Introduction
NorthWestern Energy (NWE) has a serious commitment to providing responsible,
and sustainable energy production. Their annually publishedEnvironmental Report, is a testament to their culpability in that regard. It is in this spirit, that NWE
decided to sponsor the Solar Acoustical Barriers (SAB) project. An SAB system would
potentially be a great expansion upon their new growing solar infrastructure, and
here is why.
On October 31’st of 2016, NWE’s Bozeman Solar Project was officially producing
energy for the grid. Since it’s launch, the farm has produced roughly 550 MWh at approximately
480 KWh per panel. As of 2010, the Federal Highway Administration counted 2,748 linear
miles of noise barriers built alongside U.S. highways (Noise Team, Federal Highway Administration, 2012). There are approximately 1.5x107 feet in 2,748 linear miles. Imagine,1.5x107linear feet of solar panels, producing 480 KWh annually. That is a whopping 1.8 TWh
of annual power generation! Not bad for an acoustical barrier system; which in it
of itself can improve the lives of those it is safeguarding in many ways.
Hearing loss, high blood pressure, insomnia, fatigue, and even some psychological
problems have all been linked to noise exposure (OSHA, 2006). The earliest known study
on highway noise pollution was the 1960 study performed by UCLA in response to noise
pollution coming from the Arroyo Seco Highway; that was affecting the nearby Hollywood
Bowl (Bourget, 1960). The first noise barrier was erected in 1968 alongside Interstate
680 in Milpitas, California where it remains to this day. It was not until the passage
of the Noise Control Act of 1972 that noise barriers began to advance across the country.
Although relatively new, SAB’s around the world are currently producing approximately
9MW of power annually. Many SAB systems currently in operation are effectively sound
barriers with mounted solar panels. However, the goal of this SAB project is to provide
NWE with information on designing a noise barrier system that is constructed primarily
from solar panels, which will reduce sound by a noticeable amount, and perform as
efficiently as a stand alone solar farm. In simpler terms, the group has been tasked
with providing sufficient information in response to the following question: Does
it make sense to construct a highway noise barrier mainly composed of solar panels?
The first semester goal was to generate a detailed framework of how the group
intends to properly conduct the research and experimentation required to adequately
answer the main question. In addition to laying out a framework for next semester,
several experiments were conducted which provided insight as well as identified areas
of needed improvement for the experiments done next semester. The experiments done
this semester are explained in more depth throughout this report.
The second semester goal was to perform and complete the research and experiments
that has been laid out during the first semester. Additionally, based on the results
of the research and experiments of second semester, an educated evaluation on the
implementation of a SAB in Bozeman will be given to NWE. The final decision to construct
a SAB will be the responsibility of NWE, as the construction of a SAB is outside the
scope of this project.
Motivation
Photovoltaic system farms are advantageous in that they are a source of renewable
energy and require very little maintenance. A significant drawback to utilization
of these PV farms are their large land area requirement. Highway sound barriers, devices
that reduce traffic noise and increase the quality of life for people residing near
the barrier, offer an alternate staging site for PV farms, effectively eliminating
the land-use drawback. Mass adoption and implementation of solar acoustical barriers
would increase both the general quality of life for those residing near high-traffic
roadways and provide a new influx of renewable energy, while occupying a very small
real estate footprint.
Sponsor Information
Jon Shafer | NorthWestern Energy
Engineer at NorthWestern Energy
Tel: (406) 490-6805
Email: jonathan.shafer@northwestern.com
Prof. Robert Maher| College of Engineering
Professor at Montana State University
Office: 637 Cobleigh Hall
Tel: (406) 994-7759
Email: rmaher@montana.edu
