Energy systems | Mechanical Engineering homework help

Renewable Energy Systems (ME 416/516)
Final Design Project

Analyze an existing small residential home to identify how to reduce the energy use from the baseline
conditions. Document what improvements you would recommend by showing evidence of why the
improvement is beneficial (energy savings, carbon savings, and/or cost savings). Evidence includes a
written explanation and your calculations comparing the existing system to your proposed
recommended improvement. You must include at least 1 RES in your recommended improvements.

Project Overview
Design a renewable energy system to achieve the following goals:

1) Achieve at least a 50% reduction in energy use compared to the baseline design –
documented by BTU input required for both cases. (i.e. convert all energy use into Btu/yr
AND show all calculations)

a. Detail the baseline energy use and energy cost
b. Detail your proposed system’s energy use and energy cost

2) State why your system is an optimum investment. (i.e. – justify by your system costs and
your return on investment)

3) Bonus
a. For energy reduction greater than 50%
b. For a better overall return on investment compared to the baseline case (note – you

must document your cost estimates and include installation costs)

Building:
Single story, residential house
2”x12” roof construction – 11.25” Fiberglass Batt (R‐38)
Wood, 2”x6” wall construction – 5.5” Fiberglass Batt (R‐19)
Infiltration/ventilation = 0.45 Air Changes per Hour
Windows = 0.6 U-value, 0.4 SHGC

Base design:
Natural gas furnace, 78% efficiency
Electric air conditioning, SEER = 13

70F temperature setpoint, 24/7

The minimum information required in your final report is outlined in the following table. All
information must be documented by sample calculations, explanations of methods and
appropriate documented sources for costs. Include detailed tables, charts, graphs, pictures, and
other supporting information to fully document your analysis in order to achieve the maximum
grade. Your analysis should be clear and well formatted.

Table of Required Information in Final Report

Parameter Current Proposed

Lighting Electrical Energy Use (kWh/yr) 720

Cooling Electrical Energy Use (kWh/yr) 961

Appliances & Plug Loads – Electrical Energy Use (kWh/yr) 2,650

Other Electrical Load (if any) 0

Total Electrical Energy Use (kWh/yr) 4,331

Space Heating Fuel Energy Use (Therm/yr) 604

Water Heating Fuel Energy Use (Therm/yr) 186

Total Natural Gas Fuel Energy Use (Therm/yr) 790

Other Energy (if any) 0

Total Energy Use (MMBtu/yr)

Pounds CO2 /yr Produced*

Renewable Energy Generated (-MMBtu/yr) 0

Total Net Energy Use (MMBtu/yr)

% Conventional Energy Reduction

CO2 Saved/yr* (total pounds & % savings)

Total Return on Investment (simple payback period)

Energy Savings/yr (total MMBtu/yr & % savings)

Energy Cost Savings/yr ($/yr)

* use 1,380 lbs CO2 per megawatt-hour of delivered electricity

Table of Max Grade for Final Report

Parameter
Max Grade

416 / 516

50% Conventional Energy Reduction 70% / 0%
70% Conventional Energy Reduction 80% / 70%
80% Conventional Energy Reduction 90% / 80%

Net Zero 100% / 90%
100% RE (off-grid) 110% / 100%

Minimum: 1 RES added

ME 416/516 Final Project
Base Assumptions for Current System

Furnace efficiency 78%
Furnace Natural Gas Use 604 Therm/yr

Furnace – heat into house 47,112 MBtu/yr 30,000
Peak Load –
Btu/hr

Air conditioner SEER 13
Air conditioner Elec. Use 961 kWh/yr

Air conditioner – heat out of house 12,493 MBtu/yr 20,000
Peak Load –
Btu/hr

# of Lamps (60 W incandescent) 12
Lighting (Average ‘On time’ per lamp) 1,000 hr/yr

Total Lighting W 720
Lighting Elec. Use 720 kWh/yr

Water Heater Energy Factor
(50 gal tank) 54% EF*

Water Heater Natural Gas Use 186 Therm/yr
Hot Water – average use (125F) 44 gal/day

Appliances & Plug Loads Elec. Use 2,650 kWh/yr
(Conventional Appliances)

*Energy Factor (EF) is an annual measure of the useful energy coming out of your water heater divided
by the amount of energy going into the water heater to heat the water.

Table of Energy Costs

Parameter Metric

Natural Gas $0.90/therm

Electricity $0.10/kWh
Electricity (sale price back to electric

utility) $0.04/kWh

Diesel (off-road) $3.00/gal

Biomass / wood $225/cord