Problem Statement

Project Objective

Michigan State University, in an effort to go green, will be installing a solar panel array on campus. The problem is that Michigan State University is contracting a different company to install a solar panel array and MSU is going to buy power from said company. Now since the power output from the solar panel depends on how much sunlight is shining on it, the output power is going to fluctuate based on cloud movement and time of day. Michigan State will be buying power that the solar panels produce at a reduced cost to power operations on campus. The panels will produce around 10 MW of power, therefore, if there is a sudden change in power output of the solar panels, it will cause a shortage of power needed to supply campus operations. This will force Michigan State to purchase power from the power company at the peak hour rates. The peak hour rates are approximately $11 per kilowatt. This means that a 5MW mismatch would end up costing MSU $55,000. It can clearly be seen how expensive this can become if multiple events occur. This shows the necessity of the project.

The objective of this project is to design a system to detect cloud movement around the specific area of the solar panels, and to deliver an early warning to users when the clouds will pass over the solar panels. With enough of a warning to users at the power plant, power supplying non-essential items can start to be shut down, as well as turning on power supply units. This will ensure that the entire load profile of the campus will be accounted for at all times. Sensors placed at remote locations around campus, will record the amount of sunlight being received, and send the data to a software program which will monitor these values and produce a time simulation of cloud movement around the solar panels.

Other Methods

Project Approach

There is another method to account for the quick power drop of solar panels. That method is using technology called a Tesla Powerwall. This device provides backup power when the load sensed is more than what is being generated. This is effective because it will keep spikes from the power companies at a lower height. However, they are simply lithium-ion batteries and are extremely expensive. The current cost for a 10kW backup Powerwall is over $3,000. Now a 1MW backup is desired, this would require 100 of these Powerwalls and would cost over $300,000. This is unreasonable because of the amount of Powerwalls required for a 10MW backup would be 1000 and they may not be able to function properly with that many together since they are designed for household power and energy requirements which are around 3.3kW and 7kWh, respectively. Also, the price would be around $3,000,000 assuming that everything would work as planned. This doesn’t include hook up and planning which would drive up costs more. So why not just use a website like weather.com to track the cloud movements? Well in this application, very specific cloud movements trackings are needed around the area of the solar panels. Weather.com, while shows a simulation of cloud movement, is not specific enough for the small location that the solar panels are at. Also there is not a good way to tell if the clouds will pass over the solar panels. Therefore an early warning system that is location specific, can alert users of changing cloud conditions with much higher accuracy and without the need for constant monitoring.

The approach that our design will have is to place remote sensors in any pattern around the solar panel array. Any pattern is desired so that the sensors can effectively be placed anywhere as long as they are far enough away to give enough prediction time. These sensors will be connected to a web server Online in order to upload light intensity data. The internet connection will be realized through a micro-controller with wireless capabilities. This means each sensor will be connected to the server and will constantly be putting in new solar radiance data. Once the data is uploaded, a computer program is developed with an algorithm to process it. The program also has pop-up boxes to warn the user of incoming cloud fronts even if the software is running in the background. This approach can be very successful as long as consent can be obtained from the various owners whose homes will have these sensors. The difference that this project makes, is the ability to practically design powerful solar panel arrays that minimize or exclude the negative cost effects that could come with dynamic and sporadic weather. This is always a big limiting factor in implementing an array powerful enough to impact power usage away from the grid.

Sponsor and Facilitator