GEM Hydro-Kinetic Turbine Rivers and Oceans

GEM Hydro-Kinetic Turbine (Patent's in Canada, USA, China and patent's pending in India and Brazil) sites are appraised for dimension and generation capability, and is tailored to each site. The Hydro-Kinetic Turbine will be engineered and design according to site requirements for both on grid and off grid connected locations, this includes flow velocity, flow volumes, power and other environmental and water transportation requirements.

The GEM Turbine operates on pontoons that are anchored in the river or tidal streams. The non-directional turbine attached to the pontoons with a substructure maintains a constant depth of operation while extracting kinetic energy from river or tidal flows in both directions without adjustment.

The GEM Hydro-Kinetic Turbine will be constructed out of the most environmentally sensitive CSA approved durable products available today. The GEM Turbine is designed and constructed for low maintenance and maximum longevity. The GEM Hydro Kinetic Turbine can be located near the consuming markets, due to its low environmental impact with regard to noise pollution, wild life concerns and zero head (no reservoir required). The GEM Turbine is the most efficient and durable hydro-kinetic energy turbine available today as it is constructed of substantial heavy gauge metal with a limited number of moving parts that are designed of durable, non polluting components. Our turbine will require low to zero maintenance for extended periods of time. The GEM Turbine maintains designed rotation regardless of flow direction unique to the industry. The Generators are located above the water for ease of access, maintenance and longevity.
The GEM turbine can be operated in high speed tidal currents such as the Bay of Fundy, Canada (flows in excess of 5.1 m/sec 16.7ft/sec) due to it's durable non-traditional design or in 0.5m/sec water velocity due to its high efficiencies. This unit has the ability to deflect high energy impact while maintaining the highest efficiency, of any turbine due to its non-traditional patented design. A Malaysian Technology Institute achieved 89% efficiency in a controlled flow channel test based on the GEM concept. This efficiency was conducted on a working model therefore it takes into consideration bearing efficiency loss. This efficiency would include bearing loss and any fluctuations in flow. Other turbine efficiencies are determined by theoretical efficiencies and do not include bearing loss and other inefficiencies. This efficiency validates the GEM results.     
GEM has developed the technology to improve this 89% efficiency while maintaining turbine integrity for durability and efficiency. The efficiency is in excess of 89% or approximately 1.5 times the "Betz Limit Theory" ( of 59.33% (maximum for a traditional turbine, such as wind turbines). Our efficiencies have been derived in field tests and confirmed by computer simulation (Autodesk Software). The Malaysian studies confirmed our field tests. During testing and data collection at the Canadian Turbine Test Centre the GEM corporate engineer acquired a horsepower to torque performance ratio on its concept test unit.


            The GEM Turbine

At GEM Holdings we realize that Solar is a green renewable industry and Windmills are also a green renewable industry and with the GEM Turbines tidal and run of the river technology it will now become a viable GREEN industry, all capable of similar power production and excel in tidal stream production. 

The GEM Turbine can produce power surpassing the largest of windmills and solar farms when considering efficiencies and the power output.  The GEM Turbine will have an overall capital cost advantage, an operation and maintenance cost advantage; while maintaining a superior zero wildlife and environmental impact unlike other green technologies that kill birds, bats, insects, fish, and damage forest and farmland.

GEM Holdings over the past 5 years has identified obvious areas in the design that would require innovative solutions, these are: -

