SGIP - Demand Analysis Working Group (DAWG)
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Transcript SGIP - Demand Analysis Working Group (DAWG)
Assessing Impacts in California’s Self-Generation
Incentive Program (SGIP)
Presentation to Demand Assessment Working Group
George Simons, Director
Itron
August 16, 2013
Itron, Inc. Overview
Leading technology provider to
global utility industry
110 million communication
modules
8,000+ customers in 130
countries
8,000 employees
$2.4 billion (2011 USD)
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Itron: Consulting and Analysis Group
Who we are:
Part of Itron’s Professional Services Group
Staff of ~80 C&A Professionals
Economists, Engineers, Statisticians, Load and Market Researchers
Offices in Oakland, CA; San Diego, CA; Davis CA, Vancouver, WA; and Madison,
WI
What we do:
Energy Efficiency
Demand Response
Renewables and Distributed Generation
Load Research
Market Research
Integration of Resources (IDSM and Smart Grid)
© 2009, Itron Inc.
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Renewables and Distributed Generation
Strongly focused on generation located on the distribution side of
the electricity system
Includes solar (PV and thermal), wind, biomass and conventional and
renewable-fueled generation and combined heat and power (CHP)
Services include:
Market assessments for DG/renewables/CHP
Program and project performance evaluations
Cost-effectiveness and economic analyses
Advanced DG technology cost and performance assessments
Sub-metering for evaluation and performance monitoring
Assistance related to integrating DG technologies into the grid
© 2009, Itron Inc.
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Itron’s Role in the SGIP
Itron has been the SGIP prime evaluator since 2001
Services:
Impacts evaluation
Process evaluation
Performance metering
Cost-effectiveness analysis
Topical reports and products
Examples of products
© 2009, Itron Inc.
11 annual impact evaluations
22 semi-annual renewable fuel reports
DG cost-effectiveness framework (2005)
SGIP cost-effectiveness evaluation (2007)
DG Cost-effectiveness study and model (SGIPce) 2011
Optimizing Dispatch and Location of Distributed Generation (2010)
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SGIP Impacts Evaluations
Evaluations cover:
Status of program
Critical trends
Energy impacts
Annual
Coincident peak demand
Transmission and distribution impacts
Compliance with efficiency requirements
Useful thermal (waste heat recovery)
Overall system efficiency
Reliability and performance
Greenhouse gas impacts
Foreward look at SGIP
© 2009, Itron Inc.
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Overall Approach on Assessing Impacts
SGIP population of technologies is varied
Legacy systems (IC engines, microturbines, gas turbines, fuel cells, wind)
New systems (fuel cells, wind, storage)
Based on statistical sampling
Targeting 90% confidence with 10% precision
Some legacy systems we can only achieve 70/30
Determine sample based on strata
Metered data needed:
Fuel consumed by SGIP generator
Net electricity produced by SGIP generator (interval data)
Useful thermal energy recovered (for CHP systems)
Metered data sources:
Host sites, project developers, utilities
Third party providers
Performance data providers (PDPs) emerging in SGIP
Itron installed metering (on behalf of PAs)
Net electricity (over 190)
Useful thermal energy (over 120)
© 2009, Itron Inc.
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Data Collection for Impacts Evaluation
Not a one time process
Data collected on an on-going basis throughout
the preceding year
Data collection and processing
Converting multiple sources of data in different
formats to common formats
Time/date stamp alignment
Data validation
When does zero mean zero
generation vs no communication?
QA/QC
Verifying that values “look” correct
Site Inspection Reports
Monitoring Plans
Weather Data
SiteLevel
QA/QC
Electrical, Thermal, Fuel
Raw Interval Data
© 2009, Itron Inc.
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SGIP: A Closer Look at Operational Status
SGIP represents legacy projects installed over the past eleven years and newer projects
Important to distinguish “on-line” versus decommissioned projects
Decommissioned defined as equipment has been out of service and removed from the site
On-line projects may be temporarily down at times
Not always able to accurately identify decommissioned projects
Loss of contacts and reporting from older projects leads to “unknown” designations
On-line
© 2009, Itron Inc.
