20240827Comments.pdf

RECEIVED
Tuesday, August 27, 2024
Clean Energy Opportunities for Idaho IDAHO PUBLIC
UTILITIES COMMISSION
August 28, 2024
Reference: Case No. IPC-E-24-16—Application for a CPCN for the Boise Bench Battery
Storage Facility.
Subject: Comments of Clean Energy Opportunities for Idaho
CEO supports the use of batteries and does not oppose the Commission certifying the
convenience and need for installation of a 15OMW BESS at the Boise Bench substation. BESS
offer a supply-side resource for time-shifting loads. With a concern for future affordability of
utility-supplied electricity, CEO asks that the Company be encouraged to further explore
opportunities for demand-side load shifting.
Aligning price signals with system benefits takes time to yield results. For example, consider
when price signals offer meaningful opportunity for a customer to save money by adding load
during low-cost times and/or by lowering loads during high-cost times. For a large business,
those economics might affect investment decisions or operational choices, yet investment
cycles and implementation take time.
In order to address long-term affordability, the near-term pursuit of demand-side management
opportunities is merited.
The value of load shifting is Cost (cents/kWh) in 2023 show utility-scale
high. Batteries are expensive, yet Solar is almost as cheap as Hydro, serving
the Company's application incremental peak load is very expensive
presents that the proposed BESS =0 48'91
capacity is needed for reliability
purposes.2 _ E 40
Jt
N
To scope the value of load
shifting, consider CEO's analysis =.e
that the Generation & 8
a
Transmission costs per kWh e76
dispatched by BESS in 2023 was o 3.33 3.49 ■
$.49/ kWh3.
Hydro Utility-xakSdar ~-veighted BESs
av era Re mst
Figure 1— Bulk Power System resource costs/ kWh
1 CEO notes that the Company is already making strides forward in pursuing residential Time of Use rates,and has
been open to evaluation of load shifting opportunities in the Integrated Resource Planning process.
Z Ellsworth direct testimony, page 27-"the procurement is necessary for reliability purposes".
3 Based on actual 2023 data, Figure 1 includes costs that would be functionalized as Generation or Transmission,
plus a financing charge at the approved 7.247%return is added to any Company owned Generation &Transmission
assets. Figure 1 does not include any costs functionalized as Distribution or Customer.
Clean Energy Opportunities for Idaho—IPC-E-24-16 Comments

Clean Energy Opportunities for Idaho
Given the high cost of supply-side load shifting, CEO believes that there are cost-effective
opportunities for incenting demand-side load shifting.
Good Load Hours V. High risk/High cost hours
As the proportion of solar on the grid grows,the cost to serve load grows more sensitive to
the time at which the load occurs.
Historically, IPC customers have benefitted from the low-cost generation and dispatch flexibility
that the Company's Hydro resources provide. Today, utility scale solar can provide energy at
similarly low costs to serve the Company's rapid load growth, yet with much more dispatch
constraints than Hydro. The ample supply of cheap solar energy during certain time windows
creates "Good Load" hours—times at which additional load is low-cost to serve and has
potential to improve utilization of existing infrastructure.
A recent day on the CAISO market provides an illustrative example of the gigawatts generated
by various resources:
Fuel Mix-CAISO Aug 14,2024 usiNdClk 4 P y
40GW Note the dispatch of batteries here,suggesting a time
window when cost to serve is high
30 G W
This yellow area reflects an ample
supply of cheap solar during
morning&early to mid-day hours
20 G W
10 GW -
OGW
Au q 14 6 AM 12 PM 6 PM Aug 15
Nuclear @Geothermal @Biomass @Biogas ■Large Hydro §SmallHydro @Coal @NaturalGas @Wind @Batteries @imports 4 112
Figure 2— Market conditions August 14, 2024—generation by resource type
In sum, there is opportunity to improve affordability not only by shifting load out of high cost
hours but also by shifting load into Good Load Hours. The following analyses further
characterize these time windows for Idaho Power.
4 Source: https://www.gridstatus.io/graph/fuel-mix?iso=caiso&date=2024-08-14
Clean Energy Opportunities for Idaho—IPC-E-24-16 Comments 2

