Xcel Energy Inc. · NASDAQ:XEL
Xcel Energy — West Central Telephone Association — Technical Presentation
29 slides from Xcel Energy's technical presentation
Slide 1: West Central Telephone's Road to Renewable Energy
West Central Telephone’s Road to Renewable Energy Remote Equipment Research Leads to Opportunity uli AH AA EHUALLAHAALHO A AKK04
Slide 2: Need: Remote Power to Nodes
Need: Remote Power to Nodes * Connecting copper to fiber optic lines requires switching gear at logistically mapped ¢ WCTA has 100+ nodes | ¢ Five 9’s requirement = no down time « Power outages = great challenge and expense
Slide 3: Why Use Renewable Energy?
Why Use Renewable Energy? * A generator that eventually pays for itself * Backup power for grid outages + Environmental benefits | « Public Relations benefits | ¢ The timing is right — incentives, etc. If it's good for WCTA, likely to be good for other telcos I
Slide 4: Phase Research: Can it Work?
Phase 1 Research: Can it Work? * Worked with engineers and industry experts + Decided on wind/solar hybrid for greater reliability * RFP sent to vendors * 5 selected and installed off- site for testing * Many lessons learned, but needed to take research to next level
Slide 5: Phase II: Xcel RDF Research Project
Phase II: Xcel RDF Research Project * Goals: — Select best equipment and best practices based on Phase | lessons learned \ — Install at actual live nodes | — More sophisticated monitoring l — Find best configuration | — Determine technical, economic, and market feasibility
Slide 6: Research Preparations
Research Preparations ¢ Worked with engineering consultants for study methodology and equipment | specifications ¢ Performed solar and wind site assessments ) ¢ Matched equipment to sites * Obtained permits, etc.
Slide 7: Minnesota-Made Monitoring System
Minnesota-Made Monitoring System Needed affordable way to match wind speed to wind power to create wind “power curve” Needed to see how the components interacted Needed real-time as well as historical data Needed ability to access data remotely from one computer
Slide 8: Minnesota-Made Custom Cabinets
Minnesota-Made Custom Cabinets * 3’ X 3’ shelf for electronics-- chase on both sides, back plates on 3 sides to accommodate any wiring + 3’X 3’ vented battery compartment with spill tray ¢ External mounting flanges and lifting eyes for installation | | ¢ Lockable doors, custom infusion into powder c
Slide 9: Installations — Site
Installations — Site 1 = « Very good wind, good solar * Best spot 350’ away, therefore chose wind turbine that produced higher voltage * Good turbine for net- metering -— 1.9 kW @ 21 mph wind turbine — 1.02 kW solar array
Slide 10: Marginal wind resource, good solar
¢ Marginal wind resource, tr good solar * Chose wind turbine that | could handle turbulence ¢ Grid-interactive configuration | — 9 kW @ 28 mph wind turbine — 1.02 kW solar array 10
Slide 11: Excellent wind resource, good solar
¢ Excellent wind resource, good solar * Chose wind turbine suited for higher wind speeds * Grid-interactive configuration — 1kW @ 26 mph wind turbine — 1.02 solar array 11
Slide 12: Site
Site 20 * Very good wind resource, good solar * Grid-interactive configuration — .86kW @ 28 mph wind turbine — 1.02 kW solar array 12
Slide 13: Office Site
Office Site * Good wind resource, good solar * Convenient location to test off-grid configuration — 1kW @ 25 mph wind turbine — 1.7 kW solar 13
Slide 14: Data Gathering
Data Gathering * Collected data over 6 months * Upgraded monitoring equipment during that time, changed some calibrations I ¢ 4 months of true data *« Anemometer problems at one site = erroneous power | curve 14
Slide 15: Research Results
Research Results «Plenty of power at all sites, but solar greatly outperformed wind 15
Slide 16: Published Wind Power Curves
