• Infrastructure & Network Build

Infrastructure and Network Build is essentially the traditional “dirty-boots” construction sector of our business, which was originally established back in 1999 as TESL. Like the “clean-boots” technical operations sector of our business, here we again operate across the Water, Electric and Telecoms utility sectors, and as you can see from the projects below, we have extensive experience, across each of these utility sectors.

  • Power Services


Mainline Power has the capability to install and joint cables from 20KV to 220KV. Unlike other cable installers we are unique in that the cable installation and jointing, as well as the testing (see Testing Section) is carried out in-house. For you the customer this means that Mainline Power will complete the project with experienced personnel, whom we know can deliver a quality product. We are approved by ESB Networks to install/joint cables up to 220KV.

Mainline Power provides a full underground cable duct design and installation service. We will ensure that the optimum duct type and size is installed to ensure that cable pulling tensions are within cable manufacturers guidelines while ensuring that future electrical losses are kept to a minimum.


We have over fourteen years experience in the new-build, and refurbishment of HV / MV substations with ESB, as well as within the private sector. We also carry out major refurbishment programmes for the ESB in live substations. The type of work we have completed to date includes the following:

• 110 KV Station refurbishment and protection upgrade.
• 110 KV Cubicle installation and upgrade including all civil works.
• 110 KV Islanding protection.
• 110 KV Bulk Supply Metering.
• 110/38/20 KV Duct & Cable installation and jointing.
• 20 KV Sub-station installation, maintenance and commissioning, & civil works.
• 38 KV Sub-station Design, Build and Commission.
• 38 KV Traffo Installation and Differential and Neutral Earth Fault protection upgrade.
• 38 KV Sub-station Refurbishment including all civil works.
• 38 KV Protection upgrade including build/supply protection panels.
• 38 KV Asset replacement.
• Auto-Recloser installation, testing and commissioning.


Mainline Power has the in-house capability to carry out all associated electrical testing for HV, MV and LV installations, including Particle Discharge Testing (PD), Very Low Frequency Testing (VLF), and Tan Delta Testing (TD).

The objective of any testing, whether it is carried out as part of the commissioning procedure, or as part of a preventative maintenance programme, is to maximise the reliability, and lifespan of the installation. Typically, the conversion of defects into faults starts with the initiation of a discharge at the fault location, as the cable is put under electrical stress. This leads to electrical tree growth in the cable dielectric and ultimately to a breakdown of the cable insulation. By using the above mentioned testing techniques, we can detect and monitor the following:

• Degradation of the cable and cable joint insulation.
• Mechanical damage to the cables and cable joints.
• Monitor ongoing condition of the cable (periodic testing).
• Assess suitability of the existing cable joints and termination kits.
• Pinpoint the location of potential future failure points.


Very Low Frequency (VLF) insulation Testing (or withstands tests) is usually carried out at 0.1 Hz and involves applying a test voltage of three times the nominal working voltage to the cable for one hour, or 15 minutes for older cables. VLF Testing takes longer to perform than DC insulation resistance testing, but will more reliably uncover a wider range of problems, and is less likely to cause further damage to the cable, especially older cables, enabling electrical apparatus to be better classified as either good for return to service (Go) or susceptible to imminent failure (No Go). Accordingly therefore VLF Testing provides an accurate snapshot of the functional status of a cable at a point in time (Go/No Go), but does provide an indication of possible future issues.

SMART VLF Testing: Tan Delta Testing (see below) can also be combined with VLF testing to provide an intelligent or SMART VLF Test. By analysing the Tan Delta information in real time, the Test Engineer can reduce the frequency of testing on cables which demonstrate good characteristics, and increase the frequency of testing on cables which demonstrate poor insulation characteristics


Tan Delta (TD) Testing, also referred to as Loss Angle or the Dissipation Factor Testing, is an excellent diagnostic criteria that provides an indication of the quality of the dielectric insulation, by analysing the dielectric losses in the insulation. The TD Test provides a versatile high voltage diagnostic system that is suitable for testing MV and HV cables, as well as other electrical apparatus such as capacitors, transformers and large rotating machines. Essentially with the Tan Delta Test insulation defects can be detected before they result in the ultimate failure of the equipment.

