NAZ Solar Electric supplies solar equipment, battery storage, and system design for refrigerated spaces: walk-in coolers and freezers, cold rooms, and small refrigerated storage and processing. We have been a solar equipment distributor in Flagstaff, Arizona since 1979, and we ship nationwide.

To be clear about what we do: we supply the power system behind refrigeration, not the refrigeration itself. If you have a cooler, a freezer, or a cold room and you need it to keep running when the power doesn't, that's the project we can help with. Call 800-383-0195 or talk to an engineer.

Why Refrigeration Is a Different Backup Problem

Backup power in most commercial buildings protects against inconvenience: lights, registers, a card reader. Refrigeration protects inventory. A cooler that loses power at closing time on a Friday can cost more in spoiled product over a weekend than the backup system would have cost to install.

Two things make refrigeration harder to back up than most commercial loads:

• It never really stops. A compressor cycles around the clock, in every season, whether the building is occupied or not. There is no overnight lull to coast through.
• It starts hard. A refrigeration compressor draws far more current on startup than it does running. An inverter sized to the running load will fail to restart the compressor, the same failure mode that appears on agricultural pump systems.

The upside is that refrigeration is predictable. Unlike a load that spikes with occupancy or production, a cooler's consumption can be characterized well enough to size a system against it with confidence.

Decide What the Backup Actually Protects

This decision determines the cost of the whole project.

Backing up an entire building through an outage requires a large battery bank and a large inverter. Backing up only the compressors, the controls, and the monitoring, and letting the lights, the dock door, and the office go dark, requires a fraction of both. The product stays cold either way.

A critical-load panel separates the two, so the backup system only carries what has to stay on. For a refrigerated space that usually means:

A well-insulated walk-in also holds temperature for a meaningful stretch on its own, which means the backup system often doesn't need to run the compressor continuously, only enough to hold setpoint through the outage. That distinction can cut the required battery capacity substantially. Work it out before anyone quotes you a system.

How We Size a Refrigeration Backup System

Sizing works from three numbers: what the compressor draws running, what it draws starting, and what fraction of the hour it actually runs. The first sizes the battery, the second sizes the inverter, and the third is what turns a nameplate rating into real energy consumption. Skipping the duty cycle is how systems end up oversized and overpriced; skipping the starting current is how they end up unable to restart the compressor at all.

The more of this you can send, the more accurate the recommendation:

Our solar application engineers will work through the loads with you and put together an equipment list. Design assistance is provided for systems purchased from NAZ Solar Electric. If you don't have all of these numbers, send what you have. The compressor data plate alone gets us most of the way.

Get Help Designing Your System

Grid-Connected, Battery-Backed, or Hybrid

Grid-connected solar offsets what the refrigeration consumes during daylight and nothing more. It lowers the bill, but it shuts down in an outage, because grid-tie inverters are required to disconnect so they don't backfeed a line someone may be working on. If your reason for calling is spoilage, this configuration alone will not solve it.

Battery-backed solar adds storage and a transfer arrangement so the critical panel stays energized when the utility goes down. This is the configuration most refrigerated facilities are actually looking for.

Hybrid systems coordinate solar, batteries, utility, and a generator together, with the generator as a backstop for outages longer than the battery can carry. For a facility where a total loss of refrigeration is unacceptable at any point, this is the belt-and-braces version.

A Note on Demand Charges

Many commercial utility accounts are billed on two things: total energy consumed, and the highest rate of consumption reached during the billing period. That second one is the demand charge, and on a refrigerated facility it can be a significant share of the bill, because compressors starting together create a short, sharp peak that sets the charge for the entire month.

Solar with battery storage can in principle reduce demand charges by covering those peaks from storage rather than from the grid. Whether it does in your case depends entirely on your utility's tariff structure, when your peaks occur, and how the system is controlled. We can explain how this works and how it interacts with equipment selection, but we don't analyze utility tariffs or billing data. That conversation belongs with your utility account representative or an energy consultant.

Can Solar Replace Your Generator?

For refrigeration, usually not entirely.

Batteries handle short outages cleanly and silently, with no fuel, no start-up delay, and no maintenance schedule. Sizing a battery bank to carry continuous refrigeration through a multi-day event is a different proposition, and a long outage is the scenario that destroys inventory. Batteries for the short outages and a generator held in reserve for the long ones covers both without paying for battery capacity that sits idle. The result is a generator that starts less often, runs for shorter periods, and burns less fuel, not one you can remove.

What We Supply

NAZ Solar Electric supplies the generation, storage, and conversion equipment. We do not sell coolers, freezers, or compressors. Your refrigeration contractor handles that side, and we work alongside them.

Cold Storage Solar Frequently Asked Questions