Rehoboth Solar Project Engineering W83 1 14
advertisement
01/28/2014 Rehoboth Solar Project Engineering W83 1 What would it take for Rehoboth Christian School to construct, own, operate, and maintain a solar PV energy system? 01/28/2014 Project Objective 2 01/28/2014 Site Presented by: Claire Phillippi, Jack Amick, Jordan Veltema, Jordan Mast 3 • Work Accomplished • Location Options • Decision Matrix • Climate 01/28/2014 Outline • Issues and Concerns • Installation Proposal • Current Plan • Future Options • Mounting System • Costs 4 • • • • • • • • • • Survey Decision Criteria Decision Matrix Meetings Site Alternatives Researched Cultural implications Roof Loads Researched Additional Weather Details Final Construction Outline Final Site Decisions 01/28/2014 Work Accomplished 5 • • • • • • • • New High School Existing Fitness Center Existing Band Room Fields Carport Bus Depot Middle School Dormitories 01/28/2014 Location Options 6 01/28/2014 Buildings 7 01/28/2014 Fields 8 01/28/2014 Carport 9 01/28/2014 Bus Depot 10 • Survey • Decision Matrix • • • • • • • • Aesthetics Placement Security Cost Ease of Construction Tie-In Distance Total Area Cleanliness 01/28/2014 Decision Criteria 11 01/28/2014 Decision Matrix 350 300 250 287 249 261 236 232 231 200 150 100 50 0 High School Parking Lot Fields (GROUND) Dorms Fitness Center Middle School 12 • Wind 01/28/2014 Environmental Issues • Dust Accumulation • Precipitation • Temperature 13 01/28/2014 Rehoboth Climate Annual Average Wind Speed = 15.33 mph 14 01/28/2014 Rehoboth Climate Annual Average Precipitation = 12.55 inches 15 01/28/2014 Rehoboth Climate 16 01/28/2014 Rehoboth Climate 17 01/28/2014 Wind on Roofs 18 01/28/2014 Wind on Roofs 19 1. New High School and Band Room 2. Fitness Center Roof 3. Future Options 01/28/2014 Installation Plan 20 1a. Band Room 3600 ft2 01/28/2014 Preexisting Structure 0˚ North 21 1b. New High School 12192 ft2 01/28/2014 Future Structure 0˚ North 22 2. Fitness Center 6050 ft2 01/28/2014 Preexisting Structure 5˚ SW North 23 3. Future Options • No structural plans or maximum roof loads available • Fitness Center (North Facing Roof) 01/28/2014 • Middle School • 5 degree angle facing north east • New High School (Metal Roof) • Not aesthetically pleasing 24 Roof Materials • • • • Flat roof sections Cheaper to install onto Some obstructions 20 year warranty, possible maintenance afterwards 01/28/2014 • TPO Roofing • Metal Roofing • Slanted roof sections • No obstructions • No maintenance 25 01/28/2014 Ballast Mounting Source: http://energyemp.com/ 26 01/28/2014 Inclined Mounting 27 • • • • • • Existing roofs have room for 3 pounds per square foot Band Room .9 psf Fitness 1.42 psf High School 1.28 psf High School 1.51 psf Fitness Center .9 psf 01/28/2014 Roof Loads 28 Upfront Costs Racking system: Labor: $ 20,091 $ 281,272 Total: 01/28/2014 Costs $ 301,363 29 01/28/2014 Questions? 30 01/28/2014 Panel Selection Presented by: Mr. Nate Hiemstra Mr. Mitch Hopkins Mr. Mike Houtman Mr. Tae-Hyung Lim Mr. Josh Vanderkamp 31 Outline • Overview • Final Decisions • Work accomplished • • • • 01/28/2014 • Status Panel Choice Panel Layout Energy Yield Cost Analysis • Obstacles • Future Plan • 3 Possibilities 32 • The most efficient type of solar panels (about 15-20%) • More expensive • Ideal for roofs 01/28/2014 Monocrystalline 33 • Less cost • Efficiency of approximately 13-16% • Performance decreases at higher temperatures 01/28/2014 Polycrystalline 34 Thin-Film Solar Panels • • • • • • • • Amorphous silicon (a-Si) Cadmium telluride (CdTe) Copper indium gallium selenide (CIS/CIGS) Organic photovoltaic cells (OPC) 01/28/2014 • Categories by material Efficiencies between 7–13% Mass-production is simple Can be made flexible Strong against high temperatures and shading 35 • Spatial limitations (about 4 times more