TLDR
Goal: Determine whether thermoelectric generation (TEG) is a viable power source for Ti Kaye, and if so, where to deploy it.
Conclusion: Not viable as primary power. At $10–40/W installed versus $1.50–3.50/W for solar, the economics don't work at scale. TEG is worth deploying in three specific niches only: portable guest/staff charging, diesel generator exhaust recovery, and kitchen flue scavenging.
Next steps: Build one Config A portable unit to validate the technology on-site. Measure generator exhaust temperature to determine retrofit viability. Keep expanding the 45kW solar array for all high-load needs.
Immediate requirements: $1,600–2,400 for Config A hardware. One site visit to measure exhaust temperature. No contractor required for either.
Output Reality Check
The Critical Constraint
Single module ceiling: 1W to 22W under realistic conditions. No exceptions. All planning flows from this constraint.
| Product / Manufacturer | Hot Side | Cold Side | Delta-T | Output | Status |
|---|---|---|---|---|---|
| TEGpro 10W Module (TEGmart) | 330°C | 30°C | 300°C | 10W | High-temp rated |
| TEGpro 22W Module (TEGmart) | 300°C | 30°C | 270°C | 21.6W | 56mm, 7.2V matched load |
| Hi-Z HZ-14 (Hi-Z Technology) | 230–250°C | 30°C | ~220°C | ~14W | 49 thermocouples |
| HZ-20 | 230–250°C | 30°C | ~220°C | ~20W | 71 thermocouples |
| Tecteg 30W AIR | varies | air-cooled | varies | 30W | $429 system unit |
| Global Power Technologies | varies | varies | varies | 5W–500W | Multi-module systems |
"100W" stove-top generators are not single modules. They are arrays of 5–10 individual modules sharing one hot surface and cooling circuit.
Delta-T Requirements
Power scales roughly with the square of temperature differential. The relationship is non-linear and unforgiving:
| Delta-T | Output per Module | Practical Utility |
|---|---|---|
| < 50°C | Milliwatts to 3W | Not useful |
| 100–150°C | 3–8W | Marginally useful for trickle charging |
| 200–250°C | 10–15W | Practical for battery charging |
| 270–300°C | 18–22W | Near-rated output |
The Tropical Problem: Cold-Side Heat Rejection
Even at 5% efficiency, 95% of thermal energy passes through to the cold side. A module generating 20W dumps approximately 380W of waste heat.
| Cooling Method | Cold-Side Temp Achievable | Viability at 28–32°C Ambient |
|---|---|---|
| Passive air fin | Ambient + 15–25°C | Poor (cold side 45–55°C) |
| Active forced-air | Ambient + 8–15°C | Marginal (cold side 36–47°C) |
| Water-cooled (closed loop) | Ambient + 3–8°C | Acceptable (cold side 31–40°C) |
| Ocean/rainwater heat sink | Ambient water (~28°C) | Good (corrosion risk) |
Bottom line for St. Lucia: Water cooling is mandatory. Budget for pumps and reservoir maintenance.
Configuration Realities
| Configuration | Continuous Output | Approximate Cost |
|---|---|---|
| Single 22W module, water-cooled | 15–18W | $50–80 |
| 5-module array (100W class) | 70–90W | $400–600 |
| 20-module array (400W class) | 280–360W | $1,500–2,500 |
| 50-module array (1kW class) | 700–900W | $4,000–7,000 |
Heat Sources
Evaluation Matrix for St. Lucia
| Heat Source | Capital Cost | Portability | Hot-Side Temp | Delta-T Feasibility | Suitability |
|---|---|---|---|---|---|
| Parabolic dish (1–2m) | $300–800 DIY | Low | 400–800°C | Excellent | Tier 1 |
| Diesel generator exhaust | Near zero | Fixed | 300–500°C | Excellent | Highest ROI |
| Biomass stove | $200–800 | Medium | 300–500°C | Excellent | Weather-independent |
| Commercial kitchen flue | $500–2,000 | Fixed | 200–400°C | Good | Free energy recovery |
| Laundry waste heat | Low | Fixed | 60–90°C | Poor | Insufficient delta-T |
| Geothermal (Sulphur Springs) | Extreme | None | 41–97°C surface | Marginal | 15km distant — not viable |
Recommended Heat Sources
Tier 1 — Diesel Generator Exhaust
If the property maintains diesel backup, exhaust temperatures of 300–500°C provide the highest ROI application. Retrofit cost: $800–1,500 for 300–600W recovery.
