A ‘standard’ (A19 shape, E26 base) 8W 800 lumen LED lamp costs around $5 and will use about $20 of energy over a 15,000 hour lifespan, assuming $0.15/kWh.

That works out to around $0.035 per day for the lifespan of the lamp if you run it constantly for 24 hours a day, I wouldn’t waste time thinking about it. It’s an extra $10 over 12 years, you’re still using the energy.

Investing in occupancy or vacancy sensor wall switches at $25 a piece would be the best option, then you don’t need to remember to turn the lights off!