Gas vs heat pump vs solar.
Three ways to extend swim season in Arizona. Each one wins a different use case — here's how to pick.
At-a-glance comparison.
| Spec | Natural gas | Heat pump | Solar |
|---|---|---|---|
| Installed cost | $4,500–$7,500 | $5,500–$9,000 | $4,000–$8,000 |
| Cost per million BTU | $22–$30 | $8–$14 | ≈ $0 |
| Heat-up speed | Fast (hours) | Slow (1–2 days) | Slow (days) |
| Best months in AZ | Dec–Feb | Mar–May, Oct–Nov | Mar–Nov |
| Lifespan | 8–12 yrs | 12–15 yrs | 15–20 yrs |
| Roof / panel space | No | No | ≈ pool surface area |
| Best for | Cold-snap & party prep | Daily shoulder-season use | Background heating |
Natural gas
Highest BTU output per dollar of equipment. Expensive to run but heats fast and works in any weather.
- Heats fast on demand
- Works in cold air
- Lowest equipment cost
- Highest monthly run cost
- Shortest lifespan
- Requires gas line
Heat pump
Pulls heat from ambient air. Cheap to run when air is 55°F+ — perfect for AZ shoulder seasons.
- 1/3 the run cost of gas
- 12–15 year lifespan
- Quiet operation
- Slow heat-up
- Loses efficiency below 50°F
- Higher install cost
Solar
Roof or ground panels heat pool water as it circulates. Best paired with another heater for cold weeks.
- Near-zero operating cost
- Longest lifespan
- Works through shoulder seasons
- Slow, weather-dependent
- Needs significant panel area
- Doesn't help in cloudy cold snaps
Common questions.
Which heater is cheapest to run in Arizona?
Solar is essentially free once installed. Heat pumps cost $80–$200/month for shoulder-season heating. Natural gas is $300–$600/month for active winter heating.
Can a heat pump heat my pool in January?
Below ~50°F ambient air, heat pumps lose efficiency fast. In Phoenix that's roughly 6–8 weeks/year where gas wins. Heat pumps shine February–April and October–November.
Is solar worth it on a Phoenix pool?
Yes — for shoulder-season heating it's the cheapest BTU you can buy. It cannot deliver fast heat on demand, so most owners pair it with gas or a heat pump for cold snaps and party prep.
Most AZ pools win with a heat pump + gas combo.
Heat pump handles 9 months cheaply, gas handles 8 weeks of January. Solar makes sense if you have unshaded south-facing roof and don't need fast heat.