LAGOS, Nigeria — WE call it light; “electricity” is too sterile a word, and “power” too stiff, for this Nigerian phenomenon that can buoy spirits and smother dreams. Whenever I have been away from home for a while, my first question upon returning is always: “How has light been?” The response, from my gateman, comes in mournful degrees of a head shake.

Bad. Very bad.

The quality is as poor as the supply: Light bulbs dim like tired, resentful candles. Robust fans slow to a sluggish limp. Air-conditioners bleat and groan and make sounds they were not made to make, their halfhearted cooling leaving the air clammy. In this assault of low voltage, the compressor of an air-conditioner suffers — the compressor is its heart, and it is an expensive heart to replace. Once, my guest room air-conditioner caught fire. The room still bears the scars, the narrow lines between floor tiles smoke-stained black.

Sometimes the light goes off and on and off and on, and bulbs suddenly brighten as if jerked awake, before dimming again. Things spark and snap. A curl of smoke rises from the water heater. I feel myself at the mercy of febrile malignant powers, and I rush to pull my laptop plug out of the wall. Later, electricians are summoned and they diagnose the problem with the ease of a long acquaintance. The current is too high or too low, never quite right. A wire has melted. Another compressor will need to be replaced.

For succor, I turn to my generator, that large Buddha in a concrete shed near the front gate. It comes awake with a muted confident hum, and the difference in effect is so obvious it briefly startles: Light bulbs become brilliant and air-conditioners crisply cool.