Tutorials

TUTORIALS


SOLAR ENERGY

The steepness of the solar array (typically the steepness of the roof) impacts the amount of energy the solar panels can get from the sun.  To find the tilt of the solar panel that will allow the most energy absorption, a basic rule is to use the latitude of the location and use that as the degrees from the horizontal.  This is because, using the northern hemisphere as an example, the farther north the location, the more time the sun is going to be lower in the sky, so a steeper tilt would be ideal. When using an adjusting tilt, the panels should have a steeper tilt in the winter, because the sun spends the majority of the day lower in the sky, and the panels should have a shallower tilt in the summer because the sun is higher in the sky.  To find the degree for each of the seasons, however, we used eqns 1-3. 

To calculate the power that the solar panels will generate, “E”, in kWh/day use eqn 4.  For E in kWh/month, use eqn 5.  “A” stands for the area of the solar panel. “Eff” stands for the efficiency of the solar array.  This value is typically between 15%-20%. Our group used solar panels with 19.7% efficiency.  “G" stands for solar irradiance which is a measure of how much solar power that your location receives.  This value changes throughout the year due to the weather and how the sun is positioned in the sky. Our group used averages for each month calculated using data collected over 22 years, as shown in the table.

Spring/Autumn = (Lat * 0.98) - 2.3	[1]
Summer = (Lat * 0.92) - 24.3	[2]
Winter = (Lat * 0.89) + 24 E = A * Eff * G E = A * Eff * G * Days (per month)	[3]  [4] [5]

Table: G-Value/Month
Month	G [kWh / m^2 / day]
Jan	3.02
Feb	3.66
Mar	4.05
Apr	4.47
May	5.01
June	5.53
July	5.39
Aug	5.04
Sept	4.47
Oct	4.02
Nov	2.82
Dec	2.64

EQUEST - SCHEMATIC DESIGN WIZARD

EQUEST is a “Quick Energy Simulation Tool” that allows users to input details for their building and the system can produce simulations for electrical load, HVAC equipment, utility costs, and other useful information.  Our group specifically used eQUEST to provide a simulation of electric consumption.

When using the Schematic Design Wizard, the first slide is where to input all the general information about the structure.  Information in this slide will determine what other slides of the design wizard need to be filled out.  At the bottom left corner, it will say slide x of 53, but not all 53 slides will need to be filled out depending on what sort of building is being constructed.  Fill out all slides to the best of your knowledge, but leave options as the default if you don’t have an answer for those questions.  Once you are done the program will analyze your input for any errors, then it will construct your building.  In order to run the simulation, there is a “Perform Simulation” button on the top toolbar that looks like a yellow calculator.  Selecting this will perform the electric consumption simulation, and provide you with a graph and tables for electric and gas consumption.