Tan Delta measurements are the most effective and widely used diagnostic method for detecting water trees and water degradation, the most common aging mechanism and cause of failure in old extruded insulated cables, which often go undetected with other common diagnostic techniques. Tan Delta tests can also be performed at test voltages below the normal operating voltage of the equipment under test, which minimizes the risk of a cable insulation failure, which could otherwise occur during an elevated voltage test, on a weak or old cable.


Small particles, such as dust, tiny trace substances, humidity or minute air gaps, can sometimes go undetected during the installation process, and if they are in a critical location, they can cause defects. This can lead to severe insulation failures and a reduction in the lifetime of the cable. Such subtle defects may not always be detected during a VLF Test, however they can be detected by Partial Discharge (PD) Testing, allowing an assessment of the future operational reliability of the equipment. With PD Testing it is therefore possible to categorized cables as “new”, “strongly aged” or “faulty”, thus enabling appropriate maintenance and repair measures to be planned and organised in advance. PD measurements are consequently the established diagnostic criteria used to access the majority of electrical equipment in a power system, and more importantly the quality to which that equipment was installed.

Click here for further information on the benefits of using our market leading b2 testing equipment

Combined Testing

The 1st graphic below shows the individual benefit of VLF, TD and PD Testing, all three methods of testing provide useful information, but different information. The graphic also demonstrates that no single test is sufficient to fully analyse the operational reliability of the equipment under test.


The 2nd graphic below clearly demonstrates the benefits of a combined testing regime and accordingly Mainline Power recommends that where appropriate, all testing programmes include VLF, TD and PD Testing to ensure the full extent of the operational reliability of the equipment under test is ascertained. Mainline Power has the in-house capability to carry out VLF, TD and PD Testing.



Mainline Power also has the capability to carry out duct installation, as well as all civil works associated with MV/HV substation new-build and refurbishment including the following:

• Construction of bunded transformer bases.
• Complete compound civil works and construction of MV/HV switchgear buildings and relay rooms.
• Installation of line Cubicle bases, ducting, surfacing of compounds and erection of compound fencing and support structures.

Completed Projects


Barranafaddock (Waterford): Full MV/LV fit-out and commission of GE wind turbines, including transformer Protection/Control installation.

Thornog (Tyrone): Turbine Transformer and MV/LV cable installation, Transformer Protection/Control installation, and commissioning.

Woodhouse (Waterford): Turbine Transformer and MV/LV cable installation, Transformer Protection/Control installation, and commissioning.

Knockacummer (Cork): Turbine Transformer and MV/LV cable installation, Transformer Protection/Control installation, and commissioning.

Glantane I & II (Cork): Turbine Transformer and MV /LV cable installation, Transformer Protection/Control installation, and commissioning. Plus Sub-station installation and Collector circuits installation along with VLF testing. Fibre Optic installation, jointing and testing also included.

Leiterfrack (Galway): 28 Km of 20 KV collector cables installation, as well as Fibre Optic installation.

Leitergunnett (Galway): 31 Km of 20 KV collector cables installation, as well as Fibre Optic installation.

Kerry Windfarms x 3 (Maghanknockane, Knocknagoum, Cahercullenagh): 43 Km of 20 KV collector cables installation, as well as Fibre Optic installation.

Athea (Limerick): 38KV GIS, Switchgear installation. 110KV GIS Sub Station Switchgear installation, as well as Control/Protection, and LV services.

Knockalour (Wexford): Balance of plant. Substation installation and Collector circuits installation, along with VLF testing. Fibre Optic installation, jointing and testing also included.

GarryCummer (Tipperary): Turbine Transformer and MV/LV cable installation, Transformer Protection/Control installation and commissioning.

Ballynancornan (Wexford): Balance of plant. Collector circuits installation jointing, along with VLF testing. Fibre Optic installation, jointing and testing also included.

Churchill / Chrighshane (Tyrone): Collector circuits installation. Jointing and testing, including Earth Electrode resistivity testing.

Boggeragh (Cork): 35 KM of 20 KV Collector system installation and jointing.

Bawnmore 1 and Bawnmore 2 (Cork): 26 Km of 20 KV collector systems and 20KV interconnector cable installation and jointing.

Rathcahill (Limerick): 26 Km of 20 KV Collector system installation and jointing. Sub-station Trafo and RMU Connection.


