What Is Commercial Battery Storage?

 

Commercial battery storage uses large rechargeable batteries to store electrical energy.

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The principle is similar to a domestic solar battery, but commercial systems can be considerably larger and more sophisticated.

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A system may include:

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• battery modules

• battery management systems

• inverters or power-conversion equipment

• electrical switchgear

• monitoring and controls

• thermal-management equipment

• fire-safety systems

• energy-management software.

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The battery can be charged from solar panels, from the electricity grid or potentially from other sources of on-site generation.

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Stored electricity can then be released when the building requires it.

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What Is a BESS?

 

BESS stands for Battery Energy Storage System.

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The term is commonly used for larger commercial, industrial and utility-scale battery installations.

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A BESS is not simply a collection of batteries.

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It normally combines the batteries with the equipment needed to safely control charging and discharging, convert electricity, monitor performance and integrate the storage system with the building or electricity network.

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Commercial BESS installations can range from relatively compact systems serving a business premises to large containerised installations capable of storing substantial quantities of electricity.

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Commercial Battery Storage and Solar Panels

 

One of the most obvious applications is combining commercial battery storage with solar panels.

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Without a battery, electricity generated by a solar array generally has three possible outcomes.

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It is either:

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used immediately within the building, exported when generation exceeds demand, or lost through normal system inefficiencies.

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Adding battery storage creates another option.

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Surplus solar electricity can be stored and used later.

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For example, a warehouse might generate substantial solar electricity during the middle of the day but have continuing electricity demand into the evening.

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A battery could charge while solar generation is high and discharge after the sun has fallen.

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Why Add Batteries to Commercial Solar?

 

The financial value of solar electricity can depend heavily upon what happens to it after it is generated.

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Electricity used directly within the business can reduce electricity purchased from the grid.

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Where substantial amounts would otherwise be exported, battery storage may allow a greater proportion of the solar generation to remain on site.

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This is often described as increasing solar self-consumption.

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A battery can therefore potentially increase the usefulness of an existing or proposed commercial solar installation.

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Whether it improves the overall financial return will depend upon the building's particular energy profile.

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Benefits of Commercial Battery Storage

 

Battery storage can provide businesses with several potential advantages.

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Use More Solar Electricity

Excess daytime solar generation can be stored and used later instead of being immediately exported.

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Reduce Grid Electricity Use

Stored electricity can supply part of the building's demand when solar generation is insufficient.

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Manage Peak Demand

A battery can discharge during periods when electricity demand rises sharply, reducing the amount of power that needs to be drawn from the grid at that moment.

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Take Advantage of Electricity Tariffs

Some businesses may be able to charge batteries when grid electricity is cheaper and use the stored electricity during more expensive periods.

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Support EV Charging

Battery storage can help businesses manage the increased electrical demand created by vehicle charging.

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Support Building Electrification

As buildings increasingly use electricity for heating, cooling and transport, batteries can help manage changing demand patterns.

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Improve Energy Management

Modern battery systems can automatically respond to electricity consumption, solar generation and predefined operating strategies.

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Peak Shaving With Commercial Batteries

Peak shaving is an important application of commercial battery storage.

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A business does not necessarily consume electricity at a constant rate.

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Demand can suddenly increase when machinery starts, several EV chargers operate simultaneously, air-conditioning equipment reaches maximum output or multiple electrical systems operate together.

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Instead of drawing all of that additional power from the grid, the battery can discharge during the peak.

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The battery effectively fills part of the gap between normal demand and the temporary peak.

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This can help manage the building's electrical load and may provide financial advantages depending upon the business's electricity tariff and network arrangements.

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Load Shifting

 

Battery storage can also be used for load shifting.

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The battery charges during one period and discharges during another.

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For a solar-powered business, this could mean charging around midday and using the electricity during the evening.

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For another business, it might involve charging from the grid during a lower-cost tariff period and discharging during a higher-cost period.

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This ability to move electricity consumption across time is one of the fundamental advantages of energy storage.

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Commercial Battery Storage Without Solar Panels

 

A business does not necessarily need solar panels to install battery storage.

