Emergency operations centres, mobile command posts, reception sites, logistics areas, and temporary communications points need power before normal utility service may be available. Their electrical loads can include radios, network equipment, laptops, displays, lighting, refrigeration, charging stations, pumps, and environmental controls.
A mobile battery system can support selected loads without direct exhaust or engine noise while discharging. It can also work with a generator to reduce continuous engine operation. The system still needs to be sized and integrated from a documented site assessment.
FEMA's temporary emergency power training recommends completing facility assessments before an outage, including the required power source, connection materials, voltage, phase, and installation location. The same planning principle applies to battery and hybrid systems in both Canada and the United States.
This article covers operational support loads. It does not replace the engineered, code-compliant emergency and standby systems required for hospitals, fire pumps, life-safety systems, elevators, or other regulated equipment.
Define the operating function before calculating power
The name of a facility does not establish its electrical requirement. An emergency operations centre used for coordination has a different load profile from an overnight reception centre, a medical treatment area, or a public charging site.
Start by documenting the functions expected during an outage:
- Incident command and coordination
- Radio, satellite, cellular, and internet communications
- Dispatch, mapping, and data systems
- Public information and media support
- Staff workstations and printing
- Site and task lighting
- Device, radio, and tool-battery charging
- Food, water, and temperature-controlled supply storage
- Sanitation, drainage, and water pumping
- Heating, cooling, and ventilation
- Accessibility and functional-needs support equipment
Identify which functions must operate continuously, which can follow a schedule, and which can be disconnected. FEMA guidance for critical facilities recommends considering the intended operating level and determining which operations can be curtailed during an emergency.
Complete the assessment before an incident
A pre-incident assessment reduces the amount of electrical investigation required during deployment. It should include both the load calculation and the physical connection plan.
Record at least:
| Assessment item | Information to capture |
|---|---|
| Facility or site | Address, access route, staging area, and site contact |
| Operating function | Command, shelter, reception, logistics, communications, or other use |
| Load | Equipment, quantity, running power, starting demand, and priority |
| Electrical service | Voltage, phase, frequency, panel rating, and connection point |
| Distribution | Connectors, cable lengths, panels, protection, and grounding provisions |
| Runtime | Required hours before recharge or relief equipment arrives |
| Environment | Temperature, precipitation, flooding, ventilation, and public access |
| Recharge | Grid, generator, solar, or equipment rotation plan |
| Transfer | Manual or automatic transfer method and isolation from the utility |
| Personnel | Authorized operator and qualified electrical contact |
Photographs, one-line diagrams, panel schedules, connector details, and cable routes should be stored with the emergency plan. Recheck the information after renovations or equipment changes.
Separate peak kW from daily kWh
Two calculations are required:
- Peak power in kW determines inverter, connection, and distribution capacity.
- Energy in kWh determines how long the battery can carry the planned loads.
For a steady load:
Power in kW x operating hours = energy in kWh
For a load that cycles:
Rated kW x available hours x duty cycle = energy in kWh
For example, a 0.6 kW refrigerator group operating for 24 hours at a measured 50% duty cycle uses approximately:
0.6 kW x 24 hours x 0.50 = 7.2 kWh
The same equipment may briefly draw more power when its compressors start. Starting demand affects the inverter and circuit calculation even though it contributes little to the total daily energy.
FEMA's emergency power guidance notes that emergency occupancy and operating patterns may differ from normal facility use. Normal utility bills can provide a reference, but they do not replace a critical-load schedule for the planned incident mode.
Worked example: a 24-hour coordination site
The following example represents a temporary coordination site operating for one day. It is an illustration, not a standard emergency load profile. Real sites require equipment nameplates, measured data, local code review, and an operational risk assessment.
| Load group | Planning power | Operating assumption | Energy use |
|---|---|---|---|
| Radio and communications equipment | 0.8 kW | 24 hours | 19.2 kWh |
| Network, modem, and satellite equipment | 0.4 kW | 24 hours | 9.6 kWh |
| Laptops, monitors, and mapping workstations | 1.2 kW average | 16 hours | 19.2 kWh |
| LED interior and site lighting | 0.8 kW | 16 hours | 12.8 kWh |
| Refrigerator and temperature-controlled storage | 0.3 kW average | 24 hours | 7.2 kWh |
| Radio, phone, and tool-battery charging | 0.5 kW average | 12 hours | 6.0 kWh |
| Printer and general office equipment | 0.3 kW average | 4 hours | 1.2 kWh |
| Calculated total | 75.2 kWh |
Adding a 20% planning allowance for conversion losses, load variation, and operating reserve gives:
75.2 kWh x 1.20 = 90.2 kWh
The simple running total of the listed loads is 4.3 kW. The actual peak may be higher if refrigeration starts while charging, printing, and communications loads are operating together.
The reserve should be set from operational risk rather than treated as a fixed percentage. A remote deployment, uncertain relief time, cold or hot weather, or a long distance to fuel and grid charging may justify a larger reserve.
Keep critical and discretionary loads on separate circuits
Load priority needs to be visible in the electrical design. If every outlet is treated the same, nonessential equipment can consume energy reserved for communications and shutdown.
One possible priority structure is:
- Protected operational loads: radio infrastructure, network core, dispatch, safety lighting, alarms, and required controls.
- Essential support loads: selected workstations, temperature-controlled supplies, task lighting, and authorized charging.
- Managed loads: printers, additional displays, break-area equipment, and general office circuits.
