Calculating Solar Energy System Performance & Payback

Transcription

1 Calculating Solar Energy System Performance & Payback Our integrator experts from A&R Solar, Sunergy Systems, and Whidbey Sun & Windwill present and discuss how to determine and calculate real world performance, cash flow, and payback for both solar electric and solar hot water systems. You'll also leave with an understanding of solar incentives (including the Washington State production incentive program), and comparing photovoltaic module specifications (and using independent agency evaluations). Dave Kozin, Director Member, Solar Washington Board of Directors Howard Lamb, Founder & Electrical Engineer Member, Solar Washington Board of Directors Kelly Keilwitz, Director

2 Introduction and Agenda Education (Q&A after every presenter) Incentives & how a system works Howard Lamb Micro-climates, NREL/PVWATTS data, and Shading Kelly Keilwitz Tilt & Orientation & Temperature Dave Kozin System Performance Howard Lamb Calculating system performance for $30,000 Systems Intro Kelly Keilwitz A&R Solar Methodology w/ Out-of-State Dave Kozin Whidbey, Sun & Wind Methodology w/ Out-of-State & Shading Kelly Keilwitz Sunergy Systems Methodology w/ In-State Howard Lamb Q&A ROI Models and Financial Analysis for $30,000 Systems Intro Dave Kozin Utility historical rate increases and predictions and tiers Howard Lamb A&R Solar Methodology w/ Out-of-State Dave Kozin Whidbey, Sun & Wind Methodology w/ Out-of-State & Shading Kelly Keilwitz Sunergy Systems Methodology w/ In-State Howard Lamb Q&A

3 Education 1. Incentives and How a System Works Howard Lamb 2. Micro-climates, NREL/PVWATTS data, and Shading Kelly Keilwitz 3. Tilt & Orientation & Temperature Dave Kozin 4. System Performance Howard Lamb

4 Incentives and How a System Works Howard Lamb Founder & Electrical Engineer Founder & Electrical Engineer Member, Solar Washington Board of Directors

5 Incentives for Going Solar 30% Federal Tax Credit Washington State 6170 Program -15 /kwh to 54 /kwh for all solar generated Net Metering -You get to use all your solar energy and any excess generated you get credit for with your utility company Washington State Sales Tax Exemption 5-Year Accelerated Depreciation for Businesses Increased Value of Your Property Protection from future rate increases

6 How a PV System Works

7 How WA Incentive Program Works This is In addition to Net-Metering, which means you get to use all of your generated solar kwh and you also get the WA incentive for all of the kwh that your solar generates TOO. For every unit of solar energy (kwh) generated, for equipment manufactured Out-of-State you will receive 15 /kwh and for equipment manufactured In-State you will receive 54 /kwh. The program expires on July, Payments are made annually by your utility company.

8 Micro-climates, NREL/PVWATTS data, and Shading Kelly Keilwitz Director

9 NREL s Solar Advisor Model (SAM)

10 NREL s Solar Advisor Model (SAM) Production

11 Shading - 5kW PV array in Seattle, S. facing, 26 tilt Shading Type Annual Energy (kwh) % loss None Morning, until 10A Afternoon, after 2P Winter; all Dec Winter; Nov, Dec & Jan Unshaded 9A to 3P Unshaded 8A to 4P

12 Climate & Location Weather data from NREL SAM 5kW PV array, S. facing, 26 o tilt Location Annual Energy (kwh) % +/- Seattle 5312* SeaTac Renton Snohomish Hoquiam Olympia Bellingham Oak Harbor (Whidbey) Spokane Yakima

13 Solar Access

14 Tilt & Orientation & Temperature Dave Kozin Director Member, Solar Washington Board of Directors

15 Annual Kilowatt Hours (AC) per 1 kw (DC) of Solar Tilt Angle(Degrees)

16 Inverter Output: Watts (AC) per 1 kw (DC) of Solar Temperature ( F)

17 System Performance Howard Lamb Founder & Electrical Engineer Founder & Electrical Engineer Member, Solar Washington Board of Directors

18 Real World System Performance PV Module Losses Light Induced Degradation: 0% to 5% Efficiency loss due to Temperature: Sunny Warm Day = 15%, Average Day = 7% Power tolerances and mismatch loses: 1% to 8% Efficiency loss due to low light conditions: 1% to 5% Dirt or soiling on modules: 1% to 5% Aging degradation: 0.3% to 0.5% annually System Losses Wiring Losses: <=2% Inverter Losses: 3% to 10%

19 WA Common PV Module Ratings Module CEC Efficiency LID 1) Tolerance (Minus) Efficiency Warranty Sanyo HIP-215N 92.8% 3.0% 0.0% 17.1% 5/20 SunPower SPR % 0.0% -3.0% 19.1% 10/25 Evergreen ES-A-210-fa3 90.5% 1.5% 0.0% 13.4% 5/25 Yingli YL % 3.0% -3.0% 14.1% 5/25 SolarWorld SW % 0.0% 0.0% 14.6% 5/25 Solon Blue 220/01-230W 88.4% 3.0% -3.0% 14.0% 10/25 Sharp ND-224UC1 88.2% 3.0% -5.0% 13.7% 5/25 Silicon Energy SiE195 2) 87.0% 3.0% -5.0% 13.4% 2/20 1) Approximation 2) No CEC data available, so value transposed from CEC rating of SiE 180

