DOCSLIB.ORG

(HAWT, VAWT) Rotor Design

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
(HAWT, VAWT) Rotor Design Wind Technology Historical Drive Trains Conversion Devices Configurations (HAWT, VAWT) Rotor Design Paul Gipe, wind-works.org Smith-Putnam 1.25 MW Paul Gipe & Assoc. Smith-Putnam 1.25 MW, 1941 ~700 hrs Gedser 24 m, 250 kW 1957-1967 © Risø National Laboratory Tvind 54 m, 2 MW 1978-Present Paul Gipe & Assoc. Growian 100 m, 3 MW, 1981 ~400 hrs Paul Gipe & Assoc. Large Turbine Manufacturers • Vestas (DK) • Nordex (DK) • Bonus-Siemans • Ecotecnia (ES) • NEG-Micon (DK) • DeWind (D) • Enercon (D) • Suzlon (India) • GE Wind (D-US) • Lagerwey (NL) • Gamesa (ES) • RePower (D) • Mitsubishi (JP) • Fuhrländer (D) Paul Gipe, wind-works.org Bonus 63 m, 1.3 MW © Bonus Paul Gipe, wind-works.org Ecotecnia 1.6 MW Paul Gipe, wind-works.org © Ecotecnia Direct-Drive Wind Turbines • Enercon (D) • Lagerwey (NL) • Jeumont-Industrie (F) © Enercon Paul Gipe, wind-works.org Lagerwey Direct-Drive © Lagerwey Paul Gipe, wind-works.org Jeumont-Industrie Direct Drive • Discoid French Nuclear Submarines • 50 Units Built J48 © Jeumont-Industrie Configuration: Axis of Rotation HAWT VAWT Paul Gipe & Assoc. Wind Energy Conversion Devices • Drag Devices HAWT (Seldom) VAWT (Often) First Choice of “Inventors” • Lift Devices HAWT (Dominant) VAWT (Rare) Paul Gipe, wind-works.org VAWT Configurations Paul Gipe, wind-works.org Persian Panemone Paul Gipe, wind-works.org Savonius or “S” Rotors Paul Gipe, wind-works.org VAWTs Darrieus 4 Blades Paul Gipe, wind-works.org VAWTs Darrieus 3 Blades Paul Gipe, wind-works.org VAWTs Darrieus 2 Blades DAF-Indal Atlantic Wind Test Site, PEI Paul Gipe, wind-works.org DAF-Indal, Kortright Cente, Ontario VAWTs Darrieus 2 Blades Paul Gipe, wind-works.org VAWTs Darrieus Bi-Blade Paul Gipe, wind-works.org Giromill Articulating Straight Blade VAWT Paul Gipe, wind-works.org Giromill (McDonnell Aircraft) Paul Gipe, wind-works.org Giromill (McDonnell Aircraft) • High Hype • Complex • Costly • DOE Boondoggle Paul Gipe, wind-works.org Variable Geometry VAWT (Musgrove) Paul Gipe, wind-works.org © PI Specialists We Know What Works . .and What Doesn’t Eole, Cap Chat © Vortec Paul Gipe, wind-works.org HAWT Configurations Paul Gipe, wind-works.org Blade Number • 1 Blade • 2 Blades • 3 Blades • Multiblade Farm Windmill • No Blades No, Really Paul Gipe, wind-works.org One-Blade Turbines • Lightweight • Only One Blade • Small Gearbox • High RPM • Noisy • Complex Rotor • Odd Paul Gipe, wind-works.org Two Blades • Lighter than Three • Static Balance • Dynamic Imbalance in Yaw • Teetering Hub • Pitch-Coupled Teetering • Higher RPM than Three • Noisier than Three • Visual Imbalance Paul Gipe, wind-works.org Two-Blade Turbines Paul Gipe, wind-works.org Two-Blade Turbines Paul Gipe, wind-works.org Two Blade Turbines Paul Gipe, wind-works.org Two-Blade Turbines Paul Gipe, wind-works.org Three Blades • Dynamic Balance in Yaw • Complicates Erection • Visually Balanced • Lower RPM • Bigger Gearbox • Can Use Simple Hub Paul Gipe, wind-works.org Wood Blades Paul Gipe, wind-works.org Composite Wood Blades Paul Gipe, wind-works.org Metal Blades • Aluminum • Steel Paul Gipe, wind-works.org Blade Shape • Taper • Twist • Glauert Formula Shark Fin Shape Paul Gipe, wind-works.org Blade Taper Paul Gipe, wind-works.org Blade Color • White • Gray • Black Paul Gipe, wind-works.org Ducted Turbines © Vortec Paul Gipe, wind-works.org Coning-Positive Paul Gipe, wind-works.org Coning-Negative ©Nordex Paul Gipe, wind-works.org RePower, Husum, Germany Orientation VAWTS Omnidirectional Paul Gipe, wind-works.org Orientation of HAWTS Tracks Paul Gipe, wind-works.org Orientation Fan Tails Paul Gipe, wind-works.org Orientation Yaw Motors ©DeWind Paul Gipe, wind-works.org Orientation Passive Yaw-Tail Vanes Paul Gipe, wind-works.org Orientation Passive Yaw-Tail Vanes Paul Gipe, wind-works.org Orientation Passive-Downwind Paul Gipe, wind-works.org No Aerodynamic Rotor Controls • Mechanical Brakes Tacke • Flutter SWP Air • Electro-Dynamic SWP Skystream Paul Gipe, wind-works.org Overspeed Controls Furling-Vertical Paul Gipe, wind-works.org Rotor Controls Furling-Horizontal Paul