Problems                                       Solutions

Vane fluctuation due to high and low pressure differential Opposite open and closed vanes linked together by hydraulics that also operate as a break for maintenance. The linking of the vanes allow the high and low pressure to improve performance. 
Massive weight on central drum constructed of heavy gauge metal. Buoyancy with control ballast floatation that controls load on bearings and substructure for longevity.
Massive Weight and force on vanes constructed of heavy gauge metal. Buoyancy with control ballast to reduce bearing load.
Extreme torque on designed vane hinges. Convert vane to a solid state vane at open position transferring torque to the drum at point load and then to the axis reducing load on hinge and bearings.
Adjustment to river or tidal flow surface fluctuation or flow elevation. Use of pontoons to maintain turbine immersion.
Extreme Axle stress from unwanted vertical forces (y and z directions). Substructure roller support system to secure turbine, reduce axle stress and transfer forces to pontoons and then to the anchors. Provide stability during extreme flow conditions.
The rotation variance between high and low tide velocities (as in windmills operating with variable pitch blades).  Patent pending innovation. (Not disclosed)
Debris accommodation and avoidance. Patent pending innovation. (Not disclosed)
Site design to accommodate ice flow in the north. Not disclosed.
The operation of green environmentally friendly non-corrosive bearings. CSA Approved outsourced bearings designed for 500 rpm with 20 year life expectancy but operating at a few rpm in the GEM Turbine.
Tsunami or hurricane.  In the event of a tsunami or hurricane the generators will be dis-engaged (no load) and the slow turning turbine will increase rotation without damage. This will reduce the load on the anchors as they will be able to accommodate the additional unwanted forces.
Fish Survival Deflector that maintains a space between central drum and vanes when closed and aids in the rotation efficiency while providing space for fish survival. No high velocity vanes to injure wildlife.
Change in Tidal Direction Uses identical entrance and exit design including anchors. Rotation remains the same therefore no adjustments are required.

The GEM pontoons will be anchored at both ends of the pontoons in such a manner that the tidal flows and the elevation fluctuations can be accommodated with self adjustment. The pontoons provide the stabilization of the substructure and anchor points to seabed anchors. This allows the turbine to accept all extreme unwanted forces without damage as would occur with any anchored ship. 

We are happy to announce GEM Holdings has addressed and recently provided solutions to all of these concerns with its innovative patent pending technologies. GEM Holdings Ltd. believes that this turbine is the only hydro-kinetic turbine capable of producing substantial power at a low cost from a single dependable unit but operate well in a farm environment.  

The unique design of the GEM Turbine considers the flow onto the exposed vane to be the high resistance side of the Turbine and the retracted vane to be the low resistance side of the Turbine.  In a 6 vane design (optimum) the width of the vane is equal to the radius of the drum.  The water striking the extended vane provides a force on the vane and also sustains an equal amount of force from the water striking the drum that deflects the water onto the designed vane in the amount of the radius of the drum that is equal to the width of the vane.  These forces in conjunction with the high and low pressures creates the torque on the axis.

This designed focus of water when considering the forces as well as the pressure difference can be assumed to double the vane force of the normal flow plus the drum deflected flow.  The vane can now be considered uniform when calculating vane force. If the water striking the vane without the water deflected off of the drum is considered, the point load would be 25% of the distance from the drum on the vane, but with the water deflected off of the drum the point load will move from 25% of the vane width to 50% of the vane width from the drum (Fig.3), this occurs because water is non compressive. The low resistance side of the Turbine will lose efficiency in the assisted opening of the opposite vane that is operating co-operatively in the opening and closing process.  This procedure will result in a (100% - 89%) or 11% loss of efficiency.  All forces included will result in the following calculations to determine Turbine production.  (These calculations have been confirmed by prototype testing.)




When evaluating and critiquing the non-traditional GEM Turbine one must take the Horsepower relative to distance and time into consideration in order to calculate the performance of this technology (momentum). The higher learning centre in Malaysia in conjunction with its advanced testing facility realized this aspect in calculating the performance of this unique innovation; arriving at an 89% efficiency. It is very important not to overlook this aspect during performance critiquing. 

 GEM Turbine Tutorial

Curved vane width is equal to radius (r) in a 6 vane configuration

Fig. #1 – depicts hydro flow on vane (r)

Fig. #2 – depicts point load of vane (r) from vane axis (2) is at maximum rotation and extension solid to drum. 

