CFL light bulbs consume less power than their incandescent counterparts while providing about the same amount of light. Suppose a CFL, while consuming only 20 Watts of power produces as much light as a 60 Watt incandescent bulb. Also, suppose a house has 8 lightbulbs which are all replaced by CFL bulbs and, on average, all the bulbs are on 4.6 hours per day (or night). If electricity costs 9 cents/kwh, how much money is saved over the course of 8 years when switching to CFL bulbs in dollars?

To calculate the money saved over the course of 8 years when switching to CFL bulbs, we need to calculate the energy consumption of both CFL and incandescent bulbs, find the difference in energy consumed, and then determine the cost savings.

First, let's calculate the energy consumption in kilowatt-hours (kWh) for both CFL and incandescent bulbs:

Energy consumed by CFL bulb per day = Power (in Watts) * Operating hours per day / 1000
= 20 W * 4.6 hours / 1000
= 0.092 kWh/day

Energy consumed by incandescent bulb per day = Power (in Watts) * Operating hours per day / 1000
= 60 W * 4.6 hours / 1000
= 0.276 kWh/day

Next, let's find the energy savings per day for each bulb:

Energy savings per day = Energy consumed by incandescent bulb per day - Energy consumed by CFL bulb per day
= 0.276 kWh/day - 0.092 kWh/day
= 0.184 kWh/day

Now, let's calculate the energy savings per year:

Energy savings per year = Energy savings per day * 365 days
= 0.184 kWh/day * 365 days
= 67.16 kWh/year

Since we are replacing 8 bulbs, the total energy savings per year for the house would be:

Total energy savings per year for the house = Energy savings per year * Number of bulbs
= 67.16 kWh/year * 8 bulbs
= 537.28 kWh/year

Now, let's calculate the cost savings per year:

Cost savings per year = Total energy savings per year * Cost of electricity per kWh
= 537.28 kWh/year * $0.09/kWh
= $48.35/year

Finally, let's calculate the cost savings over the course of 8 years:

Total cost savings over 8 years = Cost savings per year * 8 years
= $48.35/year * 8 years
= $386.80

Therefore, switching to CFL bulbs would save $386.80 over the course of 8 years.

To calculate the savings from switching to CFL bulbs, we need to consider the energy consumption and the cost of electricity.

1. Calculate the energy consumption per hour per bulb for both CFL and incandescent bulbs:
- CFL bulb: 20 Watts
- Incandescent bulb: 60 Watts

2. Calculate the energy consumed per day for all 8 bulbs:
- CFL bulbs: 8 bulbs * 20 Watts/bulb = 160 Watts
- Incandescent bulbs: 8 bulbs * 60 Watts/bulb = 480 Watts

3. Calculate the energy consumed per day in kilowatt-hours (kWh):
- CFL bulbs: 160 Watts * 4.6 hours/day / 1000 = 0.736 kWh
- Incandescent bulbs: 480 Watts * 4.6 hours/day / 1000 = 2.208 kWh

4. Calculate the energy consumed per year for all 8 bulbs:
- CFL bulbs: 0.736 kWh/day * 365 days = 268.64 kWh/year
- Incandescent bulbs: 2.208 kWh/day * 365 days = 805.92 kWh/year

5. Calculate the energy savings per year:
- Energy savings = Incandescent energy consumption - CFL energy consumption
- Energy savings = 805.92 kWh/year - 268.64 kWh/year = 537.28 kWh/year

6. Calculate the cost savings per year:
- Cost savings = Energy savings * Electricity cost per kWh
- Cost savings = 537.28 kWh/year * $0.09/kWh = $48.35/year

7. Calculate the cost savings over 8 years:
- Total cost savings = Cost savings per year * 8 years
- Total cost savings = $48.35/year * 8 years = $386.80

Therefore, the savings over the course of 8 years when switching to CFL bulbs is $386.80.