Emerging Hydropower Technologies - Canadian Experiences

21 May 2010

ByTony P. Tung, Hydraulic Energy Consultant

Former Manager, Hydro Energy Technology Group CanmetENERGY , Natural Resources Canada

Presentation Topics

• Introduction• Existing Small Hydro Plants Refurbishment and upgrading• Very low head (VLH) turbine to lower civil works• Fish-friendly, variable speed low-head hydro turbine and generator

systems• Development of an Axial Flow, Low Head, Fish Friendly, Pit Turbine• Exit Stay Apparatus (ESA) • Hydrokinetic energy from river/ocean current • Micro-hydro and control systems for stand-alone and net-metering • Modular Automatic Control, Governing, Protection Systems• Site Assessment, Design and Software Tools• Establishment of an Independent Turbine Testing Laboratory • North America and International Cooperation on Small Hydro

Development

IntroductionCanada has abundant resources on small and low-impact hydro:

– 20,000 MW of low-head hydro (< 15 m of head) potential – 10,000 existing low-head dams and hydraulic structures – Small hydro (<25 MW) represents about $0.5 billion in annual business activities

Generating capacity in Canada from small and mini hydro – Current installed capacity: 2,000 MW – Growing rate: 150 MW per year, with 3,500 MW in 10 years– Producers: IPP, provincial/municipal utilities, and remote communities

Further development of small hydro will largely rely on emerging technologies with increased reliability & efficiency, lower up-front costs and reduced environmental impactsR&D focusing on medium to long-term development through projects to:

– Address the technical gaps – Take advantage of the significant potential and to accelerate the small hydro

development– Contribute to GHG reduction

Existing Small Hydro Plants Refurbishment and upgrading

Better Approach:Experienced and specialized engineering firms work together with small hydro turbine equipment manufacturers, after careful examination and evaluation of the existing plants, they will recommend cost saving ways to re-build or replace the turbine runners and equipments with high efficient turbines . Avoid replacement with new different types of turbine/equipment which will lead to major civil work and cost are too high.

Example is the Energy Ottawa project :

•Replacing double Francis Camel-Back Turbines•Adapting innovative approaches by using CFD

a 20% increase in output•Generator Rewinding•Upgraded Electrical Equipment

Very low head (VLH) turbine to lower civil works

• Goals• To develop an innovative very low head turbine

system to significantly reduce the civil costs associated with the very low head hydro development (conventionally 40-50% of the total costs)

• Head range: 1.4-2.8m, Flow range: 10-30m3/s, Power: 100-500 kW

• Rationales• Very low head requires high flows with high civil

costs• Turbine manufacturers always give priority to the

reduction of equipment size and costs, but pay less attention to civil works costs

• Exploiting very low heads is technically feasible but unprofitable with available technologies

• Main partners• MJ2 Technologies SARL, France• Atelier Onmec Inc., Canada• Laval University, Canada

Complexity and extend of civil

works for different

configurations for same head and

flow characteristics

Very low head turbine being tested at Laval university

Very low head (VLH) turbine to lower civil works (Cont.)www.vlh-turbine.com

• Turbine concept/Features • Utilization of larger runners to practically eliminate the

expensive civil structures of the traditional concept• Turbine shape is a flat rectangular box, easy to install for

existing dams• Runner diameter is large enough to have very low speed

at runner exit, allowing the elimination of the draft tube• Turbine is easily accessible for maintenance• The unit is fish-friendly because of low velocity flow

through the runner• Turbine is fully submersible • Permanent variable speed generator integrated into

turbine hub

• Status (near commercial stage)• Model turbine manufactured and tested at Laval University’s

Lab. Quebec, Canada• Test results show that performance close to design

expectation • Biological design criteria integrated into prototype design• 1st prototype turbine (2.4 m head - 350 kW – Ø 4,000 mm)

installed in Millau, France, in early 2007• Several units have been manufactured. Two projects being

planned for demonstrations in Canada • Three developers in USA on the Mississippi River with Locks and

Dams have plans for large numbers of VLH installation (total 440)

Fish-friendly, variable speed low-head hydro turbine and generator systems

Goals– Development of low-cost, efficient, and

fish friendly turbine and generator systems; Demonstration.

Rationales– Water level & flow variations affect the

efficiency of the turbine operation– Conventional propeller turbine not well

adapted to variations; Double regulated turbines requires high capital costs

– Fish injury/mortality in turbine passageProject partners

– Rapid-Eau Technologies Inc., Canada– Swiderski Engineering Inc., Canada– University of New Brunswick, Canada– Laval University, Canada

Fish friendly turbine casing with spiral ramp in red

CFD Simulation

Fish-friendly, variable speed low-head hydro turbine and generator systems (Cont.)

