DEIF: Genset, power management and marine controllers made in Denmark

Overview

DEIF began in a workshop in Nørrebro, Copenhagen, in 1933, when Erling Foss and two partners founded Dansk Elektro Instrument Fabrik to make electromagnetic measuring instruments for power plants and hospitals, according to the company's history. The Danish business register records the company's start date as 1 June 1933 (CVR 15798416). Ships soon became a core market: DEIF developed rudder indicators and bridge instruments in the following decades, and moved production to Skive in north-west Jutland in 1973, where its headquarters and only factory still are. It later launched the Delomatic generator control systems for ships and power plants.

The company's position today rests on two markets it has served for decades, land power and marine, and on keeping engineering and manufacturing in Denmark. Its 2025 annual report says DEIF controllers were installed on 40% of IMO-registered newbuild ships in 2025 and that 20 to 25% of new data centres worldwide that year included DEIF solutions. Most products are delivered within seven days from Skive. DEIF also retrofits control systems on ageing wind turbines, a line that grew from its 2004 acquisition of the wind turbine control company West Control, which became DEIF Wind Power Technology.

Since 2021, under chief executive Christian Nielsen, DEIF has been moving from a supplier of genset controllers to a broader energy control company. It has launched the iE platform, whose iE 250 won the EUROPGEN Product of the Year award in 2026 (announcement), certified that platform to the maritime cybersecurity rule IACS UR E27, and started building silicon carbide power converters with AVL and Wolfspeed. The Foss family still owns all of it.

Offering

Genset and power management controllers

The AGC 150 is the compact workhorse: one hardware becomes a stand-alone genset controller, a paralleling genset controller, a mains or bus tie breaker controller, a PV hybrid controller, an engine drive controller, an ATS controller for up to three breakers or a PMS Lite controller for off-grid plants of up to 128 gensets, depending on the Stand-alone, Core, Extended or Premium software package. The AGC-4 Mk II covers larger and critical plants, with Core power management for 32 gensets, Extended power management for up to 992 gensets in 32 groups, hot standby redundancy, N+X running reserve and close before excitation that puts backup power on the busbar in six seconds. The SGC 420 Mk II and the rest of the SGC range serve OEMs and packagers who need a single-set controller for engine drive, island or AMF duty.

The iE platform

The iE 250 is a modular controller with a 7-inch touch display, a quad-core processor and feature packages for rental, critical power or hybrid plants, and it shares power management with AGC-4 Mk II and AGC 150 plants. The rack-based iE 350 controls generators, mains and bus tie breakers, with optional ANSI 87G differential protection and CODESYS. The iE Marine series, launched in August 2024, puts the same platform on ships, and the PPM 300 marine controller is being phased out in favour of the iE 350 Marine.

Hybrid, storage and other products

The ASC 150 Storage and ASC 150 Solar controllers, with the older ASC-4 range, run PV and battery storage alongside gensets in greenfield and brownfield plants. DEIF also sells the DVC 550 digital voltage regulator, MVR-200 medium-voltage protection relays, the iE 650 PLC and AWC 500 programmable controllers for wind and industrial control, switchboard instruments and transducers, and bridge instruments under the Marine Instruments business, which the annual report says will become a separate entity in 2026.

Software and services

PICUS and USW-3 are free configuration tools. Insight is a subscription remote monitoring service, alongside the Smart Remote gateway, the FX-30 data acquisition unit and the Blueflow vessel energy management system listed on the remote monitoring page. Hardware is sold directly, through 14 subsidiaries and through distributors; prices are not published.

Technology

Interfaces on the AGC 150

The AGC 150 stand-alone data sheet (revision F, software 1.35) is representative of the controllers most often integrated. It has two RS-485 ports for Modbus RTU, PLC, SCADA or Insight at 9,600 to 115,200 baud (port 1 isolated, port 2 not), an isolated 10/100 Mbit Ethernet port for Modbus TCP, NTP time synchronisation and the PC utility software, a USB-B service port and two CAN ports: CAN A for the engine ECU in DEIF's J1939 and CANopen specification and for CIO and IOM I/O modules, and an isolated CAN B for the AOP-2 operator panel and power management at 125 or 250 kbit/s. The Modbus area is configurable. The separate Modbus server user manual documents coils, discrete inputs, holding and input registers and the write functions, and the current Modbus table is a spreadsheet on the public documentation page. The controller speaks to engine ECUs from more than 30 makers, including Caterpillar, Cummins, MTU, Perkins, Scania, Volvo Penta and the main Chinese engine brands.

Other families add other buses. The AGC-4 Mk II supports Modbus over RS-485, USB and TCP/IP and Profibus. The iE 650 PLC uses EtherCAT for its I/O and supports PROFINET, Modbus TCP/RTU, OPC UA and HTTPS/WSS for cloud connections. The MVR-200 relays offer IEC 60870-5-101/103/104 or IEC 61850 Ed. 2. PICUS includes a Flexible Modbus function that remaps an iE controller's addresses to match an existing master's configuration.

Reading DEIF controllers from other systems

Victron Energy documents an integration in its GX manual: a GX device on Venus OS 3.50 or later reads AGC 150 Generator, Hybrid and PMS Lite controllers with firmware 1.19.0 (May 2024) or later over Modbus, through Ethernet or RS-485 port 1, detects them from identification values and uses them for readout and control in its connected genset integration. It supports only the default voltage scaling setting.

Security and approvals

All variants of the iE 250 and iE 350 and the iE 650 PLC carry full IACS UR E27 certification, which DEIF's cybersecurity page describes as aligned with IEC 62443 and which its iE Marine launch called a first in the maritime industry. The iE 250 also lists a DNV cybersecurity type approval and a UL certificate of compliance (EUROPGEN announcement). DEIF runs an ISO/IEC 27001 information security management system and says it is classified as an important entity under NIS2. The AGC 150 is UL/cUL listed to UL/ULC 6200:2019, rated -40 to +70 °C with an IP65 front, and the AGC-4 Mk II lists IEEE 1547, VDE-AR-N 4110 and 4105, EN 50549-1/2 and G99.