V Clean Energy Opportunities for Idaho
High cost/high risk The battery systems are being discharged during evening
hours are hours on hot July and August days.
evidenced by the
dispatch of
batteries.
For Idaho Power in
2023, BESS were
discharged primarily
on summer evenings
between 6pm-10pm
(see Figure 3 at right).
_ 1 3 9 I __ _- 13 :S 15 16 17 17 19 2C, 21 22 -_ _-
Figure 3—average BESS usage in July and August 20235
The Hemmingway and Black BESS primarily discharged onluVAugownings
Mesa BESS units were not in Jul Aug Sep Oct Nov Dec
service during the first half of 4pm 0 5 0 0 0 0
2023. Figure 4 shows their usage
(i.e. when the systems were 5pm 0 15 0 0 0 1
discharged and thus useful for 6pm 1 33 0 0 0 6
serving load) during 2H23. 7pm 43 44 0 0 0 8
Although the battery systems 8pm 54 40 0 3 1 7
were discharged in at least 9pm 53 28 0 2 1 5
negligible amounts each month,
they were always used in the late 10pm 49 a 1 2 0 4
afternoon or early evening and 11pm 12 0 1 0 0
at significant scale only during Midnight 0 0 0 0 0
July and August evenings.
Figure 4—BESS useful hours in 2023
High risk/High cost hours are concentrated on July evenings
There is a very good reason why BESS discharges focused primarily on early evening hours in
July and August—that's where the loss of load risk is highest.
s Units displayed in Figures 3&4 are average MWs discharged from the two BESS during that month and hour
Clean Energy Opportunities for Idaho—IPC-E-24-16 Comments 3

1P Clean Energy Opportunities for Idaho
The reliability risk Jan Feb Mar Apr May Jun Jul Aug Sep Oct Now Dec
review system the lam o 0 0 0 0 36 375 63 2 0 4 13
Company tam 6 o 0 0 0 14 125 12 1 0 5 13
currently employs Sam 6 0 0 0 0 11 41 9 1 0 5 13
samples hourly 4am 0 0 0 0 0 12 39 10 1 0 5 13
5am 1 0 0 0 0 13 69 11 1 0 6 13
loss of load Gam 1 0 0 0 0 17 109 15 1 0 7 15
probabilities on a lam 1 o 0 0 0 23 120 20 1 0 7 13
daily basis (highest Sam 1 0 0 0 0 25 169 27 1 0 7 15
risk hour each 9am 1 0 0 0 0 12 112 19 1 0 7 15
loam 1 0 0 0 0 4 35 6 0 0 5 14
day) and uses that llam 1 0 0 0 0 4 28 3 0 0 6 13
data to calculate Noon 1 o 0 0 0 s 15 2 0 0 5 12
an annual LOLE 1pm 0 0 0 0 0 5 35 3 0 0 5 10
measure of load 2pm o 0 0 0 0 11 122 10 0 0 5 a
loss exposure. 3pm o 0 0 a 0 20 297 29 1 0 5 a
4pm 0 o 0 0 0 32 52 1 0 5 9
5 p m 1 o 0 0 0 52 65 2 0 5 13
An alternative 6pm 1 o 0 0 0 52 67 3 0 7 15
analysis method 7pm 1 0 0 0 0 53 67 3 0 7 15
looks at loss of 8pm 1 0 0 0 0 49 67 3 0 7 15
load at an hourly 9pm 1 0 0 0 0 52 67 3 0 7 1 15
lopm 1 0 0 0 0 54 67 3 0 6 13
rather than daily llpm 0 0 0 0 0 54 67 3 0 5 a
basis as shown in MIO'I g'I1 0 0 0 0 0 53 62 2 0 3 3
Figure 5. Figure S- The average Loss of Load Probability by Hour& Month for 20266
Adding battery systems is one way of increasing service reliability on those high-risk July
evenings. Moving load from high-risk hours to good load hours can also provide reliability
benefits with the added value of lowering system cost to serve.
If we review the same data
shown in Figure 5 but group Loss of Load risk is low between 9am and 2pm all
them to show an annual
e0 yearlong
pattern, we see a pattern of so
loss of load risk. 4A
30
20
Figure 6 shows that over the i°
course of a year, load loss risk ° F F F
is lowest midday. _
Hour ending
Figure 6—the some 2026 LOLP data but sorted by hour
s LOLP data displayed in Figures 5 and 6 are based on IPC RCAT runs from September 19,2023 estimating 7011
percentile peak loads in 2026. Resources available to serve load in those runs include 607MWs of BESS and
3201VIWs of DR. In Figure 5 the sum of the risk of load loss across all hours colored green is<1%of total
annual load loss risk. Red hours represent>50%of total annual risk of load loss. 2026 estimated loss of
load risk is highly concentrated in July afternoon and evening.
Clean Energy Opportunities for Idaho—IPC-E-24-16 Comments 4