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A stand-alone commercial battery can potentially charge from the electricity grid.

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Whether this makes financial sense depends upon factors including:

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electricity tariffs, demand profile, battery cost, allowable operating strategy and the difference between electricity prices at different times.

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However, combining batteries with solar provides the additional opportunity to store electricity generated directly at the property.

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For many businesses, the technologies therefore make sense as part of the same energy assessment.

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Commercial Solar Battery Storage

 

A commercial solar battery storage system should ideally be designed at the same time as the solar installation.

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This allows the designer to examine:

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solar generation, building electricity demand, export levels and battery operation together.

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The battery should not automatically be sized according to the capacity of the solar array.

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Instead, the design should consider how much surplus electricity is actually likely to be available for storage and how much stored energy the business can realistically use.

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An oversized battery that rarely becomes fully charged may provide poor value.

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Equally, an undersized battery could regularly fill early in the day while substantial quantities of solar electricity continue to be exported.

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How Large Does a Commercial Battery Need to Be?

 

There is no standard commercial battery size.

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Two businesses with identical solar arrays can require completely different battery systems because their electricity consumption is different.

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Battery sizing may consider:

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• daily electricity consumption

• solar system capacity

• amount of surplus solar generation

• timing of electricity demand

• peak electrical loads

• EV charging requirements

• operating hours

• electricity tariffs

• backup requirements where applicable

• anticipated future energy demand.

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Good design therefore starts with data rather than simply selecting a battery from a product catalogue.

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kW and kWh – What's the Difference?

 

Commercial battery proposals commonly refer to both kW and kWh, and the distinction is important.

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kWh – kilowatt-hours describes how much energy the battery can store.

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kW – kilowatts describes how quickly the system can deliver or absorb power.

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A battery may therefore have substantial storage capacity but still be limited in how quickly it can discharge.

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For a business seeking to manage high peak loads, power output can be just as important as total storage capacity.

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Both figures should be considered when comparing commercial battery systems.

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Commercial Battery Storage for Warehouses

 

Warehouses can be particularly suitable for battery storage when they already have large solar installations.

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A warehouse roof may generate substantial electricity during daylight hours.

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Battery storage can help manage generation that exceeds the immediate needs of the building.

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Warehouses may also have significant electrical demand from:

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lighting, refrigeration, conveyors, automation, electric forklifts, ventilation and vehicle charging.

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A BESS can help coordinate these different energy requirements.

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Commercial Battery Storage for Offices

 

Office buildings generally consume electricity during daylight hours, which already provides a good match for solar generation.

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However, batteries can still be valuable.

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Electricity may be required later for:

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IT equipment, servers, security systems, evening occupation, ventilation and cooling.

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Battery storage can also help manage growing EV-charging loads in office car parks.

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The financial case should be established by comparing actual electricity consumption with predicted solar generation.

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Battery Storage for Factories

 

Manufacturing premises can have highly variable electricity demand.

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Heavy machinery starting simultaneously can create significant peaks.

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A commercial battery may potentially help smooth some of these fluctuations.

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Factories can also have substantial roof areas suitable for solar, creating opportunities to combine on-site generation and energy storage.

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For industrial users, detailed energy monitoring is particularly valuable because average annual consumption alone may conceal significant variations throughout each working day.

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Battery Storage for Farms

 

Agricultural businesses can have unusual and sometimes highly seasonal electricity demand.

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Refrigeration, milking equipment, irrigation, ventilation and processing machinery can all create substantial loads.

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Where agricultural buildings also support large solar arrays, batteries can retain surplus electricity for later use.

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This can be particularly useful for farms where electricity demand continues into the evening or overnight.

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Commercial Batteries and EV Charging

 

Electric vehicle charging can create significant new electricity demand for businesses.

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A company gradually replacing cars and vans with electric vehicles may discover that its electrical requirements increase substantially.

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Battery storage can potentially help by supplying part of the charging demand rather than requiring all electricity to come directly from the grid at the same time.

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This can be particularly useful when several vehicles are charging simultaneously.

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Solar, Battery Storage and EV Charging

 

The combination of solar panels, battery storage and EV charging can be especially powerful.

