Peak-shaving assessment requires a time-based view of demand and a clear explanation of the intended outcome. Identify when peaks occur, how long they last and which loads create them. A single maximum reading does not establish the operating duty required from generation or storage.
Review the permitted operating arrangement
The proposed source must operate within the site’s electrical arrangement and applicable permissions. Parallel operation, control interfaces and protection need competent assessment where relevant. Commercial assumptions should be stated separately from technical feasibility.
Model the intended dispatch
Identify whether the objective is to reduce a demand peak, shift energy use or provide reserve. Compare the operating strategy with the load profile and any storage contribution before claiming a cost or fuel benefit.
Compare scenarios using consistent assumptions
Fuel, maintenance, equipment costs and the relevant charging or tariff basis can affect the outcome. Use project-specific inputs and identify uncertainty. This page supports the assessment process; it does not promise savings or establish that a particular site may export or operate in parallel.
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Start Engineering Review. Share the application, location and information available so the next discussion can address your actual requirement.
Related guidance
Engineering intent
Peak Shaving should be evaluated as part of the complete power system rather than as an isolated catalogue item. Operating duty, connected load, interfaces, protection, controls, installation conditions, testing requirements and lifecycle consequences determine whether the arrangement is appropriate.
Engineering considerations
If the load is very high relative to generator capacity: Fuel cost per hour may increase and operating reserve may reduce. Review generator duty, overload margin, cooling, maintenance condition and fuel autonomy. But it must be within the generator’s rating, duty and operating condition. This is much better than assuming one fixed load all day. Scenario A — One large DG running all day Simple, but may run inefficiently at low load. Scenario B — Smaller DG for low load + larger DG for peak subject to controls, protection, load sharing and testing. fuel + maintenance + parts + AMC + repairs + depreciation + capital cost rental charges + fuel + transport + cables/DBs + operator + extras
Selection and design considerations
Where load changes materially with time, assessment should consider an appropriate observation period. A generator sized only for peak load may spend much of its life far below that condition. Peak load should represent the highest credible sustained demand. The transient may last only seconds but still influence source selection. What is the largest increase in demand the generator may experience at one time? The largest step can matter more than the total running load. After an outage, not every load necessarily needs to return immediately. Diversity recognises that not all installed loads operate simultaneously. Avoid applying one generic diversity factor across every project. Demand factor can help compare actual maximum demand against connected load.
Integration and protection considerations
A peak without context can lead to oversizing. An outlier can be either irrelevant noise or the most important transient on the site. Future allowance should be based on actual project plans and uncertainty. This determines whether the load belongs inside the generator requirement. Some loads can be intentionally removed if generation is constrained. This can reduce required emergency generation without compromising priorities. After generator transfer, restore loads deliberately where applicable. A BETTER SEQUENCE CAN BE MORE VALUABLE THAN A BIGGER GENERATOR If three large motors do not need to start together, sequencing them may reduce the transient requirement. This is a system-design decision—not merely a sizing trick.
Testing, commissioning and verification
The actual requirement depends on the engine/generator model. Do not assume a room that works in mild weather will perform under peak ambient conditions. The exhaust route should be planned before installation. The exhaust system must serve the engine, the room and the site. Excessive restriction in the exhaust path can adversely affect engine operation. Exhaust piping and silencers can introduce significant heat into or near the room. Generator noise can reach the environment through multiple paths: Generator room noise control must address the actual path.
Operating and lifecycle considerations
The generator is the result of the analysis. It should not be the assumption at the beginning. That does not automatically mean it requires a generator capable of supplying every load simultaneously. Conversely, a facility with a much smaller running load may contain one severe motor-starting event that dominates the generator requirement. Must remain powered according to the continuity requirement. This helps separate equipment inventory from real generator duty. The normal load is what the facility typically expects the generator to carry after the system has stabilised. Peak load represents the highest credible sustained operating demand. The generator must support the relevant peak condition—not just the average. A transient is a short-duration event that can still control generator selection.
Decision and application considerations
This makes the project auditable and prevents misunderstanding. Each must be specified in the written quotation. Controls modernisation for generator systems where reliability depends on correct sequencing, clear alarms, verified protection, documented wiring and practical operator control. Generator controller upgrade • AMF panel modernisation • ATS interface correction • synchronisation-control review • BMS/SCADA signal integration • remote-monitoring readiness • alarm/protection verification • functional testing • documentation A Generator Is Only as Reliable as the Service System Behind It. A diesel generator is not a one-time purchase. It is a working power asset made of mechanical, electrical, fuel, cooling, exhaust, control, battery, alternator, protection and distribution subsystems. When one subsystem weakens, the generator may still start — but it may not be ready for the outage, shutdown, peak load, motor-starting event, long runtime or emergency transfer that matters.
Direct answer
Peak-shaving assessment requires a time-based view of demand and a clear explanation of the intended outcome. Identify when peaks occur, how long they last and which loads create them.
The practical decision for Peak Shaving should be based on verified load, equipment, interface and site information. Where equipment-specific data, regulatory applicability or a project study is required, this guidance does not replace that verification.