- Deferred loads: decorative lighting, convenience appliances, and equipment that can wait for a recharge period.
Label temporary panels and receptacles by priority. The incident power plan should state who can authorize load shedding and what minimum battery reserve must remain for communications, safety, and an orderly shutdown.
Do not place medical equipment or other life-support loads on a general temporary power circuit. Those loads require a separate clinical, engineering, regulatory, and redundancy review.
Heating, cooling, and cooking can dominate the calculation
The worked example excludes space heating, air conditioning, and commercial food preparation. Adding any of these can substantially increase both peak kW and daily kWh.
A 12 kW electric heater operating for eight hours would use:
12 kW x 8 hours = 96 kWh
That single load would exceed the calculated energy used by all equipment in the example. Air conditioners and heat pumps add compressor starting demand as well as operating energy. Kettles, coffee brewers, induction appliances, and water heaters can create overlapping peaks.
Where practical, use the host building's established heating, ventilation, cooling, and food-service arrangements. If temporary equipment is required, place it in a separate load group and determine whether it should be served by grid power, a dedicated generator, a larger battery system, or a managed hybrid configuration.
Plan for deployment, weather, and access
Emergency sites can be affected by the same conditions that caused the outage. Flooding, snow, heat, wildfire smoke, debris, restricted roads, and public traffic can all affect the equipment location and cable route.
The site plan should address:
- Stable, accessible equipment placement outside flood-prone areas
- Weather-rated distribution and connectors
- Cable protection at vehicle and pedestrian crossings
- Ventilation and manufacturer clearances
- Controlled access around power equipment
- Grounding, bonding, overcurrent, and ground-fault protection
- Lighting for panels, disconnects, and operating areas
- Clear access for charging, replacement, and service equipment
- Temperature limits for storage, charging, and discharge
- A shutdown or relocation plan if site conditions change
Canada's federal outage guidance advises using rated, approved cords and qualified electrical installation for backup connections. Applicable requirements vary across provinces, territories, states, municipalities, facility types, and incident authorities. A qualified electrical professional should verify the installation.
Choose battery-only or hybrid operation
A battery-only setup can fit a defined load, a known operating window, and a reliable recharge plan. It is useful where direct exhaust, noise, or fuel handling would interfere with an indoor-adjacent command area, overnight operation, or communications work.
Longer deployments usually need more than stored energy. Recharge options include:
- Utility power when service is available at a staging location
- Scheduled generator charging
- Solar-assisted charging
- Rotation between deployed and charging battery systems
- Connection to another approved source within a temporary microgrid
The U.S. Department of Energy describes mobile storage as a way to provide localized emergency support to critical loads during an outage. It can also supplement existing generation. In a hybrid configuration, the battery carries lower and variable loads while the generator runs for defined recharge periods or high-demand equipment.
This arrangement may reduce low-load generator operation and preserve quieter periods. It does not remove the need for fuel planning, maintenance, spare equipment, or a response to a failed charger or depleted battery.
For a broader comparison, see electric generators versus diesel generators for commercial sites. The load-scheduling method is also similar to our outdoor event temporary power guide, although emergency response requires a more conservative reserve and clearer priority structure.
Where Skyridge Power systems fit
The Apex Station is the closer match for the 24-hour worked example. Its published specifications include:
- 120 kWh of LiFePO4 storage
- 30 kW continuous output
- Configurable 120/240 V output
- Single-phase and three-phase configurations
- Grid, generator, and solar charging compatibility
- Up to 30 kW of solar input
- Less than 20 ms transfer time
The example's 90.2 kWh planning figure is below the Apex Station's nominal 120 kWh capacity, and its 4.3 kW simple running total is below the published 30 kW continuous output. Actual runtime depends on usable reserve, conversion losses, temperature, equipment peaks, battery condition, and system configuration.
The Apex Mobile provides 16 kWh nominal capacity, 14.4 kWh usable capacity, and 12 kW continuous output. It may fit an isolated communications point, a small mobile command post, a charging station, or a short-duration support package. It would not cover the complete 24-hour example without load reduction or recharge.
Neither product specification alone establishes suitability for regulated emergency or life-safety service. The authority having jurisdiction, facility engineer, emergency planner, and qualified electrical contractor need to confirm the required listing, transfer arrangement, redundancy, protection, and operating procedures.
Dispatch checklist
Before deployment:
- Confirm the facility function and current site contact.
- Review the critical-load schedule and operating duration.
- Verify voltage, phase, connectors, transfer equipment, and cable lengths.
- Confirm that continuous and starting loads fit the power system.
- Set the protected reserve and load-shedding sequence.
- Confirm the recharge source, fuel plan, and expected relief time.
- Check access, weather, flood exposure, ventilation, and public separation.
- Pack distribution equipment, cable protection, labels, test equipment, and documentation.
- Assign an authorized operator and electrical contact.
- Test the complete arrangement under representative load.
After deployment, record actual kW, kWh, state of charge, charging time, and any unplanned loads. These records make the next assessment more accurate.
Primary references include FEMA's training on facility assessments for temporary emergency power, FEMA P-1019 on emergency power systems for critical facilities, the U.S. Department of Energy's review of mobile energy storage systems, and Government of Canada power outage preparedness guidance.
Image source: Meeting at State Emergency Operations Center by the Office of Governor Dan Malloy, licensed under CC BY 2.0. The image was cropped and resized to a landscape format.
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