Battery Energy Storage
Implications for Load Shapes and Forecasting
April 28, 2017
TOPICS
»
What is Energy Storage
»
Storage Market, Costs, Regulatory Background
»
Behind the Meter (BTM) Battery Storage
• Where is it used?
• How is it used?
• Real world examples (California research)
»
How to analyze storage?
• Simulations vs. Data
»
Where is the market going?
2
WHAT IS ENERGY STORAGE?
» The capture of energy produced at one time for use at
a later time.
Pumped Hydro
Compressed Air
Batteries
3
BATTERY ENERGY STORAGE
Dominating technologies
» Dominated by Lithium Ion Batteries followed by flow
batteries
4
BATTERY ENERGY STORAGE
Size categories
» Transmission connected
» Distribution Connected
» Behind the Meter
Source: Rocky Mountain Institute
5
WHY STORAGE NOW?
Falling Costs
• Tesla Gigafactory
Rising Demand Charges
• Now make up 50% or more of commercial
bills
More Intermittent Renewables
• Balance variability
• Offer the ability to line up peaks
Reliability
• Power Outages
• Hurricane Sandy
6
BATTERY ENERGY STORAGE
Grid Scale
Source: Greentech Media
» Catastrophic leak Oct. 2015 at Aliso Canyon natural gas storage
facility threatened to cause power outages across Southern CA
» 70 MW of energy storage deployed in 6 months
7
BATTERY ENERGY STORAGE
Behind the Meter – C&I
8
BATTERY ENERGY STORAGE
Behind the Meter – Residential
9
U.S. ANNUAL DEPLOYMENT FORECAST
Advanced Energy Storage, 2012-2021 (MW)
Source: Greentech Media
10
CAPITAL COSTS
Lithium Ion BTM
Source: Itron DG Cost Effectiveness Model
» Tesla data point remains unproven -claims to be ~½ price of prior
versions…
11
BTM STORAGE REGULATORY DECISIONS
Regulatory Background
» California Self-Generation Incentive Program modified to
included standalone storage in 2011
• Most recently program funding doubled to $166 million per
year (85% storage allocation)
» California Public Utilities Commission (CPUC) mandated 1,325
Megawatts of storage by 2024
» Hawaii and Australia reformed tariffs to encourage selfconsumption
» New York, Massachusetts, and New Jersey provide incentives for
energy storage
12
CALIFORNIA BTM RESEARCH
Self-Generation Incentive Program
HOW IS BTM STORAGE BEING USED IN CA?
What we know so far
» Backup Power
» PV Self-Consumption
» Demand Charge
Reduction
» TOU Bill Management
» Aggregated Demand
Response
14
WHERE IS BTM STORAGE BEING DEPLOYED?
What we know so far
Note: SGIP is ~18% of estimated U.S. annual deployment at 2016
15
WHERE IS BTM STORAGE BEING DEPLOYED?
What we know so far
Non-Res
16
SGIP DATA ANALYSIS
During 2015
» Collected interval performance data from storage systems,
merged with AMI data
• Aggregated results: 2015
• Individual case studies: 2016
» Focused on customer energy and peak demand
• Coincident and non-coincident demand
» Residential and Non-Residential
• PBI = Large C&I
17
NON-RESIDENTIAL (C&I) STORAGE
PROJECTS
ENERGY IMPACT
Distribution of 15-Minute kWh Charge/Discharge
15-Min Charge / Discharge kWh
• Most (+80%) of the time systems are idle
• Charge/Discharge patterns are fairly “symmetrical”, so annual energy impact is
negligible
19
METRICS: ROUND-TRIP EFFICIENCY
Non-residential AES projects, 2014 - 2015
RTE =
total kWh of discharge from the storage project
total kWh of charge
Program
Requirement:
63.5% annual RTE
20
CASE STUDY 1 – CITY GOV. BUILDING
2016 Data, “Narrow” Peak
Calculated Load
AMI Load
Storage Discharge (+) /
Charge (-)
21
CASE STUDY 2 – CITY GOV. BUILDING
2016 Data, “Wide” Peak
Calculated Load
AMI Load
Storage Discharge (+) /
Charge (-)
22
CASE STUDY 3 – CITY GOV. BUILDING
2016 Data, DR Example
Calculated Load
AMI Load
Storage Discharge (+) /
Charge (-)
23
CASE STUDY 4 – CITY GOV. BUILDING
2016 Data, Another DR Example
Calculated Load
AMI Load
Storage Discharge (+) /
Charge (-)
24
CASE STUDY 5 – GROCERY STORE / EV CHG.
