P12401: Wind Energy Collection to Energy Bank
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Concept Selection

Table of Contents

After generating a number of concepts in our Concept Generation document, it was time to narrow down the ideas and eventually select the final design. This was done by first automatically eliminating some of the most outlandish ideas that would clearly not be effective, or were out of the scope of the 22 week timeline. The remaining plausible ideas were organized in a series of Pugh matrices. Much like each function had its own concepts generated for it; each function has its own Pugh matrix, shown below.

In the cases of the Wind Collection and Energy Conversion matrices, the columns containing only "0" were used as comparison benchmarks from last years P11401 project. In the cases where no benchmark was used, all technologies were compared relative to each other.

A Pugh matrix is a concept selection matrix in order to narrow down the concepts that best satisfy our customer needs. Some needs were listed as selection criteria, and each concept was evaluated on a scale of +, -, and 0. The concept selection matrices for various essential system functions are below. They are put in separate matrices since the functions are truly independent of each other and have different criteria.

Click on any matrix image for a larger view.

Evaluation scale for Pugh Matrices:

Rating scale for Weighted Matrices:

Wind Collection

Pugh Matrix for Wind Collection

Pugh Matrix for Wind Collection

Based on the Wind Collection concept selection matrix, we narrowed down our choices to either a Savonius vertical axis turbine, or a conventional horizontal axis wind turbine (HAWT). Here are some pros and cons of each design.

Savonius:

HAWT:

In order to choose between our final two options, we created a weighted matrix.

Weighted Matrix for Wind Collection

Weighted Matrix for Wind Collection

Energy Storage

There are many possibilities for energy storage; whether they are electrical or mechanical. The four that we thought were most feasible are below.
Pugh Matrix for Energy Storage

Pugh Matrix for Energy Storage

Battery:

Super Capacitor:

Water Potential:

Air Potential:

Based on the Energy Storage concept selection matrix, we were able to definitively choose a battery as a storage unit. However, this does not dictate the type of battery we must use so another matrix was necessary.

Battery Type

Pugh Matrix for Battery Type

Pugh Matrix for Battery Type

Based on the Battery Type concept selection matrix, we narrowed down our choices to either a lithium-ion, or a lead acid battery. Another option is the sodium-ion battery that we may or may not have the chance to use. We do not have much information on the sodium-ion battery at this time since it is a fairly new technology, but will keep it as a possible storage device throughout the system design. Here are some pros and cons of each design.

Lithium-ion:

Lead Acid:

Sodium-ion:

Weighted Matrix for Battery Type

Weighted Matrix for Battery Type

Energy Conversion

Since battery is seemingly the best choice for storage, conversion needs to take place from the wind's collected mechanical energy to the required electrical energy.
Pugh Matrix for Energy Conversion

Pugh Matrix for Energy Conversion

Based on the Energy Conversion concept selection matrix, we narrowed down our choices to either an alternator or a brushless/step motor. Here are some pros and cons of each design.

Alternator:

Brushless/Stepper Motor:

Weighted Matrix for Energy Conversion

Weighted Matrix for Energy Conversion

Turbine Brake

While not a fundamental function of a SESE system, the a wind turbine brake is an essential part of our system. Without one, safety of the users would be compromised and one of our top customer needs would not be met. Various solutions for a turbine brake have been analyzed.
Pugh Matrix for Wind Turbine Brake

Pugh Matrix for Wind Turbine Brake

Based on the Brake concept selection matrix, we narrowed down our choices to either a dummy electrical load, or a passive wind avoidance system. Here are some pros and cons of each design.

Electrical Load:

Passive Wind Avoidance:

In order to choose between our final two options, we created a weighted matrix.

Weighted Matrix for Brake

Weighted Matrix for Brake


Mission Statement | Stakeholders | Benchmarks | Constraints | Objective Tree | Customer Needs | Engineering Specifications
Work Breakdown Structure | Function Structure Diagram | Concept Generation | Concept Selection | Risk Analysis | Initial Design Documentation | Systems Design | Detailed Design
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