C&I Battery Storage Project Pre-Design Checklist

Start with the Load Profile

The first item on a C&I battery storage pre-design checklist is the electrical load. Project managers often skip this step or rely on a single utility bill. That creates a design that misses the real peak.

Pull at least 12 months of interval data. One year captures seasonal changes, including heating and cooling loads that shift with weather patterns. If the site has a new process line or a major tenant move-in planned within two years, request a load forecast from the facility engineer. Do not assume the existing load profile will remain static. A manufacturing plant adding a paint booth or a data center adding a new rack row will change the peak demand significantly.

Check for:

1. Peak demand events and their frequency.
2. Daily load shape, including morning and evening ramps.
3. Power factor and reactive power draw.
4. Any existing battery systems or backup generators on the site.

A flat load profile suggests the storage will primarily smooth small fluctuations or shift energy usage. A jagged profile with sharp peaks points to demand reduction as the main value. The battery size and power rating change based on this data. If the peaks occur daily for more than an hour, a larger power rating is needed. If the peaks are rare and last only a few minutes, a smaller system can capture the same savings.

Review the reactive power draw. If the facility has a high power factor penalty on its utility bill, the battery inverter must be sized to provide reactive power support. This changes the inverter specification. You need to confirm whether the utility charges for low power factor or if the facility has a separate power quality penalty. These two items often appear on the same bill but have different calculation methods.

Look at the morning and evening ramps. Many commercial buildings have a spike at 8:00 AM when HVAC systems and office equipment start up. In the evening, there may be a second spike if the building stays occupied. These ramps can be captured by a smaller, higher-power battery. A flat load profile might only require a lower power rating with a larger energy capacity, depending on the goal.

Red Flags

• The utility bill only shows monthly kWh, not kW demand peaks.
• The facility manager cannot explain why a specific peak occurred.
• New equipment is being installed but has not been added to the load model.
• The existing transformer is already operating above 80 percent of its nameplate capacity.

Assess the Electrical Site Conditions

The second section of the checklist covers the physical electrical environment. The battery system is not just a cabinet. It includes switchgear, cabling, protection relays, and integration points with the existing distribution system.

Walk the substation and electrical room. Measure the available space with a laser tape measure. Record the dimensions of the room, the location of existing panels, and the clearance required for maintenance. Battery containers require specific clearances for ventilation and service access. A typical container may need several feet of clearance on all sides. If the room is tight, you may need to choose a different container size or a different installation location.

Check the weight limits on the floor where the battery containers will sit. Request the structural engineer’s report for the floor slab. If the report is not available, assume the floor is not rated for the weight. A fully charged battery system can weigh several tons. A single container may weigh between 5,000 and 15,000 pounds, depending on the capacity and chemistry. If the floor is not rated, you will need to install a steel support structure. This adds cost and time to the project.

Verify that the room has ventilation for heat rejection and that the fire suppression system is compatible with the battery chemistry. Lithium-ion batteries release heat during charge and discharge. The room must have adequate ventilation to keep the temperature within the manufacturer’s operating range. If the room is too warm, the battery system may derate its power output. This reduces the savings. If the fire suppression system uses a specific type of agent, you must confirm that the battery manufacturer approves it. Some suppression systems are not compatible with lithium-ion batteries.

Review the existing switchgear. Determine the ampacity of the main breaker and the available space for new breakers. If the main breaker is at 90 percent of its rating, you will likely need to upgrade the switchgear before adding the storage. This upgrade can double the project cost if not planned early. The new breakers must be coordinated with the existing protection relays. If the existing breakers are older than 20 years and show signs of thermal stress, replace them. Do not rely on old breakers to handle the new load.

Check the conduit routing. Long runs of high-current cable require specific bend radii and support structures. If the existing conduit is full, plan for new cable trays or conduit. Measure the distance from the battery room to the main switchgear. This distance determines the cable size and the voltage drop. A long run of cable may require a larger conductor size to keep the voltage drop within acceptable limits. This increases the cost of the cable and the labor for installation.

Red Flags

• The electrical room is already at capacity with no room for new equipment.
• The existing breakers are older than 20 years and show signs of thermal stress.
• There is no clear path from the battery room to the main switchgear.
• The floor slab has not been tested for the weight of a fully charged battery system.

Confirm Utility and Grid Requirements

Grid interconnection rules vary by region and utility. The pre-design phase is the time to contact the utility interconnection office. Request the specific requirements for your site. Do not wait until the design is complete to start this process. Interconnection applications can take months. If the utility is planning a grid upgrade in your area, find out when. This may affect the interconnection timeline.

Ask for:

• The required protection coordination study.
• The grid code for voltage and frequency ride-through.
• Any local restrictions on battery capacity or discharge rates.
• The expected timeline for the interconnection application.
• The utility’s stance on demand response programs.

