On July 24, as air conditioners labored across the Imperial and Coachella valleys, the Imperial Irrigation District’s electric system reached 1,126 megawatts of demand.
The lights stayed on. Power was procured, generators were dispatched, equipment was monitored, and field crews stood ready. In announcing the summer high, IID Chairwoman Karin Eugenio put the achievement plainly: “Keeping the power flowing on the hottest days of the year doesn’t happen by accident.”
IID Board Chair, Karin Eugenio.
But the most consequential part of the number is not that IID successfully managed it. It is how little distance remains between the demand the utility is seeing now and the demand it had been planning to face near the end of the decade.
The 1,126-megawatt load was the highest recorded so far this summer, but it was not an all-time record. IID’s system reached 1,177 megawatts in September 2024, 51 megawatts above the July peak. Demand had reached 1,152 megawatts in 2023, up 5.7 percent from 1,090 megawatts in 2022.
Still, July’s peak was only 49 megawatts below IID’s baseline forecast of 1,175 megawatts for 2030. The 2024 record had already exceeded that forecast by 2 megawatts. That does not mean demand will rise in a straight line or that IID has run out of power. Peak demand is highly sensitive to temperature, customer behavior and the timing of commercial and residential use.
It does mean the region is already operating in the range that makes IID’s next round of generation, storage, transmission and distribution investments more than a long-term planning exercise.
A Summer Shortfall Is Already in the Plan
The most detailed public view of the challenge comes from the California Energy Commission’s review of IID’s 2024 Integrated Resource Plan. The commission concluded that IID’s plan met state requirements, but it also documented several pressure points that go beyond the reassuring account of one well-managed summer afternoon.
IID’s Conserve Alerts encourage customers to reduce energy use during peak demand periods, helping support grid reliability, and reduce strain on the electric system.
IID’s system is already short of dependable capacity from June through September, according to the review. The projected shortage expands to April through October as 2035 approaches.
The distinction between demand and capacity is important. A utility cannot plan to have exactly enough power to match its highest expected hour. Generators can fail, transmission lines can go out of service, solar production can fall and purchased electricity can become scarce or expensive. IID therefore plans for resources equal to 115 percent of forecast peak demand, creating a 15 percent reserve margin.
Applied to the July peak, that standard would translate to nearly 1,295 megawatts of available capacity. For 2030, IID projects 1,253 megawatts of dependable capacity, leaving a 99-megawatt shortfall after the reserve requirement is included.
IID owns 571 megawatts of natural gas, battery, solar and hydroelectric resources and has another 240 megawatts under long-term contracts. Those nameplate totals cannot be compared directly with peak demand because different resources have different availability and dependable capacity when needed. The gap is filled through other purchases and arrangements.
That reliance carries risk. The commission’s review said IID currently depends on market purchases that can be exposed to price volatility and availability problems. By 2030, the district expects spot-market purchases to supply 22 percent of its energy.
IID’s plan calls for new wind, solar, battery storage and dispatchable reciprocating-engine generation beginning in 2027. Four-hour batteries would move solar energy into the evening, while longer-duration storage is contemplated beyond 2030. Even after planned additions, the reserve-margin calculation shows why procurement cannot be separated from growth policy.
Where the Grid Tightens After the Sun Falls
The most difficult hours are not necessarily when the sun is strongest. They arrive as solar production fades while air-conditioning and household demand remain high.
IID tells customers that its summer on-peak period runs from 4 to 9 p.m. During stressed conditions in the Coachella Valley, the utility has operated 10 to 40 megawatts of nearby natural-gas turbines for one to three hours to prevent overloads on portions of its 92-kilovolt transmission network, according to the state review. In another contingency, the planning document identified battery storage or, if necessary, customer load shedding as ways to protect the system.
That is why conservation programs are part of the capacity strategy rather than simply public-service messaging. IID’s 2026 Summer Savings initiative includes EnergyFlex, the Shift & Save time-of-use rate and other incentives aimed at moving demand away from the evening peak. The district says its longer-running efficiency and demand-response programs have produced more than 35 gigawatt-hours of verified net savings.
Customer conservation helps at the margin. It does not replace the grid expansion needed for housing, businesses, vehicle charging and other new loads.
The Eastern Coachella Valley’s Growth Is Now a Power-Infrastructure Question
IID’s own planning shows the scale of the local buildout. The state review said developer requests for residential, commercial, industrial, cannabis, resort and entertainment projects had produced 816 megavolt-amperes of forecast load in the Coachella Valley. Serving that demand could require 22 new substations and 14 capacitor-bank additions over 10 to 20 years.
The document also cited numerous requests for electric-vehicle charging stations in the 1- to 2-megawatt range, along with fleet electrification and microgrids that add complexity to substation and feeder planning.
A current example is the Avenue 58 Substation in La Quinta. In July, the Riverside County Board of Supervisors approved a funding and capacity-reservation agreement for a $23.2 million expansion. The project is expected to add roughly 40 megavolt-amperes of usable capacity for about 4,000 additional residential and commercial customers. Construction is anticipated to begin in early 2027, with the capacity available in 2028.
Ten private developers are expected to fund the project in proportion to their reserved capacity. Riverside County and La Quinta agreed to backstop potential funding gaps, while IID will retain part of the added capacity for reliability. The arrangement is a practical model for a region where development can be approved years before the electrical infrastructure required to serve it is financed and built.
The power implications become larger with data centers. IID says many new facilities seek 100 megawatts or more and operate around the clock. One 100-megawatt data center would equal almost 9 percent of the entire system demand IID served on July 24.
As GPS Business Insider reported in May, IID released a proposed tariff for customers requesting at least 20 megawatts at a capacity factor above 85 percent. The district said it had received nine large-load proposals or inquiries in varying stages of review. The proposed framework would require those customers to pay study costs, finance project-specific infrastructure, make long-term commitments and provide financial security so existing ratepayers are not left with stranded assets.
That policy is not peripheral to reliability. If even one large proposal advances, IID may need a materially different load forecast, resource portfolio and construction schedule.
Modernization Is Part of the Capacity Strategy
IID is also spending to make the existing grid more visible and responsive. After the U.S. Department of Energy withdrew an $18.3 million matching grant, the district committed $18.3 million of its own money over four years to preserve the core elements of an Advanced Distribution Management System. The original project was valued at $36.7 million.
The system is intended to improve automation, outage response and the integration of batteries, distributed solar and other smart-grid resources. IID is separately preparing to join the Western Energy Imbalance Market and Extended Day-Ahead Market in 2028, a move designed to make power trading faster and less costly while giving the utility more flexibility to balance supply and demand.
None of those investments makes the July peak a crisis. IID met the load, and the 2026 high remained below the 2024 record. But the planning record makes clear that success during one peak hour is not proof that the next decade of demand is already covered.
The questions now are measurable: How much dependable capacity has IID secured for each summer through 2030? When will planned batteries and generation enter service? Which of the 22 Coachella Valley substations are funded and scheduled? How much demand is coming from approved development, vehicle charging and large industrial proposals? And when will IID update its forecast to account for the nine large-load inquiries it has already received?
IID’s crews and operators answered the immediate test on July 24. The harder test is whether the region can add homes, businesses and new industries without allowing electricity infrastructure to become either a bottleneck to growth or a cost shifted onto the customers already connected to the grid.
Bob Marra is the CEO/Publisher of GPS Business Insider and GPS Market Intel. He has been studying, writing and giving presentations about business, economic and public affairs news and issues and the local economy in the Greater Palm Springs/Coachella Valley region for more than 20 years.