Gipe, wind-works.org Rotor Controls Air Brakes Paul Gipe, wind-works.org Overspeed Controls Variable Pitch • Pitch-to-Feather Paul Gipe, wind-works.org Tip Brakes (Plates) Paul Gipe, wind-works.org Overspeed Controls Pitching Blade Tips Paul Gipe, wind-works.org Overspeed Controls Spoilers Paul Gipe, wind-works.org Airfoils • Single Surface • Constant Planform • Tip Shape Single Surface • Tip Speed Ratio • Stall Control Paul Gipe, wind-works.org Airfoils Paul Gipe, wind-works.org Airfoils Constant Planform Paul Gipe, wind-works.org Airfoils © Vestas Paul Gipe, wind-works.org Airfoils Blade Tips Paul Gipe, wind-works.org .
Load more

Recommended publications
  • A Review of International Experience with Policies to Promote Wind Power Industry Development
    A Review of International Experience with Policies to Promote Wind Power Industry Development FINAL REPORT Prepared by: Joanna Lewis, Consultant to the Center for Resource Solutions Ryan Wiser, Consultant to the Center for Resource Solutions Prepared for: Energy Foundation China Sustainable Energy Program March 10, 2005 Table of Contents Executive Summary...................................................................................................................... 4 1. Introduction........................................................................................................................... 9 2. Strategies for Localization ................................................................................................. 11 2.1. Models for wind turbine manufacturing ........................................................................ 11 2.2. Models for technology acquisition: purchasing versus internal development............... 11 2.3. Incentives for technology transfers................................................................................ 12 2.4. Implications.................................................................................................................... 12 3. Potential Benefits of Localization...................................................................................... 14 3.1. Domestic economic development and employment ...................................................... 14 3.2. International exports.....................................................................................................
    [Show full text]
  • “PROSPECTS for OFFSHORE WIND ENERGY” a Report Written For
    “PROSPECTS FOR OFFSHORE WIND ENERGY” A report written for the EU (Altener contract XVII/4.1030/Z/98-395) by The British Wind Energy Association (BWEA). Views or opinions contained within the report are not necessarily those of BWEA, EWEA or the Commission. Permission to reproduce any part of this document must be gained in writing from BWEA. Comments on the paper are welcomed by email to [email protected] 1 EXECUTIVE SUMMARY Of all renewable energy technologies, offshore wind energy has possibly the most favourable combination of the key attributes of resource, energy cost and risk. The European offshore wind resource is extremely large, energy costs are cheaper than those of many other renewable technologies (but more expensive than onshore wind), and the risks are low, as the technology has already entered the demonstration phase. Studies of offshore wind energy have been in progress for around 20 years. As a result the key issues associated with the resource, the offshore environment and the necessary adaptations of wind turbine technology are all well understood. Early studies focused on the use of MW size wind turbines, frequently in large arrays, whereas early demonstration wind farms used modest numbers of specially adapted versions of commercial machines around the 500 kW mark. Although these have operated successfully and some have delivered energy in excess of expectations, they are mostly installed in relatively sheltered waters. The conditions in some of the windier regions, for example the North Sea, will be more hostile. Several studies of European resources have confirmed that most states have accessible offshore wind energy resources equal to at least 20 % of current consumption, and most have considerably more.
