How BESS Is Making Round-the-Clock Renewable Energy Possible for C&I Businesses

For years, the biggest question around renewable energy was simple:

What happens when the sun goes down?

Solar generation peaks during the day, while commercial and industrial businesses may continue consuming electricity well into the evening and night. This mismatch between generation and consumption has been one of the biggest limitations of renewable power.

Battery Energy Storage Systems, or BESS, are changing that equation.

Instead of consuming renewable electricity only when it is generated, a battery can store surplus power and release it later.

In simple terms:

Generate → Store → Dispatch

That ability to shift electricity across time is what is making Round-the-Clock Renewable Energy, or RTC RE, increasingly possible.

What is RTC renewable energy?

Round-the-clock renewable energy refers to renewable power structured to provide electricity with a higher degree of continuity and predictability across the day, rather than only when renewable generation is naturally available.

Consider a typical solar project.

Solar generation rises in the morning, peaks around midday and falls rapidly in the evening. But a factory, data centre, hotel or warehouse may have substantial demand after sunset.

Without storage, the renewable generation profile and the consumer's demand profile do not align.

BESS provides the bridge.

Surplus renewable electricity can be stored during periods of high generation and dispatched when generation falls or demand rises.

This makes renewable power more closely aligned with the way businesses actually consume electricity.

Why storage is becoming essential for India's renewable transition

India has already demonstrated that it can build renewable generation at scale.

Solar and wind capacity continue to expand, but as renewable penetration rises, the challenge increasingly becomes one of integration and flexibility.

The question is no longer only:

"Can we generate enough renewable electricity?"

It is also:

"Can we deliver renewable electricity when demand requires it?"

Solar output falls to zero at night, while wind generation varies with weather conditions. Electricity demand, meanwhile, follows its own pattern.

The government recognises the growing importance of storage. According to the Ministry of New and Renewable Energy, the National Electricity Plan projects a BESS requirement of 34.72 GWh by 2026–27 and 236.22 GWh by 2031–32, with energy-storage requirements potentially reaching around 1,840 GWh by 2047.

Storage is therefore becoming core infrastructure for India's renewable-energy system, rather than simply an optional addition to a renewable project.

What does a BESS actually do?

At its simplest, a Battery Energy Storage System performs three functions:

1. Charge

The battery takes in electricity when renewable generation is available.

2. Store

That electricity is held for later use.

3. Discharge

The battery releases the stored electricity when renewable generation is lower or when the consumer needs additional power.

The battery therefore changes when renewable electricity is available, without changing the underlying source of that electricity.

For a solar project, this could mean charging during the afternoon and discharging during the evening.

The C&I advantage: renewable power that matches the load

For a C&I buyer, the value of renewable energy depends not only on how much electricity a project generates, but also on when that electricity is available.

A factory operating primarily during daylight hours may be well matched to solar.

A hotel, data centre or 24-hour manufacturing facility may not be.

This is where BESS expands the usefulness of renewable procurement.

Instead of asking:

"How much solar can we consume during the day?"

a business can increasingly ask:

"How much of our electricity requirement can be served by renewable generation combined with storage?"

That opens the door to much higher renewable penetration for businesses with evening or round-the-clock demand.

Solar + BESS: a different renewable-energy product

A conventional solar PPA primarily gives a consumer access to solar generation.

A solar-plus-storage project can provide something closer to a dispatchable renewable-energy product.

The battery adds flexibility around:

• Peak demand
• Evening demand
• Scheduled delivery
• Firm power requirements
• Renewable-energy commitments
• Generation variability

The exact degree of firmness depends on the project's renewable mix, storage capacity and contractual structure.

But the fundamental shift is important:

The product is no longer just renewable generation. It is renewable electricity delivered according to a defined profile.

MW and MWh: what C&I buyers need to understand

BESS projects are generally described using two numbers.

MW = Power capacity

This indicates how much power the battery can deliver at a given moment.

MWh = Energy capacity

This indicates how much energy the battery can store.

For example:

50 MW / 50 MWh can theoretically provide 50 MW for approximately one hour.

50 MW / 100 MWh can theoretically provide 50 MW for approximately two hours.

Actual usable duration depends on factors such as operating limits, state of charge, efficiency and battery degradation.

For C&I buyers, the distinction matters because a battery's MW rating alone does not tell you how long it can support the load.

If the objective is to cover a three-hour evening demand period, for example, the battery's MWh capacity becomes critical.

BESS is fundamentally about time-shifting electricity

Imagine a solar project generating more electricity than the consumer needs at 2 PM.

Instead of allowing that surplus to go unused or relying on other mechanisms to manage it, the battery can charge.