space needed) • Structural costs • Degrade faster over time 01/28/2014 Thin-Film Solar Panels 36 • Expensive • Good looks but less efficient • Easy installation 01/28/2014 Building-Integrated Photovoltaics (BIPV) 37 Suggestions • Space - Monocrystalline Silicon, BIPV • Cost – Thin Film, Polycrystalline 01/28/2014 • Limitations • Install Site • Rooftop – Crystalline Silicon, BIPV • Field – Thin Film • Parking lot shade – Thin Film, Crystalline Silicon 38 Panel Types • • • • • SunPower E20 327W Mono Yingli 270W Mono Yingli 310W Poly SolarWorld 245W Poly SunPower E18 305W Mono • 8 Criteria Weighted: • • • • • • • • Panel Efficiency (18%) Cost (23%) Weight (9%) Size (5%) Rated Power (15%) Company Reputation (8%) Aesthetics (10%) Warranty/Degradation (12%) 01/28/2014 • 5 Panels Compared: 39 4 3.5 3.45 3.285 3 3.13 2.7 01/28/2014 Decision Matrix 2.67 2.5 2 1.5 1 0.5 0 SunPower E20 327W Yingli YL270 270W Yingli YL270 310 W SolarWorld Poly 245W SunPower E18 305 W 40 • SunPower E20/327 • 20.1% efficient • 327 Watts • Degrades at 0.25% yearly • 25 year warranty 01/28/2014 Panel Choice 41 • Goal to offset 50% of annual consumption due to power company constraints 01/28/2014 Energy Yield 296,000 kWh annual yield 42 Panel Layout Factors • Roof obstacles • 6 ft from roof edges • 2 ft spacing between panels • Panel Orientation • 15 degrees • Standard to mounting system • Aesthetics 01/28/2014 • Panel Spacing 43 01/28/2014 Fitness Center 192 Panels 108,300 kWh N 44 01/28/2014 New High School/Band Room 320 Panels 183,200 kWh N 45 01/28/2014 Total System Overview N 512 Panels 291,500 kWh 47% of total energy consumption 46 Upfront Costs Panel: $ 210,944 Total: $ 210,944 01/28/2014 System Costs Annual Costs Replacement Units (% 0.05 Upfront) Labor: Total: $ $ $ 2,845 60 2,905 47 Obstacles • Obtain official civil engineering approval 01/28/2014 • Fitness Center Loads • New High School Design Loads • Civil Engineering design work for additional loads 48 Fitness Center North Roof 01/28/2014 288 Panels 150,300 kWh 73.2% Pros: Not visible from ground, large space available, close to flat Cons: North facing, loss of ~8% energy production 49 192 Panels 114,300 kWh 67.1% Pros: Faces directly South, 15 degree incline Cons: Aesthetics, small area compared to alternatives 01/28/2014 New High School (cont.) 50 480 Panels 283,300 kWh 95.7% 01/28/2014 Middle School Pros: large space available, South facing, ~50% additional energy production Cons: Lack of building information (age, structure, loading capability, etc…) 51 01/28/2014 Questions? 52 01/28/2014 Inverters Presented by: Brandon Koster, Andrew Vriesema, and Lukas Woltjer 53 • Introduction • Considerations for Selection • Equipment Selection • • • • Inverter Type Sunny Design Optimization Monitoring Options Tie in, Combiner Boxes, Panels, and Cutoff Switches 01/28/2014 Outline • System Design and Location • Areas of Concern • Questions 54 Introduction • DC to AC • Power Quality 01/28/2014 • Purpose of Inverters • Importance of Monitoring • Ensure Maximum Production • Alerts for Equipment Failure 55 01/28/2014 AC and DC 56 Image source: Wikipedia 01/28/2014 Power Quality 57 http://oikos.com/library/energy_outlet/pq.gif 01/28/2014 Monitoring 58 http://www.sunterrasolar.com/ • Cost • Reputation • Ease of installation and maintenance • Compatibility with existing equipment 01/28/2014 Equipment Selection 59 • Micro inverters 01/28/2014 Inverter Types • String inverters • Central inverter 60 01/28/2014 Inverter Cost Comparison 61 Cost Estimations • Central Inverter (SMA SC-125U) $0.26 / Watt • Central Inverter (Solectrica 75kW) $0.31 / Watt 01/28/2014 • String Inverters (SB-8000TLUS) $0.27 / Watt 62 01/28/2014 Micro Inverters 63 http://leosunergy.com/images/solar-inverter-technology.jpg 01/28/2014 64 http://gigaom2.files.wordpress.com/2008/09/ enlighten-nichols-residence2.jpg Micro Inverter Advantages • Entire string does not suffer for shading on one panel 01/28/2014 • Each panel is constantly optimized for highest production • Production of each panel can be monitored • Troubleshooting the system is very easy 65 • Highest cost per watt 01/28/2014 Micro Inverter Disadvantage 66 01/28/2014 Micro Inverters 67 http://leosunergy.com/images/solar-inverter-technology.jpg 01/28/2014 Central Inverter 68 www.abcsolar.com Central Inverter Advantages • Fewer inverters to operate and maintain 01/28/2014 • Lowest cost per watt 69 • Array would be very large and potentially difficult to monitor and troubleshoot • New DC lines would have to be run to the location of the inverter 01/28/2014 Central Inverter Disadvantages 70 01/28/2014 Central Inverter 71 www.abcsolar.com 01/28/2014 String Inverters 72 www.sma-america.com 01/28/2014 String Inverters 73 Wall Mount Advantages • A few strings come together to form an independent array 01/28/2014 • Most commonly produced inverter • Smaller capacities allow easy integration to existing building electrical systems • Easier monitoring of production than ground mount commercial inverters 74 • Higher cost per watt than ground mount commercial inverters • More inverters to install, operate, and maintain 01/28/2014 Wall Mount Disadvantages 75 • Transformer • Proven reliability • Less efficient • Larger and heavier 01/28/2014 Transformer Types • Transformerless • Use a multi-step computerized process to invert DC power • Lighter design • Higher efficiency • Must have ungrounded wiring, held to higher safety standards • Additional overcurrent protection required • Recommend Transformerless 76 01/28/2014 Inverter Selection 77 • SMA Sunny Boy transformer-less (SBxxxxTL-US) series inverters • • • • • High efficiency Light weight Competitive cost per watt Able to tie into single and three phase electrical systems Available in different sizes 01/28/2014 Inverter Selection 78 • Used to select inverters for a specified type and number of panels • Chose inverters and panel wiring options for 100% power ratio 01/28/2014 Sunny Design 79 01/28/2014 Sunny Design 80 01/28/2014 Monitoring Options 81 • • • • Use installer-recommended provider No accurate quotes to date Cost: less than 1% of total system cost (ALSOenergy) Eastern Christian High School has used DECK monitoring 01/28/2014 Monitoring Recommendation 82 • Load centers (breaker panels) • AC safety disconnect switches • Wiring and conduit 01/28/2014 Grid Tie-in Equipment 83 01/28/2014 Tie-In Diagram Source: www.energy.ca.gov 84 • Agreement for Parallel Connection • System of up to 75 kW in parallel with the grid • Commercial Agreement • Can connect to grid once the following conditions are met: • Agreement signed • Installation complies with Appendix A • Installation inspected by State CID Electrical Inspector • Approval Form signed by CID and GJU • Appendix B signed • GJU has right to terminate agreement within 30 days written notice 01/28/2014 Tie-In Restrictions 85 Appendix A • • • • UL Standards Applicable IEEE Standards 2005 National Electric Code State and Local Codes and Regulations 01/28/2014 • RRGS and associated equipment complies with: • Prior to installation • Agreement needs to be executed • Applicable permits obtained • Prior to Connection • Inspection by GJU and CID • Anti-Islanding and Power Quality Inspected and Tested • An accessible, manual, lockable load break disconnect between inverter output and connection to grid • Permanent weatherproof diagram of the system at metering point 86 • Apply for Net Metering after Agreement has been executed • Excess energy results in a credit that will be applied to the account and carried from month to month • GJU can reconcile the account annually by buying-back the credits 01/28/2014 