BESS Thermal Management HVAC Load Calculator

What this calculator does

• Estimate thermal management HVAC energy cost for a grid-scale BESS container by combining HVAC connected load, daily operating hours, electricity rate, and MWh of storage capacity served to get total cost and cost per MWh stored.
• Use it when budgeting auxiliary load and operating cost for a BESS project and you need to know how much of the total site electricity bill is driven by thermal management HVAC in the battery containers.

Formula used

• Total HVAC energy cost per day = HVAC connected load x HVAC operating hours x site electricity rate
• Thermal management cost per MWh stored = total HVAC energy cost / usable MWh per BESS container

Inputs explained

• HVAC connected load per BESS container: Use the thermal management system nameplate or measured HVAC draw from the container energy audit or equipment specification.
• HVAC operating hours per day: Enter 24 for continuous thermal management or the average daily cooling hours from the thermal model or SCADA data.
• Site electricity rate: Use the blended site tariff including demand charges, or the utility contract rate from the project OpEx model.
• Usable MWh per BESS container: Use the nameplate or derated usable energy capacity per container from the battery system specification at beginning of life.

How to use the result

Common questions

• How does ambient temperature affect BESS HVAC load? HVAC load increases significantly in high-ambient climates. A container rated at 15 kW cooling in a 25 C ambient may require 25 to 30 kW at 40 C ambient. Use the worst-case design-day temperature from the site climate study to size thermal management and calculate peak auxiliary load.