Quest Power: Delivering 2.25MW / 4.698MWh of Off-Grid Battery Storage for Mobile Healthcare

Quest Power is transforming mobile healthcare across the UK by providing reliable energy systems for CT and MRI diagnostic units that bring life saving imaging services directly to hospitals and communities. To support these specialist mobile facilities, Quest Power required a power solution capable of supplying stable, high quality electricity for sensitive medical equipment while significantly reducing reliance on diesel generators. Immersa partnered with Quest Power and AlphaESS UK to develop a bespoke off-grid battery storage solution built around the AlphaESS TB125 and 300kVA Static Transfer Switch (STS). Following extensive development, testing and commissioning, Quest Power committed to deploying 18 battery systems for this first-phase roll-out, representing 2.25MW / 4.698MWh of installed battery capacity. This project has been nominated for 'Renewable Energy Project of the Year Award' at edie Energy & Tech Awards 2026.

Quest Power: Delivering 2.25MW / 4.698MWh of Off-Grid Battery Storage for Mobile Healthcare

Project at a Glance

One of the UK's largest commercial off-grid battery deployments, delivering reliable power for mobile CT and MRI diagnostic units.

Immersa's Role:

Engineering support, technical development, battery supply, commissioning support and product training

Customer:

Quest Power

End Customer Type:

Medical Sector

Application:

Mobile CT & MRI diagnostic units

Total Installed Capacity:

2.25MW / 4.698MWh (18 systems)

System Size:

125kW / 261kWh per unit

Project Objective:

Deliver reliable off-grid power for mobile diagnostic facilities while reducing diesel generator reliance

Core Benefit:

One of the UK's largest commercial off-grid battery deployments supporting healthcare infrastructure

Challenge

Mobile CT and MRI scanners represent one of the most demanding battery storage applications. The system needed to: deliver exceptionally stable off-grid power; respond to rapid changes in electrical demand during scanning; integrate seamlessly with diesel generators; reduce fuel consumption and emissions; and maintain uninterrupted operation for critical healthcare services. Unlike conventional commercial applications, reliability wasn't simply desirable it was essential for patient care.

Approach

  • Engineering and technical support
  • Battery supply
  • Application testing alongside AlphaESS UK
  • Software and EMS development support
  • Commissioning
  • Product training for Quest Power engineers
  • Rather than acting purely as a product supplier, Immersa helped develop and validate a solution specifically engineered for mobile healthcare environments.

Products & Services

Products

  • 18 × AlphaESS TB125 (125kW / 261kWh)
  • AlphaESS 300kVA Static Transfer Switch (STS)

Services

  • Engineering & technical support
  • Battery integration
  • Commissioning
  • Product training
  • Application testing

Solution

At the heart of each mobile unit is the AlphaESS TB125, integrated with a 300kVA Static Transfer Switch. Rather than using the diesel generator as the primary energy source, the battery powers the CT and MRI equipment throughout the day. Once the battery reaches a predefined state of charge, the generator automatically starts, recharges the battery overnight and then shuts down, allowing the battery to resume supplying power the following day. This intelligent operating strategy significantly reduces generator runtime while maintaining uninterrupted power for highly sensitive diagnostic equipment. The TB125's ability to temporarily deliver 110% rated output also ensures it can comfortably manage the rapid power demands created during CT and MRI scans.

Results & Impact

  • Following extensive validation, Quest Power committed to deploying 18 battery systems across its growing mobile diagnostic fleet
  • 18 battery systems deployed
  • 2.25MW / 4.698MWh installed capacity
  • Reduced diesel generator operating hours
  • Lower fuel consumption and emissions
  • Stable power for CT & MRI scanners
  • Lower operating costs
  • Scalable platform for future fleet expansion
  • Beyond the technical performance, the project supports earlier diagnosis of lung cancer and other serious health conditions by enabling dependable mobile healthcare services throughout the UK.

Value Delivered

  • This project demonstrates how battery energy storage can move beyond traditional commercial applications to support critical national infrastructure.
  • By working closely with Quest Power and AlphaESS UK, Immersa helped deliver one of the UK's largest off grid commercial battery deployments for the healthcare sector. The result is an innovative, scalable energy solution that improves operational efficiency, reduces emissions and provides dependable power for life-saving diagnostic services.
  • We look forward to attending the edie Energy & Tech Awards 2026 with Quest Power and AlphaESS UK.

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