Is it cheaper to run a lamp or a main light?

In terms of electricity consumption, running a lamp (such as a table or floor lamp) is generally cheaper than running a main light (like a ceiling light). However, this comparison depends on several factors, including the type of lamp and light bulb you're using, how much wattage the light consumes, and how long it's on.

Factors to Consider:

1. Wattage of the Bulb:

   • The more wattage a bulb uses, the more electricity it consumes.
   • Main lights (such as ceiling fixtures) often use higher-wattage bulbs (e.g., 60W to 100W incandescent bulbs or 12W to 20W LED bulbs for standard lighting).
   • Lamps, especially small desk lamps or reading lamps, tend to use lower-wattage bulbs (e.g., 5W to 15W LED or CFL bulbs).

2. Type of Light Bulb:

   • LED bulbs are more energy-efficient than incandescent or halogen bulbs. A 10W LED bulb produces the same light output as a 60W incandescent bulb but consumes much less energy.
   • CFL bulbs are also energy-efficient but not as much as LEDs.

3. How Long the Light Is On:

   • Main lights are often left on for longer periods, especially if they are in the center of the room or used for general illumination.
   • Lamps may be used more intermittently, often only for specific tasks like reading or working, which could reduce their total energy usage.

4. Number of Fixtures:

   • If you have multiple main lights (like in a large room with multiple ceiling lights), the total consumption can be higher.
   • Lamps tend to be used in smaller quantities, usually in specific areas like a desk or beside a sofa.

Comparison of Running Costs:

• A 60W incandescent bulb running for 1 hour will consume 0.06 kWh (kilowatt-hours) of electricity.
• A 10W LED bulb running for 1 hour will consume 0.01 kWh, producing the same light output as a 60W incandescent bulb.
• A 100W incandescent bulb running for 1 hour will consume 0.1 kWh of electricity.

Cost Calculation Example:

Let's say your electricity cost is about $0.12 per kWh (this varies by location).

• Running a 60W incandescent bulb for 1 hour would cost:
  60W / 1000 = 0.06 kWh × $0.12 = $0.0072 per hour.

• Running a 10W LED bulb for 1 hour would cost:
  10W / 1000 = 0.01 kWh × $0.12 = $0.0012 per hour.

Conclusion:

• Lamps (especially those with energy-efficient LED bulbs) are generally cheaper to run compared to main lights, especially if the main light uses higher-wattage bulbs or stays on for long periods.
• If you're using a low-wattage LED bulb in your lamp and a high-wattage incandescent bulb in the main light, the lamp will typically be more energy-efficient and cheaper to run.

Ultimately, to save energy and reduce costs, it's important to opt for energy-efficient lighting (like LED bulbs), use dimmers where appropriate, and limit the amount of time lights are on.