Some utilities require a detailed single-line diagram before they will approve the interconnection. Others require a specific type of protection relay or a communication protocol with the grid. If the utility requires a communication protocol, you must select a battery system that supports that protocol. This may limit your choice of battery manufacturers.

If the grid is expected to be unstable, the battery system may need additional support to maintain power quality. This could include a larger inverter or a specific control algorithm. Confirm the utility’s expectations for power quality. If the utility has a strict power quality standard, the battery system must meet it. This may require a more expensive inverter.

Red Flags

• The utility has not responded to the interconnection inquiry.
• Local code requires a fire marshal inspection before the battery can be connected.
• The utility demands a 50 percent increase in the transformer size for the storage system.
• There is no clear timeline for the interconnection approval.

Define the Business Case and Performance Goals

The third section of the checklist focuses on the project’s economic and operational goals. A C&I storage project is a financial instrument as much as a technical one.

Define the primary use case. Is it demand reduction? Peak shaving? Energy arbitrage? Backup power? A system designed for demand reduction will have a different power rating than one designed for backup. If the goal is demand reduction, the power rating must be high enough to reduce the peak demand. If the goal is backup power, the energy capacity must be high enough to support the critical load during an outage.

Estimate the expected savings. Use the utility’s tariff schedule. Calculate the cost per kWh during peak hours versus off-peak hours. Subtract the estimated cost of the system, installation, and maintenance. Use the actual utility rates, not the average rate. The average rate does not reflect the time-of-use pricing. If the utility charges a demand charge based on the highest 15-minute interval, the savings are calculated differently than if the utility charges a flat rate.

Include the incentive value. Check for local, state, and federal incentives. Some incentives are available for demand reduction, others for backup. Some require the system to be installed within a specific timeframe. Confirm the eligibility criteria for each incentive. Do not assume that all incentives apply to all use cases. Some incentives require the system to be used for a specific purpose.

Red Flags

• The project is based solely on a single year of energy prices.
• The savings model does not account for the cost of financing or leasing.
• The backup power requirement is not clearly defined.
• The project does not have a clear owner for the interconnection application.

Review Fire Safety and Structural Requirements

The fourth section covers safety and structural compliance. Battery storage systems are subject to strict fire codes. The pre-design checklist must include a review of the local fire code and building code.

Determine the required fire suppression system. Some codes require a specific type of fire extinguisher or a water-based suppression system. Others require a specific distance from the battery to the fire door. Confirm the fire code requirements for the specific battery chemistry. Lithium-ion batteries have different fire code requirements than lead-acid batteries. Do not assume that the existing fire code applies to the new battery system.

Check the structural load. A battery system can weigh several tons. The floor must be able to support this weight. If the battery is on an upper floor, the structural engineer must verify the load capacity. If the floor is not rated, you will need to install a steel support structure. This adds cost and time to the project.

Review the ventilation. Batteries release heat during charge and discharge. The room must have adequate ventilation to keep the temperature within the manufacturer’s operating range. If the room is too warm, the battery system may derate its power output. This reduces the savings. If the room is too cold, the battery system may not operate correctly. Confirm the manufacturer’s operating temperature range.

Red Flags

• The fire marshal has not been contacted.
• The room has no fire suppression system.
• The floor is not rated for the weight of the battery system.
• The ventilation system is not sized for the heat output of the battery.

Prepare the Project Team and Document Flow

The final section of the checklist is about the project team. A C&I storage project involves multiple stakeholders. The project manager must define the roles and responsibilities of each team member.

Identify the key stakeholders:

• The facility engineer.
• The electrical contractor.
• The battery system integrator.
• The utility interconnection specialist.
• The fire safety consultant.
• The project finance team.

Create a document flow diagram. Define which documents go to which stakeholder and when. This prevents version control issues and ensures that everyone is working from the same data. The document flow diagram should include the load data, the single-line diagram, the protection coordination study, the fire code review, the structural load verification, and the business case definition.

Assign a single point of contact for each stakeholder. This prevents confusion and ensures that questions are answered quickly. If the facility engineer is not involved in the pre-design phase, the project may face delays. The facility engineer knows the building and the electrical system. Their input is critical for the design.

Red Flags

• The facility engineer is not involved in the pre-design phase.
• The electrical contractor has not been selected.
• There is no single point of contact for the utility.
• The project finance team has not reviewed the savings model.

Pre-Design Checklist Summary

Use this table to track your progress. Mark each item as complete, pending, or not applicable.

Item	Status	Notes
12 months of load data	Pending
Switchgear capacity check	Not Applicable
Utility interconnection requirements	Complete
Fire code review	Pending
Structural load verification	Not Applicable
Business case definition	Complete
Project team roles defined	Pending
Document flow diagram created	Not Applicable

Keep this checklist updated as you move into the design phase. If an item changes, update the checklist and notify the relevant stakeholders. This simple practice prevents the most common cause of project delays.