2016 Data, Idle
Calculated Load
AMI Load
Storage Discharge (+) /
Charge (-)
25
SMALL C&I PROJECTS (NON-PBI)
Charging not coordinated
Total kWh of Discharge (Charge) per kW Rebated Capacity, Non-PBI Projects 2015
0
1
2
3
4
5
6
7
8
9
H 10
o 11
u 12
r 13
14
15
16
17
18
19
20
21
22
23
1
-0.12
-0.18
-0.06
-0.13
-0.19
-0.27
-0.30
-0.19
-0.32
-0.23
-0.19
-0.26
-0.21
-0.33
-0.20
-0.22
-0.16
-0.10
-0.17
-0.18
-0.15
-0.15
-0.15
-0.15
2
-0.10
-0.09
-0.12
-0.13
-0.23
-0.15
-0.04
-0.06
-0.18
-0.28
-0.23
-0.17
-0.01
-0.32
-0.08
-0.31
-0.20
-0.02
-0.12
-0.23
-0.11
-0.10
-0.09
-0.11
3
-0.11
-0.14
-0.10
-0.10
-0.05
-0.07
-0.09
-0.12
-0.21
-0.18
-0.29
-0.35
-0.14
-0.29
-0.15
-0.29
-0.22
-0.11
-0.16
-0.19
-0.12
-0.12
-0.12
-0.10
4
-0.07
-0.10
-0.09
-0.12
-0.15
-0.13
-0.05
-0.13
-0.23
-0.22
-0.32
-0.32
-0.07
-0.29
-0.06
-0.27
-0.24
-0.11
-0.17
-0.24
-0.16
-0.14
-0.12
-0.11
5
-0.12
-0.08
-0.11
-0.16
-0.16
-0.10
-0.12
-0.15
-0.25
-0.19
-0.23
-0.37
-0.12
-0.21
-0.11
-0.25
-0.25
-0.16
-0.18
-0.18
-0.14
-0.14
-0.12
-0.14
Month
6
-0.14
-0.08
-0.05
-0.03
0.00
-0.13
-0.08
-0.11
-0.28
-0.31
-0.31
-0.32
-0.24
-0.35
-0.13
-0.29
-0.24
-0.14
-0.18
-0.20
-0.14
-0.14
-0.12
-0.13
7
-0.12
-0.06
-0.04
-0.06
-0.04
-0.16
-0.09
-0.10
-0.25
-0.27
-0.23
-0.31
-0.20
-0.26
-0.12
-0.28
-0.19
-0.11
-0.19
-0.17
-0.15
-0.12
-0.12
-0.13
8
-0.18
-0.12
-0.13
-0.10
-0.05
-0.20
-0.14
-0.15
-0.23
-0.24
-0.31
-0.36
-0.16
-0.15
-0.34
-0.33
-0.28
-0.20
-0.20
-0.16
-0.12
-0.20
-0.23
-0.16
9
-0.10
-0.07
-0.06
-0.05
-0.05
-0.08
-0.07
-0.09
-0.14
-0.12
-0.17
-0.21
-0.07
-0.11
-0.29
-0.25
-0.23
-0.14
-0.15
-0.13
-0.12
-0.12
-0.11
-0.10
10
-0.09
-0.07
-0.10
-0.07
-0.06
-0.09
-0.04
-0.05
-0.11
-0.11
-0.15
-0.22
-0.02
-0.06
-0.30
-0.28
-0.26
-0.18
-0.18
-0.16
-0.13
-0.12
-0.11
-0.08
11
-0.08
-0.12
-0.13
-0.09
-0.09
-0.12
-0.10
-0.12
-0.11
-0.14
-0.06
-0.04
-0.03
-0.15
-0.13
-0.25
-0.22
-0.17
-0.16
-0.15
-0.11
-0.11
-0.10
-0.05
12
-0.08
-0.15
-0.18
-0.14
-0.13
-0.16
-0.09
-0.13
-0.17
-0.12
-0.04
0.00
-0.05
-0.13
-0.14
-0.25
-0.28
-0.20
-0.15
-0.13
-0.11
-0.11
-0.09
-0.03
26
LARGE C&I PROJECTS (PBI)
Large C&I (PBI) Projects Charge Overnight, Discharge in Evening
Total kWh of Discharge (Charge) per kW Rebated Capacity, PBI Projects 2015
H
o
u
r
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
1
-0.05
-0.04
-0.04
-0.04
-0.04
-0.03
-0.02
-0.01
-0.01
0.01
0.00
-0.01
-0.01
0.02
-0.01
-0.02
0.04
0.02
0.00
0.01
-0.01
-0.01