Clean Energy Opportunities for Idaho
GOOD load hours occur mid-day most all months of the year and are
much more abundant than the high risk hours.
The data displayed in Figures 5 and 6 show that the high-risk hours occur in a relatively tight
band: a few hours per day and mostly in one month of the year. The Good load hours are 10x
more abundant and occur throughout the year.
It is not a coincidence Good load hours: Idaho Solar provides excellent generation between
that the LOLP analysis 10am & 3pm from February through November, with smaller but still
shows the lowest
annual loss of load significant amounts in December and January
hours occur during Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
the midday. lam 0 0 0 0 0 0 0 1 0 0 0 0 0
tam 0 0 0 0 0 0 0 0 0 0 0 0
Sam 0 0 0 0 0 0 0 0 0 0 0 0
Midday loads are 4am 0 0 0 0 0 0 0 0 0 0 0 0
generally lower than Sam 0 0 0 0 0 0 0 0 0 0 0 0
6am 0 0 0 0 0 0 0 0 0 0 0 0
the twin morning and lam 0 0 0 0 8 20 11 1 0 0 0 0
evening winter peak Sam 0 2 5 34 103 140 133 56 13 0 1 0
pattern and the late gam 12 61 53 169 249 275 303 237 155 49 55 14
p loam 89 201 149 265 316 326 361 336 307 222 165 91
afternoon and 11 am 146 252 211 297 346 358 385 365 344 30Q 200 144
evening summer peak Noon 157 260 239 321 363 393 398 377 356 311 217 147
Sp m 166 254 254 322 365 385 400 377 354 296 216 144
periods. 2pm 164 2% 263 321 3s8 381 399 372 353 289 220 139
3p m 156 252 257 325 350 378 399 365 350 293 224 141
Those midday hours 4 p m 134 237 241 314 325 361 393 350 345 292 192 118
5p m 65 177 204 299 295 343 3W 3" 333 2W 71 31
are also when solar 6pm 5 49 150 271 277 307 379 326 313 195 8 0
power is most 7pm 0 1 74 217 219 266 352 266 186 38 0 0
8p m o 0 11 AU 124 179 246 119 27 0 0 0
abundant and 9pm 0 0 0 3 22 55 66 12 0 0 0 0
reliable. lopm 0 0 0 0 0 1 1 0 0 0 0 0
ilpm 0 0 0 0 0 0 0 0 0 0 1 0 0
Midnet
Figure 7—Solar is abundant at mid-day all year long'
All source procurements can't change rate design
IPC has indicated that they intend to file at least two more CPCN requests involving solar and
BESS systems. But the "all source" procurements upon which CPCN decisions are made do not
avail themselves of an alternative method for reliably serving that growing load.
'Figure 7 displays average solar MWs supplied in each day and hour of 2023
Clean Energy Opportunities for Idaho—IPC-E-24-16 Comments 5

! Clean Energy Opportunities for Idaho
In sum, the growing supply of low-cost solar is creating time windows which are low cost to
serve, while the high costs of batteries are needed for serving loads occurring during a narrow
range of high-risk hours. Correspondingly, incremental load growth during those low-cost hours
has the potential to lower average costs per kWh, while load growth during those high-risk
times raises average costs per kWh. CEO suggests that it now makes sense to think not only
about acquiring supply to align with load but about incenting load to meet supply.
CEO believes a combination of utility-scale solar and battery systems can play key roles in
maintaining reliable and affordable service in the face of rapid load growth. Given the
magnitude of anticipated growth and the high value of load shifting, further exploration of
demand management via load shifting is merited.
Clean Energy Opportunities for Idaho—IPC-E-24-16 Comments 6