By its progressive digital energy plant (VPP), Arizona Public Service (APS) harnessed good house gadgets to save lots of 190 MW throughout a historic heatwave, shifting peak demand and proving essential capability for grid reliability. The utility’s coordinated demand response packages are setting new requirements for power administration and buyer engagement.
Final summer time, Arizona recorded its hottest July within the state’s historical past. As temperatures surged over three brutal weeks, Arizona Public Service (APS), a utility that serves about 1.4 million properties and companies in 11 of Arizona’s 15 counties, marked a surprising surge in power use. “We sat on a complete lot of [temperature] file highs—most days over 110F and 115F,” mirrored Kerri Carnes, director of Buyer Expertise and Applications at APS.
Prospects had beforehand set a file of seven,660 MW on July 30, 2020, however in the course of the July 2023 heatwave, the all-time peak soared to eight,162 MW on July 15, 2023, she mentioned. Prospects “used extra power than the 2020 peak file over a streak of 9 days straight,” and through an intense interval, consumption exceeded the earlier peak file on 18 completely different days.
On the time of the 2023 peak demand, the utility’s reserve margin was 18%. Whereas APS had an satisfactory provide powered by its numerous mixture of power sources, together with renewables, nuclear, and versatile pure gasoline, the intense warmth occasion allowed APS to check the performance of the utility’s digital energy plant (VPP) for reliability wants. Primarily a assortment of APS’s demand response (DR) packages, the VPP represents a digital community of good house merchandise—resembling good thermostats, industrial and industrial DR, behavioral DR and batteries.
Throughout the excessive warmth occasion, empowered by buyer conservation, these “grid-edge” gadgets supplied an astonishing financial savings of a mixed 190 MW, Carnes mentioned. The impact proved so monumental that the VPP “truly modified the height day final 12 months,” she famous. “We exercised the complete VPP on July 26—and had we not, July 26 would have been our peak day. So, I simply suppose that basically exhibits the reliability that these sources can present.”
Launching the Digital Energy Plant
APS first started considering that DR would play a extra essential function in the way forward for its energy system in 2016. Whereas the utility was cognizant that developments would proceed to permeate the ability business and extra utilities had been adopting DR as a conservation instrument, APS on the time grappled with a lower in averted prices. As the corporate’s 2017 Built-in Useful resource Plan (IRP) suggests, low pure gasoline and wholesale energy costs challenged the cost-effectiveness of demand-side administration (DSM) packages, “significantly those who incent financial savings throughout noon hours when photo voltaic era is at its highest and wholesale energy costs are amongst their lowest.”
“We had been speaking very regularly with [the Arizona Corporation Commission] about our must have an enhanced give attention to peak load administration,” Carnes mentioned. The corporate ultimately set its give attention to creating DSM packages that may as an alternative give attention to power financial savings in the course of the late afternoon and early night high-demand durations. Because the IRP notes, the trouble sought to rigorously goal financial savings to load profiles that greatest match useful resource wants and built-in power effectivity with load-shifting and demand-response alternatives.
Through the years, the imaginative and prescient has advanced right into a complete suite of packages. Launched in 2018, APS’s “Cool Rewards,” a residential thermostat program, has grown to be the most important element of the corporate’s VPP, encompassing greater than 90,000 thermostats. This system manages power consumption in direct response to the electrical load demand fluctuations inside the energy grid by working with thermostat producers to barely enhance thermostat setpoints, thus decreasing a house’s cooling load. These minor temperature changes by APS prospects actually add up, leading to decreasing the general load on the system in the course of the hottest days. However it additionally boasts the aptitude to shed greater than 138 MW of power, including to its reliability and power avoidance advantages.
In parallel, the Peak Options Business and Industrial DR program takes versatile capability advantages by tailoring packages designed completely for industrial prospects for megawatts of DR every summer time season. Yet one more key program is the APS Residential Battery Pilot program, via which the utility companions with residential prospects who’ve choices to take part in a data-share assemble. On this assemble, they dispatch their battery in step with their time-of-use on-peak hours for day by day load shifting and share that information with APS, or APS can dispatch taking part batteries for DR. Lastly, the VPP additionally contains Vitality Saving Days. This voluntary behavioral DR program is designed on gamified buyer engagement to supply improved power and demand financial savings.