Published Wind Power Curves Fairly Accurate Rating: $kW @ 28 mph 16
Slide 17: System Optimization: Inverter/Charge Controller
System Optimization: Inverter/Charge Controller * “Refloat set point” needs to be low enough to allow renewable energy to be used to it’s fullest (otherwise grid charges the batteries too frequently) ‘Ged Volts SELECTED PERIOD = 10/01/09 Yo 10/31/09 ral I 17
Slide 18: System Optimization: Batteries
System Optimization: Batteries * Off-grid sites require at least 8 batteries Battery Volts SELECTED PERIOD - 10/01/09 to 10/31/09 0+ 1—t pe a : HARTA UE af NGA, CNL g TWO alt Dole G1 G2 03 04 05 06 07 08 09 10 11 12 B 14 15 16 17 18 19 2 21 22 23 ee we ee A October 18
Slide 19: System Optimization: Solar vs. Wind Controllers
System Optimization: Solar vs. Wind Controllers + Wind controllers not designed to work with solar controllers . | | : | | \ * Is solar charging } 7 = | i i ESAT TY vay =" oo pore wind LMA AWrAN ets a chance? ; inva 9 RUE ASZ ONL IBA | Berind controller | “ieee ere swnnnungrenwnannsay ane | failures
Slide 20: Technical Feasibility
Technical Feasibility * All sites produced sufficient power for node requirements on average * 3 days battery back-up recommended Site 1 Site 7 Site 10 Site 20 Office Max # of consecutive days without producing required power (September) 0 1 20
Slide 21: Economic Feasibility
Economic Feasibility PP Summary Configuration Sitel Site? Site10.—Site20.-— Office Site | Average Projected Power Produced 10 Years | 10 Years | 12 Years | 12 Years 9 Years 10.6 Years Actual Power Produced (July ~ Sept 2009) 14 Years | 12 Years | 14 Years | 13 Years | 11 Years | 12.8 Years Double Wi
Slide 22: Economic Feasibility
Economic Feasibility Also must consider: . Need power and backup to the nodes either way Eventual payback versus constantly paying Changing regulatory landscape (carbon credits, renewable energy credits, etc.) Possible cost reductions Great public relations New service possibility? 22
Slide 23: Market Feasibility
Market Feasibility * Solid telco market ¢ Many other possible markets: — Farmers and ranchers — Developing countries — Residential 23
Slide 24: Bringing the Product to Market
Bringing the Product to Market -Branded “Zenergy” -Developed website and brochures -Minnesota Solar Tour -Presented at MTA annual conventions -Carbon Busters Award 24
Slide 25: Project Benefits - Research
Project Benefits - Research * Independent verification of power curves for five U.S. wind turbines * New information about wind efficiency estimates/wind controllers * Optimized equipment configurations and settings for hybrid system * Technical, economic, and market feasibility verified * Ongoing r
Slide 26: Project Benefits - Products
Project Benefits - Products * Cost-effective monitoring software developed for researchers (e.g., now used by MREA) — Could be built upon for Smart Grid applications * Customized cabinet * Telco kit 26
Slide 27: Project Benefits — Telco Kit
Project Benefits — Telco Kit WUT TTT * Kit will: — Reduce consumption by ~1,000 kWh/year each node (lowering IT energy use is a goal of FCC’s national broadband plan) — Fortify telecommunications infrastructure (homeland security) — Create local jobs (manufacturing and installation) — Provide eventu
Slide 28: Project Benefits — Telco Opportunity
Project Benefits — Telco Opportunity * Telcos often the economic cornerstone of rural areas — But future uncertain — need to diversify or lose jobs — Kits at nodes excellent advertising * Qualified highly trained installers = safer, more reliable renewable energy « Another step toward a smarter grid
Slide 29: Questions?
Questions? Tony Mayer, CEO West Central Telephone 218-837-5151 800-945-2163 tonym@wcta.net www.zenergyquide.com 29
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