1 / 42

Residential Solar Power in Midwest

Residential Solar Power in Midwest. Patrick Chapman Associate Professor University of Illinois at Urbana-Champaign. Example: Illinois Energy Picture. Dominated by nuclear, coal Some wind power Solar power << 1% New Illinois Power Agency reportedly:

reid
Download Presentation

Residential Solar Power in Midwest

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Residential Solar Power in Midwest Patrick Chapman Associate Professor University of Illinois at Urbana-Champaign

  2. Example: Illinois Energy Picture • Dominated by nuclear, coal • Some wind power • Solar power << 1% • New Illinois Power Agency reportedly: • Requires 25% of Illinois energy from renewable sources by 2025 • Requires 2% by June 1, 2008 • 75% of this must be wind • Governs net metering and other aspects of power

  3. Illinois Energy 2006 data: 5th in population 10.37¢/kWh residential 18 GWh of generation 17.3 GWh =coal + nuke

  4. Illinois Solar Map ~ 4000 Wh/m2 per day Source: DOE

  5. More-Detailed Maps Provided by Angus Rockett, Univ. of Illinois

  6. Growth Internationally Chart from US Photovoltaic Industry Roadmap (NREL, 2001).

  7. PVWatts (NREL) • Based on collected solar data (only select years) • More reliable that clear-sky calculations • Available for certain sites • Specifications • Tilt = latitude • Azimuth = true south • 0.77 derating factor • “Solar Advisor Model” from NREL

  8. PV Economic Viability • Varies from place to place • Solar radiation • Cloud cover • Price of electricity • Real-time pricing vs. fixed pricing • Installation costs (labor) • Demand for modules • Availability of installers • Rebates and incentives

  9. Calculations for Select Sites • For a 1-kW array • Rockford: 1212 kWh/yr ($0.089/kWh) • Springfield: 1281 kWh/yr • Quick multiplier: 1250 kWh/yr/kW-installed • Long Beach: 1449 kWh/yr ($0.136/kWh) • Tucson: 1617 kWh/yr • Portland, ME: 1280 kWh/yr ($0.128/kWh) • National average in 2007: $0.097/kWh (all sectors) – Hawaii is about $0.21/kWh

  10. Specifications • Tilt • Tilt = latitude good rule of thumb • Slightly shallower is optimal • Diffuse and reflected light are significant • Azimuth • True south optimal • +/- 15 degrees OK • Watch out for magnetic south • Derating – 77% typical starting point • PV module hero numbers (few %, temperature) • Inverter efficiency (94%) • Wires (98%-99%) • Dirt, aging (few %) • Mismatches (few %)

  11. PV Module Efficiency • Ratio of electrical power out to sunlight power in • Notice, not included in specifications • Somewhat overrated figure of merit • Higher efficiency = smaller space • Higher efficiency = higher cost (usually) • Key figure of merit is $/W or $/Wh • Aesthetics also important • 10% to 14% typical for silicon • 22% for SunPower modules

  12. Illinois Rebate Programs • State rebate program • 30% of project costs • Maxes out at $10,000 <<< Note, taxable grant • Limited budget (ran out of money last FY) • Straightforward application, but takes time/care • Federal tax credit • 30% of project costs • Maxes out at $2,000 • Commercial – similar programs • Illinois Clean Energy Community Foundation • Other, larger scale projects

  13. Case Study in Urbana • 2.87-kW array • Based on Springfield data • 3669 kWh/yr • 30-degree tilt (pitch 7’x12’) • 15 degrees west of south • 0.77 derating (conservative) • SunPower system • 14 205-watt modules • 3300-watt inverter

  14. Photos Case Study • Initial work

  15. More Photos • Racking

  16. More Photos • Modules

  17. More Photos (Inverter and Monitor) • Inverter and Monitor

  18. Finished Project

  19. Connecting to Ameren • Somewhat complicated, but cooperative • Register with FERC as QF • Qualifying Facility • Self-certify – not difficult, just annoying • Submit schematic and specs to Ameren • Pay $100 • Their engineer will approve drawings • Sign connection agreement • Can request waivers on insurance, etc. • Sign QF Rider agreement • Pick real-time pricing or normal rates ($333 meter)

  20. Example Schematic

  21. Real-Time Pricing • Price peaks more/less with sun

  22. Pricing • Smart Power Pricing program • Administered by CNT • $2.25 per month participation • Get wholesale price (Ameren providing wires, this is fair) • Recent legislation allows net metering • Get the retail price • Eliminate Smart Power Pricing? • The Public Utilities Act is amended by adding 5 Section 16-107.5 as follows… • Ameren to provide free meter… (?)