-0.05
-0.05
2
-0.29
-0.27
-0.26
-0.22
-0.14
-0.08
-0.03
0.00
0.05
0.07
0.07
0.08
0.07
0.07
0.09
0.10
0.16
0.21
0.18
0.14
0.03
-0.12
-0.31
-0.29
3
-0.39
-0.31
-0.28
-0.22
-0.19
-0.18
-0.13
-0.04
-0.01
-0.01
-0.01
0.06
0.11
0.10
0.12
0.14
0.16
0.24
0.24
0.17
0.08
-0.11
-0.20
-0.30
4
-0.54
-0.40
-0.33
-0.30
-0.23
-0.16
-0.11
0.01
0.12
0.03
0.03
0.09
0.09
0.09
0.20
0.27
0.23
0.21
0.21
0.12
0.03
-0.16
-0.17
-0.38
5
-0.94
-0.56
-0.19
-0.07
-0.05
-0.03
-0.02
-0.02
-0.01
0.00
0.02
0.13
0.12
0.14
0.36
0.62
0.60
0.20
0.18
0.19
0.13
-0.57
-0.45
-0.94
6
-1.35
-0.91
-0.39
-0.15
-0.09
-0.05
-0.03
0.00
0.03
0.03
0.06
0.22
0.37
0.44
0.52
0.65
0.46
0.12
0.17
0.26
0.23
-0.65
-0.31
-1.01
7
-1.43
-0.73
-0.18
-0.11
-0.06
-0.04
-0.02
-0.01
0.00
-0.05
-0.01
0.03
0.08
0.11
0.25
0.68
0.63
0.14
0.26
0.48
0.38
-0.72
-0.08
-0.98
8
-1.65
-1.15
-0.66
-0.43
-0.26
-0.18
-0.12
-0.01
0.07
-0.01
0.07
0.21
0.29
0.26
0.39
0.82
1.12
0.54
0.53
0.68
0.56
-1.13
-0.40
-1.62
9
-1.63
-1.14
-0.56
-0.31
-0.16
-0.11
-0.07
-0.03
0.03
-0.02
0.04
0.18
0.20
0.24
0.31
0.48
0.39
0.17
0.88
1.06
0.75
-0.97
-0.49
-1.31
10
-1.49
-1.23
-0.77
-0.57
-0.37
-0.37
-0.27
-0.17
-0.02
0.08
-0.02
0.16
0.23
0.20
-0.17
-0.17
-0.10
0.11
1.23
1.51
1.42
-0.64
-0.10
-1.06
11
-1.18
-1.55
-1.27
-0.79
-0.59
-0.45
-0.39
-0.28
-0.12
0.02
0.06
0.24
0.28
0.28
-0.08
-0.06
0.01
0.02
0.44
1.58
1.68
0.99
-0.71
-0.11
12
-1.07
-1.18
-1.07
-0.76
-0.56
-0.47
-0.39
-0.31
-0.16
-0.01
0.00
0.15
0.27
0.16
-0.22
0.07
-0.09
-0.03
0.28
1.34
1.50
1.26
-0.59
-0.20
• Charging overnight, when energy is cheap, discharging in evening, when demand
is highest and energy most expensive
27
LARGE C&I (PBI) PEAK DEMAND REDUCTION
Average Non-Coincident Peak Load Reduction by Month, per Customer (PG&E)
• Significant increase in non-coincident peak load reduction during summer
months, compared to the rest of the year
• PBI projects saved an average of ~$0.8 per kW rebated storage capacity in
demand charges
28
2015 COINCIDENT PEAK IMPACTS
Only Large C&I (PBI) Project Contributed to Coincident Peak Demand Reduction
29
NON-RESIDENTIAL AES CO2 IMPACTS
Alignment of grid emissions with charge/discharge
0.8
0.6
0.4
0.2
0
60
40
20
0
-20
-40
-60
0.6
0.4
0.2
0
1 3 5 7 9 11 13 15 17 19 21 23
1 3 5 7 9 11 13 15 17 19 21 23
Hour of Day
Hour of Day
Marginal Emissions
Net Discharge
Marginal Emissions
Marginal Emissions Compared to Aggregate Discharge (Charge), No-residential, Non-PBI Projects, 2015
