline. The $1,077 second pump fix worked, but we could have avoided the first winter’s struggles by starting with more capacity.
The Numbers: What It Cost, What It Saves
Total Investment (2023-2024)
| System | Gross Cost | Tax Credits/Rebates | Net Cost |
|---|---|---|---|
| Solar (25.2 kW) | $72,707.00 | -$22,312.10 | $50,394.90 |
| Geothermal | $58,898.00 | -$17,669.40 | $41,228.60 |
| EVs (premium over gas) | $18,000 | -$7,500 | $10,500 |
| EV Charger | $800.00 | -$240.00 | $560.00 |
| TOTAL | $150,405.00 | -$47,721.50 | $102,683.50 |
Annual Savings
| Category | Annual Savings |
|---|---|
| Solar electricity offset | $3,025 (21.3 MWh × $0.142) |
| Heating (oil + pellets replaced) | $2,750 |
| Gasoline avoided | $4,340 (~1,400 gal × $3.10) |
| Subtotal | $10,115 |
| Geothermal maintenance | -$450 |
| Net grid electricity cost | -$2,045 (14.4 MWh imported) |
| Net Annual Savings | ~$7,620 |
Payback
- Simple payback: ~13.5 years ($102,684 ÷ $7,620/year)
- With 4% annual energy cost increases: ~11 years
- Equivalent investment return: ~7-9% over 25 years
(See the Monday business post “I Did the Math: Why Our $112K Investment Returns 8.9%” for detailed ROI breakdown)
Why Rural Wisconsin?
Most zero-emissions homes are in California, Colorado, or the Pacific Northwest—places with mild climates, high electricity costs, and strong renewable energy cultures.
We’re in rural Wisconsin:
- Cold climate: Winter lows regularly hit -20°F (we’ve tested at -18°F with -22°F wind chill)
- Lower electricity costs: $0.142/kWh (national average is $0.16/kWh)
- Low adoption: Solar, geothermal, and EVs are still uncommon here
- Rural location: 30+ miles to La Crosse; public EV charging sparse but improving
If it works here, it works almost anywhere in the continental US.
What “Zero Emissions” Actually Means
What it includes:
- Zero direct fossil fuel combustion for heating
- Zero gasoline consumption for transportation
- 60% of electricity from solar, 40% from grid
What it doesn’t include:
- Embodied carbon in manufacturing solar panels, heat pump, EVs
- Grid electricity consumed (winter deficit after summer credits)
- Emissions from food, goods, services, air travel
Honest framing: We’re not carbon-neutral. We’re zero direct fossil fuel consumption for home energy and local transportation. That’s about 40-50% of a typical household’s carbon footprint, depending on how you calculate it.
The remaining emissions come from:
- Grid electricity (Wisconsin grid is ~60% fossil fuels—mostly natural gas and coal)
- Everything else we buy, eat, and do
Zero emissions ≠ zero impact. It means we’ve eliminated the biggest controllable sources of household fossil fuel use.
Is This Replicable?
What made this possible for us:
- Homeownership - Can’t install solar/geothermal as a renter
- Lot size - Our 1/2 acre lot accommodated 7 vertical bore holes (vertical loops need less space than horizontal)
- Roof condition - We were already replacing the roof (upgrading from standard shingles to metal standing seam), so solar made sense
- Capital access - $151,000+ before tax credits requires cash or financing
- Rural location - Easier permitting, no HOA restrictions, space for equipment
- Federal tax credits - 30% IRA credits reduced net cost by ~$48,000
- Net metering - Wisconsin allows 1:1 retail rate credits (not all states do)
Barriers for most people:
- Upfront cost is the #1 barrier (even with tax credits)
- Renters can’t make these decisions (26% of US households)
- Small lots can’t accommodate geothermal loop fields (~21% of homes)
- Information gap - Many people don’t know about incentives or how systems work
- Installer scarcity - Few contractors do geothermal, especially in rural areas
We had advantages most people don’t. That doesn’t mean it’s impossible for others—it means the barriers are real and need addressing.
What’s Next: Living With the System
This post is the overview. Future Wednesday posts will dive deeper into:
- Solar in Wisconsin winters - Production data, snow management, net metering economics
- Geothermal performance - How it handles -20°F, maintenance, lessons learned
- EV range reality - 35,000 miles in rural Wisconsin, winter range loss, charging strategies
- Monitoring and optimization - How we track production/consumption, what we learned
- Maintenance and longevity - What breaks, what doesn’t, long-term costs
We’ve been living with geothermal since June 2023 (2.5 years) and solar since August 2024 (17 months). It works. It saves money. And it’s not as complicated as it sounds once you understand how the pieces fit together.
Related Content
Monday Business (Coming Soon):
- “How I’d Project-Manage Your Zero-Emissions Home” - The PM approach to sequencing vendors and managing timelines
- “I Did the Math: Why Our $112K Investment Returns 8.9%” - Full ROI analysis and payback calculations
Wednesday Wisdom (Coming Soon):
- “25.2 kW of Solar in a Place That Gets Winter”
- “Geothermal Heat: The Technology 20 Years Ahead of Adoption”
- “Two EVs, 35,000 Miles, Zero Gas Stations”
Zero emissions doesn’t mean zero impact. It means we’ve eliminated direct fossil fuel consumption for heating and transportation—the biggest controllable sources of household carbon. What’s left is grid electricity (which will get cleaner as the grid does) and everything else modern life requires. It’s progress, not perfection.
NOTES FOR JEAN - DELETE BEFORE PUBLISHING
Status: READY FOR FINAL REVIEW (Updated January 30, 2026)
Completed:
- ✓ All placeholders filled with verified data
- ✓ Photos organized in /images/geothermal/ folder
- ✓ EV mileage confirmed (35K miles/year)
- ✓ Solar production corrected to 21.3 MWh (2025 actual)
Before publishing:
- Tone check: Is this conversational enough for Wednesday blog voice?
- Cross-check ROI numbers against Monday ROI post when drafted
- EDIT IMAGE: Remove serial number from geothermal equipment summary image (
/images/geothermal/waterfurnace-7-series.jpeg). Use Photoshop, GIMP, Preview, or Canva to blur/crop/cover the serial number before publishing. - Add missing photos when available:
- Solar panels on roof (wide shot)
- EVs in garage with L2 charger visible
Data sources used:
- Enphase Enlighten 2025 annual data (21.3 MWh produced, 35.7 MWh consumed, 60% offset)
- Geothermal equipment details (WaterFurnace 7 Series, 7 × 150 ft bore holes)
- January 2026 performance snapshot (aux heat OFF at -18°F)
- Cost data from expenses spreadsheet
- Heating costs from background/zero-emissions-home-conversation.md ($2,750/year oil + pellets)