Cost of Operating a 30-Watt Bulb: Detailed Breakdown Comparison

When we consider the usage of small electrical appliances in our daily lives, such as a 30-watt bulb, we often wonder about the cost and energy consumption. In this article, we will break down the cost and energy usage of a 30-watt bulb used for 12 hours. Additionally, we will compare these figures in a real-world scenario in Denver, Colorado, to give a clearer picture.

Understanding the Energy Consumption

First, let's discuss the basic energy consumption. The wattage is a measure of power, and to find the energy consumption over a period of time, we multiply the power by the duration. Thus, for one hour of usage, the energy consumption is:

30 W x 1 hr 30 Wh (Watt-hours) .030 kWh (Kilowatt-hours)

Now, let's consider the cost. If the price of electricity is 7 Rs per kWh, the cost for one hour would be:

0.030 kWh x 7 Rs/kWh 0.210 Rs

However, in practical applications, we often need to know the cost for longer durations. For 12 hours of usage, the energy consumption is:

30 W x 12 hr 360 Wh 0.360 kWh

And the cost would be:

0.360 kWh x 7 Rs/kWh 2.52 Rs

Real-World Scenario: Denver, Colorado

While the above calculations might be useful, they might not always reflect the reality in different regions. For example, in Denver, Colorado, the cost of electricity is different. In Denver, a domestic kWh costs approximately 0.115 USD. Let's see how this affects the cost of operating a 30-watt bulb for 12 hours:

30 W x 12 hr 360 Wh 0.360 kWh

Thus, the cost in Denver would be:

0.360 kWh x 0.115 USD/kWh ≈ 0.0414 USD

Covering the cost in cents, this translates to a little over 4 cents for 12 hours of usage.

Conclusion

By understanding the energy consumption in terms of watt-hours and converting it into kWh, we can easily calculate the cost of operating a 30-watt bulb for specific periods. As shown, the cost can vary significantly based on the local electricity rates. For instance, in a place with a higher cost of electricity, like the one in Denver, operating the bulb for 12 hours would cost around 4 cents, which is relatively low, making it a cost-effective solution for lighting needs.

Keywords

30-watt bulb, electricity cost, kWh