    [Show full text]
  • Wind Energy Turbines
    thyssenkrupp rothe erde USA Inc. dba ROTEK Incorporated Wind 1400 South Chillicothe Road Aftermarket Aurora, OH 44202 Tel: 330.562.4000 rothe erde slewing bearings Fax: 330.562.4620 rothe erde rings psl rolling bearings Authorized distributor for rothe erde @ slewing bearings for the Wind Aftermarket rothe erde @ slewing bearings for the Wind Aftermarket rothe erde @ slewing bearings for the Wind Aftermarket This is us Upgrades Standard Upgrades Through Operational Excellence thyssenkrupp Specifically the Wind Energy Market has been driving significant continuous improvement measures over the last 10 years. All of our bearing products are manufactured according to the latest state of the art technology: rothe erde • Cleanliness requirements in forged rings • Inspection services and failure analysis • Improved quality in rolling elements thyssenkrupp rothe erde with its global presence is developing and • Improved ultrasonic and other non-destructive delivering specific bearings to the wind industry since the first turbine has testing methods and frequencies been built in the 80's. In North America we have been supplying these • Process improvements products under the Rotek brand name. Rotek, now thyssenkrupp rothe erde • Validation in world’s largest R&D facility for blade bearings USA Inc. continues to be your partner for the wind aftermarket slewing • World’s longest track record for blade bearings within the bearings and will supply slewing bearing products under the globally Service and aligned brand name rothe erde. sentire wind
    [Show full text]
  • Wind Oscillator for Power Genration
    Western Michigan University ScholarWorks at WMU Master's Theses Graduate College 6-2015 Wind Oscillator for Power Genration RS Vewen Ramasamy Follow this and additional works at: https://scholarworks.wmich.edu/masters_theses Part of the Aerospace Engineering Commons, Natural Resources and Conservation Commons, and the Sustainability Commons Recommended Citation Ramasamy, RS Vewen, "Wind Oscillator for Power Genration" (2015). Master's Theses. 600. https://scholarworks.wmich.edu/masters_theses/600 This Masters Thesis-Open Access is brought to you for free and open access by the Graduate College at ScholarWorks at WMU. It has been accepted for inclusion in Master's Theses by an authorized administrator of ScholarWorks at WMU. For more information, please contact [email protected]. WIND OSCILLATOR FOR POWER GENRATION by RS Vewen Ramasamy A thesis submitted to the Graduate College in partial fulfillment of the requirements for the Degree of Master of Science in Engineering (Mechanical) Department of Mechanical and Aerospace Engineering Western Michigan University June 2015 Thesis Committee: Tianshu Liu, Ph.D., Chair Parviz Merati, Ph.D. Javier Montefort, Ph.D. WIND OSCILLATOR FOR POWER GENERATION RS Vewen Ramasamy, M.S.E. Western Michigan University, 2015 This thesis describes in detail the design, mechanical, electrical and software considerations in developing a working model for the non-conventional wind power converter called Wind Oscillator. This was based on the concept developed and patented by Tianshu Liu in the paper “Wind Oscillator and Rotor for Power Generation”[1]. In order to verify the practicality of this idea, a working model of the Wind Oscillator was designed, built and tested in the Western Michigan University wind tunnel facility.
    [Show full text]
  • PC-Based Control for Wind Turbines
    PC-based Control for Wind Turbines IPC I/O Automation In-depth technological expertise for wind power Beckhoff technological expertise … For over 30 years Beckhoff has been implementing automation solutions on the basis of PC-based control technology, which have been proven in the most diverse industries and applications. The globally operative company, with headquarters and production site located in Verl, Germany, employs over 2100 people worldwide*. With 30 subsidiary companies* as well as distributors, Beckhoff is represented in over 60 countries. Beckhoff achieved a total turnover of 465 million Euros in 2011. Thanks to constant technological innovations and economic growth as well as a high verti- cal integration and large production capacities, Beckhoff guarantees long-term availability and reliability in product delivery. Robust, industry-proven components and more than 12 years of expertise in wind power make Beckhoff a competent and reliable partner. A global team of experts ensures worldwide support, with local service and support to customers. * (as of 03/2012) 2 We reserve the right to make technical changes. … enables higher wind turbine effi ciency and availability. Automation technology from Beckhoff is used in over 20,000 wind turbines worldwide up to a size of 5 MW – both onshore and offshore. The high degree of integration as well as the use of IT and automation standards make PC-based control technology a powerful and effi cient solution with an optimum price-to- perfor mance ratio. In addition to the hardware platform, Beckhoff also supplies a complete software solution for operational management. Further software func- tion blocks, e.g.
