My Home Solar PhotoVoltaic (PV) System 2010 through 2017 How s It Doing?

Transcription

1 July 8th, 2017 My Home Solar PhotoVoltaic (PV) System 2010 through 2017 How s It Doing? Bill Neukranz bneukranz@verizon.net /15/18 Bill Neukranz

2 My System: Grid Tied, No Batteries, String Inverter Power grid Solar panels Electric meter AC loads DC to AC Converter Circuit Breaker Box 09/15/18 Bill Neukranz

3 Consideration Points Least expensive system type is: grid-tied, no batteries. Panels won t work without grid power Winning strategy fundamentally requires: Unshaded Southerly exposure Good system design Quality components Obtaining available subsidies These items appreciably influence subject: Grid retail kwh pricing 7.9 cents Availability of net metering None Two purchase options mission is to achieve shortest time to break even: Purchase at installation (up front cash, house loan, etc.) Lease 09/15/18 Bill Neukranz

4 My Home Solar PV System Details Overview System Capacity: 8.1 kw STC Commissioned: Feb., 2010 System Type: Grid-tied, batteryless Mounting Location: Residential rooftop Location: Texas, 32.8 N, 97.0 W Solar Resource: 5.5 avg daily sun-hours (kwh/m²/day) Record Low / Avg High Temps: +1 F / 76 Annual/Monthly Production (2016): 8360/697 kwh Efficiencies: Panels 14% (2010), System 52% (2016) Export to Utility Annually (2016): 34% Utility Electricity Bill Reduction: 28% (2016) System Components Panels: 36 Astronergy monocrystalline, 225 W STC, Vmp 28.7 V, Imp 7.86 A, Voc 37.3 Isc 8.48 A, 1.64 m² (17.7 ft²) Array: 59.1 m² (636 ft²); 3 strings of 12 series-connected panels each; each string: Vmp 344 V, Imp 94 A, Voc 448 V, Isc 102 A Junction boxes: Carlon Molded Nonmetallic 6P Rated Array Installation: Unirac SolarMount rails, 35 tilt, 210 azimuth for 2 strings, combination of 210 and 285 azimuth for 1 string Rails Installation: Lag screw direct penetration to rafters, with adhesive caulk Inverter: SMA Sunny Boy 7000, 7 kw rated continuous output, 96.0% CEC weighted efficiency, 600 VDC maximum input, VDC MPPT operating range Energy Savings Monitoring: Web Energy Logger (WEL) Costs Financing: Leased system, 3 rd party owned, subsidized with ONCOR rebate and Federal tax credits Break Even: Immediate Cash Flow: $21/mo pos (2011); currently $15/mo negative (2017) 09/15/18 Bill Neukranz

5 My Neighborhood 09/15/18 Bill Neukranz

6 My Panels 09/15/18 Bill Neukranz

7 My Panels High quality, UL Listed 09/15/18 Bill Neukranz

8 My Panels Made for Ice, Snow, Hail 09/15/18 Bill Neukranz

9 My String Inverter Name Brand: SMA (Sunny Boy W) 09/15/18 Bill Neukranz

10 My String Inverter Placed Inside Garage (Out of Elements), Near Circuit Breaker Box 09/15/18 Bill Neukranz

11 My String Inverter With Connecting Outside Items 240/120 VAC disconnect from string inverter s output Solar kwh meter required by Oncor (utility) Connection to bottom of circuit breaker box 09/15/18 Bill Neukranz

12 Operational Fundamentals House load reduced (above yellow line); meter spinning slows down Full house load (no solar avail) Using power from grid Exporting to grid 7:30 PM Solar output Cloud More solar power than house load ( meter spinning backwards ) 2:30 PM 09/15/18 Bill Neukranz

13 When is Peak Production During the Year? Mid-April 09/15/18 Bill Neukranz

14 Shading 2. Chimney (Winter (Dec.) times) 1. Exposure not directly South (it s SW) 3. Trees along backyard alley 09/15/18 Bill Neukranz

15 Shading String Inverter Aggravates Shading Problems Mar, /15/18 Bill Neukranz

16 Shading & System Design vs String vs Micro Inverter 09/15/18 Bill Neukranz

17 How s My System Performing? Solar Harvest 16,139 kwh/yr = Nameplate adjusted for Ft. Worth historical weather at fixed temperature 100% 64% 62% 60% Actual production influenced by: - Temperature - Tilt - Azimuth - Equip performance - Shading - Inverter type - System design 57% 53% 52% Age contributes 3.7% per year decline 09/15/18 Bill Neukranz

18 How Much of Solar Harvest Actually Used? 100% 95% 90% 85% 78% of solar harvest used. Influenced by: - System size - Load shifting to day time hrs 80% 75% 70% 65% 60% 71% 61% 58% 68% 66% 63% 55% Remainder of solar harvest goes out to grid 50% /15/18 Bill Neukranz

19 How Big of PV System Should Be Installed? Nov 17 Mar 18 Using it all 09/15/18 Bill Neukranz

20 Reduce costs: Lower operating costs: a. Instant visualization tool - stimulates usage reduction (i.e., adjust tstats, turn off lights/appliances) raises consciousness of being more energy frugal. b. Provides information needed to adjust maintenance settings. Lower maintenance costs - Anticipate repair needs in advance of more catastrophic expenses. Increase satisfaction: Confirm improvements, enhancements, corrective actions were effective. Verify advertised equipment performance Ensure results occur, surprises don t happen, promised savings materialize. Enhance decision making: Optimize decisions by providing quantitative feedback: a. Provides base line to compare future actions to. b. Identifies what to work on next facilitates pareto analysis. c. Offers data for informational and analysis purposes perform ROI analysis. Enables questioning of unusual anomalies to identify more opportunities. Speed up repairs / problem solving: Fix specific problems quicker / more accurately. Energy Monitoring Why? What do I use? Web Energy Logger (WELserver.com) 09/15/18 Bill Neukranz

21 Large Variety of Supported Sensors Temperature (Dry Bulb), humidity Power/energy/peakdemand/powerfactor/negative-solarenergy-flow, gas/fluid flow/volume Pulse Counting Inputs On/off, thermostat modes Pressure, irradiance/insolation, indoor air quality (in dev) 0-10V Analog In Cloud Post More inputs supported: wind speed, CO2, AC & DC voltage/current and others Internet Appliance Processor Serial Log 09/15/18 Bill Neukranz

22 Monthly Cost Five Key Functions Delivered Pulse Counting Inputs Real time display 0-10V Analog In Cloud Post Cloud (any browser display, anywhere) Serial Log PC Monthly spreadsheet download (using browser) Logged data storage Charts (any browser display, anywhere) Heating & Cooling Monthly Cost (starting 2008) (3400 sf single-story residence, at stated grid rate (no solar PV included), Plano, TX 75074) $180 $160 $140 $120 $100 $80 $60 (to , text messaging) Predictive / $40 $20 Fault Detection $0 Dec-07 Jun-08 Dec-08 Jun-09 Dec-09 Jun-10 Dec-10 Jun-11 Dec-11 Jun-12 Dec-12 Alarms (4 Month Cost Each Month 12 Mo Avg Spreadsheets accumulation & analysis included, 7 optional 09/15/18 Bill Neukranz

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25 Questions? Bill Neukranz /15/18 Bill Neukranz