• Turbine-Generator concepts• Turbine concept (L Shaped Vaneless Turbine)

• Special turbine casing with spiral ramp, no stay vanes• Improved non-regulated propeller turbine design with less but longer and thicker

runner blades preventing fish injury/mortality caused by mechanical and cavitation effects

• CFD simulation (shear and pressure change) and lab tests to design a fish-friendly turbine that will reduce drastically fish mortality and injury while keep high turbine efficiency

• Generator concept• Permanent magnet technology with high numbers of poles, turbine/generator will

be operating at variable-speed operations to improve system efficiency • Generated power at variable frequency to be converted through power converters to

utility quality power

• Benefits of the system • Increased power generation: turbine operating at variable-speed over a wide

operating range with high efficiencies and high turndown ratio • Environment-friendliness

• Status • The new design is based on Rapid-Eau’s patented “L-type” turbine that was used

on a number of small hydro sites in Canada and abroad• Review for fish mortality conducted and incorporated into turbine design• Final design and model turbine testing completed. Demonstration projects

planned

CFD Simulation: critical shear stress zone (S.E.)

CFD Simulation: critical pressure change zone (S.E.)

Development of an Axial-Flow Low-Head Fish-Friendly Pit TurbineGoals

Developed a structurally simple non-regulated axial-flow fish-friendly low-head turbine system for small low-head hydro applications with head less than 5.0 m

Rationales• On-going research on fish friendly-turbine, such as developed

by ARL/NREC team, generally targeted a higher head range . This project focus on low-head (< 5.0 m)

• The turbine system encompasses a unique Pit intake design along with specific distributor vanes concurrently providing structural support and pre-rotation for the flow entering the runner.

• This turbine system was designed by using a multi-objective design optimization algorithm and CFD simulations. The relevant design criteria included the hydrodynamic factors, factors for economic viability of the equipment, and factors for fish-friendliness such as static pressure change rate and the hydrodynamic shear stress.

Project partners and Status• Swiderski Engineering Inc., CanmetEnergy NRCan• Model testing and manufacturing prototype under planned

Power transmission – general arrangement

Exit stay apparatus (ESA)

Goal• To improve the Francis turbine efficiency at part load with no

significant alteration of efficiency at nominal load• To reduce the pressure pulsations amplitude at part load to increase

equipment life expectancy

Rationale• Francis turbines, due to the deregulated market, often operate under

off-design conditions depending on market energy demand and price• Francis hydraulic turbines, experience vortex rope’s formation at

partial loads• Francis hydraulic turbines, working off-peak, experience a significant

loss of efficiency• Operation under off-peak condition has significant detrimental effects

on turbines because of exposure to pressure pulsation and dynamic loadings, which cause material fatigue & reduce the life expectancy

Main partners• A. Gokhman, Ph.D, Consultant, Inventor, USA• Norcan Hydraulic Turbines Inc., Canada• Hydraulic Machinery Laboratory at Laval University, Canada

Vortex rope in the drafttube (picture from WEB)

A Francis turbine model at LavalUniversity’s Hydraulic Machinery Laboratory (LAMH)

Exit stay apparatus (ESA) (Cont.)Technological aspects

• ESA is a device that comprises a stay crown and exit stay vanes that are put immediately behind the conventional Francis runner exit

• ESA is to eliminate the central vortex rope, increase the energy efficiency at off-peak loads, reduce the pressure pulsation/ instability, and achieve reliable operation

• ESA can be incorporated into newly manufactured Francis turbines, or be retrofitted into existing Francis turbines if draft tube cones are not embedded

Benefits of the system• A substantial increase in efficiency at part loads. At nominal head,

about 5% at 50% load, and 2% at 70% load• Drastic decrease in the amplitude of pulsation at operating regimes

off the optimum resulting in more stable operating conditions and longer life expectancy for the equipment and power plant

Status • Mechanical and structural design completed. • Completed tests at Laval University: Efficiencies; Pressure pulsation;

Cavitation; with/without ESA have been reportedNew Development by Inventor Dr. Alex Gokhman

A new patent has been granted for a new Bulb turbine entitled “Hydraulic Bulb Turbine with Mixed-flow Propeller Runner” (US Patent Application, No. 12/386,011, 04/30/2009). It includes ESA at runner exit

Hydrokinetic energy from river/ocean current

Goal• To develop/commercialize vertical axis Darrieus water

current turbines to use the vast “zero head” river and ocean energy potential

• To demonstrate the power generation capability from the water current turbine in various configuration and applications

Project scope• Development of the 5 kW and 25 kW VAHT systems• Demonstration in various configurations (250 KW)

- Industrial outflow – wastewater treatment- Irrigation canal- River systems- Off-grid application

Turbine features• 2 configurations - Ducted and non-ducted• Water velocity - 1 to 4 m/s• Expected efficiency up to 40 to 45%• Slowly rotating turbine blades are fish friendly

5kW prototype installed at BonnybrookWastewater Treatment Plant, Calgary

Hydrokinetic energy from river/ocean current (Cont.)

