Motor Efficiency Upgrade Savings

Both motors deliver the same shaft power.

This selection changes review context only. Formulas and example inputs stay unchanged. Check the model assumptions and applicability for the actual process.

Identify the actual asset, process, work boundary, source documents, units and assumptions. Confirm that the selected model or template applies before using its results.

1 Inputs

Minimum: 0.1

Minimum: 1 · Maximum: 100

Minimum: 0

Minimum: 1 · Maximum: 100

Minimum: 1 · Maximum: 100

Minimum: 0

Minimum: 0

Minimum: 0

2 Results

Annual energy savings
$2,680
Energy saved / year
22,335 kWh
Reduction
6%
Simple payback
0.9 yr
CO₂ avoided / year
8.9 t
ΔE = P × L × h × (1/η₁ − 1/η₂)
Both motors deliver the same shaft power. Use efficiencies at actual load, not only full-load nameplates. Negative savings mean the proposed motor consumes more; verify duty, installation cost and the local carbon factor.

Worked example

Example values are illustrative. Replace them with your measured data.

InputValue
Motor rated power75 kW
Average load factor75 %
Operating hours / year6000 h
Existing efficiency90 %
New (premium) efficiency95.7 %
Electricity rate0.12 $/kWh
Price premium of new motor2500 $
Grid emission factor0.4 kg CO₂/kWh

Annual energy savings: $2,680

Related tools

About this calculator

How it works

You enter rated power, average load factor, operating hours, existing and new efficiency, electricity rate and the price premium of the new motor. Shaft power = rated × load. Input kWh = shaft power × hours ÷ efficiency, for each motor. Saving = old − new; payback = premium ÷ annual saving.

Worked example (illustrative inputs)

75 kW at 75% load = 56.25 kW shaft, 6,000 h. At 90%: 375,000 kWh; at 95.7%: ≈ 352,665 kWh. Saving ≈ 22,335 kWh (6%) ≈ $2,680 at $0.12; payback ≈ 0.9 years on a $2,500 premium.

How to read the result

The tool marks payback of 3 years or less as good and above 6 as poor. CO₂ uses a fixed 0.4 kg/kWh.

When to use it

Use it at motor failure or rewind decisions, to check whether a premium-efficiency replacement pays back. Run it with the real load factor.

À propos de ce calculateur

Traduction (brouillon) — à relire.

Fonctionnement

Vous saisissez la puissance nominale, le taux de charge moyen, les heures, les rendements actuel et nouveau, le tarif et le surcoût du nouveau moteur. Puissance à l'arbre = nominale × charge. kWh absorbés = puissance arbre × heures ÷ rendement, pour chaque moteur. Économie = ancien − nouveau ; retour = surcoût ÷ économie annuelle.

Exemple chiffré (valeurs d'illustration)

75 kW à 75 % de charge = 56,25 kW à l'arbre, 6 000 h. À 90 % : 375 000 kWh ; à 95,7 % : ≈ 352 665 kWh. Économie ≈ 22 335 kWh (6 %) ≈ 2 680 $ à 0,12 $ ; retour ≈ 0,9 an pour 2 500 $ de surcoût.

Lire le résultat

L'outil juge un retour de 3 ans ou moins bon et au-delà de 6 ans faible. Le CO₂ utilise un facteur fixe de 0,4 kg/kWh.

Quand l'utiliser

Utilisez-le lors d'une panne ou d'un rebobinage, pour vérifier si un remplacement à haut rendement est rentable. Utilisez le taux de charge réel.

حول هذه الحاسبة

ترجمة (مسودة) — للمراجعة.

طريقة الحساب

تُدخل القدرة المقننة ومعامل الحمل المتوسط وساعات التشغيل والكفاءة الحالية والجديدة والتعرفة وفرق سعر المحرك الجديد. قدرة العمود = المقننة × الحمل. kWh الداخلة = قدرة العمود × الساعات ÷ الكفاءة، لكل محرك. التوفير = القديم − الجديد؛ والاسترداد = فرق السعر ÷ التوفير السنوي.

مثال محسوب (قيم توضيحية)

75 kW عند حمل 75% = 56.25 kW على العمود، و6000 ساعة. عند 90%: ‏375,000 kWh؛ وعند 95.7%: ‏≈ 352,665 kWh. التوفير ≈ 22,335 kWh ‏(6%) ≈ 2680 $ عند 0.12 $؛ والاسترداد ≈ 0.9 سنة لفرق سعر 2500 $.

قراءة النتيجة

تعدّ الأداة استردادًا خلال 3 سنوات أو أقل جيدًا، وما فوق 6 سنوات ضعيفًا. ويُحسب CO₂ بمعامل ثابت قدره 0.4 kg/kWh.

متى تستخدمه

استخدمها عند تعطل محرك أو قرار إعادة لفّه، للتحقق مما إذا كان الاستبدال بمحرك عالي الكفاءة مجديًا. استخدم معامل الحمل الفعلي.

In one line

Both motors deliver the same shaft power. Use efficiencies at actual load, not only full-load nameplates. Negative savings mean the proposed motor consumes more; verify duty, installation cost and the local carbon factor.

Worked example

EXAMPLE

Illustrative values (the calculator defaults), not data from a real site.

Inputs
Motor rated power75 kW
Average load factor75 %
Operating hours / year6000 h
Existing efficiency90 %
New (premium) efficiency95.7 %
Electricity rate0.12 $/kWh
Price premium of new motor2500 $
Grid emission factor0.4 kg CO₂/kWh
Results
Annual energy savings$2,680
Energy saved / year22,335 kWh
Reduction6%
Simple payback0.9 yr
CO₂ avoided / year8.9 t

Frequently asked questions

Is it worth replacing a working motor with a premium one?

Usually yes if it runs many hours: energy is around 95% of a motor's lifetime cost. For high-runtime motors the payback on the price premium is often 1–3 years; for rarely-used motors, replace on failure instead.

What efficiency values should I use?

Use the nameplate efficiency of the existing motor and the IE3 (Premium) or IE4 (Super Premium) value of the replacement at the actual load point — efficiency drops at low load, so enter a realistic load factor rather than an assumed 100%.

What load factor should I enter if I don't know it?

If you have no measured data, 75% is a common planning assumption for continuously-running industrial motors, but measuring actual current draw with a clamp meter against nameplate full-load amps gives a far more accurate figure. Motor efficiency curves flatten between roughly 50–100% load and drop off below that.

Should I replace motors proactively or wait for failure?

For motors that run many hours a year, replacing proactively often pays back faster than waiting, since every delayed year is avoidable extra energy cost. For motors that run rarely or are hard to access, replacing on failure is usually the more economical choice — run the payback for your specific runtime to decide.

Does this account for rewinding instead of replacing?

No — it assumes a straight new-motor purchase. A rewound motor typically loses one to two efficiency points versus new, so if rewinding is your real alternative to replacement, enter the rewound motor's lower efficiency as your existing-efficiency input for an accurate comparison.

How reliable is the CO2 figure?

It uses a generic grid emission factor as a placeholder, and actual factors vary significantly by region and grid mix — coal-heavy grids run notably higher, hydro- or nuclear-heavy grids run much lower. For a report you'll actually submit, substitute your utility's or country's published emission factor.

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