Technology
No. of
Projects
Rebated
Capacity
(MW)
IC Engines
176
115.4
Fuel Cells
109
Gas Turbines
Microturbines
Decommissioned
Percent
Total
Rebated
Capacity
Unknown
Percent
Total
Rebated
Capacity
No. of
Projects
Rebated
Capacity
(MW)
Percent
Total
Rebated
Capacity
No. of
Projects
Rebated
Capacity
(MW)
62%
33
14.9
76%
46
25.9
57%
28.6
15%
6
1.3
6%
16
8.4
19%
7
24.5
13%
0
0
0
1
1.2
3%
92
18.3
10%
21
17%
27
3.1
7%
Wind
0
0
0
0
0
0
10
6.8
15%
Total
384
186.8
100%
60
19.6
100%
100
45.3
100%
3.4
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SGIP: Capacity and Utilization
Capacity reflects program participation
Enables measurement of trends by technology, fuel, etc.
Utilization reflects use of capacity
Critical in assessing impacts
Also provides valuable information on aging trends
© 2009, Itron Inc.
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Examples of Trending with Utilization and Capacity
Utilization trending can help identify how project age
affects capacity factor
Figure at left shows clear increase in off-line capacity with age and
associated decline of average annual capacity factor
Capacity trending can show impacts due to capacity changes
Graph at right demonstrates how lower growth in IC engine capacity
affected annual energy delivery from IC engines over time
© 2009, Itron Inc.
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Treatment of Calendar vs Year in Operation (Age)
Calendar year provides information that allows year to year comparisons
and trending
Figure on left shows annual capacity factor trends by year
Year in operation (year) provides information on how performance of
technologies vary with time in the field
Figure on right shows changes in capacity factor as the technology ages
© 2009, Itron Inc.
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SGIP: Annual Energy Impacts
Annual energy impacts
estimated at different
levels and timeframes:
Program-wide and at
Program
Administrator level
Broken out by
technology and fuel
type
By quarter and annual
Trended over time
Can be by technology
or portfolios
© 2009, Itron Inc.
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SGIP: Peak Demand
We look at peak impacts at
various levels
CAISO system demand
Summer peak
Impacts at top 210 hours
Utility system peak demand
Peak at distribution feeders
Peak at customer site
Intent is to determine
influence of SGIP technologies
on resource adequacy
Are SGIP DG technologies
available when needed?
Assess using hourly capacity
factors during peak
© 2009, Itron Inc.
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SGIP: Transmission and Distribution System Impacts
With increasing amounts of
DG capacity projected for
the future, peak impacts
occurring below the CAISO
and utility peak demand
become more important
Began examining DG
generation impacts on
distribution feeder peaks
Significantly different
investigation
Findings:
DG can help unload
distribution feeder peaks
Unloading impact tied to
DG capacity and may
become more pronounced
with increasing amounts of
DG
DG impacts tied to feeder
characteristics (e.g.,
customer mix, length, etc)
© 2009, Itron Inc.
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SGIP: Optimizing DG Dispatch
Feeder studies showed
DG can help unload
distribution system
Occurred haphazardly;
without design by
project or utility
Shown by example in
top figure
Same demand curve
Can DG resources be
operated to meet both
needs of site and utility?
Led to study on
optimizing dispatch and
location of DG resources
under the SGIP
Bottom figure shows
how load following
generator can help
address feeder
demand
© 2009, Itron Inc.
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SGIP: Optimizing DG Dispatch (cont’d)
Affects of blending
multiple DG resources?
Looked at same
representative feeder
with intermittent PV
and multiple load
following DG
Same demand curve
Multiple DG not only
addresses feeder
demand but firms
intermittent PV
Created representative
“look-up” tables
Full set of results in
topical report:
“Optimizing Dispatch
and Location of
Distributed Generation”
© 2009, Itron Inc.
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SGIP: Combined Heat & Power Efficiencies
CHP makes up an increasing amount of SGIP capacity
Important to determine efficiencies
Useful thermal energy efficiency
Overall system efficiency
𝐸𝐶𝐸 =
© 2009, Itron Inc.
