Construction Site Battery Storage & Hybrid Generator Power: 90kVA Victron BESS for Croudace Homes

How Energy Monkey, Envirolec and Gale Power Solutions combined a 90kVA three-phase Victron inverter system, 102.4kWh BSLBATT battery storage, 21.8kWp solar PV, bespoke 500A three-phase transfer switching and a 250kVA JCB generator to reduce diesel dependency on a major construction site in Essex.

Energy Monkey Ltd has recently been involved in the delivery of a major commercial construction site battery storage and hybrid generator power system for housebuilder Croudace Homes at a new-build development in Essex.

Working alongside Envirolec and Gale Power Solutions, Energy Monkey supplied the Victron Energy inverter/charger equipment and BSLBATT lithium battery storage and provided specialist system specification and technical support for this substantial containerised power installation.

The resulting system combines 90kVA of Victron inverter capacity, 102.4kWh of BSLBATT lithium battery storage, 21.8kWp of solar PV, bespoke 500A three-phase transfer switching and a 250kVA JCB generator.

Reducing Diesel Generator Use on Construction Sites

Large construction sites need substantial and reliable temporary electrical supplies.

Where a suitable grid connection is unavailable, the traditional solution has often been to install a large diesel generator and operate it for extended periods throughout the construction programme.

The problem is that site demand isn’t constant.

Site offices, welfare facilities, heating, lighting, tools, chargers and other electrical equipment all create a constantly changing load profile. A generator sized to accommodate the site’s higher loads may therefore spend considerable periods operating while only a fraction of its available capacity is actually required.

Over the lifetime of a large housing development, unnecessary generator runtime can translate into significant diesel consumption, servicing requirements, operating costs and carbon emissions.

The Croudace Homes project takes a different approach, using construction site battery storage to break the link between site demand and generator runtime.

Instead of relying entirely on continuous generator operation, the development uses a hybrid construction site power system combining battery storage, solar PV, high-power Victron inverter/chargers and generator support.

Stored battery energy can supply the site when appropriate, solar generation can contribute renewable electricity, and the generator remains available when additional power or battery charging is required.

The principle is simple: use stored and renewable energy wherever practical, and use the generator when it is actually needed.

For construction companies, housebuilders and developers, this provides an alternative approach to conventional generator-only temporary site power.

90kVA Three-Phase Victron Commercial Off-Grid System

At the heart of the installation are:

6 × Victron MultiPlus-II 48/15000 inverter/chargers

The six Victron MultiPlus-II 48/15000 inverter/chargers are configured as a three-phase system, with two units operating in parallel per phase, providing a total installed inverter capacity of 90kVA. Energy Monkey currently lists this exact 48/15000 model within its MultiPlus-II range.

This is considerably beyond the scale of a typical domestic battery installation and demonstrates how Victron MultiPlus-II inverter/chargers can be incorporated into demanding commercial, industrial and construction site power applications.

The MultiPlus-II inverter/chargers form the heart of the battery system, converting stored DC battery energy into AC electricity while also providing high-capacity battery charging as part of the wider generator-integrated installation.

102.4kWh BSLBATT Commercial Battery Storage

Energy storage is provided by:

20 × BSLBATT 51.2V 100Ah lithium batteries

Together, the batteries provide approximately 102.4kWh of lithium battery storage.

The installation uses Energy Monkey’s BSLBATT 51.2V 100Ah 5.12kWh rack-mounted lithium battery platform, with 20 batteries providing the substantial energy reserve required for this commercial application. The current Black Edition is a 5.12kWh LiFePO4 rack battery designed for scalable on-grid and off-grid energy storage and is compatible with Victron systems.

Instead of requiring the diesel generator to remain operational simply because electrical demand exists, energy stored within the batteries can be converted by the Victron inverter system and used to supply site loads.

This ability to store energy and separate generator operation from immediate site demand is one of the major advantages of using construction site battery storage, delivered as a Battery Energy Storage System or BESS, alongside conventional generation.

For businesses considering similar projects, Energy Monkey supplies a wider range of BSLBATT commercial and industrial battery storage solutions for scalable energy-storage applications.

21.8kWp Solar PV on the Construction Site Cabins

The system doesn’t rely solely on battery and generator power.

Available roof space across the site’s temporary cabins has been utilised to accommodate:

40 × 545W solar panels

Providing approximately 21.8kWp of installed solar PV capacity.