The VPP has grown steadily since its launch, pushed by progressive approaches by APS’s Buyer to Grid Options workforce, Carnes mentioned. “After I moved into this function in 2019, we had been at perhaps 20 MW value. Final summer time, we had been capable of obtain 190 MW throughout all of our packages,” she famous. “I actually do attribute that to fascinated by the shopper expertise,” she added.
Within the fall of 2020, for instance, the workforce launched “APS Market,” an internet platform the place prospects should buy “qualifying” good house expertise gadgets. “It was an actual game-changer” in driving main enrollment development. The platform immediately eliminated obstacles for purchasers, permitting them to simply entry and enroll in demand response packages, she mentioned. “It’s a seamless, frictionless expertise for our prospects. You don’t should mail us your receipt anymore. You don’t have to attend for the incentives or rebates to be utilized. All of it will get utilized on the level of sale, making these applied sciences extra inexpensive and extra attainable for our prospects.”
APS’s give attention to bettering buyer engagement and expertise has been a central side of constructing its VPP, Carnes added. APS is constantly evolving its advertising methods to recruit extra individuals and make potential individuals conscious of program advantages—together with that the shopper finally retains management over their gadgets. “We leverage varied advertising ways and we’re always gauging the effectiveness of these ways and sort of revamping and evolving these over time,” she mentioned.
A Distinctive Dispatch Method
However on the identical time, APS has additionally been working to maximise the effectiveness of its VPP. The VPP operates effectively underneath a single useful resource working platform developed by Vitality Hub. A single level of reference limits human efficiency errors, represents affordability for purchasers, and simplifies dispatch throughout occasions of excessive demand, Carnes mentioned.
Nonetheless, “We’ve all the time tried to mess around with completely different dispatch methods to check what occurs with efficiency, what the degradation appears to be like like,” she famous. Final summer time, for the primary time, the utility demonstrated a “staggered dispatch,” which Carnes mentioned could also be more and more essential because the utility continues to develop the VPP. “We prefer to say we’re taking part in Tetris with the gadgets—it helps us stretch their contribution out over the on-peak interval as a result of our retail on-peak truly ends earlier than the system peak ends,” she defined. “So being able to stretch that out helps clean the snapback that naturally happens on the finish of the on-peak interval.”
Occupied with easy methods to most effectively dispatch the belongings flexibly will enable APS to develop the portfolio past thermostats, for instance, to incorporate a whole-home distributed power system or an actively managed electrical car charging program, Carnes famous. Making an attempt these methods out in additional measurable methods earlier than these applied sciences start to make an actual influence on the grid is a part of the utility’s service to its prospects, she recommended. “It’s to guarantee that we’re creating deep and trustful relationships with our prospects.”
When APS developed its Cool Rewards program, for instance, “it was essential for us to guarantee that prospects perceive that we view this as an extremely essential a part of sustaining reliability and affordability for our prospects each summer time. However on the finish of the day, they preserve management,” mentioned Carnes. Nonetheless, not all APS packages have been profitable. “We tried a water heater program, however we couldn’t maintain them wi-fi related, so we shut it down, although we haven’t given up on that,” she mentioned.
By incorporating buyer suggestions into the event course of, APS ensures the packages meet buyer wants and expectations, she defined. “My workforce works very onerous to guarantee that we’re incorporating the voice of our prospects at each a part of the event course of. We actually are. We don’t subscribe to designing a program that is smart to a bunch of utility people after which pushing it out and hoping for the perfect. We test in with prospects.”
Getting ready for Tomorrow’s Masses
Trying forward, Carnes expects the VPP will play a fair bigger function as load development surges upwards, pushed by electrification and information facilities. Carnes and her workforce are actually taking pictures to exponentially increase the VPP capability from the present 190 MW over the following ten years.
“Over the following 10 years, we’re going to be difficult all of my groups and albeit our enterprise companions throughout the enterprise to assist us actually anchor the infrastructure and applied sciences that we’d like,” Carnes defined. The advantages of the VPP lengthen past reliability, translating into price financial savings for all prospects. “Consider the startups that we saved on typical era, the gas that we save. All of that interprets into financial savings that get handed to all of our prospects, whether or not they’re a participant in this system or not, and that may be a good factor. That’s reliability and affordability in motion,” she emphasised. “Having flexibility via customer-sited packages and partnerships, we expect, is simply going to be such an essential a part of the general answer.”
—Sonal Patel is a POWER senior editor (@sonalcpatel, @POWERmagazine).