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Solar panels generate electricity.

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The business uses what it needs.

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Surplus electricity can charge the battery.

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The battery can then contribute towards vehicle charging when required.

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Smart controls can decide when electricity should flow between the solar array, battery, building, vehicle chargers and grid.

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Instead of treating these technologies as separate installations, they can be designed as one integrated energy system.

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Commercial Battery Storage and Air Conditioning

 

Battery storage can also complement air-conditioning and cooling systems.

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Commercial buildings can experience significant electricity demand during hot summer periods.

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This demand often coincides with strong solar generation, making solar particularly suitable for contributing towards cooling.

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A battery can add flexibility by storing excess solar electricity and making it available later as cooling demand continues.

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For offices, hotels, shops and other air-conditioned premises, solar + battery + air conditioning can therefore form a coherent energy strategy.

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Solar, Batteries, EV Charging and Building Electrification

 

The commercial energy system of the future is likely to involve considerably more coordination between technologies.

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A business may eventually operate:

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solar PV + battery storage + EV charging + heat pumps + air conditioning + smart energy controls.

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Each technology changes the building's electricity profile.

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Designing them independently can result in missed opportunities or unnecessary electrical infrastructure.

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Considering them together allows the business to establish how energy will actually move around the property.

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This is particularly valuable when a building is being substantially refurbished or its electrical infrastructure is already being upgraded.

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Smart Energy Management

 

Modern commercial battery systems can be controlled by sophisticated energy-management software.

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Instead of simply charging whenever electricity is available, the system can make decisions according to predefined objectives.

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For example, it may prioritise:

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storing surplus solar, reducing peak demand, maintaining a minimum battery reserve or charging during particular tariff periods.

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More advanced systems can coordinate multiple electrical loads across the property.

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This can include solar panels, batteries, EV chargers and heating or cooling equipment.

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Battery Storage and Grid Constraints

 

Some commercial properties would like to increase their electrical capacity but are constrained by their connection to the electricity network.

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Adding multiple EV chargers or electrifying heating can significantly increase peak demand.

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Battery storage may sometimes help manage these peaks by providing additional power locally rather than drawing everything simultaneously through the incoming supply.

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However, batteries do not automatically solve every grid-capacity issue.

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The electrical design and connection requirements still need to be properly assessed.

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Can Commercial Batteries Provide Backup Power?

 

Potentially — but not every commercial battery installation automatically provides backup during a power cut.

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A standard grid-connected battery may shut down if the electricity supply fails.

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Providing backup or islanded operation requires the system to be specifically designed for that purpose, including appropriate controls, switching and electrical protection.

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Businesses requiring resilience for critical equipment should therefore make this requirement clear from the outset.

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Backup capability should never be assumed simply because a battery is installed.

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Battery Storage for Critical Loads

 

Where backup capability has been specifically designed into the system, businesses may choose to prioritise certain essential loads.

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These could include:

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servers, communications equipment, security systems, refrigeration, emergency equipment or selected lighting.

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It may not be practical or economical to support the entire building during an outage.

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Identifying critical circuits can therefore help determine the appropriate battery and backup strategy.

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Commercial Battery Storage Costs

 

There is no single commercial battery storage cost because BESS installations range enormously in size.

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A smaller commercial system serving an office may bear little resemblance to a containerised industrial battery installation.

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Cost can depend upon:

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battery capacity, power output, battery chemistry, inverter equipment, switchgear, controls, installation location, electrical modifications and fire-safety measures.

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Integration with existing solar, EV charging or energy-management equipment can also affect the project.

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The appropriate question is therefore not simply “How much does a commercial battery cost?”

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It is:

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What does the battery allow the business to save, manage or achieve over its operating life?

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Commercial Battery Payback

 

Battery payback can be more complicated to calculate than solar-panel payback.

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A solar panel generates measurable electricity.

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A battery primarily changes when electricity is available and how it is used.

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Financial value might therefore come from several sources:

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increased use of solar electricity, reduced peak demand, time-of-use tariff savings or improved management of new electrical loads.

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A realistic financial assessment should model how the battery is expected to operate rather than assuming that every stored unit of electricity produces the same saving.