At 6 PM, when solar output has fallen and the business is still consuming heavily, the battery can discharge.

The electricity has effectively moved from a period of high renewable availability to a period of higher consumer need.

This time-shifting capability is one of the most important reasons BESS is becoming central to RTC renewable projects.

Beyond solar: why wind + solar + BESS can be even stronger

Solar and wind have different generation profiles.

Solar generation is concentrated during daylight hours, while wind generation can occur at different times depending on location and weather.

Combining the two can create a more diversified renewable-generation profile.

Adding BESS provides another layer of flexibility.

Conceptually:

Solar + Wind → More diverse generation

BESS → Time-shifting and dispatch flexibility

Together → A more predictable renewable supply profile

The objective is not necessarily to make every renewable unit available every second.

It is to design a portfolio whose combined generation and storage profile is better aligned with the consumer's demand.

How BESS changes the renewable PPA

Adding storage makes the commercial structure more sophisticated.

A conventional solar PPA may focus on:

• Generation
• Tariff
• Plant availability
• Performance
• Curtailment
• Minimum offtake

An RTC renewable PPA also needs to address:

Delivery profile

When is renewable power expected to be delivered?

Storage availability

What happens if the BESS is unavailable?

State of charge

What operating range must the battery maintain?

Round-trip efficiency

How much energy is lost during charging and discharging?

Degradation

How does battery performance change over the contract period?

Replacement

Who is responsible if battery components need replacement?

Shortfall

What happens if the project cannot deliver the contracted renewable energy?

Backup

What happens when renewable generation and storage cannot meet the contracted requirement?

These details determine whether an RTC product actually delivers the electricity profile the buyer expects.

The economics: is RTC worth paying more for?

BESS adds a storage component to the cost of renewable electricity.

As a result, RTC renewable power may cost more than daytime solar alone, depending on the project's design, renewable mix and storage duration.

But comparing the two purely on tariff misses the value of dispatchability.

A C&I buyer should compare:

Solar-only

Lower generation cost, but more variable availability.

Solar + BESS

Higher system cost, but greater flexibility and better alignment with the consumer's load.

The more useful question is therefore:

What is the cost of reliable renewable electricity delivered when the business needs it?

For a business with significant evening or round-the-clock demand, that can be more valuable than simply finding the cheapest solar tariff.

Why BESS economics are improving

India is actively building a policy and market framework around energy storage.

The Ministry of Power has reported measures supporting storage deployment, including recognition of Energy Storage Systems within the electricity framework, integration of storage into resource-adequacy planning and a national framework for energy storage.

The government has also introduced Viability Gap Funding (VGF) support for BESS projects, while MNRE's energy-storage policy repository includes the VGF framework and provisions relating to inter-state transmission charges for energy storage systems.

These measures can help address one of the historical challenges of storage:

Storage is essential for renewable integration, but costs are harder to justify when deployment is limited.

As deployment increases, economies of scale, improving technology and greater market experience can improve project economics.

India is planning for a storage-heavy power system

The scale of India's planned storage requirement is significant.

The National Electricity Plan projections cited by the government indicate approximately:

8.68 GW / 34 GWh by 2026–27

and:

47.24 GW / 236 GWh by 2031–32.

The estimated investment requirement for BESS by 2031–32 is around ₹3.49 lakh crore.

These numbers demonstrate that storage is moving beyond pilot projects and becoming a major component of India's electricity infrastructure.

For C&I businesses, that means storage-backed renewable procurement is likely to become increasingly available as the market develops.

BESS does more than enable RTC power

RTC is one of the most important applications of BESS, but storage can provide several other services.

Peak shifting

Store electricity during periods of high renewable availability and discharge during peak demand.

Renewable firming

Reduce the impact of short-term fluctuations in renewable generation.

Energy arbitrage

Charge when electricity is cheaper and discharge when it is more valuable, where the applicable market structure permits it.

Grid balancing

Respond to short-term changes in supply and demand.

Frequency support

Provide rapid-response grid services where permitted.

Resilience

Support critical loads during certain grid interruptions, depending on system design.

Curtailment reduction

Store renewable electricity that might otherwise be curtailed during periods of excess generation.

This means a BESS can potentially create value beyond simply acting as a backup battery.

There is no one-size-fits-all RTC solution

Every C&I consumer has a different load profile.

A factory may have high daytime consumption.

A data centre may operate at a relatively constant load.

A hotel may peak in the evening.

A cold-storage facility may operate around the clock.

The right RTC configuration therefore depends on:

• Load profile
• Renewable resource
• Solar/wind mix
• Battery duration
• Desired renewable percentage
• Grid tariff
• Open-access charges
• Banking rules
• Contract requirements
• Reliability expectations

The battery should be sized around the consumer's requirement, not simply around the size of the renewable plant.