Tier 2 — Parabolic Concentrator
1.5m diameter dishes achieve 400–800°C at focus. Requires thermal buffer/heat pipe to throttle to module-safe temperatures (200–250°C).
Power Tier Mapping
| Tier | Device | Wattage | TEG Viability | Strategy |
|---|---|---|---|---|
| 1 | Qi wireless charging | 5–15W | Primary viable | Single module + battery |
| 1 | USB-C device charging | 5–65W | Primary/Hybrid | Small array + LiFePO4 buffer |
| 2 | Laptop charging | 45–100W | Hybrid only | 5×22W array + battery |
| 2 | POS terminal | 15–22W | Primary viable | Same as Tier 1 |
| 2 | LED lighting (10 fixtures) | 200W | Hybrid | TEG supplements PV |
| 3 | RO water pump | 50–250W | Hybrid | TEG + PV + battery |
| 4 | Golf cart charger | 900–1,500W | Not viable | PV primary |
| 6 | HVAC (1 ton) | 800–3,000W | Not viable | Grid or generator |
TEG is viable as primary source for Tiers 1 and low Tier 2 (under 100W). Above 500W, cost-per-watt becomes prohibitive versus PV.
System Configurations
Config A — Portable Charging Station
Wheeled cart for off-cable mobility.
- Modules: 6× TEGpro 22W (series-parallel)
- Hot side: Copper heat spreader, 200°C target
- Cold side: Water-cooled block, 5L reservoir, 12V pump (5–10W parasitic)
- Net output: 60–80W continuous
- Battery: 2× 12V 100Ah LiFePO4 (24V 100Ah = 2.4kWh usable)
- Cost: $1,560–2,750
Config B — Fixed Mid-Power Node
Semi-permanent installation (pool area, farm, equipment building).
- Modules: 20× TEGpro 22W = 440W rated; 280–360W realistic
- Heat source: Parabolic trough (2–3m aperture) with synthetic oil at 300–350°C
- Storage: 4× 12V 200Ah LiFePO4 (48V 200Ah = 9.6kWh)
- Inverter: 2kW pure sine wave
- Cost: $7,100–14,300
Config C — Property-Scale Hybrid
TEG as marginal supplement to existing 45kW PV.
[Diesel Generator] --exhaust--> [TEG Array, 500–1000W] ──┐
[Parabolic Concentrators] -----> [TEG Array, 800–1500W] ──┤
[45kW PV] ---------------------> [48V Battery, 50–100kWh] ─┤
↓
[Bidirectional Inverter, 10–20kW]
- TEG contribution: 300–500W average; 1,300–2,230W maximum (intermittent)
- Cost (TEG layers only): $39,600–76,400
Sourcing
| Component | Supplier | Price Range | Notes |
|---|---|---|---|
| 22W Modules | TEGmart (TEGpro) | $50–80 each | High-temp rated, reliable |
| 20W Modules | Hi-Z Technology | Contact | Industrial grade |
| Solar Cooker | Amazon (1.5m parabolic) | $200–400 | Modify absorber plate |
| LiFePO4 Batteries | Renogy / GoldenMate | $250–350 per 100Ah | IP65 minimum for tropics |
| Charge Controllers | Victron SmartSolar | $80–120 | Verify Voc compatibility |
Verdict
Where TEG Excels
Portable Low-Power Charging (Tier 1–2)
A Config A unit delivers phone/laptop charging anywhere on property without cable runs. No comparable off-the-shelf product exists at this scale.
Waste Heat Recovery
Diesel generator exhaust retrofit costs $800–1,500 and recovers 300–600W of otherwise wasted energy. Positive ROI within 1–2 years.
Night-Time Biomass Operation
Unlike PV, TEG with wood stove input generates at 2am. Valuable for off-grid resilience.
Hard Limits
- Cost per watt: $10–40/W installed for TEG versus $1.50–3.50/W for PV
- Practical ceiling: 400W continuous is the maximum for solo operator maintenance
- Tropical maintenance: Water cooling circuits require service every 3–6 months (algae, corrosion, pump seals)
TEG is not viable as primary resort power. It is viable and valuable in three niches: portable charging, generator exhaust recovery, and kitchen flue scavenging. Deploy as a supplement, not a competitor, to the existing 45kW PV array.
March 2026. Pricing approximate; St. Lucia import duties add 25–40% to North American landed costs.