Power Calculator

Real power in kW is what does useful work, apparent power in kVA is what the supply must provide, and reactive power in kVAR is the difference between the two. For an industrial site running motors, transformers and switched-mode loads, knowing all three numbers is what lets you have a sensible conversation with the DNO about your Maximum Import Capacity (MIC), with your supplier about your reactive demand charges, and with your insurer about your transformer and switchgear rating margins. One number is never enough.

For a head of engineering signing off a load assessment ahead of a refit, a new line, or a capacity uplift, the full power calculation is the document that decides whether you stay inside the existing MIC or have to apply for an increase. An MIC uplift is not a trivial process: lead times can run to many months and the connection charge depends on local network headroom. Demonstrating that real-plus-reactive load sits inside the existing kVA agreement, with margin, is what keeps a project on schedule.

For a finance lead reviewing capacity charges line by line, real and apparent power is also the framing for the conversation about whether you are paying for more headroom than you use. A site running at 60 percent of agreed MIC year-round is paying availability charges on capacity that is doing nothing. A documented power calculation across realistic load scenarios, including transient inrush on the largest motors, is the evidence base that supports a reasoned application to reduce MIC and recover that overhead permanently.