20 PV System Losses for Evergreen Solar Array De-rating Item Resulting Efficiency Module CEC rating of its manufacture STC rating: 90.5% Module System Efficiency after Initial Light Degradation: 98.5% Module System Efficiency after Tolerance Losses: 100.0% Module System Efficiency after Module Mismatch Losses: 98.8% Wiring Losses (AC and DC): 98.0% Soiling of Panels: 99.0% Inverter CEC Efficiency Rating: 95.5% Total Real World System Efficiency: 81.5%

21 Calculating system performance for $30,000 Systems 1. Intro Kelly Keilwitz 2. A&R Solar Methodology w/ Out-of-State Dave Kozin 3. Whidbey, Sun & Wind Methodology w/ Out-of- State & Shading Kelly Keilwitz 4. Sunergy Systems Methodology w/ In-State Howard Lamb 5. Q&A

22 A&R Solar Methodology w/ Out-of-State Dave Kozin Director Member, Solar Washington Board of Directors

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26 Sunergy Systems Methodology w/ In- State Howard Lamb Founder & Electrical Engineer Founder & Electrical Engineer Member, Solar Washington Board of Directors

27 System Losses for Silicon Energy Array De-rating Item Resulting Efficiency Module CEC rating of its manufacture STC rating: 87.0% Module System Efficiency after Initial Light Degradation: 97.0% Module System Efficiency after Tolerance Losses: 95.0% Module System Efficiency after Module Mismatch Losses: 97.5% Wiring Losses (AC and DC): 98.0% Soiling of Panels: 99.0% Inverter CEC Efficiency Rating: 96.0% Total Real World System Efficiency: 72.8%

28 System Losses for Silicon Energy Array De-rating Item Resulting Efficiency System STC Output 2.9 kw Average Annual Daily Solar Hours: 3.83 Days in the Year 365 Total Real World System Efficiency: 72.8% Shading, Tilt Angle & Array Orientation Losses: 99.7% Annual Real World Energy Output: 2,968 kwh

29 ROI Models and Financial Analysis for 1. Intro Dave Kozin $30,000 Systems 2. Utility historical rate increases and predictions and tiers Howard Lamb 3. A&R Solar Methodology w/ Out-of-State Dave Kozin 4. Whidbey, Sun & Wind Methodology w/ Out-of- State & Shading Kelly Keilwitz 5. Sunergy Systems Methodology w/ In-State Howard Lamb 6. Q&A

30 Basic Idea of Tiered Electric Rates Utility Rates Explained The basic idea is this: the more electricity you use the more you are charged per unit of electricity (Kilowatt-Hour or kwh). The utility company is trying to get you to conserve by charging a lot more if you use or waste a lot of electricity. Low energy users pay less per kwh than high energy users. Here in Seattle City Light and Puget Sound Energy territory there are 2 tiers for the rates you are charged for electricity. Tier 1 -The first tier is called "baseline". Tier 2 -The next tier is the upper baseline amount. The baseline is a rate per kwh you are charged and when your usage goes over this "baseline" amount you are charged a higher rate. Large Difference in Electric Rates Between Lower and Upper Tiers The other very noticeable part of this rate structure is that the baseline is significantly less expensive than the upper tier. Roughly 20% for PSE and 50% for SCL for the upper tier compared to the baseline rate. This is a strong reason to conserve power and generate solar electricity because they "shave off" the electricity you pay for in the upper tier FIRST! Solar removes the top tier from your electric bill first so your savings is more substantial.

31 Tiers In All Their Glory Fortunately we are blessed with low electric rates in Washington State, but the graph below shows how this works in California where the nation s highest electric rates occur.

32 PSE Utility Rates and Increases 25.0% 20.0% PSE Rate Increases 15.0% 10.0% 5.0% 0.0% -5.0% $0.120/kWh PSE Base and Peak Rates $0.100/kWh $0.080/kWh $0.060/kWh $0.040/kWh Base Peak (Solar) $0.020/kWh $0.000/kWh

33 A&R Solar Methodology w/ Out-of-State Dave Kozin Director Member, Solar Washington Board of Directors

39 Whidbey, Sun & Wind Methodology w/ Out-of-State & Shading Kelly Keilwitz Director

40 NREL s Solar Advisor Model (SAM) Financial

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42 Sunergy Systems Methodology w/ In- State Howard Lamb Founder & Electrical Engineer Founder & Electrical Engineer Member, Solar Washington Board of Directors

43 Solar Net-Metering as Pre-Tax Value High Income Tax Brackets:Residential electricity expenses are paid with after tax dollars they aren t tax deductible. Higher customer income tax brackets make after-tax costs more expensive with respect to income. That is, as tax rates goes up, the customer needs to earn more money to have same amount left to pay the electric bill after taxes are applied. Comparable To Other Investments:In order to compare solar to other investments, all should be on the same side of the tax equation. Since most investments are taxable (i.e. stocks, savings interest, etc.), it is advantageous to covert solar savings to pre-tax value so all investments are measured on an even playing field. This demonstrates the increased value of a dollar saved with solar and is how Sunergy Systems incorporates solar net-metering savings into its financial analysis. Excerpts from -

44 Financial Model for 5% Utility Escalation Rate and Utility Savings Based on Pre-Tax Dollars

45 Financial Model for 7.5% Utility Escalation Rate and Utility Savings Based on Pre-Tax Dollars