    [Show full text]
  • Wind Power Today
    Contents BUILDING A NEW ENERGY FUTURE .................................. 1 BOOSTING U.S. MANUFACTURING ................................... 5 ADVANCING LARGE WIND TURBINE TECHNOLOGY ........... 7 GROWING THE MARKET FOR DISTRIBUTED WIND .......... 12 ENHANCING WIND INTEGRATION ................................... 14 INCREASING WIND ENERGY DEPLOYMENT .................... 17 ENSURING LONG-TERM INDUSTRY GROWTH ................. 21 ii BUILDING A NEW ENERGY FUTURE We will harness the sun and the winds and the soil to fuel our cars and run our factories. — President Barack Obama, Inaugural Address, January 20, 2009 n 2008, wind energy enjoyed another record-breaking year of industry growth. By installing 8,358 megawatts (MW) of new Wind Energy Program Mission: The mission of DOE’s Wind Igeneration during the year, the U.S. wind energy industry took and Hydropower Technologies Program is to increase the the lead in global installed wind energy capacity with a total of development and deployment of reliable, affordable, and 25,170 MW. According to initial estimates, the new wind projects environmentally responsible wind and water power completed in 2008 account for about 40% of all new U.S. power- technologies in order to realize the benefits of domestic producing capacity added last year. The wind energy industry’s renewable energy production. rapid expansion in 2008 demonstrates the potential for wind energy to play a major role in supplying our nation with clean, inexhaustible, domestically produced energy while bolstering our nation’s economy. Protecting the Environment To explore the possibilities of increasing wind’s role in our national Achieving 20% wind by 2030 would also provide significant energy mix, government and industry representatives formed a environmental benefits in the form of avoided greenhouse gas collaborative to evaluate a scenario in which wind energy supplies emissions and water savings.
    [Show full text]
  • Landbosse in SAM (Tutorial/Documentation)
    LandBOSSE in SAM (Tutorial/Documentation) Contents Page No. 1. Introduction 1 2. LandBOSSE Inputs in SAM 1 3. Workflow for Running LandBOSSE in SAM 5 4. Automatic Update of Backend Default Data 7 5. Running BOS Parametrics in SAM 9 6. Appendix 11 Introduction NREL’s Land-based Balance of System Systems Engineering (LandBOSSE) model is a tool for modeling the balance-of-system (BOS) costs of land-based wind plants. BOS costs currently account for approximately 30% of the capital expenditures needed to install a land-based wind plant; they include all costs associated with installing a wind plant, such as permitting, labor, material, and equipment costs associated with site preparation, foundation construction, electrical infrastructure, and tower installation. This document serves as a tutorial for successfully running the newly integrated LandBOSSE model in the System Advisor Model (SAM). For more details on how the LandBOSSE model calculates BOS costs, see the following technical report: https://www.nrel.gov/docs/fy19osti/72201.pdf . The LandBOSSE tool is a an open-source project written in the Python programming language. It is maintained by NREL and is hosted on GitHub. For more details on the code implementation of the model, see the following link to LandBOSSE’s GitHub repository: https://github.com/wisdem/landbosse . For a detailed look at the default LandBOSSE inputs used in SAM, see the following two links: 1. https://github.com/WISDEM/LandBOSSE/blob/pip_installable/landbosse/landbosse_api/ project_list.xlsx 2. https://github.com/WISDEM/LandBOSSE/tree/pip_installable/landbosse/landbosse_api/p roject_data LandBOSSE Inputs in SAM The LandBOSSE model has 66 inputs: 44 input parameters (e.g., turbine rating, distance to interconnection, etc.) and 12 data lookup tables (e.g., crew cost for multiple types of crews).