Winter
Net Discharge (MWh)
Summer
» With low efficiency,
net charging in all
hours
0.8
Tons CO2 per MWh
60
40
20
0
-20
-40
-60
Net Discharge
Small
C&I
Winter
Summer
0
0
0.7
0.5 -0.5
0.5
-1
0.3
0.1 -1.5
0.1
0.7
-0.5
-1
0.3
-1.5
-2
-0.1
-2
-0.1
1 3 5 7 9 11 13 15 17 19 21 23
1 3 5 7 9 11 13 15 17 19 21 23
Hour of Day
Hour of Day
Net Discharge
Marginal Emissions
Net Discharge
Tons CO2 per MWh
» Generally
discharging during
higher marginal
emission hours
Marginal Emissions Compared to Aggregate Discharge (Charge), PBI Projects, 2015
Net Discharge (MWh)
Large
C&I
Marginal Emissions
30
NON-RESIDENTIAL CO2 IMPACTS
Population of estimates
Large
C&I
» Net increase in GHG
emissions for both large
and small C&I systems
» Round trip efficiency losses
outweigh GHG savings for
large C&I systems despite
on-peak discharge
» More variable discharge for
small C&I  larger
increase in GHG emissions
» Note: these impacts do not
include the contribution of
storage to integrating
renewables
Small
C&I
31
RESIDENTIAL STORAGE PROJECTS
RESIDENTIAL PROJECTS
Appear to be charging from solar and responding to rates
Total kWh of Discharge (Charge) per kW
Rebated Capacity, Residential Projects, 2015
H
o
u
r
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
1
-0.28
-0.28
-0.28
-0.28
-0.29
-0.28
-0.28
-0.28
-0.31
-1.50
-2.90
-1.60
-1.05
-0.72
-0.82
-0.42
-0.63
-0.47
-0.22
-0.22
-0.24
-0.27
-0.28
-0.28
2
-0.25
-0.25
-0.27
-0.25
-0.25
-0.25
-0.25
-0.26
-0.62
-2.17
-2.85
-0.46
-0.33
-0.67
-0.45
-0.44
-0.55
-0.52
-0.30
-0.21
-0.23
-0.25
-0.25
-0.25
3
-0.28
-0.28
-0.28
-0.28
-0.28
-0.28
-0.28
-0.44
-1.47
-3.65
-1.71
-0.31
-0.29
-0.36
-0.56
-0.72
-0.33
-0.56
-0.48
-0.27
-0.27
-0.27
-0.27
-0.27
4
-0.25
-0.25
-0.25
-0.25
-0.25
-0.25
-0.32
-0.78
-2.25
-3.30
-0.64
-0.45
-0.44
-0.24
-0.74
-0.50
-0.36
-0.55
-0.43
-0.31
-0.25
-0.25
-0.25
-0.25
5
-0.26
-0.26
-0.26
-0.26
-0.26
-0.27
-0.50
-1.10
-2.59
-2.73
-0.47
-0.31
-0.35
-0.37
-0.83
-0.40
-0.50
-0.62
-0.50
-0.39
-0.26
-0.26
-0.26
-0.26
Month
6
-0.26
-0.26
-0.26
-0.26
-0.26
-0.27
-0.54
-0.94
-2.20
-3.06
-2.05
-2.14
-2.05
-1.65
-0.88
-0.61
1.39
2.01
2.79
-0.47
-0.23
-0.23
-0.24
-0.25
7
-0.28
-0.29
-0.29
-0.29
-0.29
-0.29
-0.48
-0.97
-2.19
-3.77
-2.95
-3.58
-4.01
-3.81
-1.63
-1.18
4.19
4.44
4.54
-0.53
-0.25
-0.25
-0.27
-0.28
8
-0.29
-0.29
-0.29
-0.30
-0.30
-0.30
-0.37
-0.79
-2.05
-3.91
-2.88
-3.29
-3.53
-3.32
-1.12
-0.56
3.46
3.81
