Energy Alternative Supplement Design
Dec07-04 Project website: http://seniord.ece.iastate.edu/dec0704
Problem Statement
Reduce client's energy bill Use alternative energy systems -Wind -Solar Projections -Energy use -Energy production -Future building plans Determine mode of operation Economic analysis program Modes of Operation Stand alone system -Independent of the grid -Always meets full load -Stores energy Primary -Connected to grid -Provides more than half of consumed energy Backup -Connected to grid -Provides less than half of consumed energy No change
Wind Power Calculation
January Rayleigh Distribution
90 80 70
Input Page
Hours
60 50 40 30 20 10 0
Requirements
System Requirements
Operates -30 to 120 degrees F 60 Hz Automatic Protection from backfeeding to grid during an outage Package deal
Wind Speed (m/s)
Program Requirements
Calculate net present worth of each system Calculate break even year Account for changes in energy usage Account for cost increase of energy Include loan options Estimate system production Determine optimal system User friendly interface Power Output (kW)
Program Requirements
X
2.5 2.0 1.5 1.0 0.5 0.0
-One contractor does all installation work -All system components must be compatible -Available for installation in Iowa
Example System Power Curve
Energy System
The input page is part of the user interface where the user is able to enter estimates for future power usage and costs. A list of systems and towers are available for the user to analyze. Data for financing the system is also entered on this page. The information is then run through the program calculations to return the output page below. Wind Speed (m/s)
=
January Power Output
100 90
Output Page
Output (kWh)
Economic Analysis
80 70 60 50 40 30 20 10 0
Wind Speed (m/s)
Testing
System Testing
Pre-installation Power quality Power usage Post-installation financial Track savings Actual power output Proper Installation -Grounding -Automatic disconnect if utility power is lost -Structural stability -Starting and stopping of turbine Monitoring system performance
The wind power calculator uses the Rayleigh probability distribution to estimate wind speed frequencies each month. The power curve for each wind generator is given by the manufacturer. The wind power calculator multiplies the Rayleigh distribution for each month by the power curve to calculate the power output for each month. The area under the power output curve is the total energy output for that month in kilowatt-hours.
Program Testing
User interface testing Sanity checking for valid user inputs Verify economic analysis results by independent calculations Wind speed probability distribution -Weibull shape and scale parameters -Compare with Rayleigh distribution Vertical wind speed profile -Compare with Iowa Energy Center
The output page displays economic savings and energy production values for the selected system. The "Cost vs Time" graph displays the overall lifetime costs of installing ...