What RTC does, and does not, mean

The term round-the-clock renewable energy can sometimes create the impression that every RTC project guarantees 100% renewable electricity every second.

That is not necessarily the case.

The actual product depends on the project design and contract.

A buyer should understand:

• Renewable-energy percentage
• Hourly matching requirements
• Guaranteed availability
• Storage duration
• Generation profile
• Backup arrangements
• Shortfall treatment

A well-structured RTC contract should make these parameters clear.

The buyer should know exactly what is being guaranteed.

The shift from renewable capacity to renewable availability

This is perhaps the biggest change BESS brings to renewable procurement.

For years, renewable-energy discussions focused heavily on:

"How many MW of solar will India install?"

As renewable penetration increases, another question becomes increasingly important:

"How much clean power can be delivered when the consumer needs it?"

Capacity tells us how much generation exists.

Storage helps determine when that generation can serve demand.

That is why BESS is so important to the next phase of renewable-energy growth.

What this means for C&I procurement

The evolution of storage is likely to change how businesses evaluate renewable power.

The first generation of C&I renewable procurement was largely about:

Getting a cheaper solar tariff.

The next generation will increasingly be about:

Getting the right renewable-energy supply profile at a competitive landed cost.

Buyers will need to compare more than tariff.

They will increasingly look at:

• Renewable percentage
• Delivery profile
• Storage capacity
• Availability
• Generator credibility
• Project location
• Grid charges
• Contract duration
• Performance guarantees

The cheapest renewable tariff may not necessarily be the most valuable renewable product.

The better question is:

Which solution provides the best combination of cost, renewable content, reliability and predictability for our load?

Where Wattmatch fits in

As renewable procurement evolves from straightforward solar PPAs to hybrid and storage-backed structures, comparing projects becomes more complicated.

A C&I buyer may have to evaluate:

Solar vs. Solar + BESS vs. Wind + Solar vs. Wind + Solar + BESS

with different tariffs, generation profiles, storage durations and contract structures.

That makes transparent price discovery and standardised comparison increasingly important.

Wattmatch's marketplace model is designed around this problem.

Instead of finding one developer, negotiating one proposal and then trying to determine whether the price and structure are competitive, a buyer can compare multiple vetted generators through a structured process.

As storage-backed renewable projects become more common, the relevant question is no longer simply:

"Who offers the lowest tariff?"

It is:

"Who offers the best renewable-energy product for our load?"

The next generation of renewable PPAs will be about the shape of power

A traditional PPA largely answers:

How much electricity will the project generate?

An RTC PPA needs to answer:

When will that electricity be available to the consumer?

That is a much more useful question for a business.

A factory does not consume electricity as an annual number.

It consumes electricity throughout the day, with peaks and valleys that depend on its operations.

BESS allows renewable projects to respond more closely to that shape.

The road ahead

India's renewable transition is entering a new phase.

The first phase demonstrated that solar and wind could compete economically with conventional generation.

The next phase is about making renewable electricity more firm, flexible and dispatchable.

BESS is central to that transition.

It allows solar power generated during the day to support evening demand, improves the alignment between generation and consumption, and gives renewable projects greater flexibility in how electricity is delivered.

India's projected storage requirements and policy support reflect the scale of this transition.

The direction is clear:

Solar made renewable energy cheap.

Wind diversified the renewable generation profile.

BESS is making renewable power more dispatchable.

Together, they are bringing India closer to a future where businesses can rely on renewable electricity not only when renewable resources are available, but when their operations actually need it.

What should C&I businesses be asking now?

The question is no longer simply:

"Can renewable power run our business?"

The more useful question is:

"What renewable configuration can deliver the right electricity, at the right time, at the right cost?"

For some businesses, the answer will remain rooftop solar.

For others, it will be open-access solar.

For others, a wind-solar hybrid may make more sense.

And for businesses with significant evening or round-the-clock demand, the answer may increasingly be:

Renewable energy + BESS

That is the next evolution of C&I renewable procurement.

As battery costs, project scale, policy support and market structures continue to develop, RTC renewable energy can move from a specialised product toward a mainstream way for Indian businesses to decarbonise their electricity consumption.

The future of renewable energy isn't just about generating more clean power. It's about making clean power available when businesses need it.

That's what BESS makes possible.

Wattmatch is building the marketplace for that future, connecting C&I buyers with vetted renewable generators and helping businesses compare, procure and manage renewable-energy solutions that fit their actual electricity needs.

Run your business. We'll run your renewables.