QDTB® Transformer

Micro-Hydro Power Station Calculator

Enter head and design flow to select the turbine type (impulse / Francis / Kaplan), generator, step-up substation and get annual generation, LCOE and a complete BOM.

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How a micro-hydro station is sized

Hydro output is P = ρ·g·Q·H·η. The head decides the turbine type — impulse (Pelton) above 200 m, Francis from 30–200 m, Kaplan/propeller below 30 m. The calculator sizes the generator, the 0.4→10.5 kV (or 35 kV) step-up station, and estimates annual energy by the capacity-factor method.

Worked Example — Micro-Hydro Station

Example 1 — 1.6 MW Francis Hydro Station (10 kV grid)
Small hydro station · Francis
1570 kW
H 80 m · Q 2.5 m³/s · η 80% · 2000 kW generator
Annual energy
6,875 MWh
LCOE
$16.7/MWh
Est. BOM (FOB)
POA
📦 Bill of Materials
EquipmentModelSpecQty
Hydro turbine-generator set1570 kWFrancis · H 80 m · Q 2.5 m³/s · η 80% · incl. governor + excitation · purchased equipment (外购件)1
Step-up transformer2222 kVA0.4/10 kV · oil-immersed (GB/T 17467) · >1600 kVA outside catalogue1
Ring main unit (RMU)10 kVSF6 RMU 630 A · 4-circuit · 10 kV1
LV switchgear (GGD)0.4 kVincoming breaker + feeders · complete cubicle1
Protection & control (secondary)relaymicroprocessor protection 50/51/51N + metering + SCADA interface1
Summary
Estimated total (FOB Qingdao, EXW) — priced equipmentPOA
📐 Single-line diagram
Intake / PenstockH = 80 mTurbineFrancis - 2.5 m3/sGenerator2000 kW - 0.4 kVGrid10 kV connection
LEGENDBreaker (52)CTCT (current transformer)PTPT (voltage transformer)50/51Protection relay 50/51/51NkWhMeter (kWh)SPD (surge protection)
📏 Standard basis
TopicStandard
Turbine model testIEC 60193 — hydraulic turbines (model acceptance tests)
Field acceptanceIEC 60041 — field acceptance tests for hydraulic machines
Hydro-generatorGB/T 15468 — fundamental technical specifications for hydro-generators
Step-up transformerGB/T 1094 — power transformers
🧮 How it was calculated
1. Output P = ρ·g·Q·H·η = 9.81 × 2.5 × 80 × 0.80 = 1570 kW
2. Turbine type: H = 80 m → Francis (impulse >200 m · Francis 30–200 m · Kaplan <30 m)
3. Generator: 1570 kW ÷ 0.95 → standard 2000 kW (2222 kVA @ pf 0.9)
4. Step-up: 0.4 kV → 10 kV
5. Annual energy = 1570 kW × 8760 h × CF 0.50 = 6,875 MWh/yr
6. LCOE = (CAPEX×CRF + OPEX) ÷ energy = $16.7/MWh (illustrative, turnkey factor 1.6)
📋 Design notes
Pricing basis: Turbine-generator set priced per-kW from the hydro-turbine-sets reference (FOB Qingdao, complete unit incl. governor + excitation; draft, pending final review). Step-up transformer uses the box-type-substations catalogue (≤1600 kVA); larger and 35 kV switchgear are quoted per project (POA).
Capacity factor: Annual generation uses the capacity-factor method (default 50%, adjustable 20–70%). Actual hydro output depends on seasonal flow duration curves and must be verified with site hydrology.
LCOE basis (illustrative): Full-cost LCOE annuitizes CAPEX over 30 years at 7% and adds 2%/yr OPEX. The turnkey factor 1.6 covers civil works (intake, penstock, powerhouse), installation and commissioning — actual costs vary widely by site.
Off-grid mode: Grid-connected mode sells all generation to the grid.
Design review: This is a preliminary sizing. A licensed hydro engineer must verify the turbine selection, penstock head-loss, cavitation margins and generator protection before procurement.

How it was calculated

Core formulas

P = 9.81 × Q × H × η (kW). Annual energy = P × 8760 × capacity factor. LCOE = (CAPEX × CRF + OPEX) ÷ annual energy (full-cost, illustrative).

Applicable standards

IEC 60193 (turbine model tests), IEC 60041 (field acceptance), GB/T 15468 (hydro-generators), GB/T 1094 (power transformers).

Frequently asked questions

What turbine type does my head need?

Head above 200 m suits an impulse (Pelton) turbine; 30–200 m a Francis turbine; below 30 m a Kaplan or fixed-blade propeller turbine. The calculator selects the type automatically from your head.

How is annual generation estimated?

By the capacity-factor method: rated output × 8760 hours × capacity factor (default 50%, adjustable 20–70%). Actual output depends on the seasonal flow-duration curve of the site.

Which equipment is priced in the BOM?

The turbine-generator set (per-kW reference), step-up transformer, ring main unit / HV switchgear and LV switchgear. Protection & secondary and, in off-grid mode, the diesel backup and battery, complete the list — larger transformers and 35 kV switchgear are quoted per project.

What is LCOE here?

Levelised cost of energy: annualised CAPEX (30 years at 7%) plus OPEX, divided by annual generation. It is illustrative — a turnkey factor 1.6 covers civil works (intake, penstock, powerhouse).

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Results are engineering estimates for reference. Final design must be confirmed by a licensed local engineer against site conditions and applicable codes. Prices are FOB Qingdao (EXW) and do not include freight, duty or installation.

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