Source: Robert Miller Consulting, LLC submitted to NRP
ENRICHING RURAL AMERICAN FARMERS AND THEIR COMMUNITIES BY ENABLING BROADCASTERS TO POWER TRANSMITTERS WITH WIND ENERGY
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
SMALL BUSINESS GRANT
Reporting Frequency
Annual
Accession No.
0225159
Grant No.
2011-33610-30427
Cumulative Award Amt.
(N/A)
Proposal No.
2011-00466
Multistate No.
(N/A)
Project Start Date
Jul 1, 2011
Project End Date
Feb 29, 2012
Grant Year
2011
Program Code
[8.6]- Rural & Community Development
Recipient Organization
Robert Miller Consulting, LLC
9 Plainsboro Road
Cranbury,NJ 08512
Performing Department
(N/A)
Non Technical Summary
Regions in the US with wind levels suitable for producing substantial renewable energy are located in the predominantly agricultural center of the country where population density and therefore demand for electrical power are low. Transport of power from wind farms in this section of the country to the coastal regions where population and the need for power are high is limited by the capacity of the electrical grid, which was designed to link power sources (mainly coal and nuclear plants) located close to demand centers. Television and radio broadcasters are heavy consumers of electrical power with transmission facilities distributed across all regions of the US. Most regions are served by broadcasters with transmitters on or adjacent to farmland. In many cases, the placement of 1 turbine on each of these farms would generate enough power for both the farmer and the broadcaster. TV and FM broadcasters spend more than $400MM annually on transmitter power. A distributed wind cooperative among broadcasters and farmers will bring many benefits to both local economy and environment. Immediate benefits to the agriculture industry include a new, reliable, on-site cash generating "wind energy crop" that can be sold locally. The project will enable substantial amounts of money spent for energy to remain in local, rural communities. It will also help to provide a steady income for farmers and prevent the sale or repossession of the "family farm" due to financial hardship. These distributed, local community-based, renewable power systems have been prevalent in Europe for decades. Distributed wind energy systems circumvent the national power grid constraints by utilizing the power directly, on site. There are approximately 1,200 TV and 2,600 FM transmitters in the 12 windswept Midwest states and another 14,000 transmitters in the remaining states. If fully realized, distributed wind turbines serving all TV and FM markets have the potential to produce approximately 4 TW hours of renewable energy and eliminate 2.5 million metric tons of CO2 annually. It has been well established that wind turbines can cause interference to TV and Radio transmissions. Phases 1 and 2 of this project will develop an interference prediction model that can be used to properly place turbines on farms in close proximity to transmission towers while eliminating or mitigating problems with signal interference. Phase 3 will demonstrate the full technical and economic performance of an operating transmitter powered by and co-sited with a fully operational wind turbine.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
4025310202080%
6086099308020%
Knowledge Area
608 - Community Resource Planning and Development; 402 - Engineering Systems and Equipment;

Subject Of Investigation
5310 - Machinery and equipment; 6099 - People and communities, general/other;

