Modern high-output electrode boilers are redefining how industrial facilities and district heating networks generate steam and hot water. Designed to operate using high-voltage electricity, today’s systems can deliver output capacities of up to 68 MW and steam pressures reaching 39 barg, placing them firmly in the range traditionally occupied by large fossil-fired boilers.
As demand for electrification increases, however, the technology itself is no longer the primary challenge. Instead, attention is shifting toward how these systems are delivered, integrated, and operated. It is increasingly uncommon for electrode boilers to be purchased as standalone pieces of equipment. Instead, projects are typically executed by third-party contractors responsible for full system integration, reflecting the growing complexity of modern boiler installations.
In many cases, an EPC contractor is appointed to oversee the full scope of work, covering engineering, procurement, and construction. Certain elements, such as process design and the development of building layout and architectural concepts, are handled internally, while the remaining work is performed by specialized subcontractors for piping installation, electrical work, and structural fabrication.
Now that model is increasingly being replaced by single-source providers that perform all the work in-house, delivering fully integrated turnkey solutions. These offerings include the boiler along with all ancillary equipment necessary for installation and may be constructed directly at the site or delivered as prefabricated units for rapid assembly. These modular designs can reduce project time from months to just a few weeks while also reducing overall costs. By limiting on-site work, they avoid the complexity and expense of installing equipment in existing spaces crowded with piping and steel structures.
“Designing and building a new boiler house off-site allows the work to be completed more efficiently,” says Juha Mäntynen, Chief Executive Officer of CT Industrial Oy (CTI), a Finland-based CleanTech provider specializing in turnkey, zero-emission, high-efficiency energy systems, including high-voltage electrode boilers for industrial and district heating applications across 19 European countries.
“All the steel structures for the building, concrete work, pipe assembly, electricity, and control systems—everything is included,” adds Mäntynen, adding that at CTI, this requires an in-house team of approximately 35 fitters and welders responsible for fabrication and installation work, along with engineers for overall project management, both process and mechanical engineering, automation, and electrical systems and commissioning.
Turnkey delivery allows customers to take a largely hands-off approach to boiler upgrades, avoiding the complexity and coordination burden typically associated with large infrastructure projects.
“This method is less risky,” Mäntynen says. “The customer doesn’t need to commit employees to a project management group. They can focus on their own business and manage this kind of project with just a few people. Having one fixed price also makes budgeting easier.”
The Boiler Defines the System
According to Mäntynen, the scope of a project depends on the customer’s existing infrastructure and available space. Some facilities already have a building prepared for the boiler installation, while others do not. When a project involves an existing building, a plant manager typically allocates a designated space for the boiler system. CTI begins by conducting an on-site assessment and performing a detailed 3D scan of the room. This scan is converted into a digital model, allowing the boiler and associated equipment to be accurately fitted within the available space.
In situations where no existing structure is available, CTI can assume responsibility for both the design and construction of the facility. Under this approach, the process begins with the architectural and engineering design of the boiler house. The boiler type and its specific use for hot water or steam generally determine the overall layout and dimensional requirements.
Hot water systems require fewer components, whereas steam boiler installations involve additional subsystems such as feedwater systems, pump feeds, pressure-reduction equipment, and water-treatment systems.
For the electrode boilers, CTI partners with North America-based Acme Engineering, a manufacturer of industrial and commercial boilers, to provide high-voltage electrode boilers to the European market. The electrode boilers are offered in horizontal configurations with capacities typically reaching approximately 10 to 12 megawatts. When higher output is required, a vertical configuration becomes necessary, which directly affects overall unit height. Horizontal models provide a compact profile, generally limited to about 3.5 meters in height, whereas vertical models commonly range from six to eight meters tall.
Electrical infrastructure must also be addressed. While customers typically supply a main transformer to power the boiler, contractors can assume responsibility for this as well. This could include a complete electrical system, starting with a 110 kV high-voltage supply that steps down to 20 kV, with all necessary switchgear.
In an electrode boiler system, a low- voltage transformer is typically required to supply power for control and automation systems such as PLCs, instrumentation for temperature, pressure, flow, and water conductivity measurement, human–machine interfaces, safety interlocks, alarm systems, and control circuits for auxiliary equipment such as valves and pumps.
A Modular Approach
While integrating new equipment into existing facilities may appear advantageous, such environments often contain extensive piping, steel structures, and other constraints. These limitations restrict layout options and typically require substantial on-site modifications, leading to increased installation complexity, longer schedules, and higher overall costs. By contrast, a prefabricated boiler house provides significantly greater flexibility and efficiency. Full control over the layout enables the system to be optimized from the outset, including the strategic use of modularization and prefabrication to reduce site work, improve quality, and streamline installation.
In many cases, the complete hot water or steam boiler system can be assembled in CTI’s facility as a single module similar in size to a shipping container. Factory-built modules reduce overall cost, require less on-site space, and significantly simplify installation. All piping connections, alignment verification, and functional testing are fully completed before the unit is transported. These modular solutions are suitable for both steam and hot-water applications and can be implemented in either horizontal or vertical configurations. For applications where ceiling height is restricted or overall system dimensions must comply with shipping limitations, a horizontal unit may be indicated.
Mäntynen says Acme Engineering is unique in offering a horizontal hot water boiler design that is particularly well-suited for retrofit projects. Acme Engineering also offers vertical boilers including the jet boiler, capable of handling higher pressures with zero to 100 percent modulating capacity, and the immersed electrode boiler, which can be configured for either hot water or steam applications.
According to Mäntynen, in a recent project the complete boiler structure built around a horizontal unit from Acme Engineering that measured approximately 19 meters in length, 7.5 meters in width, and 6 meters in height. For larger installations, the boiler system can be divided into multiple transportable sections that are shipped worldwide and require only minimal on-site assembly.
In another example in a large cheese manufacturing facility in Valio Haapavesi, the existing boiler room had no available space for the new equipment. As a result, a boiler building was constructed next to the original. The existing and new systems were then connected by a dedicated piping run to balance and operate both as a single plant. CTI is in the early stages of expanding this approach for electric boilers, but market interest is already strong. Mäntynen says EPC contractors across Europe are turning to CTI for modular boiler installations, as are customers looking to reduce costs.
“We have customers who are very interested in this approach because the transportation cost for a big boiler house is very high, and with the prefabricated modules, we can cut that price to one third,” states Mäntynen.