Overview of Article
This article will go over the Solar Energy Project for Midnight Sun XIV as it stands on 6/18/2019, describing the the physics behind the system, inputs of the system, its projected outputs, and the work left TO DO.
Physics of System
Midnight Sun is a solar car vehicle, and therefore receives most (ideally all) of its energy from the sun. This makes it imperative to understand the physical systems that underlie that power generation.
A fuller version of this description can be found here https://www.pveducation.org/pvcdrom/properties-of-sunlight/calculation-of-solar-insolation
The first concept that needs to be understood is Solar Insolation. Solar Insolation is the measure of total electromagnetic received by an area over a period of time (typically denoted in kWh/m^2/s). As the suns position changes over the day, the total amount of solar insolation to a flat plate changes with angle of the sun.
We must then understand array tilt. Solar Energy is maximized when the array is tilted to towards the sun, and affect the solar energy generation formulas (see above link for further treatment of the subject). For our purposes, we can treat our array, which has a range of angles, as a single tilted array, where the angle is the integral of the total angles of the area over its surface.
Lastly, we are concerned with cell efficiency. Treated more effectively in the section above, the cell efficiency is a measure of the ratio between the solar energy received by the vehicle and the amount added to the battery.
Inputs of System
We will be given latitude and longitude values, as well as the day of the year and expected 'cloudiness' (a fudge coefficient that reconciles measured solar insolation with predicted solar insolation).
Outputs of System
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Project Summary
We are a solar car. And are powered by the sun. Therefore it is critical that we as a team have an understanding of the solar energy that our car is able to convert to electrical energy over the course of a race, as that does charge our battery pack and give us an extra boost in range.
Goals
Utilize the weather model to determine the amount of sunlight that is expected along the race route during the day
Get an accurate calculation of the expected energy intake from the solar array over a period of time
Inputs
Calculations for expected angle of sunlight at a given time in the day for a latitude/longitude point of the world
Data from weather on the expected sun levels for a geographical point
Solar array layout and cell efficiencies
Outputs
Expected energy absorbed by the solar array that is added to the battery pack.
Notes
Calculations were mostly completed by Carson Bay before his departure from the team and the incomplete code is available in Github for calculating the solar intake depending on time of day
The above code can be used as a basis, however with the switch to challenger most of these calculations will not be very useful and will have to be retooled for MSXV