New Energy Corporation (NECI) unique projects• Electricity from a 5 kW EnCurrent Power

Generation System started to flow into the micro-grid in Ruby Alaska on August 6, 2008. This represents the first hydrokinetic implementation in Alaska

• Will displace diesel fuel . Energy cost at $0.98/kWh

• Installation of 25 kW EnCurrent Power Generation System The 25 kW System was mounted in the pontoon boat using a cradle and pivot arms to assist in deployment and anchoring of the system. Partners with Manitoba Hydro and Univ. of Manitoba producing grid-connected electricityStandard product from New Energy for the 5, 10 and 25 kW models using plastic pontoons http://www.newenergycorp.ca/

Micro-hydro and control systems for stand-alone and net-metering

Thomson and Howe Energy Systems:Pemberton BC Project- second direct AC net metering

system tied into B.C. Hydro. Commissioned on March 27, 2010.

• Net head is 131 meters.• Design output is 50 KW.• Single nozzle Canyon Ind. (USA) Pelton Turbine with

manually adjustable spear valve.• Product "HM" Turbine Controller for automatic start-

up after utility outage.District of North Vancouver Operation on March 24, 2010.

This is the first direct AC net metering system to be intertied to B.C. Hydro.

• This Pump-as-turbine is in series with a pressure reducing valve for the city water system.

• The turbine inlet pressure is 195 psi.• The turbine outlet pressure is 140 psi.• The generator output is 23 kW using 80 lps.

Modular Automatic Control, Governing, Protection Systems

Powerbase Energy Systems Inc.• PowerPAC II is a comprehensive controller for the

automation, governing and protection of small hydro-generators up to 50 MW.

Small Hydro projects:• ABB-Abitibi Consolidated: retrofit of multi-stations

is ongoing. Average unit size is 1.8Mw, stations vary from 2 to 10 units. Scope of supply is unit controls, protection, hydraulics, governor and operator training

Biogas Projects:• Now have seven systems under contract of which three

are substantially completed. Scope of supply includes anaerobic digester, digester support building, containerized heat and power system (typically each has a 250Kw capacity), optimized heat exchanger system. A new innovation for this industry is that Powerbase is now offering a BOO model for farmers. Powerbase will build, own and operate facility while providing the farmer with some income for the use of his manure.

Powerbase's Hydraulic Power Unit, (HPU)

PowerPAC II

Anaerobic Digester

Site Assessment, Design and Software Tools

1. Development methodologies for site assessment and design, and Software Tools: RETScreen International : Clean Energy Project Analysis Software(includes small

hydro). More than 200,000. users from 222 countrieshttp://www.retscreen.net/

IMP - Hydrological forecasting for ungauged hydro sites

HydroHelp - Pre-feasibility, costing and site optimization

More than 1000 registered users

Website: www.hydrohelp.ca

2. Recent Reports by CanmetENERGY:

Report 1) "Low Head Hydro Market Assessment" by Hatch Energy, 2008http://canmetenergy-canmetenergie.nrcan-rncan.gc.ca/eng/renewables/publications.html?H327842.201.01

Report 2) "Emerging Hydropower Technologies R&D in Canada- A Strategy for 2007-2011" by CanmetENERGY NRCan

http://canmetenergy-canmetenergie.nrcan-rncan.gc.ca/eng/renewables/small_hydropower/publications.html?2009_Hydro_01

Establishment of an Independent Turbine Testing Laboratory • The Laval University Hydraulic Machinery

Laboratory (LAMH) is the only independenthydro turbine testing laboratory in Canadahttp://lamh.gmc.ulaval.ca/en/home/

• LAMH aids research in North America in thedevelopment of both small and large hydraulic turbines by helping improve efficiency, reliability, and reduce environmental impacts

• Perform classical measurements of efficiency hill charts, cavitation and other hydraulic turbine characterizations

• Since 2007, established an industrial consortium with six industries, utilities and a government agency. It is building a detailed measurement database of unsteady flows in different sections of a model propeller turbine, in order to help the development CFD simulations.

• Help train highly qualified people for the hydro industry

The Hydraulic Machinery Laboratory atLaval University, Sainte-Foy, Quebec

North America and International Cooperation on Small Hydro Development

• US – Canada Clean Energy Dialogue was established in February 2009. Action Plan includes cooperation in developing clean energy technology. Under the Clean Energy R&D and Develop a More Efficient Electricity Grid, the two subjects have been identified: http://www.ecoaction.gc.ca/news-nouvelles/20090916-3-1-eng.cfm* Tidal and River Current Energy ( Technology to Generate Electricity from Rivers and Tidal Currents)* Low Environmental Impact Hydro ( Technology for Electricity Production from Low Head Waterways) : To implement the breakthrough turbine technology through on-site demonstrations of its performance, cost-effectiveness, fish-friendless for low head sites (less than 3m head) in North America.

• US-Canada-Mexico Tri-lateral Energy Cooperation: small hydro projects can be initialled

• IEA Hydropower IA- Small Hydro Task Force (Annex II) participation• European Small Hydro Association (ESHA) cooperation • China , India and other Asia countries cooperation under APP (Asia-Pacific

Partnership)