Energy Economics Tool

Savings & Payback
Calculator

Compare the annual energy losses of two transformers and calculate how quickly a more efficient unit pays back the price premium through energy savings.

How It Works

Transformer Energy Cost Comparison

01
Get Loss Data for Both Transformers

Pull no-load (core) and full-load copper losses in watts from each transformer's nameplate or test report. Manufacturers must provide this under DOE 2016 regulations. The difference between standard and premium-efficiency units can be 20–40% lower losses.

02
Set Your Operating Parameters

Enter your average load factor (typically 50–80% for most facilities), hours per year in service, and electricity cost. Use your actual blended electricity rate including demand charges if possible — even $0.01/kWh difference changes the payback period significantly.

03
Calculate Annual Losses

No-load losses accumulate 8,760 hours/year regardless of loading. Copper losses scale with load-factor squared and only during hours in service. The tool calculates total annual energy lost to heat for each transformer.

04
Review Payback Period

If Transformer B costs more but loses less energy, the annual savings eventually pay back the price premium. A well-engineered premium transformer typically pays back in 2–5 years — with 20–25 years of remaining service life delivering pure savings thereafter.

Formulas
Annual Losses (kWh)
Pcore(W)/1000 × 8760 + L² × Pcu(W)/1000 × H_year
Annual Cost Savings ($/yr)
(Losses_A − Losses_B) kWh × $/kWh
Simple Payback (years)
(Price_B − Price_A) / Annual Cost Savings
CO₂ Reduction (kg/yr)
(Losses_A − Losses_B) kWh × CO₂ factor (kg/kWh)
FAQ

You need the no-load (core/iron) losses in watts and the full-load copper losses in watts. These are available on the transformer nameplate, in the test report, or in the manufacturer's data sheet. For DOE 2016-compliant units, typical values are published in NEMA TP-1 and DOE efficiency tables.

Copper losses scale with the square of the load current. A transformer running at 50% load has only 25% of the copper losses it would have at full load. No-load losses, however, run 24/7 at constant levels. So for lightly loaded transformers, the no-load loss difference between two units dominates the annual energy savings calculation.

Simple payback = (Price of B − Price of A) / Annual cost savings. It tells you how many years of energy savings it takes to recover the premium paid for a more efficient transformer. This is a pre-tax, undiscounted figure — consult a financial model for a more rigorous lifecycle cost analysis.

The default 0.4 kg CO₂/kWh is a rough average for a mixed North American grid. Actual values vary significantly: Ontario's nuclear-heavy grid is around 0.04–0.10 kg/kWh, while Alberta's gas-heavy grid is 0.55–0.65 kg/kWh. Use the actual grid emissions factor for your region for an accurate carbon calculation.

Savings & Payback Calculator
Operating Parameters
Transformer A
Transformer B

Need Loss Data for a Candron Transformer?

Our engineering team can provide complete test reports including no-load and full-load loss data for any transformer in our inventory or custom-built to your specification.