Castletownbere 38KV Substation (Cork): Conversion to 20KV, including Trafo replacement, Station Protection Upgrade, replace AAP, relocation of Interface Trafo, installation of 3 No. RMU’s, and installation of Unit Sub. Undergrounding of all MV Networks in the Station, Refurbishment of all MV cubicles and 38KV Trafo cubicle. All civil work associated with the refurbishment including bunded Trafo base.

Causeway 38 KV Substation (Kerry): Removal of Trafo from Trien 38KV Substation and installation in Causeway. Work included HV / MV Trafo cubicles, protection upgrade, AAP replacement, and all associated civil works.

Smearla 38KV Substation (Kerry): Complete refurbishment of existing outdoor station and conversion to Hi-Bred station, including installation of outdoor 38KV Substation, indoor 20KV Substation, all protection and all civil works.

Newcastlewest 38 KV Substation (Limerick): Extension of the 38KV busbar, construction of 2 No. 38 KV Cubicles, diversion of 38KV lines within the station, and all associated civil works.

Charlville 110KV Substation (Cork): Protection upgrade of two 38 KV Lines including construction and installation of two Protection panels.

Monateen 110KV Substation (Limerick): Complete refurbishment of station including outdoor compound equipment upgrade and full protection upgrade.

Aughinish 110KV Substation (Limerick): Installation of islanding protection and upgrade of existing protection.

ESB Networks (Kerry): Construction of 38KV distribution Substation at Lacha, Ballydesmond Co Cork.

ESB Networks (Kerry): Install Differential Protection on 38 KV Transformers in 6 distribution Substations. Kenmare, Woodford, Ballybunion, Dingle, Ballard and Milltown.

ESB Networks (Kerry): Install Earth Fault Tripping in all 10 KV cubicles in Tralee and Killarney.

ESB Networks (Kerry): Replace Auto Recloser in Kenmare 38KV Substation.

ESB Networks (Limerick): Replace 2 No. Oil CBs with Auto Reclosers in Kilrush 38KV Substation.

ESB Networks (Limerick): Install Bulk Supply Metering in Tullybrack 110KV Substation.

ESB Networks (Limerick): Install new 38KV Cubicle in Tullybrack 110KV Station for Moanmore Windfarm connection. Work included installation of all support steelwork, Circuit Breakers, CT /VTs’ Cabling, panel assembly and wiring, protection, alarms and SCADA.

ESB Networks (Limerick): Install Earth Fault tripping and replace Protection and Alarm panels at Southill and Ballinacurra, 38 KV Sub-stations in Limerick.

ESB Networks (Limerick): Construction of 10KV cubicle at Cahirdavin 38KV Substation including installation of Circuit Breaker, CT / VT’s, Disconnects, all cabling, Protection, Alarms and SCADA.

ESB Networks (Limerick): Install SCADA on all cubicles in Tullybrack 110KV Substation.

ESB Networks (Clare): Install Unit-Sub including underground MV/LV cabling at Kilkee.

ESB Networks (Limerick): Upgrade 2 No. 110KV line cubicles and protection at Monateen 110KV Substation, including building, wiring and installing new protection panel. Installing new Busbar Protection Panel and associated wiring. Installing SCADA. Replacing CT/VT’s, CB’s Line Traps and all associated primary and secondary and control wiring and alterations to supporting steelwork.

ESB Networks (Kerry): Upgrade 2 No. 110 KV Line cubicles at Tarbert Generating Station. Including Circuit Breaker replacement, CT / VT replacement, and control wiring.

ESB Networks (Limerick): Construction of 10KV cubicle at Southill 38KV Substation, including Installation of Circuit Breaker, CT/VT’s, Disconnects, All cabling, Protection, Alarms and SCADA.

ESB Networks (Limerick): Convert Three Pole tripping to Single Pole tripping on circuit breakers on Moneypoint 220KV line at Prospect 220KV Station.

ESB Networks (Galway): Replace 2 No. Line Auto Reclosers at Claregalway 38KV Distribution Substation.

Athea Windfarm (Limerick): 110KV Gas Insulated (GIS) Sub-station Switchgear installation and 38KV GIS Switchgear installation. 110Kv Cable installation including control and protection.

