Developing Nebraska s Solar Potential. Michael Shonka

Transcription

1 Developing Nebraska s Solar Potential Michael Shonka

2 Agenda Why Go SOLAR Solar Myths Solar System Components System Design Applications and Impacts

3 Why Go SOLAR? FREE and abundant natural resource Non-polluting Low maintenance Scalable Build on structure, parking lot, etc. Current generation is problematic Hedge against cost increases

4 Solar Myths Nebraska

5 Solar Myths

6 Solar Myths <$3/W <$4/W

7 Solar Myths Myth: PPAs work for Nebraska Fact: Nebraska s unique culture of all Public Power provides opportunities for contracts that provide broader participation of the ratepayer - owners. PPAs are one financial tool but not the best suited tool. PPAs ship our energy dollars from Wyoming to New York City Cost Residential Solar Commercial Solar PPAs Community Solar Participation

8 Solar Components Module converts sun to electricity Inverter DC solar to AC Mounting roof, ground, pole

9 Typical PV Module

10 Inverter DC Solar to AC Central vs. String vs. Micro-inverters

11 Micro Inverter One inverter: one module < 300 Watts Economies of scale High volume production Low R & D Standardized Simple start / but no service More AC wiring

12 String Inverter Predominant topology < 100 kw Scalable High volume production R & D applicable to families More standardized Easy start / service Reduces DC wiring

13 Central Inverter Fewer in field to service >250 kw Economies of scale? Low volume production High R & D Not standardized Complex start / service More DC wiring

14 Mounting Systems Pole -Small systems -Low wind -Higher cost -30% better performance Ground -Small to large arrays -Good wind tolerance -Moderate cost -Average performance

15 Mounting Systems Roof -Small to medium systems -Good wind tolerance -Low cost -Average performance Roof - ballast -Small to large arrays -Good wind tolerance -Moderate cost -Average performance

16 System Types Grid-tie solar electric system -most popular -least cost -best ROI Grid-tie + Battery Back-up -higher reliability and cost OFF Grid Battery -highest cost, special uses

17 Solar Electric: Grid Tie - Modules produce DC power with sunlight - The inverter changes the power to AC - Power is connected at the service panel - Excess energy is exported to the grid X

18 Grid Tie - Best Uses -Small systems for homes < 5 kw -Larger systems for businesses >10 kw -Community Solar >50 kw -Special applications -Irrigation pumping ~25 kw -Sign and street lighting - PPAs > 1 MW

19 Grid Tie + Battery Back Up Rural home with solar hot water for radiant floor and PV for pumps and lights

20 Grid Tie Installation Over Three Dormers Lincoln Police Department 1501 North 27th Street Lincoln, NE

21 Grid Tie on Flat Roof Bellevue Public Safety Bldg Wall St. - Bellevue, NE

22 Grid Tie - Commercial

23 Inverters - 50 kw Grid Tie

24 Grid Tie Installation - Irrigation

25 Nebraska s First Solar-Assisted Irrigation System Ron Rose (Nebraska Public Power District) and Michael Shonka (Solar Heat and Electric) install the last of 200 modules on the 25 kw PV system just west of Lindsay, NE on HWY 91. Michael Beller (farmer and landowner) took the picture; system started on July 28, 2013

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27 Actual First Year Production Over 40,000 kwh Reference: PV Watts v.1 National Renewable Laboratories * predicted output Cost side of 25 kw; If rate averaged 10 /kwh $3547 x 10 years = $35,470 $3547 x 20 years = $79,940 If rate averaged 12.5 /kwh $4434 x 10 years = $44,340 $4434 x 20 years = $88,680 35,000 kwh / year* per 25 kw PV array

28 Solar Electric - Simple Payback Initial Cost (~$3 / Watt) $75,000 30% Federal Tax Credit $22,500 Balance $52,500 5-Year Accelerated Depreciation? Avoided Costs ($3000 to $4000+ / year)? REAP Grant (state incentives?)? Estimated payback period (in years) 5-7 (Internal Rate of Return 8-12%)

29 Solar Irrigation vs. Community Solar Reduce costs for farmer Reduce utility peak demand Simple installation but there is a learning curve Cost about $3/Watt Payback 5-7 years Nebraska s energy outlook investor / owner same local labor < $3/Watt same positive

30 Long Term Impact - Engineer s Role Make It Happen Reduces energy trade imbalance for state s economy Local investor owners can provide decentralized build out of new capacity Investment income produces returns which can be reinvested into capacity or local community Creates sustainable jobs with construction and service of new solar fields Create new manufacturing opportunities

31 Community Solar: Where Do We Go From Here? Central City, NE; December 2014

32 Michael Shonka

33 Perfect solar day

34 Good solar morning Cloudy afternoon

35 Cumulative Totals