Appendix A: Net Metering Appendix B • Liability Protection 87 Conversations with GJU • Might have to pay a flat fee 01/28/2014 • 75 kW is negotiable • Must go before city council • GJU has never ruled on a proposal above 75 kW 88 • Parapet Wall • Side Wall • Near Meter 01/28/2014 Placement Options 89 Upfront Costs SunnyBoy 5000 TL (3): SunnyBoy 8000 TL (2): SunnyBoy 10000 TL (13): Deck Monitoring System: Tie-in components: Total: $ 6,642 $ 4,548 $ 39,806 $ 5,633 $ 4,226 01/28/2014 Costs $ 60,855 90 • School electrical system • Can tailor PV system for multiple grid configurations • Integrating monitoring system 01/28/2014 Issues and Concerns • Waiting for DECK about integration with SMA inverters • 75kW limit set by Gallup • Negotiate 150 kW system, tied in at two locations 91 01/28/2014 Questions? 92 01/28/2014 Financial Presented by: Allen Bosscher, Karl Bratt, Jonathan Haines 93 • • • • • Work Accomplished Issues and Concerns Next Steps Summary Questions 01/28/2014 Outline 94 • • • • • • Financing Options Additional Grant & Tax Incentives Electric Bill Analysis PPA & Solar Lease Research Cost Models and Analysis L.L.C. Research 01/28/2014 Work Accomplished 95 • • • • Direct Financing Limited Liability Corporation Power Purchase Agreement Solar Lease 01/28/2014 Financing Options 96 Direct Financing Process 01/28/2014 • PV System is Purchased • Donation vs. Loan Advantages Disadvantages • Independent • Higher Potential • One-time Cost • • • • High Upfront Cost Responsible for Damages Non-profit Company High Risk 97 Privately Owned L.L.C. • Donation vs. Loan • Roof is Rented Property • Billed for Electricity 01/28/2014 Process • At least 50% utility cost rate • Annual donation of revenue back to school (lawyer) Advantage • For-profit federal and state tax incentives 98 Power Purchase Agreement Process Advantages • For-profit federal and state tax incentives • Reduced Cost of Electricity • No Upfront Cost 01/28/2014 • Roof is Rented Property • PV System 3rd Party Owned • Billed for Electricity Usage Disadvantages • 20-25 Year Contract 99 Solar Lease Process 01/28/2014 • PV System is Leased • Set Monthly Payment Advantages Disadvantages • For-profit federal and state tax incentives • Set Monthly Payment • Low Upfront Cost • 20-25 Year Contract • Responsible for Damages 100 Grant Possibilities • Federal Grant • Applicable to: Nonprofits and Schools • Max Incentive = $3 million 01/28/2014 • USDA High Energy Cost Grant • Eligible in areas where average home energy costs are 275% above national average • NOT applicable to Rehoboth • New Mexico Avg. Home Energy Cost = $0.0809/kWh • National Avg. = $0.113/kWh 101 • USDA Rural Energy for America Program (REAP) • • • • Federal Grant Applicable to: “Schools” $2,500 - $500,000 Max Incentive = 25% of total project cost 01/28/2014 Grant Possibilities • Eligible for colleges and universities • NOT applicable to Rehoboth (K-12 School) Might be available with a L.L.C. 102 State Incentives • 6% tax credit • Max incentive = $60 million • Applicable to commercial sector 01/28/2014 • New Mexico Corporate Tax Credit • Sustainable Building Tax Credit • Based upon LEED certification • $0.30 - $6.25/ft2 • Non-profit = No tax • Receive credit and sell to a for-profit entity 103 • Business Energy Investment Tax Credit • 30% Tax Credit on Capital Investment • No Max Incentive • Applicable to commercial sector 01/28/2014 Federal Incentives • Applicable To: • PPA • Solar Lease • L.L.C. 104 $8,000 Monthly Energy Demand Charges Rehoboth 2012-2013 $7,000 $6,000 Cost $5,000 $4,000 $3,000 $9,400 Additional kW Surcharge Usage Surcharge Environmental Surcharge Cost per kWh 01/28/2014 Electricity Invoice Analysis $16,440 $2,742 $42,699 $2,000 $1,000 $- Annual Total = $ 69,892 105 $9,000 Monthly Energy Projection Rehoboth 2014 $8,000 $7,000 Additional