𝐸𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑎𝑙 𝑂𝑢𝑡𝑝𝑢𝑡
𝐹𝑢𝑒𝑙 𝐼𝑛𝑝𝑢𝑡 (𝐿𝐻𝑉)
𝑈𝑠𝑒𝑓𝑢𝑙 𝐻𝑒𝑎𝑡 𝐶𝑜𝑛𝑣𝑒𝑟𝑠𝑖𝑜𝑛 𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦 =
𝑈𝑠𝑒𝑓𝑢𝑙 𝐻𝑒𝑎𝑡 𝑅𝑒𝑐𝑜𝑣𝑒𝑟𝑒𝑑
𝐹𝑢𝑒𝑙 𝐼𝑛𝑝𝑢𝑡 (𝐿𝐻𝑉)
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SGIP: Useful Thermal Energy
Investigated applications
for thermal energy
The majority of projects
recovered waste heat to
offset boilers
However, a significant
amount of CHP capacity
used recovered energy
for combined heating
and cooling
Electric only DG
technologies have
emerged in recent years
Useful waste heat
recovery rates vary by
building type also
© 2009, Itron Inc.
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SGIP: Overall System Efficiencies
Non-renewable CHP
systems must achieve a
high overall system
efficiency to achieve GHG
benefits
Represents sum of
electrical and thermal
energy efficiency
Several observations:
Gas turbines achieved the
highest system
efficiencies, followed by
IC engines
All electric fuel cells
achieve modest system
efficiencies
Realizable useful thermal
efficiencies dependent on
thermal loads at host sites
and coincidence to
electrical loads
© 2009, Itron Inc.
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SGIP: Trending of Electrical and Thermal Energy
We examined delivery of energy by electricity and thermal from inception of
the SGIP going forward
Interestingly, fuel cells have increasing capacity and associated electricity delivery
but provide little thermal energy delivery
We’re seeing growth in fuel cell capacity. Most of emerging fuel cell capacity tied
to all electric fuel cells. Implications to GHG aspects?
© 2009, Itron Inc.
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SGIP: Greenhouse Gas Emissions
A primary goal of
SGIP is to achieve
net GHG emissions
reductions
(relative to
baseline use)
Reductions tied
to:
Electrical
load
Heating load
Cooling load
Also affected
by use of
renewable
fuels
Estimates based
on 8760 hour
per year
treatment
© 2009, Itron Inc.
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SGIP: GHG Emissions from Non-Renewable CHP
Electricity:
Baseline: CA mix of resources
and GHG from E3 calculator
SGIP: generated electricity on
8760 basis
Heating:
Baseline: boiler fuel used onsite
SGIP: useful waste heat is
assumed to offset boiler fuel
Cooling:
Baseline: on-site cooling from
electric chillers
SGIP: useful waste heat
directed to absorption chillers
Observations:
Fuel cells and gas turbines
showed net GHG emission
reductions for non-renewable
CHP
What is happening and why?
© 2009, Itron Inc.
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SGIP: CHP Electrical Efficiency & GHG Emissions
SGIP net GHG emissions driven
by several factors:
CA electricity mix
Historically driven by mostly
natural gas fueled central
station systems
– Most of the year, the grid
supplies electricity from
efficient (45% plus)
combined cycle systems
– During peak (< 500 hrs per
year) is generated from
older, less efficient (3035%) combustion turbines
SGIP CHP resources
With exception of fuel cells,
SGIP CHP have low electrical
efficiency
– Can’t “beat” combined
cycle for most of the year
on an efficiency basis
– Results in grid having lower
GHG emissions than SGIP
generator
© 2009, Itron Inc.
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SGIP: Thermal Efficiency & GHG Emissions
Except for all electric fuel
cells, non-renewable CHP
can’t rely on electrical
conversion efficiency to
obtain net GHG reductions
Instead, must rely on
useful heat recovery to
obtain net GHG reductions
Examined SGIP CHP
historical useful heat
efficiencies
Compared to theoretical
useful heat recovered
needed to obtain net GHG
reductions
In general, non-renewable
CHP must consistently
have higher than observed
useful waste heat
recovery to achieve net
GHG emission reductions
© 2009, Itron Inc.
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SGIP: Looking to the Future (CHP)
2030 technical potential
Source: ICF
© 2009, Itron Inc.
