Most tower operators can tell you their generator’s rated capacity. Far fewer can tell you how many hours of generator runtime it logged last year, or what that cost in fuel and truck rolls. Evoltix built the ZPM to close exactly that gap: the space between rated capacity and actual cost of ownership, where a meaningful share of avoidable telecom tower OpEx hides.
That pattern holds up in the deployments Evoltix has documented, including a rural Alaskan WISP that cut generator runtime by 91% after switching to the ZPM (full field result below). The Evoltix Zero-Glitch Power Module (ZPM), a power intelligence system built around a battery-first architecture, exists to shrink runtime and the fuel and maintenance costs that come with it.
Why Generator Runtime Is the Hidden Line Item in Tower OpEx
Industry estimates for how much energy costs represent of telecom operating expenses vary by source, site type, and region, from single digits at some large carriers to as much as 40% at remote or off-grid sites, with several independent analyst reports converging on a 15 to 40% range as 5G densification pushes per-site power draw higher. Source: TEOCO utility expense management research, 2026.
State air quality permitting data from tower operators document actual annual generator use ranging from 52 to 2,000 hours per year depending on grid stability and regional weather patterns. Source: West Virginia Department of Environmental Protection, Division of Air Quality, Permit Determination Form, Ntelos Wireless Sissonville Tower site (ID 039-00631), January 2016.
At typical diesel consumption rates of 0.07 to 0.1 gallons per kWh, a 30 to 50 kW generator running the mid-range of that operational spectrum (500 hours annually) incurs fuel costs alone of roughly $2,500 to $5,000 per year, before adding maintenance. When preventive maintenance is factored in — service intervals every 250 to 500 hours, plus annual inspections — total annual fuel and maintenance costs typically range from $3,000 to $8,000 per site per year depending on load profile and regional fuel pricing. Source: Generator manufacturer fuel consumption benchmarks; maintenance cost data from industry service providers.
None of this shows up as a single line item on a budget. It is scattered across a fuel vendor invoice, a maintenance contract, and a dispatch log, which is exactly why it tends to go unmanaged.
Battery-First Design Changes When the Generator Runs, Not Just How Often
A diesel-forward or propane-forward site treats the generator as the default power source and the battery as a bridge. A battery-first design built around the ZPM reverses that relationship: the battery bank carries the site load first, and the generator is brought online only once the battery can no longer cover it, not as a matter of routine.
On Vault Power Shelter deployments, that handoff is documented and automatic. The shelter’s control system draws from the battery bank first and starts the generator only when battery state of charge drops to a set low threshold, running it until the battery recovers to a set high threshold before shutting the generator back off.
A standalone ZPM on an on-grid site is built around the same battery-first priority, using its own onboard controls rather than the shelter’s. IntelliCore, the software layer that runs on every ZPM, coordinates grid, generator, solar, and auxiliary inputs through the System Control Module’s relay and dry-contact interfaces, giving operators generator control alongside every other power source. IntelliCore then optimizes the priority between grid, battery, and generator inputs as a microgrid controller, so the generator is called online only once the grid and the battery both fall short, not on a fixed schedule.
Cutting generator runtime isn’t about buying a bigger generator. It’s about needing the one you have less often.
The Math Behind the Runtime Reduction
Evoltix’s CapEx and OpEx comparison analysis modeled a Vault Power Shelter deployment (lithium-ion batteries, ZPM, solar arrays, and a propane generator) against a traditional diesel-forward shelter and generator setup at a comparable site. The battery-first configuration reduced generator runtime by more than 90%, with proportional reductions in fuel consumption and maintenance costs adding up to over $650,000 saved over 10 years. The diesel-forward configuration in that model ran at roughly 10 times the combined fuel and servicing cost of the battery-first system.
That is a single-site model built from a New Mexico site analysis, and actual results vary by location, renewable configuration, and fuel market conditions, as the report itself notes. But the direction is consistent with what Evoltix sees across deployments: once a battery bank is doing the daily work and the generator is called in only to recharge it rather than to run continuously, both fuel burn and service intervals drop sharply, and they tend to drop together.
Real-World Result: 91% Less Generator Runtime at a Remote Tower Site
A rural Alaskan WISP operating remote tower sites in some of the most demanding conditions in North America cut generator runtime by 91% after deploying the ZPM. That is not a lab figure. It is a field result from a site where cold weather, limited road access, and generator fuel logistics all work against the operator, which is exactly the environment where runtime reduction pays for itself fastest.
Is Your Site a Candidate?
- Tower sites with mixed AC and DC equipment loads running a generator on any regular schedule, not just for emergencies
- Remote or off-grid sites where a Vault Power Shelter houses the ZPM alongside the generator and any renewable input
- Any site where generator servicing requires a dedicated truck roll, since fewer running hours also means fewer service visits
- Networks tracking fuel deliveries, maintenance tickets, and generator hours as separate budget lines rather than one combined OpEx number
If your team wants a site-specific estimate of fuel and maintenance savings, Evoltix’s Total Cost of Ownership Studio can model it against your actual load and site conditions. Request a session at https://evoltixenergy.com/contact/.
Prefer to see the fuller comparison first? See how the ZPM stacks up against a UPS and a traditional DC power plant: ZPM vs. UPS vs. DC Power System.