Field Of Science
2020 - Engineering; 3080 - Sociology;
Goals / Objectives
American Broadcasting and wind energy technology present a tremendous, yet untapped revenue opportunity for small and middle sized farms across the nation. There are approximately 18,000 TV and FM broadcast transmitters distributed across the US. In the Midwest states, the majority of broadcast transmitters (many consuming between 100MWh and 1,500MWh annually) are located on or directly adjacent to farmland. Wind turbines may be sited on farm land surrounding these transmitters to the benefit of the farmer, broadcaster and the nation in general. The farmer's benefit may be derived by utilizing a small portion of his land, and leveraging local, state and national incentives to purchase a wind turbine and sell all or part of the electricity to the broadcaster. Or, he may lease land to the broadcaster or a third party investment company for the development of a turbine project. In all cases, the local farmer, broadcaster and nation benefit by supplemental income, lower utility costs, and reduction of carbon emissions. Before broadcasters will allow wind turbines to be sited near their transmitters the risks to their signal integrity must be removed. Rotating blades are known to introduce interference when turbines are located between transmitters and receivers. However, interference due to turbines sited at or very near a digital TV transmitter is unexplored. The objective of this project is to characterize that interference and develop a set of guidelines for siting wind turbines near digital transmission facilities that will assure negligible interference. In Phase I, feasibility will be established by developing a basic engineering model and verifying it for a set of fixed variables by taking signal interference measurements of transmitters situated near existing turbines. In Phase II, feasibility will be further proven by extending the model to the full range of variables by taking measurements near a transmitter using a movable, full-size "dummy turbine" with rotating blades. In Phase III, all technical risk will be removed by building an actual full size turbine that powers a co-sited transmitter and tracking its performance under sustained operation. The output of this project will be a validated engineering guide that will assist with the placement of distributed wind energy on farms and mitigate signal interference with adjacent broadcast facilities.
Project Methods
In Phase 1 the basic technical feasibility of locating a wind turbine very near a TV transmitter without interfering with reception in its coverage area will be established. A baseline interference model will be developed and verified for variables that can be observed by taking measurements near an existing antenna and wind turbine. The model will be verified for dimensional parameters that are fixed by the siting of the existing turbine and transmitter and for non-dimensional parameters that can be varied, including rotational speed of turbine blades, direction and distance of receivers from antenna and turbine, and vertical height of receiver. The work will consist of three components: 1) Development of a baseline model for estimating interference to TV signals as a function of variables related to siting of a wind turbine near a TV transmitter. The model will define the amplitude, phase and multipath distortion to the signal passing near or through the turbine blades as functions of the relevant variables: antenna height, turbine height, distance between antenna and turbine, blade material, turbine rotational speed, direction and distance of receivers from antenna and turbine. 2) Prediction of the sensitivity of digital TV receivers to interference due to rotating wind turbine blades located very near the TV broadcasting antenna. The effect of amplitude, phase and multipath distortion of the type caused by the signal passing through or near turbine blades will be predicted on the two critical DTV receiver subsystem: the DTV equalizer and the DTV Automatic Gain Control (AGC). The impact of interference on these subsystems will be characterized in terms of the Channel Impulse Response (CIR) of a reference DTV receiver over the range of relevant variables. 3) Evaluation of the model by measuring the sensitivity of a DTV receiver at a variety of distances and directions from an existing broadcasting antenna near a wind turbine. The Channel Impulse Response (CIR) and its impact on performance of the DTV receiver's equalizer and AGC will be measured over a range of variable conditions (signal level, rotor speed, blade type and material). The CIR will be captured using a receiver designed for DTV signal evaluations. It will use the ATSC RF Watermark signal (Pseudo-Random Bit Sequence), to measure echoes in both time and amplitude relationships to the main RF signals. This will allow a determination of the Equalizer Response needed in the DTV receiver to remove the impairments. In this way, the CIR can be measured and compared with the predicted values.