McDonagh St. (Kilkenny City): Construction of new indoor GIS 38KV station.

Nurnwood (Portloise): 38KV Sub-station. Complete Electrical installation of new Hybrid 38KV station at ESB Networks training school including 10KV/20KV/38KV GIS switchgear.

Oakfield (Sligo): 38KV Sub-station. Complete refurbishment of 38KV Sub-station and conversion to Hybrid Station.

Pallas 110KV Substation (Laois): Green field site new build of 2 No. line cubicles and a Traffo Cubicle along with a Relay room and a client 20KV switchgear room and control building.

Asset Replacement: We have replaced in excess of 50 No. Reclosers, MV Circuit-breakers and 38 KV Circuit-breakers in Clare, Limerick, Tipperary and Laois. We have also replaced a large number of battery-chargers in these stations. The majority of this asset replacement work also required substantial civil works.

HV/MV Grid Connection

Barranafaddock (Waterford): 38KV Grid Connection, installation and jointing of 20 Km of 38 KV Cable and Communication fibre optic from
Barranafaddock Windfarm to Barrymore ESB 38 KV Substation.

Salthill (Galway): 110KV Substation to Lettergunnet Windfarm. Grid Connection, installation and Testing of 30km of 38KV cables.

Glenlara (Cork): 110KV Substation to Knockacummer Windfarm Grid Connection, installation and testing of 110KV cables for ESB.

Carlow: 38KV Substation to Gortahile Windfarm Grid Connection, installation and Jointing of 20km of 38 KV Cable and Communication fibre optic.

Trien (Limerick): 110KV Substation to Knockwarriage Windfarm 38 KV Grid connection, installation and Jointing of 96 km of 38 KV Cable and Communication fibre optic.

Trein ( Limerick): 110 KV Grid Connection to Athea Windfarm, installation of 110KV U/G Cables for ESB Networks.

Dromada (Limerick): Trien 110KV Substation to Dromada Windfarm Grid Connection, installation of 110KV U/G Cables, 10KV Ducting and Cable.

Rathkeale (Limerick): Grouse Lodge Windfarm to Rathkeale 110KV Substation Grid connection, installation and jointing of 12 km of 38 KV Cable and Communication fibre optic.

Bawnmore (Cork): Macroom 110 KV Substation to Bawnmore Windfarm 1 & 2 Grid Connection: installation and jointing of 30 km of 38 KV Cable and Communication fibre optic.

Ballyvane (Cork): 110KV Substation to Ballylickey Windfarm 38KV Grid connection, installation and jointing of 22 km of 38 KV Cable and Communication fibre optic.

Salthill (Galway): 110KV Substation to Lettergunnet Windfarm 38KV Grid connection, installation of 14km of 38 KV Cable and Communication fibre optic.
Knocknalour (Wexford): 20 KV grid connection from Knocknalour Wind farm to Crory Sub- station. Cable installation, jointing and Partial Discharge testing.

Glenlara (Cork): Glenlara 110 KV Sub-station to Dromdiveen Windfarm grid connection. Installation and Jointing of 51 Km of 38 KV Cable and communication fibre optic.

Garrycummer (Tipperary): Cauteen 110 KV Sub-station Garrycummer Wind Farm grid connection. Installation and Jointing of 51 Km of 38 KV Cable and communication fibre optic.

Gibbet Hill (Wexford): Grid connection to Crory Sub-station. Installation, Jointing and testing of 13 Km of 2 x 3 x 400sq. 20 KV underground cable.

Boggeragh (Cork): Glashavoon 220KV Sub-station to Boggeragh windfarm 110KV grid connection. Installation and Jointing 16 Km of 110KC Cable and communication fibre optic.

Ballycadden / Ballyduff (Wexford): Crory 110KV Sub-station To Ballycadden/Ballyduff Windfarms. Installation of 30 Km of 3x 400sq. 20KVv underground cable and installation of communication fibre optic.

Civil Works

ESB Networks Civil Sub Station Frame work Contract 2014 to 2017: One of 2 approved Contractors on the Framework in Munster.

Newcastlewest (Limerick): 38Kv Substation ducting, cubicle bases, & erection of support structures.

Trien (Limerick): 110Kv Substation, installation of 110 KV ducting, installation of 110KV Line cubicle bases, and installation of access road.

