Mini-hydro services and the steps they cover
A guide to each stage of a small hydro project, from site survey to long-term maintenance.
What a project involves
A mini-hydro project is usually delivered in six linked stages. Each one produces information that the next stage depends on, so skipping a stage tends to cost more later. The sections below describe what each stage covers and what a finished output looks like.
Site assessment
Site assessment measures the available head and flow across the year. It uses gauge records, a topographic survey and a check of the existing structures. The output is a head and flow duration curve, which is the basis for turbine selection.
Consent and environmental support
This stage prepares the abstraction or impoundment application, the planning submission and any screening reports. Good support work reduces the number of requests for further information from regulators.
- Prepare flow and compensation calculations
- Produce the landscape and ecology summary
- Assemble the planning drawings and access plan
Design and equipment selection
Turbine choice
Matches turbine type to head and flow. Common options include Francis, Kaplan, cross-flow and Archimedean screw designs.
Civil design
Covers the intake, weir modifications, penstock, powerhouse and tailrace, each sized to the selected equipment.
Installation and grid connection
Installation covers civil works, mechanical and electrical fit-out, and commissioning. The grid connection is agreed with the network operator and must be in place before export begins.
Side note: installation windows are often limited by river conditions and fish migration periods.
Commissioning and operation
Dry and wet tests
Performance proving
Operating manual
Maintenance and monitoring
Ongoing maintenance keeps the scheme within its licence conditions. It includes screen clearing, lubrication, generator checks and recording flows so that compensation requirements can be shown to be met.
Choosing how to proceed
You can manage each stage yourself, or appoint specialists for one or more of them. Ask for written scope, deliverables and responsibilities before work starts, and compare proposals on the same basis.
No prices or delivery times are given here, because they depend on the site, the consents and the equipment chosen.