Track energy in and out each cycle quickly. See losses, savings, and performance targets today. Use it for storage, cranes, elevators, and pumps onsite.
Meta description: Estimate round trip efficiency for site energy systems. Compare measured inputs with component losses and costs. Improve battery, hoist, and regen setups using clear metrics.
Typical values for an onsite storage cycle. Use your project-specific measurements for decisions.
| Scenario | Input (kWh) | Useful output (kWh) | Efficiency (%) | Losses (kWh) |
|---|---|---|---|---|
| Measured cycle | 120.000 | 102.000 | 85.00 | 18.000 |
| Component estimate (aux 2 kWh) | 120.000 | 100.460 | 83.72 | 19.540 |
| Improved conversion chain | 120.000 | 106.900 | 89.08 | 13.100 |
Round trip efficiency (%) = (Useful Output Energy ÷ Input Energy) × 100
Losses (kWh) = Input Energy − Useful Output Energy
Overall chain efficiency = ηcharger × ηstorage × ηinverter × ηdistribution × ηmachine
Useful Output = (Input − Auxiliary) × Overall chain efficiency
Use consistent measurement points to avoid double counting conversion stages.
Round trip efficiency compares energy taken in during charging with useful energy delivered after discharge. It helps teams judge whether batteries, regenerative drives, or hybrid power packs are worth the added complexity. A higher percentage means less fuel or grid energy is wasted as heat in cables, converters, and machines. Use the metric when evaluating cranes with regen, hoists, elevators, pumps, or temporary microgrids. It also supports carbon reporting by linking wasted energy to emissions factors from your fuel and grid mix.
For a measured method, log input energy at the supply meter for one complete cycle. Then log output energy at the load side over the same cycle window. Keep timestamps consistent and exclude unrelated loads. If output appears higher than input, recheck meter direction, CT polarity, or interval alignment. Repeat several cycles and use an average to reduce noise.
When measured output is unavailable, estimate using component efficiencies. Multiply charger, storage, inverter, distribution, and machine efficiencies to form an overall chain. Add auxiliary energy such as cooling fans, controllers, heaters, and hydraulic power units as a direct subtraction from input. This approach is useful during design and procurement, when only datasheet values exist.
Losses show where attention pays back. Large cable runs, undersized conductors, and poor power factor increase distribution losses. High converter temperatures signal switching and conduction losses. Battery internal resistance rises with age, low temperature, and high C rates, lowering retention efficiency. Improve efficiency by shortening runs, adding ventilation, tuning drive settings, and scheduling charging during stable ambient conditions.
Pair efficiency with price per kilowatt hour and daily cycle count to translate losses into currency. This supports decisions on generator sizing, solar plus storage, and peak shaving plans. Export results to a spreadsheet for trend tracking across weeks. Use PDF reports for commissioning records, maintenance meetings, and vendor comparisons on similar duty cycles.
Use it for batteries, regenerative drives, hybrid generator sets, temporary microgrids, and any charge–discharge process where input and delivered output energy can be measured or estimated.
It usually indicates mismatched time windows, reversed meter polarity, incorrect CT orientation, or mixing other loads into the output channel. Verify intervals, sign conventions, and measurement points for one complete cycle.
Choose measured when you have reliable meters at input and load points. Choose component when you are planning or when output metering is not installed, using datasheet efficiencies plus auxiliary consumption.
Yes. Fans, cooling, heaters, controls, and hydraulics consume energy that does not reach the useful load. In the component method, auxiliary energy is subtracted from input before applying the efficiency chain.
Losses represent heat and conversion waste per cycle. Compare them across equipment options, cable lengths, and operating temperatures. Multiply by cycles per day and price per kWh to estimate daily cost impact.
For stable operations, average at least five to ten representative cycles. For variable duty, sample different loads and ambient conditions, then report a weighted average that matches the typical daily operating pattern.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.