3.56
-0.42
-0.25
-0.27
-0.28
-0.29
9
-0.29
-0.29
-0.29
-0.29
-0.29
-0.29
-0.30
-0.61
-2.00
-3.87
-3.16
-3.42
-3.76
-3.24
-1.22
-0.68
4.28
3.78
3.25
-0.19
-0.24
-0.27
-0.27
-0.28
10
-0.29
-0.29
-0.29
-0.29
-0.29
-0.29
-0.29
-0.44
-1.84
-4.08
-3.47
-2.92
-2.30
-1.10
-0.17
0.17
1.41
1.53
1.62
0.55
-0.29
-0.29
-0.29
-0.29
11
-0.24
-0.24
-0.25
-0.25
-0.26
-0.26
-0.26
-0.30
-1.12
-3.42
-5.18
-6.04
-5.95
-3.23
-0.56
1.08
1.80
2.93
3.30
2.89
2.27
-0.23
-0.24
-0.24
12
-0.26
-0.26
-0.26
-0.27
-0.27
-0.27
-0.28
-0.28
-0.50
-1.89
-3.07
-2.36
-2.04
-1.31
-0.89
-0.55
-0.07
0.25
0.26
0.24
0.24
-0.23
-0.24
-0.25
Total kWh of Solar Output,
Residential Projects, 2015
H
o
u
r
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
1
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.43
70.69
751.56
1681.15
1211.06
1054.19
977.38
1031.63
664.60
526.38
247.94
13.75
0.00
0.00
0.00
0.00
0.00
2
0.00
0.00
0.00
0.00
0.00
0.00
0.00
3.61
240.20
1175.95
1725.66
585.37
545.29
704.08
629.47
582.05
519.67
341.06
111.18
0.19
0.00
0.00
0.00
0.00
3
0.00
0.00
0.00
0.00
0.00
0.00
0.72
89.60
738.17
2077.80
1089.06
431.15
499.39
544.40
716.49
780.99
478.07
416.54
238.62
18.75
0.00
0.00
0.00
0.00
4
0.00
0.00
0.00
0.00
0.00
0.04
33.84
302.35
1209.20
1920.67
502.17
494.85
554.83
563.56
832.44
706.62
511.51
451.67
266.92
98.44
0.11
0.00
0.00
0.00
5
0.00
0.00
0.00
0.00
0.00
1.37
132.22
492.07
1426.98
1643.83
435.73
436.46
508.31
604.52
918.46
680.45
633.21
548.50
336.40
180.85
7.08
0.00
0.00
0.00
Month
6
7
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
5.22
1.24
160.17
117.25
402.76
412.66
1221.52 1205.92
1847.94 2238.92
1317.05 1854.55
1423.47 2274.63
1406.07 2567.07
1257.41 2527.71
895.37 1362.99
740.71 1084.70
795.12
448.78
458.04
405.89
310.78
331.93
246.09
279.27
35.61
30.37
0.00
0.00
0.00
0.00
0.00
0.00
8
0.00
0.00
0.00
0.00
0.00
0.04
45.73
305.38
1113.81
2284.08
1778.56
2061.77
2226.06
2148.21
981.09
643.98
433.37
341.22
285.48
177.88
2.88
0.00
0.00
0.00
9
0.00
0.00
0.00
0.00
0.00
0.00
6.02
198.64
1065.01
2249.48
1934.10
2124.16
2360.23
2112.89
1061.76
748.22
374.86
354.30
217.36
23.03
0.00
0.00
0.00
0.00
10
0.00
0.00
0.00
0.00
0.00
0.00
0.56
89.79
960.35
2366.15
2156.00
1936.95
1648.94
1082.45
774.02
786.27
594.82
356.38
60.59
0.02
0.00
0.00
0.00
0.00
11
0.00
0.00
0.00
0.00
0.00
0.00
0.01
13.29
516.22
1940.27
3044.13
3624.31
3687.04
2411.80
1316.87
736.53
412.73
150.26
0.91
0.00
0.00