kW Surcharge Usage Surcharge Environmental Surcharge Cost per kWh $10,526 01/28/2014 Electricity Invoice Analysis Cost $6,000 $5,000 $18,413 $2,843 $4,000 $3,000 $47,840 $2,000 $1,000 $- Annual Total = $ 79,621 Difference ≈ $10,000 106 Electricity Rate Analysis General Service Medium General Service Small 1,534.43 - 15.90 - - 14.45 0.0791 0.1285 Bill Sections First 100 kW or Less ($) Additional Demand ($/kW) First 100 kWh ($) Energy Charge ($/kWh) 01/28/2014 Tier General Service Medium Requirements: For 3 Consecutive Months… 40,000 kWh Monthly Usage ~OR~ 100 kW Monthly Peak Usage 107 Electricity Rate Analysis Gallup Joint Utilities General Small vs. Medium Rate Schedules 01/28/2014 $9,000 $8,000 $7,000 Monthly Cost $6,000 $5,000 $4,000 32,000 kWh $3,000 Medium (Current kW Peak) Medium (101 kW Peak) $2,000 Small $1,000 108 $0 10,000 20,000 30,000 40,000 50,000 Monthly Consumption (kWh) 60,000 70,000 80,000 Electricity Rate Analysis $0.09 $18 11.97% Cost per kWh ($/kWh) 6.16% $0.07 8.95% 0.23% 4.04% 2.41% 3.95% 12.04% $14 9.80% $12 10.86% $0.06 7.34% $0.05 2.40% $16 4.51% $10 0.17% $8 $0.04 Cost Per kWh Additional Surcharge Average ≈ 5% $0.03 $6 Additional Surcharge ($/kW) $0.08 01/28/2014 Gallup Joint Utilities Cost of Electricity Growth Rate $4 109 $0.02 2004 $2 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Contacts • Patricia Mattioli 01/28/2014 PPA & Solar Lease Research • Consolidated Solar Technologies • Mark Durmmond • Positive Energy Solar 110 Cost Modeling Annual Growth Rates (%) Inflation Discount Cost of Energy Panel Degregation Cost of Energy ($/kWh) Current PPA Cost Estimates ($/W) Solar Lease Monthly Payment Inverter Cost per Watt Installation Cost per Watt Mounting Cost per Watt Desired Outputs Solar Capacity (%) Energy Production (MWh/yr) 2.81% 4.50% 4.95% 0.25% 01/28/2014 General Inputs $0.133 $0.07 $0.01 $0.30 $1.68 $0.43 50% 321 111 01/28/2014 Cost Modeling Option Inputs Option 1: Band Room & Fitness Center Number of Panels Electricity Production (kWh/yr) Peak Energy Production Rate (W) Option 2: New High School Flat Roof Number of Panels Electricity Production (kWh/yr) Peak Energy Production Rate (W) 240 136900 78480 272 154600 88944 112 TOTAL Upfront Costs Site Panel Inverter $ 301,363 $ 210,944 $ 60,855 Total: 01/28/2014 Cost Modeling $ 573,162 TOTAL Annual Costs Panel $ Total: $ 2,905 2,905 113 01/28/2014 Cost Modeling General Outputs TOTAL Peak Energy Production Rate (kW) Cost per Watt ($/W)) Estimated Energy Production (MWh/yr) Solar Production (%) 167 $3.40 292 46.8% 114 Cost Modeling Rehoboth Solar Project 30 Year Forecast of Financing Alternatives 01/28/2014 $1,400,000 $1,200,000 $1,000,000 Net Present Value $800,000 $600,000 $400,000 $200,000 ≈ 23 Years $0 -$200,000 -$400,000 0 5 10 15 12 Years 10 Years -$600,000 -$800,000 Year 20 25 30 Direct Financing L.L.C PPA Solar Lease 115 Effective Rates $0.16 01/28/2014 25 Year NPV Cost of Energy ($/kWh) $0.141 $0.14 $0.12 ($/kW) $0.10 $0.086 $0.08 $0.063 $0.069 $0.070 Solar Lease PPA $0.06 $0.04 $0.02 $0.00 No Solar Donation Direct Purchase Donation L.L.C. 116 • • • • • • Solar Lease Quote 75 kW Capacity Limit Legal Concerns with School Owned L.L.C. Cost Flow Assumptions Donation Fundraising Financial Institution Financing 01/28/2014 Issues & Concerns 117 • Poster 1/28 • Final Report 1/28 • Solar Lease Quote 1/30 • Engineering Department Seminar 2/12 01/28/2014 Next Steps 118 What would it take for Rehoboth Christian School to construct, own, operate, and maintain a solar PV energy system? 01/28/2014 Summary Rehoboth Strategic Objectives: • Offset 50% of total electricity demand by 2020 • Focus on managing school, not managing energy infrastructure 119 01/28/2014 We recommend that Rehoboth install a 167 kW Solar PV system in 2015, financed by a Solar Lease N 120 01/28/2014 Questions? 121