Solar charging is managed through:

• 1 × Victron SmartSolar MPPT RS 450/200
• 1 × Victron SmartSolar MPPT RS 450/100

The SmartSolar MPPT RS range is designed for high-voltage PV arrays on 48V battery systems, making it particularly suited to larger professional off-grid and energy-storage applications.

During suitable conditions, the solar array can contribute energy towards site consumption while also helping replenish the construction site battery storage bank.

Bespoke 500A Three-Phase External Transfer System

One of the most important engineering elements of this project is something that may not be immediately obvious from looking at the inverter and battery equipment:

The bespoke 500A three-phase external transfer arrangement

At this scale, integrating a 90kVA three-phase Victron inverter system with a 250kVA generator and the wider construction site electrical infrastructure requires a very different approach from a conventional smaller off-grid installation.

The solution incorporates a heavy-duty 500A three-phase contactor as part of a bespoke external transfer relay system.

The external switching arrangement allows the high-capacity AC supply to be managed externally rather than attempting to pass the full available site supply through the internal transfer switches of the MultiPlus-II inverter/chargers.

The result brings together 90kVA Victron inverter capacity, 102.4kWh BSLBATT battery storage, 21.8kWp solar PV, 250kVA generator capacity and 500A three-phase external transfer switching into one integrated commercial hybrid power system.

Thermal Imaging & High-Current Commissioning

With a commercial electrical installation of this scale, specification is only part of the job. Commissioning and verification are equally important.

As part of the commissioning process, thermal imaging was used to inspect high-current electrical connections and switching equipment while the installation was operating under load.

The thermal images captured during commissioning showed temperatures across the inspected areas in the region of approximately 27°C to 34°C at the time the images were taken.

250kVA JCB Generator: Available When It’s Needed

Generator capacity remains an important part of the installation.

A 250kVA JCB generator supplied by Gale Power Solutions, complete with remote telematics, provides substantial generating capacity when required.

The aim of the project isn’t simply to remove the generator. It’s about using it more intelligently.

With a conventional generator-only installation, the generator may need to remain operational whenever the construction site requires electricity, irrespective of whether the load is high or low.

Battery storage changes that relationship. When conditions allow, stored battery energy can supply the site through the Victron inverter system. Solar generation can contribute further energy during daylight hours. When site demand, battery state of charge or other operating conditions require additional energy, the generator remains available.

This creates a hybrid generator and battery storage system where each part of the installation performs the role it is best suited to.

Reducing unnecessary generator operating hours has the potential to reduce diesel consumption, fuel costs, generator servicing, emissions, noise and the overall carbon impact of temporary construction site power.

A Three-Way Partnership

A commercial off-grid project of this scale requires more than simply supplying equipment.

The Croudace Homes installation has been delivered through collaboration between Energy Monkey Ltd, Envirolec and Gale Power Solutions, bringing together expertise across battery storage, Victron power electronics, electrical installation and commercial generator systems.

Energy Monkey Ltd

Energy Monkey supplied the Victron Energy and BSLBATT equipment, supported the specification of the power system and provides specialist technical support.

Envirolec

Envirolec delivered the installation and project for its customer Croudace Homes, integrating the equipment into the containerised construction site power system.

Gale Power Solutions

Gale Power Solutions supplied the 250kVA JCB generator and associated generator expertise.

The collaborative approach provides Croudace Homes with support across the complete hybrid installation rather than treating the generator, battery storage and inverter systems as completely separate technologies.

Containerised Construction Site Battery Storage Built to Move

One of the most interesting aspects of the Croudace Homes system is that it isn’t permanently tied to the Essex development.

The main power equipment has been installed within a dedicated containerised power system. Once construction at the development is complete, the installation can be disconnected, packed up and transported to the next Croudace Homes building site, then recommissioned to begin reducing generator dependency on another development.

For a major housebuilder operating multiple construction projects, this transforms the installation into a reusable commercial energy asset rather than infrastructure that has to remain permanently attached to a single site.

The same Victron inverter system, BSLBATT battery storage and associated electrical infrastructure can potentially be utilised across numerous developments during its working life.

This makes containerised battery storage particularly interesting for temporary construction site power, remote power applications, infrastructure projects and developments awaiting permanent grid connections.