  23. Sample Billing (9/24-10/23) PSP Billing (net energy consumed) Total Energy: 861 kWh Total Price: $51.37 = $0.0596/kWh This is the energy supply charge. Distribution (“the wires”) costs $0.0245/kWh Total = $0.084/kWh $0.71 at noon, 10/8

  24. Sample Days Saving $20 to $40 per month compared to flat rate

  25. Generated Power • -133 kWh

  26. One Day Example (kW-hr vs. hr) Peaks nearly line up, maximizing the benefit Note this is net generation On “negative load” generation, effectively get the retail price

  27. Economics • Upfront cost, about $27,000 • $9 per peak watt, installed • Breakdown in cost per watt • $4.50 for PV modules • $1.00 for inverter • $3.50 for installer labor and markup • Rebates • $8,100 for IL (took eight months to receive check) • $2,000 for Federal • Net cost: $16,900

  28. “Investment” Analysis • At $0.10/kWh = $366.90/yr yield • Simple payback, a mere 46 years! • This is unfair to PV • (PV held to near impossible standard) • Need to look at • Amortized cost (buying all power upfront) • Equity • Increases in electricity prices (real time price?) • Environmental advantages

  29. More Econ • Realtors estimate $1,000 savings = $20,000 equity • $366.90  $7,338 in equity, and rising • Net out-of-pocket = $9,562 • Assumes there is a willing buyer • 4% rise in rates = 50% increase in prices in 10 years – effects payback and equity

  30. More Econ • As part of home mortgage • 6.75% (30-yr) mortgage, interest is initially $95/month ($66.50 after taxes) • $33.58 in energy per month – about $33 per month deficit • Year 15, prices go up, interest is down • $55/month savings, $49/month interest • Equity is $13,200, not much less than the $16,900 upfront cost

  31. Other “investments” • A 4% CD would have generated $13,536 in income on $16,900 principle • After taxes, this is ~$10,000 yield • 15 years of electric savings lost • About $500 per year on average • ~$6,000 in 15 years of savings lost • Net yield on the (CD – electricity) is $4,000 • This is about an $8,000 deficit • This is about $44/month average “luxury” price for the electricity, or about $0.15/kWh • Gets better with more time

  32. For Comparison • Other things that cost $17,000… • BMW 500 over a Toyota Prius • Extra bedroom • One semester out-of-state tuition at Illinois • Etc. • Conservative? • Rates may go up faster • PV costs will go down • Home interest rates lower • Unconversative? • Repairs, maintenance, other risks

  33. Cost Drivers and Trends • Manufacturing costs for PV modules going down • Prices still high due to shortage • Competition in China coming fast • Must achieve $3/Wp installed cost and 25 year warranty to have grid parity PV Module Costs Source: Evergreen Solar

  34. 2007 Solar Decathlon • Dept. of Energy Sponsored Event • Large national media attention – National Mall • Draw awareness to solar power • 20 universities to build solar houses • 10 events (with overall prizes)

  35. Contests • Architecture (200 pts) • Engineering (150 pts) • Marketability (150 pts) • Communications (100 pts) • Comfort Zone, Getting Around, Hot Water, Lighting, Appliances (100 pts) • Energy Balance (100 pts)

  36. Univ. of Illinois Finish • 9th overall • 1st in • Comfort Zone (best passive solar and HVAC design) • Marketability (very affordable, ordinary building materials, expandable) • Homes limited to 800 sq. ft. • Multitude of other limitations and rules • Accepted for 2009 competition

  37. Final Illinois House on the Mall ($450k) Source: SD07 photos from solardecathlon.org

  38. Winning Overall House • Darmstadt ($2M)

  39. Other Remarkable Houses • Georgia Tech, Missouri-Rolla

  40. Other Remarkable Houses, cont’d • Santa Clara, Lawrence Tech

  41. Passive Home Design for 2009 • Passive heating and cooling is largely feasible in the Midwest • PassivHaus Institute US (PHIUS) is located in Urbana • Superinsulated homes (1200 sq. ft.) • No central air conditioning of furnace • Earth-tube intake • Southern exposure adequate for PV – a 1-kW system = zero net energy Source: e-colab.org

  42. Summary • PV taking off but still just off the ground • “normal” people now taking notice • Midwest is a poor economic case • Environmental improvement is worth? • Still makes most sense to do conventional efficiency improvements first • Insulation, sealing • Compact fluorescent lighting • Better HVAC (geothermal, etc)

More Related