Smearla (Kerry): 38 KV Substation, complete compound civil works and construction of 20KV switchgear building and relay room.

Parkway to University of Limerick: Installation of 20KV/38KV ducting from Parkway roundabout to entrance of University of Limerick along the old Dublin road.

Parteen Weir Co Clare to Corbally (Limerick): 38KV Substation, installation of steel 38KV ducting. Approximately 1.5 km’s of this route was through tidal along the Shannon bank while the remaining 2 km’s was urban. Also installed and jointed 3 x 630sq. 38KV cable.

Unit Sub Refurbishment/Replacement (Limerick City): All civil works required to refurbish all 10KV / 20 KV Substations in Limerick City, including ducting, trafo bases, and concrete enclosures.

Shannon (Clare): URD Replacement, install mini-pillars/unit sub. Install and backfill ducting, road and footpath refurbishment,

Westside (Galway City): Installation of 38 KV / 110KVv ducting to facilitate underground all incoming lines to Westside 38KV Substation, and also to prepare for construction of new 110KVv Substation. This work included providing a temporary roadway for traffic on the main outer ring road at Westside and reinstatement of the City park and playing pitches after duct work was completed.

Coomergerlahy (Kerry): 110KV Sub-station. Installation of line Cubicle bases, tarmacadam of compound and erection of compound fencing.

Mary Immaculate College (Limerick): Refurbishment of paved areas, in several college locations across the city.

Dromoland Castle (Clare): Construction of refuse compound, construction of golf course machinery store/workshop and refurbishment of existing listed buildings.

Indaver, (Duleek, Co. Meath): Construction of bunded transformer base as well as a switchgear room

  • Rooftop Solar

  • Construct - Lease - Rent a Roof

Who are we?


Amarenco Mainline is the combination of a large scale solar developer & investor and an experienced utility contracting company.

Amarenco is an independent power company that develop, finance, construct and operate solar Photo Voltaic (PV) power plants in Europe, with over €190m of assets under management.

Mainline Group is a leading provider of Network Construction and Support Services within the Water, Telecom & Energy sectors.

Why us?

Amarenco has a proven track record in the finance, development and construction of large solar plants in Europe. Mainline Group has extensive experience and leading expertise in electrical utility and grid infrastructure. In 2014 and 2015 Mainline Group was awarded one of Ireland’s “Best Managed Companies” by Deloitte.

Together our collective competence spans all aspects of the energy sector, and our partnership is focused on the provision of best in class rooftop solar solutions to Industrial, Commercial and Agricultural clients.

We offer our Clients a number of turn-key Solar PV options including, some or all of following, specific to your requirements, and preferred Finance solution:

•  Design
•  Construction
•  Operations
•  Finance
•  Asset Management


CONSTRUCT – We design and construct the most suitable solution for your roof space

LEASE – We design, finance, construct and manage the Rooftop Solar solution at no cost to your company and we deliver cheaper electricity.

RENT A ROOF – We agree a 25 year lease period for your rooftop space. No construction cost to your company and you receive dividend payments











Rent a Roof






Energy Costs




CO2 Reduction

Tax Efficient


On Case by Case Basis

Annual Charges


CO2 Reduction

Reduced Cost
Agreed Rate
Asset Ownership


0€ - No Upfront Costs
Pay for Energy Produced
Buyout Option


Rent a Roof

CO2 Reduction

Annual % of Solar Energy Turnover


0€ - No Upfront Costs
Host for a fixed term


Contact Us for more information:

Amarenco Mainline Group

Mainline Place, Sarsfield Road,
Wilton, Cork
T: +353(0)21 4800060


  • Water SERVICES

Within our Water Division, our technically competent and experienced staff offer turnkey solutions in the management, repair, maintenance, design and construction of water network infrastructure, from the underground pipework and associated fittings and chambers, to the water and waste-water treatment facilities.

Our team has an extensive track record of successfully delivering large scale projects, coupled with innovative solutions such as our Meter Information Management System (MIMS) and Work information Management System (WIMS), both of which provide the Client with up-to-the-minute comprehensive project data.


