Most facility managers know how much energy their plant consumes on a monthly basis. But far fewer know what their highest 15-minute electrical draw is, or what it actually cost them.
Having a thorough understanding of a facilities electrical consumption can offer an operation important insight on potential cost saving opportunities and decreasing its carbon footprint.
A battery energy storage system (BESS) can be an important tool employed by operations, providing them with available power during demand spikes, rate hikes, and down grids.
In short - a battery energy storage system for reserve power is a cabinet unit containing multiple rechargeable batteries that store electricity from a source such as the power grid, solar panels, and more. This power can be discharged immediately when needed. A BESS combines energy storage with advanced power electronics that offers operations flexibility over their power usage.
The operating cycle of a BESS has four steps:
1. The system charges during off-peak or low-price windows.
2. Energy is stored.
3. An operation uses the stored energy during peak demand windows, high-price periods, or outages.
4. Repeat (usually daily)
An onboard energy management system monitors this cycle based on setting preferences such as facility load, utility rates, and grid conditions. In other words, nobody has to stand at a panel flipping switches.
|
Component |
What It Does |
|
Battery cells and modules |
Stores energy. Individual battery cells are grouped into battery modules, and modules into racks or strings, to reach the required voltage and capacity. |
|
Battery management system (BMS) |
Monitors cell voltage, temperature, and state of charge. Keeps every battery cell inside within safe operating limits. |
|
Power conversion system (PCS continued) |
Converts stored DC power to AC for facility or grid use, and back again when charging. |
|
Energy management system (EMS) |
Monitors when to charge and discharge based on setting preferences. |
|
Thermal management |
Holds battery modules in their optimal temperature range. |
|
Enclosure and safety systems |
Houses the equipment and provides fire detection, gas detection, and suppression. |
Battery energy storage system design follows the same logic as a modern HAWKER lithium-ion battery: cells into modules, modules into a managed pack, with electronics governing the whole thing. DC output from the modules routes to the PCS, then through transformers and switchgear to the facility or the grid connection.
US electricity demand is growing again after roughly two decades of flat consumption. The EIA expects commercial electricity use to outpace residential in 2027 for the first time on record, with industrial consumption rising 1.0% in 2026 and 4.0% in 2027.
Predictably, data centers are the largest driver. Goldman Sachs Research projects US data center power demand rising from 31 GW in 2025 to 41 GW in 2026 and 66 GW in 2027, with their share of peak summer demand climbing from 4.1% to 8.5%.
Right now, supply isn’t keeping pace. Deloitte notes roughly two terawatts of capacity sitting in interconnection queues, nearly twice what’s currently installed, with peak demand projected to grow about 26% by 2035. And industrial electrification is expected to add 25 GW of that demand by 2030.
Grid capacity is turning into a scheduling problem, not just a purchasing problem. Anyone electrifying a fleet, adding chargers, or expanding a building is asking the utility for more capacity at the exact moment it’s hardest to get and most expensive to buy.
Facilities that can shift when they draw power gain room to maneuver. Facilities that can’t are stuck waiting in the queue—or paying the price.
Your electric bill has two fundamentally different parts:
Energy charges bill you for kilowatt-hours consumed. If you use less overall, you pay less.
Demand charges bill you for kilowatts, meaning the rate at which you draw power. The utility measures average draw in 15-minute intervals, takes the highest one in the billing period, and multiplies it by the demand rate. One spike sets the charge for the entire month, no matter how efficiently you run the other intervals.
In a warehouse, usual spike sources are:
NREL’s 2017 survey of more than 10,000 utility tariffs across 48 states found that demand charges typically account for 30% to 70% of a commercial electric bill and identified roughly 5 million commercial customers who could potentially cut costs with behind-the-meter storage.
That’s where peak shaving comes in.
Peak shaving with backup power is an energy management strategy that helps businesses curb the costs and bottlenecks associated with high-demand usage times. The BESS charges during low-demand periods, then discharges to hold metered demand below a target threshold when facility load spikes.
These terms sometimes get tossed around interchangeably, but they’re not the same thing.
Peak shaving targets the demand charge by capping your highest interval.
Load shifting targets the energy charge by moving consumption into cheaper time-of-use windows
A BESS can do both. Which one carries more value depends entirely on your electrical billing. Some facilities have punishing demand rates and flat energy rates. Others have the reverse. Know which before you pursue a BESS project.
Sizing depends on the shape of your demand curve, not your total consumption. Two facilities with identical monthly kWh might need completely different systems. Interval data from your utility is the input you need to size to the actual duty cycle rather than the assumed one.
Questions to Ask Before You Start
Answering the first three usually requires interval data and rather than monthly bill summaries.
The facilities that benefit most are those that experience sharp, brief, recurring demand spikes.
Strong Candidates:
Weaker candidates:
For most of the past two decades, industrial energy management meant using less. Grid conditions are shifting the question toward when you use it. A battery energy storage system is one of the few tools that gives a facility flexibility over that timing, and understanding how and when your facility draws power is the first step.
The HAWKER Harness the Power™ on-site assessment analyzes fleet utilization, run times, and utility and maintenance costs to produce data-based recommendations.
Connect with your local HAWKER representative to schedule an assessment.