Progress 07/01/11 to 02/29/12

Outputs
OUTPUTS: Activities: There were three major activities in the Phase I program. First, we identified a site for field measurements of interference to television signals caused by nearby wind turbines. For this purpose we developed a database with the locations and dimensions of all the existing television broadcast towers and wind turbines in the country so candidate sites with a wind turbine very near a television transmitter could be found and compared. Second, we made field measurements of the interference to the television signal in the vicinity of the turbines at the selected site (Shirley, Wisconsin). For this purpose we took a transportable suite of television signal monitoring instruments to the site to measure and record the received signal strength and properties as a function of receiver position relative to the transmitter and wind turbine. Third, a we developed a mathematical model that predicted interference to the received signal for different signal paths through and above the wind turbine blades, and the model was verified vs. the experimental results. Events In September 2011 we submitted an abstract for a paper titled "Wind Turbines and Interference to Broadcast Signals" to the American Association of Wind Energy (AWEA) for presentation at the WindPower 2012 Conference and Exhibition in Atlanta Georgia in June 2012. The abstract was accepted for a poster presentation. Services On November 16, 2011 we gave a tutorial presentation at the November meeting of the Association of Federal Communications Consulting Engineers (AFCCE) about wind turbine interference to television broadcasting in the United States, which included an overview of the USDA sponsored SBIR Phase I research project. Dissemination Earlier this year, we created the Broadcast Wind website (wwwlbroadcastwind.com). This site serves as an important market development platform for the company. In addition to hosting our blog, it contains an educational component that gives the reader a primer on the character and history of wind turbine interference, industry best practices, updates on our ongoing research, and several social media links to help increase circulation, exposure and discussion. We'll continue to use the site and the related social media links to post content, video and other critical information from our conference presentations and to keep current and potential clients up to date on our latest activities. Thus far, the feedback from broadcasters and wind developers has been very positive. Our early commercialization efforts have led to two new wind energy developer clients and several inquiries into collaborative efforts following a successful Phase II. We have also been approached by a major television station operator seeking to have one or more of their TV stations serve as pilot sites for wind powered transmitters during Phase III. PARTICIPANTS: Robert Miller. Mr. Miller is the President of Broadcast Wind, LLC, a broadcast and communications renewable energy venture and Robert Miller Consulting, LLC. He is a 27 year veteran of the Broadcasting Industry with an extensive background in large technical project management, including the NBC Universal local stations' conversion to HD, control room automation, and working with the FCC, the State Broadcast Associations, and the National Association of Broadcasters to prepare the nation's markets for the DTV conversion. Mr. Miller has developed detailed technical operating plans for NBC Network Operations, NBC TV Stations, MSNBC, Telemundo Networks and several other successful media properties. Mr. Miller has an MBA in Finance from Rider University and a BS in Accounting from Penn State University. Dennis Wallace. Mr. Wallace is Managing Partner of Meintel, Sgrignoli, & Wallace, LLC., well -known consultants on DTV Spectrum Policy, DTV Transmission Systems, Channel Allocations and Planning, and DTV Measurements. He is a broad-based, RF oriented engineer and manager, with proven hands-on system design, field engineering, and product development skills, who has successfully created and managed both television station facilities and broadcast transmitter products. He has completed system design and field engineering operations for several broadcast stations and transmitter manufacturers, as well as the development and application of new digital television technologies. Mr. Wallace has worked with major wind farm developers on RF analysis and signal interference mitigation in several locations in the US including Waymart, PA, Sweetwater Texas, Butler Ridge, Wisconsin and Peoria, IL. He has authored several papers on Digital Television transmission and testing DTV systems, which have been published in the IEEE Transactions and other publications. He has been a presenter at the IEEE Broadcast Technology Symposium, NAB, and several SBE Conferences, as well as providing DTV presentations for SCTE and IEEE Chapters. He has made extensive field measurements of both Digital and Analog Television and Radio systems, including over 5,000 DTV field measurements. Dr. Frank Marlowe. Dr. Marlowe has led major initiatives in the development of television broadcasting, digital signal processing, cable television, satellite broadcasting, semiconductor design and microwaves at Sarnoff Labs in Princeton NJ. He has also conducted research in Liquid crystals, flat-panel displays, television, computer memories and digital integrated circuits. Dr. Marlowe holds 15 US patents issued in television, computers and related fields. He has a PHD in Electrical Engineering from Rutgers University and an MSEE from Princeton University TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Change in knowledge The state of knowledge in the wind energy industry about the effects of wind turbines on television reception was improved and altered by the activities of the Phase I research. A baseline engineering data and modeling system was created to predict the interference to television reception caused by wind turbines located close to television transmitters. "Baseline" means the model's input parameters consisted of only geometric dimensions of the structures and distances between them, but not other non-dimensional parameters such as blade material, weather, reception area topography, etc. The model was verified by field experiments conducted at a wind turbine near a television transmitter in Shirley Wisconsin. The results of this model and its verification provided previously unknown understanding about the permissible placement of turbines relative to television transmitting antennas. Previously it was thought that wind turbine blades had to be well below the line-of-sight between transmitting and receiving antennas to avoid causing interference to the received signal by the spinning blades. This meant turbines would have to be smaller and at lower heights than desired for high efficiency. As a result of our modeling and experimental verification it is now understood that turbines blades may intersect the line-of site without causing interference as long as the center (hub) of the blade rotor is sufficiently below the line of sight. The significance of this result is that accurate modeling of RF interference is critical for several aspects of wind project development including efficient design, successful permitting and financial commitment. Technical and economic efficiencies of wind turbines depend upon their size, height and siting. Prospective RF interference with TV/FM reception can engender strong regulatory and community resistance to the project. The uncertainty of prospective mitigation costs (including requirements to provide alternative service to affected reception areas) can compromise prospective project economics and impede financial commitment. A more comprehensive model with additional classes of input parameters will be developed in Phase II

Publications

  • Publications Marlowe, F, and Miller, R, (2012) Wind Turbines and Interference to Broadcast Signals. American Wind Energy Association annual meeting, WindPower 2012, Poster, Atlanta