Water Projects

Cork Non-domestic Water Metering – D&B and O&M

Mainline Group was the sole supplier to Cork County Council to design, build and install 20,000 non-domestic water meters in Cork County. The Design & Build (D&B) contract was completed in 2010. In conjunction with this, Mainline Group Operates and Maintains (O&M) the 20,000 non-domestic water meters on behalf of Cork County Council / Irish Water. The O&M contract commenced in 2006 and continues until 2021. Under the O&M contract, we read, repair and maintain all 20,000 meters, as well as manage all other aspects of the water meter infrastructure, including identification of new Customers, surveying and new meter installations. The O&M project also deals with the capital replacement of all installed meters. The replacement of meters will commence in year 11 of this 15-year project.

Irish Water Domestic Water Metering

In September 2013, in conjunction with our lead project partners J Murphy & Sons, we commenced delivery of meter installations services to Irish Water for two of the eight domestic water metering regions. The two regions, the South West and West, include the installation of over 275,000 domestic water meters, and have a combined contract value of circa €100m. Installation of the water meters commenced in September 2013, less than 6 weeks after signing of Contracts, and will continue for 3 years with a 2 year extension option. This high profile project employs over 300 Direct and Indirect Staff across Cork, Kerry, Limerick, Tipperary, Clare and Galway.

Irish Water Minor Civil Works

In October 2014, Mainline Group signed the Minor Civils Framework Contract with Irish Water for several Local Authority Regions in the South and West of the country. The Framework includes 5 Lots, covering installation and repair of Water and Sewer Pipelines and Connections, as well as Minor Building Works. Significant works are expected to be issued under this Term Contract in 2015.

Irish Water First Fix -Leak Repair

In early 2015, in conjunction with our lead project partners J Murphy & Sons on the Domestic Meter Installation Contract with Irish Water, we commenced provision of “First Fix” services in the West and South West Regions. This substantial project involves the provision of Leak Investigation Services, as well any subsequent necessary Leak Repair Works, to the external “Customer Side” pipework of Irish Water Customers.


Within Mainline Group’s Telecoms Division our highly qualified engineers have extensive knowledge of both fixed and wireless networks. With the advent of Next Generation Networks, we can respond to rapidly changing technical demands. We deliver innovative solutions including equipment transfer, engineering, and network services to our Clients.

When it comes to fixed line telecoms, our technical knowledge spans both core and access networks. Our range of services includes the planning, installation and commissioning of Next Generation Network M-SAN equipment, as well as the provision and uplift of access networks, including cabling, poling and civil works.


Telecom Projects

Eircom Payphones

Mainline Group is the sole provider of repair, maintenance and coin collection services for over 2,000 payphone units and internet terminals nationally. We have worked hard together with our Client since 2008 to repeatedly deliver innovative solutions resulting in several cost savings.

Eircom WI-FI

Mainline Group has to date installed over 2,800 Wi-Fi hotspots for Eircom nationwide. Working together with the Client from conception stage, we agreed a pricing structure based on an open-book approach, and developed an in-house IT app based Job Management System (JMS) solution, with a Web access portal which enables the Client to receive live progress updates and reports.


Mainline Group has provided transmission design engineers to Vodafone/Netshare for over eight years. Currently we have seven engineers working at Vodafone’s HQ in Dublin. We also manage and configure Vodafone’s femtocell product “Sure Signal” and carry out drive testing of the Vodafone network following various network configurations.


Mainline Group completed a project to deliver 50 repeater site solutions throughout Ireland on a turnkey basis including planning, design and network integration.

ESB Telecoms

Mainline Group is one of two national framework suppliers to ESB Telecoms for underground network maintenance and extensions to the network. To date we have completed over 15 projects nationwide, involving the construction of underground ducting, access chambers, as well as the installation of fibre optic cable, splicing, termination and testing.

Eircom Networks

Mainline Group previously supplied circa €20 million per annum of access network services to Eircom. As part of this contract, we successfully delivered services across all network components, from underground to kerbside to overhead.

Huawei – MSAN

(Multi Service Access Node) and Soft Switch Exchange installation, testing and commissioning including technical support. Mainline Group completed MSAN installations at more than 40 sites as part of the local loop unbundling programme for Smart Telecom and Eircom.


Mainline Group previously provided a design, build and maintenance fibre ducting service to E-net, as part of the Government’s national fibre broadband network roll-out in Ireland.