With every hour that a hydro plant is not running, money is being lost! Moreover, having made a significant investment in the construction of a new station, it is important to maximise the potential income by minimising the unplanned downtime. “Everyone knows this” says Hydroplan’s head of Operations, Adam Veitch “but the reality of round-the-clock monitoring is quite onerous”. This service is traditionally known as “O&M” but in reality a better description is Operations, Maintenance, Monitoring and Management (OM-3).
Proportional Response
A weekend or evening call-out is expensive but in many cases it is justified because of the loss of income. However, it is always important to judge the benefit in comparison to the loss – especially on small schemes. “Where faults occur, in low income situations, it is sometimes more economically sensible to leave the turbine running at low power or even switch it off” says Gavin Hart, Operations Manager, “this is particularly relevant when river flows are low”.
Data, Data, Data
A modern control system can be configured to provide a breadth of data – 15 to 60 minute logs of every function of the turbine and generator can be made available. And it is not just the equipment in the powerhouse that matters. Sensors and weather stations at the intakes provide a fantastic amount of information which can be analysed and used to identify faults. Moreover, with the advent of cheaper digital cameras, it is possible to get a real-time view of what is happening at intakes and in the river.
Processing the data is done for 2 purposes:
• Real time (on line) – short term analysis to identify (and in many cases rectify remotely) faults which have happened
• Post processing – longer term analysis to identify trends in performance of the various elements of the scheme. Together with the site log, this is a useful tool for informing the future maintenance operations e.g. pipe cleaning or turbine refurbishment.
Reporting is crucial to keeping clients informed about the health of (and income generated by) their hydro station. Daily reports are often useful, especially straight after commissioning a plant where there can be a recurring problem. However, a weekly ‘catch-up’ combined with a monthly report and a review every 6 months is usually sufficient.
On-site
With abundant data available online, it is easy to forget that there is a physical reality to a hydro scheme. This “reality” involves the need for regular inspection and maintenance visits. A contract with a local competent person or company for the daily/weekly checks is essential. Similarly maintenance and service level contracts are useful for ensuring prompt and timely services.
Hydroplan can offer a Total Asset Management service, but not every client wants or needs it. So OM-3 packages are tailored to each individual client’s needs.
Mandatory Compliance
There are three areas where on-site checks are mandatory:
• Post construction planning conditions Many schemes have ongoing planning conditions to monitor and report on aquatic life, habitat and protected mammals.
• Flow regime (compensation flow)
checking and monitoring that the legal requirements described in the abstraction licence are being met are essential in order to avoid prosecution.
• Dam Safety – this is the most onerous (legally) of the compliance checks. It involves weekly records plus annual inspections from a highly experienced and qualified engineer. Hydroplan has an experienced All Reservoir Panel Engineer as part of the team.
Adapting to the Environment
The regulatory and technical environment changes over time. It is often necessary to design and manage modifications to stations as a result of operating experience. This can include changes to fishpass design and river bank revetment as well as the design and implementation of new civil and mechanical structures. However, most commonly, changes are related to the control and monitoring systems and consistent and reliable data is key.
“Things change…” says Adam “and our job is to predict the trends before they become a problem.”
Hydroplan specialise in hydropower, High Voltage, control and water related projects.
For more information, please visit
www.hydroplan.co.uk or call 01202 886622