A Proven Concept for Croudace Homes

The Essex project isn’t the first large hybrid battery system delivered for Croudace Homes.

A previous system of a similar scale was installed at a Croudace Homes development in Reading and has now been operating successfully for a number of years. Following the performance of that installation, the concept has been repeated for the Essex development.

This is particularly significant. For Croudace Homes, hybrid construction site power is no longer simply a theoretical exercise or trial of new technology. The approach has already been used in a real construction environment over an extended period.

Croudace Homes has calculated that adopting this approach across its projects has the potential to generate multi-million-pound savings in diesel costs, while also substantially reducing the carbon impact associated with powering its construction sites.

Construction Site Battery Storage: A Different Approach to Temporary Power

The construction industry continues to look for practical ways to reduce emissions, improve energy efficiency and decrease its dependence on fossil fuels. Temporary site power represents a significant opportunity.

Battery storage doesn’t necessarily mean that generators have to disappear from construction sites altogether. Instead, solar PV, lithium battery storage, inverter technology and conventional generation can work together as one hybrid power system.

• The generator provides substantial energy when required.
• The batteries store energy for later use.
• The Victron inverter system supplies and manages AC power from the battery bank.
• Solar PV provides renewable generation whenever conditions allow.
• The bespoke three-phase transfer system brings these different elements together at a scale appropriate for a major construction project.

The result is a much more intelligent approach to commercial temporary power generation.

“Fantastic to See Building Sites Moving to Greener Power”

Paul Collins, Technical Sales Manager at Energy Monkey Ltd, commented:

“It is fantastic to see building sites of this scale moving towards more modern and greener ways of powering their sites.

Projects like this show what can be achieved when battery storage, solar, generator capacity and intelligent power management are designed to work together.

The site still has access to the reliable power it needs, but without having to depend entirely on continuous generator operation. It’s great to see this approach already proven on one Croudace Homes development and now being rolled out again.”

The Croudace Homes Construction Site Battery Storage System at a Glance

Commercial Battery Storage & Hybrid Generator Systems from Energy Monkey

Energy Monkey Ltd specialises in the supply, specification and technical support of Victron Energy power systems and BSLBATT lithium battery storage solutions for demanding commercial applications.

Our experience extends beyond conventional domestic and small off-grid installations to include large three-phase Victron systems, commercial battery energy storage systems, generator integration, containerised power systems and high-capacity off-grid installations.

Businesses planning similar projects can explore Energy Monkey’s Victron inverter and inverter/charger range, BSLBATT battery storage range and wider renewable energy hardware range.

The Croudace Homes project demonstrates what can be achieved when commercial battery storage, solar generation, high-power inverter technology and diesel generation are treated as parts of a single integrated energy system.

For organisations currently relying on large diesel generators, a hybrid battery energy storage system could provide an opportunity to reduce generator runtime while maintaining the reliability and peak power capacity required by the site.

Applications can include construction sites, housebuilding developments, temporary site compounds, civil engineering projects, infrastructure projects, remote industrial sites, welfare facilities, temporary offices, events, agricultural sites and commercial locations awaiting grid connection.

Related Commercial Victron Project

Interested in seeing another large-scale Energy Monkey installation?

Take a look at our previous project exploring three-phase power from a single-phase grid using Victron Energy, featuring a large Victron system with MultiPlus-II inverter/chargers, SmartSolar RS solar charging and battery storage.

Together, these projects demonstrate how Victron commercial energy storage and three-phase power systems can be engineered for applications far beyond conventional domestic installations.

Looking to Reduce Diesel Generator Use on Your Site?

If your construction site or commercial project currently relies on a 100kVA, 150kVA, 200kVA, 250kVA or larger diesel generator, Energy Monkey can help explore whether construction site battery storage, solar PV and intelligent generator integration could reduce the amount of time it needs to run.

From commercial BESS and containerised battery storage to three-phase Victron inverter systems, generator integration and bespoke off-grid power solutions, we can help specify the equipment and provide the technical support required to deliver a system around your project’s actual power requirements.

You can also explore the Energy Monkey online shop for Victron Energy, BSLBATT and associated renewable-energy equipment.

Energy Monkey Ltd, Commercial Victron Energy & BSLBATT Power System Specialists.

Generate. Store. Manage. Use the generator when you actually need it.