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Battery Degradation

 

Rechargeable batteries gradually lose some storage capacity as they age and complete charging cycles.

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This is known as degradation.

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Commercial battery proposals should therefore consider expected performance over time rather than assuming that the battery will retain its original usable capacity indefinitely.

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Manufacturers normally provide warranties based upon factors such as:

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years of operation, throughput or retained capacity.

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The warranty conditions should be examined when comparing different systems.

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Battery Chemistry

 

Several battery technologies are available, although lithium-based systems are currently common within commercial energy storage.

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Different battery chemistries can have different characteristics relating to:

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energy density, cycle life, operating temperature and safety.

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Rather than choosing a battery solely according to chemistry, businesses should consider the complete tested and certified system supplied by an experienced installer.

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System design, controls and installation quality are just as important as the battery cells themselves.

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Where Are Commercial Batteries Installed?

 

The installation location depends upon the size and type of system.

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Smaller systems may be installed within appropriate plant areas or dedicated enclosures.

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Larger commercial BESS equipment may be housed externally in cabinets or purpose-designed containers.

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The location should consider:

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access, ventilation or thermal management, electrical connections, security, maintenance and fire safety.

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The installer should also consider separation from building users and other site activities where appropriate.

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Fire Safety and Commercial Battery Storage

 

Fire safety is an important part of commercial battery design.

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Modern systems incorporate battery-management and protection equipment intended to monitor operating conditions.

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However, a large energy-storage installation should still be carefully located and specified.

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The design may need to consider:

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battery chemistry, enclosure construction, detection, ventilation, emergency access, separation distances and manufacturer requirements.

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The fire-safety strategy should be proportionate to the size and location of the installation.

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Large BESS installations require substantially greater consideration than a small residential battery.

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Planning Permission for Commercial Battery Storage

 

Whether planning permission is required depends upon the scale, location and physical form of the proposed battery installation.

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A relatively small battery within an existing commercial building presents different planning considerations from a large external containerised BESS.

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Larger installations can potentially raise issues involving:

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appearance, noise, access, landscaping and the relationship with neighbouring properties.

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Planning requirements should therefore be checked during the early design stage.

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Noise From Battery Storage Systems

 

Battery cells themselves are generally quiet, but commercial battery systems can contain equipment that produces noise.

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Cooling fans, air-conditioning equipment, transformers and power-conversion equipment may all contribute.

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For systems positioned close to neighbouring homes or other sensitive receptors, noise may therefore form part of the site assessment.

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Careful equipment selection and positioning can help minimise potential disturbance.

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Connecting Commercial Batteries to Existing Solar

 

An existing commercial solar installation may sometimes be upgraded with battery storage.

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Whether this is straightforward depends upon the existing system.

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The installer will need to consider:

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solar capacity, inverter arrangements, electrical distribution equipment and the proposed battery operating strategy.

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The existing solar-generation data can be particularly useful because it shows how the system actually performs rather than relying solely upon theoretical predictions.

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Adding Batteries When Installing New Solar

 

Where a business is considering both technologies, designing solar and battery storage together provides greater flexibility.

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Cable routes, equipment locations and electrical infrastructure can all be coordinated.

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Even where the battery is not installed immediately, it may be sensible to make the solar system battery-ready if storage is likely to be added later.

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This can potentially avoid unnecessary alterations in the future.

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Commercial Battery Storage and Roof Solar

 

The battery itself does not normally need to be located beside roof-mounted solar panels.

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Solar electricity can be connected through the building's electrical system to batteries located at a suitable plant or external location.

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This can be useful on warehouses and commercial buildings where roof space is extensive but safe battery access is better provided at ground level.

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The complete cable route and electrical arrangement should be established during design.

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Large-Scale Battery Storage

 

Very large BESS installations can function as energy infrastructure in their own right.

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These projects can comprise multiple battery containers together with:

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transformers, substations, switchgear, access roads, fencing and monitoring systems.

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They may be developed alongside solar farms or independently from renewable generation.

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This type of installation falls into a different category from normal behind-the-meter commercial battery storage and usually requires specialist energy-development expertise.

