Site services

We are hands-on.  We have capacity to deliver mechanical, electrical and civil aspects of projects, as well as operating projects. 

Mechanical work

Plant installation - lifting, grouting, allignment, commissioning, acceptance testing etc.
Analysis - oil contamination, bearing vibration, thermal imaging
Plant reconditioning - bearings, packings, casting repairs, resurfacing, rebushing etc.
Screening equipment - upgrades for best practice

Electrical work

Control system installation and repair - Mains work, instrumentation, panel fault finding and repair
Generator works - repair and replacement







Civil work

Channel repairs - tanking, grout injection and shotcrete
Weir reconstruction - dewatering, temporary works, demolition, construction in different materials
Reinforced concrete - all manner of water retaining and associated structures
Soft engineering - sensitive solutions for structures where needed

Asset Management

Sites across South West England

Based at our South West England offices, our maintenance team oversee and operate a small fleet of hydro plants on a contract or ad hoc basis, dependant on the client needs. 

To best maximise output On Stream prefer to ensure good quality broadband connections into modern industrial PLC based control systems, but we also look after many small sites which either have 3G based site communications, or even for small sites no remote monitoring. 

Our staff’s long experience with the most widely employed hydro control systems and turbine types pays off with a clear understanding of the potential issues and appropriate maintenance regime.

In association with day to day maintenance, longer term planned jobs are also necessary on plants and On Stream can plan and provide these services.  Items such as pipeline pigging, screener maintenance and upgrade, control and actuation improvements, instrumentation and a host of minor modifications are routinely carried out. 

Dart Renewables

Dart Renewables operate a 300kW hydro plant on the Dart at Totnes, On Stream carry out services in support of operation of this plant, such as fault finding, replacement of parts and oil contamination testing.

Buckfast Abbey

Buckfast Abbey operate two hydro plants on the Dart and Holy Brook with a capacity of around 100kW, and are developing a third system.  On Stream provide a full operation service to the existing systems.


Principal contractor - Design and Build

Lee Moor

On Stream Energy carried out all licensing and design, and for this small 40kW medium head scheme acted as the principal contractor for all of the project including all civil works.  The system had been designed to be simple to construct, and it proved possible to build the entire project, including all excavation, reinforced concrete work, structures, pipework and M&E installation in under 120 man days.

The inlet is a Coanda screen system with simple bypassing arrangements, adjacent to an engineered section of river.  This feeds into 250m of HDPE butt welded pipe, which runs downhill to a basic timber clad blockwork powerhouse.  The powerhouse houses a JLA crossflow turbine and directly driven induction generator mounted on a skid for simple installation. 

On Stream designed and fabricated the skid system to support the swift on site installation.

On Stream now also carries out full on site asset management including all routine operation work, out of hours attendance, servicing and periodic maintenance.


Rehabilitation of sites

Castle Drogo

On Stream worked at National Trust’s Castle Drogo site carrying out a full rebuild of 2 wallplate Francis turbines which had been inoperative since 1994.  The scope of this work was a removal, full rebuild including repair and replacement of damaged castings, new main shafts, seals and bearings, plus fitting new gearbox and generators, and all associated installation.