Electrical work at the pool means breaker off, and a licensed electrician when anything past the bulb swap is involved. GFCI protection on pool lights isn't optional.
Pool lights are a rare easy win: the wattage gap between incandescent and LED is 5–10×, the light output is comparable, and the swap is often just a bulb. The only pools where the math gets slow are short seasons with short evenings — and even those eventually collect the bulb-life savings.
A worked example
A 400W bulb, 4 hours a night, 6-month season, at $0.17/kWh: $50 a year to run. A 40W LED doing the same job: $5 — saving $45 a season, so a $90 retrofit bulb pays for itself in two seasons and then saves every year after. Add the avoided incandescent replacements (roughly one $25 bulb a season at those hours) and the real payback is closer to one.
While you're thinking about the power bill
The light is the appetizer — the pump is the meal. If your pool still runs a single-speed pump, the variable-speed savings calculator routinely finds $300–600 a year, and the heating and cover calculators cover the other big lines on a pool's power bill.
Frequently asked questions
How much does it cost to run a pool light?
A classic 300–500 watt incandescent pool light running 4 hours a night costs $70–130 a year at typical electric rates. The LED equivalent draws 20–70 watts for the same light — $6–18 a year. Enter your bulb, hours, and rate above for your exact numbers.
Are LED pool lights worth it?
Almost always, and faster than people expect: the electricity savings alone typically pay back a $50–150 retrofit bulb in 1–2 seasons, and LEDs last 15,000–30,000 hours against an incandescent's ~1,000 — so you're also skipping years of bulb swaps (and possibly a service call each time).
Can I just swap an LED bulb into my existing pool light?
Often yes — retrofit LED bulbs fit many standard fixtures (Pentair/Hayward-style wet-niche housings) and that's the cheap path. Full LED fixtures cost more but add color modes and better seals. Either way, anything involving the fixture behind the lens ring is a job for the breaker OFF and, if in doubt, a pro — water and electricity earn the caution.
How long do LED pool lights last?
15,000–30,000 rated hours — at 4 hours a night, that's 10–20 years. In practice drivers and seals usually give out before the diodes do, which is why the warranty (look for 2+ years) matters more than the hour rating.