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SGIP: Getting to There from Here (CHP)
These are the greatest areas of
CHP potential in the industrial
sector at 2030
•
•
© 2009, Itron Inc.
Chemicals and food industries represent
over 1,300 MW in CHP sizes up to 5 MW
Over 700 MW of potential in the 5 – 20
MW range
Smaller scale CHP has good potential
across the commercial sector
•
•
Commercial buildings, hotels, hospitals and govt
buildings represent over 3,000 MW of potential
capacity in CHP sizes up to 5 MW
Universities have over 500 MW of technical
capacity at sizes larger than 5 MW
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Capacity Growth is Only One Goal
Meet the CARB
Scoping Plan GHG
target for CHP
• 6.7 MTons of GHG
reductions by 2020
• Be cost effective
GHG method
Develop DG/CHP that
is responsive to utility
and customer needs
• Provides ramping
as needed
• Cost effective peak
relief measure
• Helps firm the
electrical grid
© 2009, Itron Inc.
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Increasing and Competing Demands in the Next
Decade
Decisions being made now are fashioning the future grid
Interconnection of
intermittent
renewables
Significant Reductions
in GHG Emissions
Growth of DG and
CHP
© 2009, Itron Inc.
50% of RPS
interconnected by
2013; 65% by 2016;
and 75% thereafter
6.7 million metric tons
from CHP alone by
2020
12,000 MW of DG and
6,500 MW of CHP by
2020
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Currently, Conflicting Results from SGIP Projects
GHG Emissions
Peak Demand
How to realize
these benefits
from mixing and
blending projects
Mixed GHG reductions
Consistent GHG reductions
How CHP systems respond to thermal or
electrical demand can affect GHG
emission outcomes
© 2009, Itron Inc.
Many Peak Demand Targets
High Volatility When Unplanned
DG and CHP projects currently target customer
demand; not utility demand. Left unplanned,
future DG & CHP projects may exacerbate
peak demand and congestion issues
Begin by
examining site
electrical and
thermal
demands
among high
potential end
uses
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Investigating High Opportunity Approaches
We have 8760 hourly
electrical and thermal
demand profiles for each of
these commercial end uses
based on SitePro
We can use these profiles
to determine:
•
Smaller scale CHP has good potential
across the commercial sector
•
•
© 2009, Itron Inc.
Commercial buildings, hotels, hospitals and govt
buildings represent over 3,000 MW of potential
capacity in CHP sizes up to 5 MW
Universities have over 500 MW of technical
capacity at sizes larger than 5 MW
•
•
Sizing to meet thermal demand
and reduce GHG emissions
Sizing to meet on-site electrical
demand that does not lead to
thermal dumping
Identification of possible
electricity export to the grid
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Electrical Demand: Inland Hospital Summer Weekdays
Targeting this
electrical load
with a self
generator
could help
offset the
hospital’s peak
demand over
typical summer
weekdays
14 hrs duration
~ 350 kW
“Peak” electrical demand for 13 hours
(7 am to 8 pm) ranging from approximately 250 kW to 350 kW
© 2009, Itron Inc.
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Thermal Demand: Inland Hospital Summer Weekdays
This is the
hospital’s thermal
load that could
be offset using
waste heat
recovery from a
CHP system.
Note that only
thermal uses are
offset (i.e.,
cannot offset
cooking from
natural gas with
CHP)
15 hrs duration
~ 1 MM Btu/hr
A minimum of 1 million Btu/hr of thermal demand for 15 hours
(5 am to 8 pm)
© 2009, Itron Inc.
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Example of Optimizing GHG Reductions
GHG reductions
can be achieved at
realistic heat
recovery rates
From earlier work, we know that
heat recovery rates between 2 to 6
kBtu/kWh are needed to achieve
GHG reductions for non-renewable
CHP systems.
15 hrs duration
If an ICE CHP system is used to meet the 1
MMBtu/hr thermal demand at the hospital, a
heat recovery rate of at least 4 kBtu/kWh is
needed to achieve GHG reductions.
• Generator = (1,000 kBtu/h)/4 kBtu/kWh
• Generator = 250 kW
© 2009, Itron Inc.