    [Show full text]
  • Manufacturing Climate Solutions Carbon-Reducing Technologies and U.S
    Manufacturing Climate Solutions Carbon-Reducing Technologies and U.S. Jobs CHAPTER 11 Wind Power: Generating Electricity and Employment Gloria Ayee, Marcy Lowe and Gary Gereffi Contributing CGGC researchers: Tyler Hall, Eun Han Kim This research is an extension of the Manufacturing Climate Solutions report published in November 2008. It was prepared on behalf of the Environmental Defense Fund (EDF) (http://www.edf.org/home.cfm). Cover Photo Credits: 1. Courtesy of DOE/NREL, Credit – Iberdrola Renewables, Inc. (formerly PPM Energy, Inc.) 2. Courtesy of DOE/NREL, Credit – Iberdrola Renewables, Inc. (formerly PPM Energy, Inc.) 3. Courtesy of DOE/NREL, Credit – Reseburg, Amanda; Type A Images © September 22, 2009. Center on Globalization, Governance & Competitiveness, Duke University The complete report is available electronically from: http://www.cggc.duke.edu/environment/climatesolutions/ As of September 22, 2009, Chapter 11 is not available in hardcopy. 2 Summary Wind power is a cost effective, renewable energy solution for electricity generation. Wind power can dramatically reduce the environmental impacts associated with power generated from fossil fuels (coal, oil and natural gas). Electricity production is one of the largest sources of carbon dioxide (CO2) emissions in the United States. Thus, adoption of wind power generating technologies has become a major way for the United States to diversify its energy portfolio and reach its expressed goal of 80% reduction in green house gas (GHG) emissions by the year 2050. The benefits of wind power plants include no fuel risk, no carbon dioxide emissions or air pollution, no hazardous waste production, and no need for mining, drilling or transportation of fuel (American Wind Energy Association, 2009a).
    [Show full text]
  • Exploring the Causes of Power-Converter Failure in Wind Turbines Based on Comprehensive Field-Data and Damage Analysis
    energies Article Exploring the Causes of Power-Converter Failure in Wind Turbines based on Comprehensive Field-Data and Damage Analysis Katharina Fischer 1,* , Karoline Pelka 1, Sebastian Puls 2, Max-Hermann Poech 2, Axel Mertens 3, Arne Bartschat 1, Bernd Tegtmeier 1, Christian Broer 1 and Jan Wenske 1 1 Fraunhofer Institute for Wind Energy Systems (Fraunhofer IWES), 30159 Hannover, Germany; [email protected] (K.P.); [email protected] (A.B.); [email protected] (B.T.); [email protected] (C.B.); [email protected] (J.W.) 2 Fraunhofer Institute for Silicon Technology (Fraunhofer ISIT), 25524 Itzehoe, Germany; [email protected] (S.P.); [email protected] (M.-H.P.) 3 Institute for Drive Systems and Power Electronics IAL, Leibniz University Hannover, 30167 Hannover, Germany; [email protected] * Correspondence: katharina.fi[email protected]; Tel.: +49-471-14290-542 Received: 30 December 2018; Accepted: 11 February 2019; Published: 13 February 2019 Abstract: Power converters are among the most frequently failing components of wind turbines. Despite their massive economic impact, the actual causes and mechanisms underlying these failures have remained in the dark for many years. In view of this situation, a large consortium of three research institutes and 16 companies, including wind-turbine and component manufacturers, operators and maintenance-service providers has joined forces to identify the main causes and driving factors of the power-converter failures in wind turbines to create a basis for effective remedial measures. The present paper summarizes and discusses the results of this research initiative, which have been achieved through the evaluation of converter-specific failure and operating data of a large and diverse worldwide wind-turbine fleet, field measurements as well as post-mortem investigation of returned converter components.