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Commercial Battery Maintenance

 

Battery systems should be monitored throughout their operating life.

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Modern systems can provide remote information covering:

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state of charge, energy throughput, temperature, system status and faults.

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Maintenance requirements vary between manufacturers.

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Businesses should understand who will provide:

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system monitoring, software support, inspections, fault response and replacement components.

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For significant commercial installations, an appropriate maintenance arrangement should be established before commissioning.

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Battery Monitoring

 

Monitoring is fundamental to getting value from commercial storage.

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A business should be able to see when the battery:

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charges, discharges and reaches its operating limits.

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This information can help establish whether the original energy strategy is working as expected.

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For systems integrated with solar, monitoring can also show:

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solar generation, building consumption, grid imports, grid exports and battery activity.

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This provides a much clearer picture of the property's complete energy flow.

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Choosing a Commercial Battery Storage Company

 

Businesses considering battery storage should look for installers with appropriate commercial electrical and energy-storage experience.

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Commercial BESS projects can require expertise in:

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electrical design, solar integration, controls, network connections and fire safety.

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The cheapest battery quotation may not provide the best overall solution.

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The system needs to be correctly sized and integrated with the property if it is to deliver meaningful value.

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Comparing Commercial Battery Storage Quotations

 

Quotations should provide enough information to allow meaningful comparison.

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Important information can include:

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battery capacity in kWh, power rating in kW, usable capacity, inverter specification, warranty, expected cycle life, monitoring and proposed operating strategy.

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The quotation should also explain what installation work is included.

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This might involve:

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electrical equipment, switchgear, cabling, foundations, enclosures and commissioning.

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A proposal that simply gives a battery size and price without explaining how the system will operate is difficult to assess properly.

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Commercial Battery Storage for New Buildings

 

New commercial buildings provide an excellent opportunity to consider battery storage from the outset.

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Instead of adding separate systems later, the building can be designed to accommodate:

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solar PV, battery storage, EV chargers, electric heating and cooling.

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Electrical infrastructure can then be sized and arranged around the expected future demand.

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Space for batteries, inverters and associated equipment can also be planned before the building is constructed.

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Battery Storage During Commercial Refurbishment

 

Major refurbishment provides a similar opportunity.

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If switchgear is being upgraded, roofs altered or new electrical services installed, it makes sense to consider the building's future energy requirements at the same time.

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Even where a battery is not immediately affordable, provisions can potentially be incorporated to simplify future installation.

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Thinking several years ahead can avoid repeatedly altering the same building services.

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The Integrated Commercial Energy System

 

The most interesting development in commercial energy is the move away from treating each technology separately.

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A modern business may have:

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solar panels generating electricity

battery storage managing when it is used

EV chargers supplying vehicles

air conditioning providing summer comfort

heat pumps supplying heating

smart controls coordinating the entire system.

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The individual technologies become components of one larger energy strategy.

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This can be particularly valuable for businesses expecting electricity consumption to increase as transport and heating become increasingly electrified.

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Is Commercial Battery Storage Worth It?

 

Battery storage can be an excellent addition to some commercial properties, but it is not automatically right for every business.

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The strongest cases tend to exist where there is a clear reason for shifting electricity from one time to another.

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That could involve:

surplus solar generation, high evening demand, significant electrical peaks, time-dependent tariffs or increasing EV charging

requirements.

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The starting point should therefore be the building's actual electricity data.

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Once the business understands when it generates and consumes electricity, it becomes much easier to determine whether storage provides a worthwhile solution.

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Planning a Commercial Battery Storage System?

 

A successful commercial battery storage project should begin with an assessment of the building's complete energy requirements rather than simply selecting a battery.

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Electricity consumption, solar generation, peak demand, operating hours, EV charging and future electrification should all be considered.

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For businesses already considering commercial solar, it is particularly worthwhile assessing solar PV and battery storage together, even if the battery is installed at a later stage.

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APN Solar can help businesses and commercial property owners connect with experienced solar and battery specialists able to assess the property, analyse its electricity requirements and provide proposals for an appropriately designed commercial battery energy storage system.

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