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Matching Electrical to Thermal Demand: Inland
Hospital Summer Weekdays
hrsfuel
duration
10014kW
cell for
remaining electrical needs
25015
kW
system for
hrsCHP
duration
thermal and some
electrical needs
To optimize GHG reductions, we set the CHP system to recover 4 to 5 MBtu per kWh of generated electricity. Per our
example, to ensure consistent recovery of 1 MM Btu/h of thermal energy using 4 MBtu per kWh, this could mean using
an ICE CHP generator capacity of 250 kW.
Note that this also provides the customer site with 250 kW of “peak” electricity that does not have to be procured
and delivered by the utility. However, a 250 kW CHP system does not fully meet the electrical needs of the site.
An all electric fuel cell with a rating of up to 100 kW could provide the remaining electrical need and not increase
GHG emissions (i.e., no thermal dumping of waste heat that could not be used by the site).
© 2009, Itron Inc.
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Electrical Demand: Inland Hotel Summer Weekdays
Hotels are
another
example of a
high potential
end use
~ 250 kW
16 hrs duration
Targeting this
electrical load
with a self
generator
could help
offset the
hotel’s peak
demand over
typical summer
weekdays
“Peak” electrical demand for 16 hours
(6 am to 10 pm) ranging from 125 kW to 250 kW
© 2009, Itron Inc.
36
Thermal Demand: Inland Hotel Summer Weekday
This is the
hotel’s thermal
load that could
be offset using
waste heat
recovery from
a CHP system.
Note that only
thermal uses
are offset
15 hrs duration
~ 600,000 Btu/hr
A minimum of ~ 600,000 Btu/hr of thermal demand for 15 hours
(5 am to 8 pm)
© 2009, Itron Inc.
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Matching Electrical to Thermal Demand: Inland Hotel
Summer Weekdays
100
fuel cell
16
hrs kW
duration
for remaining
electrical needs
hrs duration
15015kW
CHP system for
thermal and some
electrical needs
To optimize GHG reductions, we set the CHP system to recover 4 to 5 MBtu per kWh of generated electricity. To
ensure consistent recovery of 600,000 Btu/h of thermal energy using 4 MBtu per kWh, this could mean using an
ICE CHP generator capacity of 150 kW.
Note that this also provides the customer site with 150 kW of “peak” electricity that does not have to be provided
by the utility. However, a 150 kW CHP system does not fully meet the 250 kW electrical needs of the site. An all
electric fuel cell with a rating of up to 100 kW could provide the remaining electrical need and not increase GHG
emissions (i.e., no thermal dumping of waste heat that could not be used by the site)
© 2009, Itron Inc.
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What About Differences Between Summer and Winter Demands?
14 hrs duration
17 hrs duration
Winter electrical demand is 50% of summer demand but
more consistent and of longer duration
15 hrs duration
15 hrs duration
Winter thermal demand (magnitude and duration) is about
the same as the summer demand but more consistent
This suggests that the CHP unit be sized to meet the
thermal demand and meet lower electrical demand to be
operated year round. Use of an all electric fuel cell would be
limited to meeting increased hospital demand during the
summer and could provide export during winter.
© 2009, Itron Inc.
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Summary of Matching Electrical and Thermal
Demands to Coordinate Benefits
Achieving Simultaneous GHG and Responsiveness Benefits
Requires:
Establish GHG Baseline
- Thermal and electrical
Size Electrical
Identify:
demand profiles (8760 profiles
ideally)
- Balancing of thermal and
electrical loads
- May require multiple
generation systems to achieve
GHG reductions and peak
relief
- Minimum thermal demand
across largest duration
- Extent to which thermal
demand varies (ramping)
- CHP heat recovery rate
needed to achieve GHG
reductions (based on
technology)
Developed on:
- Electrical generation tied to
thermal load
- Any additional generation
needed to meet customer
electrical demands
- Identification of amount and
timing of any generation that
has potential for export to grid
However, this doesn’t address responsiveness for utility needs; must
also balance electrical generation with distribution and transmission
needs. Possible interplay of DG within microgrid settings.
© 2009, Itron Inc.
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