Define the duty before the capacity
Required power in MW and usable energy in MWh answer different questions. Duration, charge and discharge windows, expected cycling, operating limits and availability requirements establish the basis for sizing.
Battery energy storage systemsBESS EPC in India.
Start with the duty.
BESS engineering, procurement, construction and integration for renewable energy, industry and grid-connected projects in India. Start with the duty. Design the battery energy storage system around it.
The project perspectiveA battery is a component.
A battery is a component.
Flexibility is a system.
A battery energy storage system (BESS) connects batteries, power conversion, controls and electrical infrastructure. Its value depends on the job it must do: shift renewable energy, support a peak requirement, manage a load profile or meet a defined dispatch obligation.
Resus brings storage assessment, engineering, procurement and project delivery into a connected scope. Standalone storage and integrated renewable configurations are evaluated against duty, grid conditions, safety requirements and lifecycle economics.
Scope shaped around the opportunityDecisions that belong
Decisions that belong
in the same conversation.
Design the interfaces as one system
Battery systems, power conversion systems (PCS), transformers, switchgear, protection, metering and plant controls must work together. Battery management systems (BMS) and energy management systems (EMS) have distinct roles that need clear integration.
Make safety part of the configuration
Site layout, access, thermal management, fire detection and protection, emergency response and applicable technical requirements inform equipment and integration decisions. Safety is assessed for the proposed technology, location and operating duty.
Evaluate performance over time
Usable capacity, efficiency, degradation, warranty conditions, service support and potential augmentation affect lifetime cost. Procurement and acceptance criteria should reflect the same operating assumptions used in the project case.
The project brief defines the agreed scope, delivery responsibilities and specialist partners required.
Connected by purposeGeneration, storage and grid.
Generation, storage and grid.
One operating question.
BESS cannot be sized in isolation from the energy available to charge it or the requirement it must serve. Solar and wind profiles, grid limits, import arrangements and dispatch priorities shape the storage duty. Coordinated controls and commissioning tests then determine whether the combined system behaves as intended.
Why we think in systemsExperience behind the questionsJudgment across
Judgment across
the project lifecycle.
Resus is led by people whose careers span renewable energy development, engineering, procurement and project execution in India and international markets. That experience helps connect the early choices with their consequences during construction and operation.
Meet our peopleHow we buildUseful questionsClarity before
Clarity before
commitment.
What is the difference between MW and MWh in BESS?
MW describes power: the rate at which the system charges or discharges. MWh describes energy: how much usable energy it can store or deliver under defined conditions. Dividing usable MWh by discharge MW gives a nominal duration; actual operation also depends on limits, losses and state of charge.
Can BESS work with an existing solar or wind project?
Potentially. Integration requires assessment of the existing connection, electrical equipment, protection, controls, space and operating permissions, as well as charging sources and commercial arrangements. The appropriate AC- or DC-coupled configuration depends on the project.
What does BESS EPC integration involve?
It connects equipment selection and technical specifications with civil and electrical works, controls integration, testing and handover. Responsibilities for the battery supplier, PCS, EMS, balance of plant and grid interface must be explicitly allocated and tested.
What determines the cost of a BESS EPC project?
Required MW and usable MWh, duration, cycling, site conditions, grid works, controls, safety provisions, warranty terms and service scope all influence cost. Compare proposals at the same measurement boundary and operating duty; a price per MWh without those assumptions is incomplete.
From specification to acceptanceA storage contract needs
A storage contract needs
an operating definition.
A BESS EPC scope should establish the measurement boundary, usable energy at the point of connection, rated power, expected cycling, efficiency assumptions and the conditions for acceptance testing. A battery nameplate alone does not define the energy available to the customer.
Clarify responsibility for civil works, battery enclosures, PCS, transformers, switchgear, EMS, protection, communications and the grid interface. Align warranties, degradation assumptions, maintenance access and any future augmentation with the same operating duty.
Read the BESS sizing perspectiveConnect storage with grid infrastructureBegin with the brief
What should a BESS project brief include?
Share the use case, location, grid connection, required MW and MWh if known, and expected operating windows. Demand or generation time-series data, cycling assumptions, site constraints and the proposed commercial structure help turn a broad storage requirement into an engineering basis.
Discuss your BESS project