Hydro Turbine Consulting FAQ | Kosonen Consulting LLC

Question 1

What does a hydro turbine consultant actually do?

Accepted Answer

A hydro turbine consultant provides independent, field-level expertise on turbine condition, performance, and maintenance strategy. That means conducting hands-on inspections, reviewing maintenance records, identifying wear patterns, recommending rehabilitation scopes, and advising on operational best practices — all without the bias of an OEM or contractor who profits from the work itself.

Question 2

When should I bring in a consultant versus calling the OEM?

Accepted Answer

OEMs are the right call for warranty work, proprietary parts, and factory-level technical support. A consultant adds value when you need an independent second opinion, when you're evaluating whether OEM recommendations are necessary, when you're preparing for a major overhaul and want unbiased scope development, or when your in-house team needs supplemental expertise for a specific project.

Question 3

Do you work on-site or remotely?

Accepted Answer

Both. Many assessments begin with a document and data review that can be done remotely — maintenance records, inspection reports, vibration data, efficiency curves. On-site work is typically required for physical inspections, condition assessments, and overhaul oversight. The scope of each engagement determines the right mix.

Question 4

What size facilities do you work with?

Accepted Answer

Experience ranges from small run-of-river installations up to units in the 250MW range. The turbine type and condition matter more than the nameplate capacity — Pelton and Francis turbines of any size fall within the core competency.

Question 5

What is the difference between a Pelton and a Francis turbine?

Accepted Answer

A Pelton turbine is an impulse design — water jets strike buckets mounted on the runner rim, converting kinetic energy to rotation. It's suited for high-head, lower-flow sites. A Francis turbine is a reaction design — water flows through the runner radially and exits axially, with pressure doing the work. Francis turbines are used across a wide range of heads and flows and are the most common turbine type in large hydro installations worldwide.

Question 6

How do I know if my Pelton turbine needs a nozzle overhaul?

Accepted Answer

Key indicators include reduced efficiency at rated head, visible erosion on needle tips or seats, increased vibration during load changes, and water hammer events. Nozzle wear is gradual and often underestimated — a targeted inspection of needle geometry, seat condition, and deflector alignment can identify issues before they become forced outages.

Question 7

What causes cavitation in Francis turbines and how serious is it?

Accepted Answer

Cavitation occurs when local pressure drops below the vapor pressure of water, forming and collapsing bubbles that erode metal surfaces. In Francis turbines it typically appears on the runner suction side, draft tube, and guide vanes. Left unaddressed, cavitation causes progressive material loss, vibration, and efficiency degradation. Early detection through inspection and vibration analysis is far less costly than runner replacement.

Question 8

How often should hydro turbines be inspected?

Accepted Answer

Inspection intervals depend on operating hours, water quality, and historical wear rates. A general baseline is a visual inspection every 2–4 years and a full disassembly inspection every 8–12 years, but high-sediment environments or units with known wear issues warrant more frequent attention. Condition-based maintenance — driven by vibration data and efficiency trending — is more reliable than calendar-based schedules alone.

Question 9

What is O&M advisory and what does it include?

Accepted Answer

O&M advisory covers the operational and maintenance strategy for your generating assets — maintenance scheduling, lifecycle planning, spare parts strategy, staff training support, and best-practice guidance drawn from field experience across multiple facility types. The goal is to extend equipment life, reduce unplanned outages, and make maintenance spending more predictable.

Question 10

Can you help us develop a maintenance plan from scratch?

Accepted Answer

Yes. Starting from a review of your equipment inventory, operating history, and current maintenance practices, a structured maintenance plan can be developed that aligns with your operational goals and budget constraints. This includes interval recommendations, inspection checklists, and priority rankings based on criticality and condition.

Question 11

We had an unexpected failure — can you help with root cause analysis?

Accepted Answer

Yes. Post-failure investigations are a core part of the work. This involves reviewing the failure mode, examining physical evidence, analyzing operating data leading up to the event, and identifying contributing factors. The output is a clear root cause finding and recommendations to prevent recurrence — not just a repair scope.

Question 12

How do engagements typically start?

Accepted Answer

Most engagements begin with a conversation about the facility, the equipment, and the specific challenge or question at hand. From there, a scope of work is defined — whether that's a single inspection visit, an ongoing advisory relationship, or a project-specific consulting role. There's no standard package; every engagement is scoped to what's actually needed.

Question 13

What geographic areas do you serve?

Accepted Answer

The majority of project history is concentrated in the Pacific Northwest and California, but Kosonen Consulting is available for projects throughout North America. If the work is the right fit, geography isn't a barrier.

Question 14

Do you work with public utilities as well as private operators?

Accepted Answer

Yes. Project history includes work with public utility districts, investor-owned utilities, independent power producers, and municipal operators. The consulting approach is the same regardless of ownership structure — field-first, independent, and focused on the equipment.

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