Customers

Rental and genset builders

Sunbelt Rentals, with more than 1,300 locations in North America, has standardised its generator fleet on DEIF: it started with AGC-4 seven or eight years before the case study, now uses AGC-4 Mk II every day and has added AGC 150 for gensets and ASC 150 for battery storage. Its power and HVAC managers describe DEIF as their power generation ecosystem management platform of choice, and the two companies developed the TDU 107 touch display together. Atlas Copco Rental moved its twin-power units from the DVC 310 to the DVC 550 regulator in May 2020 to deliver any voltage between 380 and 690 V and stop shutdowns caused by transformer magnetisation peaks. Chinese builders Shanghai Cooltech Power, which has made DEIF controllers standard in its critical power solutions since 2012, and AGG, which chose DEIF in 2019 for synchronising, are among the genset makers named. Dutch rental company HOB Aggregaten, a DEIF user since 2002, runs a hydrogen combustion genset with grid take-over and grid support on a DEIF control platform.

Power plants, data centres and hospitals

For the Bangladesh Power Development Board, APR Energy built a 300 MW plant near Keraniganj with about 250 CAT and MTU gensets on AGC-4 controllers; DEIF's power management brings it to 300 MW in under 15 minutes and provides automatic MVAr voltage support. The Lefdal Mine Datacenter in western Norway runs its emergency power, including two 2.5 MW generators, on AGC-4 and ALC-4 controllers. At Ullevål Hospital, part of Oslo University Hospital, a fragmented building-by-building emergency power system was rebuilt with DEIF controls and remote monitoring, designed with the consultancy COWI.

Hybrid microgrids

In Egypt, KarmSolar operates two off-grid hybrid microgrids built on DEIF controllers with DEIF's distributor ATOS Generators, one supplying a Cairo 3A poultry farm through a 22 kV overhead line. ATOS lists itself as an authorised DEIF agent on its own site.

Markets

DEIF sells worldwide from Denmark. Its 2025 annual report lists 14 wholly owned subsidiaries at the end of the year, in Norway, Germany, the UK, Spain, China, Brazil, the United States, India, France, Singapore, the United Arab Emirates, Korea, Mexico and Austria, with new subsidiaries in Croatia, Turkey and Australia established in 2026 and a joint venture in Japan due to start in 2026. Products go to system integrators, genset manufacturers, switchboard builders and asset owners such as data centre, hybrid plant, ship and wind farm owners, directly, through subsidiaries or through distributors, and the company is rolling out a channel partner strategy for dealers.

Regions

The report describes double-digit growth in the Americas in 2025, strongest in Mexico and Brazil, with authorised dealer and service partners added in Florida, Texas, Seattle and Connecticut; strong growth in India, Saudi Arabia, Nigeria and South Africa driven by battery storage and data centres; modest growth in a mature European market; and significant growth in China, Korea and Singapore. In August 2025 DEIF formalised a partnership with LEES Power for Australia and New Zealand, and in October 2026 it opened an office and converter lab in Zagreb for South-Central and Eastern Europe.

Segments

Land power covers data centres, hospitals, airports, infrastructure, telecom, rental, mining and power stations, plus hybrid PV, battery and diesel plants. Marine covers commercial, offshore, fishing and passenger vessels, where DEIF supplies power management, AC and DC hybrid control and bridge instruments, and is a partner in the EU ALL-DC-SHIPS project on DC grids for ships. Wind covers control retrofits: by the end of 2025 DEIF had supported the upgrade of 782 turbines, in projects that typically cover 50 to 250 turbines in Europe and the US.

Company

Legal entity and ownership

The operating company is DEIF A/S, CVR 15798416, at Frisenborgvej 33, 7800 Skive, Denmark (register record). The 2025 annual report states that all shares are owned by FJV Foss Holding A/S of the same address, and the Foss family has owned DEIF since 1933. A 2023 company press release names the owners as Toke Foss and his three children (factory announcement). Subsidiaries are registered abroad as well; DEIF (UK) Limited, for example, was incorporated on 15 May 2000 and lists DEIF A/S as its person with significant control at Companies House.

Leadership

Toke Foss was chief executive from 1986 to 2021 and has chaired the board since 2021. Christian Nielsen, in executive management since 2002, became group CEO in 2021. The executive team also includes Chanette Nyrup Oksborg (product, technology and operation), Marjanne Grønhøj (HR, communication and sustainability) and Henrik Sykes Bjerregraard, who joined executive management for finance in 2026. The board has three family members, deputy chair Malene Richter Christensen, CFO of Telenor Denmark, Kamstrup chief executive Søren Kvorning, DESMI chief executive Humphrey Lau and three employee representatives.

Growth and investment

Revenue reached DKK 869 million in 2025, up 14% on DKK 766 million in 2024 and the fifth consecutive year of growth, according to the annual report and the 2024 results release. EBITDA was 13% and EBIT 3.7%, which DEIF attributes mainly to currency movements and to spending 18% of revenue on R&D. The group had 649 full-time employees at the end of 2025, 403 in Denmark and 246 abroad. DEIF opened a new automated electronics factory in Skive in January 2024, formed a converter partnership with AVL in April 2024 and began converter production in 2025. It won the EY Entrepreneur Of The Year 2023 award in the ESG category (announcement) and had its emissions targets approved by the Science Based Targets initiative in 2024. Its stated ambition is to triple revenue by 2033, the company's centenary.