1. NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy operated by the Alliance for Sustainable Energy, LLC Technical Review Committee Meeting May 16, 2011 Debra Lew National Renewable Energy Laboratory Golden, Colorado USA Western Wind and Solar Integration Study: Scenarios and Data Inputs

2. NATIONAL RENEWABLE ENERGY LABORATORY Agenda Status update Scenarios Data refinements 2

3. NATIONAL RENEWABLE ENERGY LABORATORY Status 3 Contracts underway or being processed with Wind Wear, and Intertek/APTECH (cost shared with WECC) GE contract being scoped DOE approval of wind/solar scenarios Plexos model up and running WECC 2020 database completed and being tested

4. NATIONAL RENEWABLE ENERGY LABORATORY Scenarios 4

5. NATIONAL RENEWABLE ENERGY LABORATORY Proposed Scenarios Penetration by Energy High WindIntermediateHigh Solar 11%WECC TEPPC 2020 8% wind 3% solar 22% 33%25% wind 8% solar 16.5% wind 16.5% solar 8% wind 25% solar 5 Use NREL ReEDS model to expand generation fleet subject to geographical and electric power system constraints (and select regional distribution) Solar consists of 40% CSP and 60% PV CSP has 10 hours of storage *note that related side sensitivity analyses in FY12 may include Plexos runs of various penetrations of solar with various PV/CSP ratios

6. NATIONAL RENEWABLE ENERGY LABORATORY High wind (25% wind, 4.8% PV, 3.2% CSP)

7. NATIONAL RENEWABLE ENERGY LABORATORY Intermediate (16.5% wind, 9.9% PV, 6.6% CSP)

8. NATIONAL RENEWABLE ENERGY LABORATORY High solar (8% wind, 15% PV, 10% CSP)

9. NATIONAL RENEWABLE ENERGY LABORATORY Scenario Development Tasks Select locations of wind and solar sites based on capacity factor and proximity to transmission Map sites to HV buses Run unconstrained and constrained transmission cases in Plexos Develop transmission expansion plan to accommodate 33% wind/solar Run a final iteration in Plexos to determine if transmission expansion is adequate 9

10. NATIONAL RENEWABLE ENERGY LABORATORY Transmission zones Run zonally initially. Nodal runs at a later date for deeper dives. Propose to use these 20 TEPPC zones. Aiming at more rather than less zones to better approximate actual current operations. Commit and dispatch within each zone with hurdle rates between zones to allow for interzone transfers. 10

11. NATIONAL RENEWABLE ENERGY LABORATORY Data Refinements 11

12. NATIONAL RENEWABLE ENERGY LABORATORY Wind “Actuals” Dataset 3TIER Western Wind Resources Dataset Increased variability at 3-day seams – was not found to be a problem with hourly MAPS simulations in WWSIS1. Every 3 rd day was removed from statistical analysis in WWSIS1. We will use this for hourly Plexos simulations for WWSIS2. Subhourly analysis will have to be evaluated to see if seams create problems. Capacity factors differ from measurements in some areas, eg CO – Impact will be on geographic diversity because more sites will be needed to get at the same energy penetration. This is not deemed to have significant impact. 12

13. NATIONAL RENEWABLE ENERGY LABORATORY Wind Forecast Dataset 13 Western wind dataset has a positive bias in the day-ahead forecasts Use measured wind forecast error distributions to correct bias

14. NATIONAL RENEWABLE ENERGY LABORATORY Solar “Actuals” Dataset Utility-scale PV Existing WECC PV dataset has 50 MW PV plants modeled for 10km grid cells Filter function under development to model utility-scale PV plants up to 500 MW. We will need to size and site these. Propose 50/50 split between metropolitan and remote areas. DG PV Use DG rooftop PV dataset from WWSIS1 Distribute generation identical to load in each load bubble CSP Rerun CSP profiles for 10 hours of storage Select best sites 14

15. NATIONAL RENEWABLE ENERGY LABORATORY Solar Forecasts Dataset Obtaining solar forecast error distributions Check existing solar forecast dataset against measured forecast error distributions Refine existing solar forecast dataset as necessary to match measured distributions 15

16. NATIONAL RENEWABLE ENERGY LABORATORY Heat rate penalties (heat input or CO 2 ) Unit typePart-load penalty Ramping penalty Startup penalty Coal5.1%0.4%110% Gas CC15.6%0.3%32% Gas CT12.4%0.3%32% 16

17. NATIONAL RENEWABLE ENERGY LABORATORY Other emissions (NO x,SO 2 ) Unit typePart-load penalty Ramping penalty Startup penalty Coal (NO x )1.2%2.8%290% Gas CC30%**0.7%950%** Gas CT19%0.8%670%** Coal (SO 2 )5.4%13.4%270% **These numbers are highly sensitive to input assumptions (percent loading) and/or a small number of extreme outliers (some are bad fits). 17

18. NATIONAL RENEWABLE ENERGY LABORATORY Retirement Scenarios Other analysis shows plant retirements to have significant impact on cycling/ramping costs Data options WECC TEPPC DWG retirements are based on CAISO 33% study GE analysis on plant retirements 18