Micro-Hydro in Scotland - Ecovillage Findhorn · PDF fileMicro-Hydro In Scotland How can I use it? ¥Hydropower basics ¥Constraints to development ¥Low head site selection and system

Micro-Hydro in Scotland

How can I use it?

Micro-Hydro In ScotlandHow can I use it?

• Hydropower basics

• Constraints to development

• Low head site selection and systemdesign

– Tea Break

• High head site selection and systemdesign

• Development process

• Grants, financing and income

Hydropower basics

• Theoretical power from the water

• Typical system components

• Energy losses

• Actual power available from water

History of Waterpower

Since the invention of thebasic waterwheel toharness the power ofmoving water(Estimatedto have been around theeighth century inEngland)Boyle (2004),man has used thispotential to grind cornand raise water forirrigation.

Theoretical Power

Power (kW) = Flow (m3/s) X Gravity (m/s2) X

Height (m)

P = Qgh

Low head: P = Qgh

High head: P = Qgh

Typical Components

• Intake weir

• Pipeline, leat or both

• Turbine

• Tailrace

Energy Losses

• Intake

– Screening head-loss

• Pipeline or leat

– Friction losses

• Turbine

– Turbulence and friction losses

• Electro-mechanical

components

– Heat

Actual Power Available

Power (kW) = System Efficiency X

Flow (m3/s) X Gravity (m/s2) X Height (m)

P = !Qgh

Constraints to DevelopmentWhere can I put one?

• Geographic

• Environmental

• Planning

• Electrical

Geographic Constraints

• Land ownership

• Difficult terrain

Environmental Constraints

• Operational Constraints

– Designated areas

– Water environment

– Fish migration

– Compensation flows

• Construction Constraints

– Protected species

– General construction risks

Planning Constraints

• Environmental constraints

• Fisheries

• Noise

• Visual Impact

• Amenity

Electrical Constraints

• Up to 3.7 kW per phase

– No problem

• Up to 50 kW

– Simplified connection procedure

– Permission required

• Over 50 kW per phase

– Permission required

– Connection fee likely

Low Head Site Selection and

System DesignWhere should I put one?

• Typical sites

• Site layout

• Turbine and control systems

• Case study: Strathdon

Typical Sites

• High flow

• Low head (1 to 10 m)

• Existing weirs

• Old mill sites

Site Layout

• Intake

• Leat

• Turbine

• Tailrace

Turbine Types

• Kaplan propeller turbine– Reasonable part-flow efficiency

– High rate of rotation

– Fine screens required

• Francis inward-flow turbine– High rate of rotation

– Generally poor part-flow efficiency

– Fine screens required

Archimedes Screw– Actuated sluice control before turbine

– Good part-flow efficiency

– Slow rate of rotation

– Fish friendly no screens required

Case Study: Strathdon

• Gross head = 3.8 m

• Available flow = 2600

l/s

• Power from water =

97 kW

• Electrical power = 70

kW

Intake and Leat

• 2600 l/s abstraction

• Existing weir

• New side intake

above weir

• Existing concrete pipe

to turbine house

Turbine

• Open-compact

Archimedes screw

• 2.6 m diameter

running at 28 rpm

• 70 kW Power

• 288,000 kWh/year

• 280,000 kWh in first

eleven months

• Power for 57 Houses

After the Break

• High head site selection and system

design

• Development process

• Grants, Financing and Income