CHP in the E3 GHG Model Proposed Changes for Stage 2

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CHP in the E3 GHG Model Proposed Changes for
Stage 2

• April 1, 2008

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Process Notes

• Presentation describes the E3 proposed approach
  for including CHP in Stage 2
• Hoping for consensus on reference case cost,
  performance, and penetration inputs
• Sensitivity analysis can be done by users and
  inputs can be changed to evaluate alternative
  cases
• All parties will have the opportunity to comment

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Agenda

• CHP in E3 Stage 1 Model
• Key CHP issues
• CHP regulatory status under AB32
• Data availability
• Thermal/electric split
• On-site/grid export split
• E3 Proposed Stage 2 model changes
• Existing CHP
• Adding new CHP
• Reference case cost performance assumptions
• EPUC/CAC proposed assumptions

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CHP in Stage 1 Model

• Stage 1 model contains the CHP units that are in
  the WECC databases
• Stage 1 model does not specify CHP generation as
  a separate category
• Stage 1 model does not have a way to add new CHP
  generation
• Parties requested E3 to add CHP as separate
  category
• E3 requested help from parties in identifying CHP
  units in the WECC databases

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CHP Regulatory Status under AB32

• CARBs GHG inventory treats CHP as a separate
  category from non-CHP generation
• However, CARB considers part of CHP emissions to
  be included in CAs electricity sector - i.e.
  all those that are not associated with useful
  thermal output
• Currently, CARB considers emissions associated
  with useful thermal output to be point source
  emissions, not electricity sector emissions, so
  separately regulated
• CARB reviewing approach to CHP regulation and
  reporting - status could change

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Data Availability

• Major data shortcomings for CA CHP
• No single source that has capacity, generation,
  and emissions for all CA CHP
• Different capacity size cutoffs for different
  databases
• Little reliable data for small (lt1 MW) CHP
• WECC databases dont identify CHP units
• Difficult to match EIA Form 920 list to WECC
  names
• Unclear if WECC CHP heat rates are net or gross
• E3 model makes assumptions about existing CHP
  based on best available data

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Thermal/Electric Split

• Emissions for thermal and electric regulated
  separately under current scheme
• CARB inventory split based on EIA Form 920
  (generation fuel use) and predecessor data
• EIA methodology changed ca. 2003, changing the
  split significantly
• CARB emissions electric 1990-2003 63
• CARB emissions electric 2004 78
• What is a reasonable thermal / electric split?

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On-Site/Grid Export Split

• EIA and CARB do not distinguish on-site (i.e.
  behind the meter) from grid export generation
• CEC estimates on-site non-PV generation in load
  forecast, data reliability and overlap with
  EIA/CARB data uncertain
• Plexos does not model on-site generation
• What is reasonable assumption for on-site/grid
  export split for existing CHP fleet?

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Proposed Changes in Stage 2 Model

• Add CHP as new generation option
• Account for CHP generation and emissions
  separately from non-CHP generation
• Provide user controls for cost, performance, and
  penetration assumptions for user cases
• Provide user controls for thermal/electric and
  on-site/on-grid splits for user cases
• Separate treatment of existing and new CHP

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Existing CHP in Stage 2 Model

• On-site CHP generation already embedded in load
  forecast so no adjustment is necessary
• On-grid CHP many CHP units are not identified in
  WECC database, so CHP fleet generation is
  underestimated in the Plexos model
• This is corrected by adjusting CHP fleet
  generation and emissions to hit expected values
  based on historical data
• Existing CHP generation and emissions in Plexos
  summarized, then adjusted in E3 calculator to
  expected value
• Non-CHP generation decremented by the same amount
  in E3 calculator

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CHP Data for 2003 2004
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CA CHP Capacity by Unit Size
Source EEA database, 2006 data
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Existing CHP Expected Values

• Units lt 5 MW (380 MW, 30 c.f.) generation
  estimated at 1000 GWh, assumed all on-site
• CEC self-gen 11,000 GWh, so 10,000 GWh from
  units gt 5 MW and 1,000 GWh from units lt 5 MW
• 10-year average EIA total CHP generation and CARB
  emissions show no trend, so can use for expected
  CHP
• generation 44,000 GWh
• emissions 30 MMT
• electric share of generation and emissions 63
• Use CHP net heat rate implied in EIA data to be
  consistent with CARBs present methodology
  however, calculator will track thermal fuel use
  efficiency proposed by CAC/EPUC

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Existing CHP Expected Values
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Formulation of Existing CHP Adjustment
Col A
Col B
Col C
Col D A-B
Col E BD A
Col F C-D
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New CHP in Stage 2 Model

• Two categories of new CHP
• gt 5 MW nameplate Large CHP (cogen)
• lt 5 MW nameplate Small CHP (self-gen)
• Division at 5 MW based on SGIP criteria
• Characteristics of large CHP represented by 40 MW
  gas turbine
• Characteristics of small CHP represented by 3 MW
  gas reciprocating engine

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E3 Proposed2020 BAU Reference Case Assumptions
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E3 Proposed2020 Aggressive Ref Case Assumptions
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E3 ProposedNew CHP Cost and Performance
Assumptions
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EPUC/CAC New CHP Data
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EPUC/CAC Existing CHP Data
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Thank YouAny Questions?