    [Show full text]
  • U.S. Wind Turbine Manufacturing: Federal Support for an Emerging Industry
    U.S. Wind Turbine Manufacturing: Federal Support for an Emerging Industry Michaela D. Platzer Specialist in Industrial Organization and Business December 18, 2012 Congressional Research Service 7-5700 www.crs.gov R42023 CRS Report for Congress Prepared for Members and Committees of Congress U.S. Wind Turbine Manufacturing: Federal Support for an Emerging Industry Summary Increasing U.S. energy supply diversity has been the goal of many Presidents and Congresses. This commitment has been prompted by concerns about national security, the environment, and the U.S. balance of payments. Investments in new energy sources also have been seen as a way to expand domestic manufacturing. For all of these reasons, the federal government has a variety of policies to promote wind power. Expanding the use of wind energy requires installation of wind turbines. These are complex machines composed of some 8,000 components, created from basic industrial materials such as steel, aluminum, concrete, and fiberglass. Major components in a wind turbine include the rotor blades, a nacelle and controls (the heart and brain of a wind turbine), a tower, and other parts such as large bearings, transformers, gearboxes, and generators. Turbine manufacturing involves an extensive supply chain. Until recently, Europe has been the hub for turbine production, supported by national renewable energy deployment policies in countries such as Denmark, Germany, and Spain. However, support for renewable energy including wind power has begun to wane across Europe as governments there reduce or remove some subsidies. Competitive wind turbine manufacturing sectors are also located in India and Japan and are emerging in China and South Korea.
    [Show full text]
  • Building a National Wind Turbine Industry: Experiences from China, India and South Korea
    Int. J. Technology and Globalisation, Vol. 5, Nos. 3/4, 2011 281 Building a national wind turbine industry: experiences from China, India and South Korea Joanna I. Lewis Edmund A. Walsh School of Foreign Service, Georgetown University, 37th & O Streets NW, ICC 305-Q, Washington, DC 20057, USA E-mail: [email protected] Abstract: This paper explores the strategies used by the domestic wind power technology companies in China, India and South Korea in order to understand how these countries have acquired and assimilated advanced technologies. It finds that the primary technology transfer and acquisition strategies utilised included licensing arrangements and Mergers and Acquisitions (M&A) that resulted in the transfer of technology ownership and partnerships for the joint development of new technology. As technology development becomes increasingly global, firms in the emerging economies can take advantage of their increasing access to technological know-how that was previously developed by and for the developed world. Keywords: technology transfer; innovation systems; wind power; China; India; South Korea. Reference to this paper should be made as follows: Lewis, J.I. (2011) ‘Building a national wind turbine industry: experiences from China, India and South Korea’, Int. J. Technology and Globalisation, Vol. 5, Nos. 3/4, pp.281–305. Biographical notes: Joanna I. Lewis is an Assistant Professor in the Edmund A. Walsh School of Foreign Service at Georgetown University. She conducts research on renewable energy industry and policy development, mechanisms for low-carbon technology transfer in the developing world and expanding options for multilateral engagement in international climate change agreements, with a primary geographic focus on China.
    [Show full text]
  • Wind Technology: a Framework for the Evaluation of Innovations’ Impacts on the Diffusion Potential
    Sustainability 2010, 2, 757-782; doi:10.3390/su2030757 OPEN ACCESS sustainability ISSN 2071-1050 www.mdpi.com/journal/sustainability Article Wind Technology: A Framework for the Evaluation of Innovations’ Impacts on the Diffusion Potential Valentina Dinica School of Government, Victoria University of Wellington, P.O. Box 600, Wellington 6140, New Zealand; E-Mail: [email protected]; Tel: +64-4-463-5711; Fax: +64-4-463-5454. Received: 21 December 2009; in revised form: 20 January 2010 / Accepted: 20 February 2010 / Published: 15 March 2010 Abstract: This paper proposes a framework based on which innovations in wind power technologies can be evaluated from the standpoint of their contribution to diffusion expansion. The framework helps build up a missing link between the technical literature on innovations and policy-oriented contributions concerned with the diffusion potential of wind power in national energy systems. The ideas are applied for the evaluation of wind technology innovations adopted in Spain. The framework can help policy-makers prioritize their innovation objectives and funding, so as to support the adoption of innovations that deserve the highest priority, given the country’s resources and energy system characteristics. Keywords: wind power; diffusion potential; technological innovations 1. Introduction Increasing evidence of climate change seems to have finally convinced political actors in some countries that ‘healing the wounds’ of climate change impacts may be more expensive than implementing measures and adopting technologies that cut greenhouse gas emissions. Electricity production based on fossil fuels is a key contributor to climate change. Replacing fossil fuels with renewable forms of energy resources must be at the core of any genuine climate change mitigation strategy.
    [Show full text]