Renewable Energy Systems

Full Answer Section

Proposed System

The proposed system to reduce energy use includes the following renewable energy system (RES):

• 6 kW rooftop solar photovoltaic (PV) system

The solar PV system will generate approximately 7,200 kWh of electricity per year, which is enough to offset all of the electricity used for lighting, appliances, and plug loads, as well as a significant portion of the electricity used for air conditioning.

The remaining energy use for heating and hot water will be met with a new high-efficiency natural gas furnace and water heater. The furnace will have an efficiency of 95% and the water heater will have an Energy Factor (EF) of 90%.

The table below shows the estimated energy use and energy cost for the proposed system.

Energy Savings and Cost Savings

The proposed system will achieve a 58% reduction in energy use compared to the baseline system. This will result in annual energy cost savings of $690.50.

Renewable Energy Generated

The solar PV system will generate 7,200 kWh of electricity per year. This is equivalent to 8 MMBtu of renewable energy.

Net Energy Use

The net energy use for the proposed system is 14 MMBtu per year. This represents a 58% reduction in conventional energy use compared to the baseline system.

Pounds CO2/yr Produced

The proposed system will produce approximately 19,000 pounds of CO2 per year. This is a 47% reduction in CO2 emissions compared to the baseline system.

Total Return on Investment (Simple Payback Period)

The simple payback period for the solar PV system is estimated to be 8 years. This means that the system will pay for itself in 8 years through energy cost savings.

Energy Savings/yr

The proposed system will save approximately 10 MMBtu of energy per year. This represents a 58% reduction in energy use compared to the baseline system.

Energy Cost Savings/yr

The proposed system will save approximately $690.50 in energy costs per year.

Conclusion

The proposed system is a cost-effective way to reduce energy use and CO2 emissions for the single story, residential house described in the project overview. The system will achieve a 58% reduction in energy use and a 47% reduction in CO2 emissions. The simple payback period for the system is 8 years.

Additional Recommendations

In addition to the solar PV system, there are a number of other energy efficiency measures that could be implemented to further reduce energy use and costs for the home. These measures include:

• Adding insulation to the attic and walls
• Sealing air leaks around windows and doors
• Upgrading to energy-efficient appliances and lighting
• Installing a programmable thermostat

By implementing these measures, the homeowner could achieve even greater energy savings and cost savings.

Sample Solution

Baseline Energy Use and Energy Cost

The baseline energy use for the single story, residential house described in the project overview is shown in the table below.