0.00
0.00
0.00
12
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1.20
120.95
1003.33
1750.61
1389.51
1304.05
976.69
789.36
613.50
351.38
97.80
0.25
0.00
0.00
0.00
0.00
0.00
Box shows hours that correspond
with utility’s higher TOU rate
• All residential projects in our sample are paired with solar
33
WHAT’S NEXT?
Rates, etc.
» Storage prices will continue to drop, seeing a shift towards longer
duration storage (4hr vs 2hr)
» If utilities continue phasing out NEM tariffs, solar + storage value
proposition will increase
• Hawaii, Australia, Arizona, Nevada, California…
• In CA, SGIP will now prioritize projects paired with PV
» Increased demand charges -> increased storage
» Increased ability for utilities to control load
34
HOW TO THINK ABOUT STORAGE?
» Annual, monthly, and daily energy impacts are negligible (small
net increase)
» Impacts on the customer load shape are somewhat unpredictable
in both magnitude and timing
• Not all peaks are “shaved”
» We don’t expect to see any mitigation of the “duck curve” until
NEM or feed in tariffs are phased out
• Will lead to solar self consumption
35
HOW TO MODEL STORAGE?
» Dispatch models (AMI data + PV data + tariff + storage info)
• Typically assume perfect optimization based on load,
customer generation, and rates
• Not representative of current storage technologies
• Not representative of current
» Sub-metering
• Can be costly, not always actionable
36
KEY TAKEAWAYS FOR LOAD FORECASTING
» Energy impacts at all levels (customer/feeder/system) are
negligible
» Storage behavior can largely (albeit imperfectly) be predicted
based on tariffs
• Commercial customers with high demand charges will
primarily act to mitigate peak demand
• Residential customers on TOU rates will primarily act to shift
load across periods
• Customers on “NEM 3.0” tariffs will primarily act to maximize
PV self consumption
37
THANK YOU
www.itron.com
BACKUP
METRICS: STORAGE UTILIZATION
Non-Residential 2014 and 2015
Storage discharge “capacity factor” defined as:
𝒌𝑾𝒉 𝑫𝒊𝒔𝒄𝒉𝒂𝒓𝒈𝒆
𝑯𝒐𝒖𝒓𝒔 𝒐𝒇 𝑫𝒂𝒕𝒂 ×𝑫𝒊𝒔𝒄𝒉𝒂𝒓𝒈𝒆 𝑪𝒂𝒑𝒂𝒄𝒊𝒕𝒚×𝟔𝟎%∗
*60% represents the
SGIP Handbook
assumption of 5,200
discharge hours per yr
(5,200 / 8,760 = 60%)
70%
Discharge Capacity Factor
60%
50%
40%
30%
20%
10%
0%
1
3
5
7
9
11
13
15
17
19
21
23
Months of Data Available
PBI
Non-PBI
• 18 of 21 (86%) PBI projects had capacity factors of at least 10% (required to
receive full PBI payment)
40