Fig. #3 -- depicts point load of vane (r) plus point load drum flow that is equal to vane width (r). A portion of the water may be deflected off of the outside of the preceding extended vane as well as the drum, but the total will be equal to the radius flow plus the extended vane. 

Fig. #3 -- depicts the point load at the center of the vane, therefore the point load and the center of force are located at the same point. 

Force - Calculated on vane from axis 2.

Torque - Calculated on axis 1 that is welded at center of the drum and rotates on upper and lower structure bearings.  

This occurs because water is non-compressive.

The resulting force will be 2 times the vane force times the vane efficiency (72%).

 The point load will occur at the center of the vane therefore the torque on axis #1 will be (2 X vane force) (l.5r) (vane efficiency or 0.72) in a 6 vane configuration as the force transferred from the vane to the drum at the vane center of the force or point load and then to the axis.

GEM Turbine Power Output Calculations

GEM Concept Prototype Test Example - 3 foot Drum


The Point load travels through the high resistance side of the turbine (extended Vane and then through the low resistance side of the turbine (closed vane) as depicted.

Figure 1 Point Load Circumference (PLC) passes through the centre of the vane or 50% of the vane width from the drum.

Figure 2 Point Load Circumference (PLC) passes through the vane at 25% of the vane width from the drum.  The PLC travels an equal distance from the axis.  

Conclusion: The Point Load Circumference will be of equal distance in Figure 1 and Figure 2, but when calculating the vane force Figure 1 must be used for the correct calculation of force and torque transfer to the drum and axis. It is irrational to consider the point load travelling outside of the turbine. 

The momentum or point load distance will be the water flow velocity times the efficiency of 89% or 0.89 x water velocity. In identifying the point load location the force of the water is considered; the high and low vane pressure impact the direction of the flows onto the vanes. The only reasonable method of identification is by prototype or by computer simulation.

There are two factors or efficiencies in calculating a turbine performance.  One is the vane efficiency relative to the force that determines the torque.  This aspect is often overlooked by many consultants and engineers, and has led to the failure of many innovations in high energy tidal streams.   Excess water flow must be allowed to escape and not be forced into compression that causes an increase of force on the structure and result in efficiency loss, and often structural failure. This oversight continues today at extreme costs to developers and Governments.  The second efficiency, or aspect, used to calculate momentum or point load distance and is the one that most engineers and consultants refer to as it is usually higher.  The GEM Turbine has the highest efficiency in the world, in this category, at approximately 89%.  This high efficiency combined with the extremely high vane efficiency of 72% (most vanes are 10 – 35%) results in a highly efficient turbine in the conversion of kinetic energy to mechanical energy.  The energy required for power generation is absorbed and the balance is deflected by the rotary effect of the GEM Turbine as opposed to the stalling effect of the excess energy, as in most other technologies.  This feature allows the GEM Turbine to increase its “rpm”, when exposed to excess forces with no damage as it is designed to accommodate higher rpm.

Important to all investors and governments investing in new innovations be sure to research both efficiencies before investing.  Most innovations being tested in Canada have a vane efficiency between 10-35% with flat vanes in computer simulation testing at the low end (near 10%). Most other vane efficiencies are less than the Betz limit of 59.33% with the exception of the GEM vertical axis vane design with a efficiency of 72%, proven with computer simulation and field testing.

GEM Turbine Power Output Calculation


 GEM Prototype Concept Turbine (3 Foot Drum)

            1:        GEM Vane efficiency (EV) = 72% or 0.72 (Validated)        

            2:        GEM Turbine efficiency (E) = 89% or 0.89 (Validated)

            3:         1 (hp) = 550 ft. lbs./sec. or 0.74 Kilowatts

            4:         Water Weight (WW) = 62.5 lbs./cu. ft.

            5:         Water Velocity (WV) = _2.5____ft./sec. or _150___ft./min. (Site Tested)

            6:         Vane Width (VW) = __1.5___ft.

            7:         Vane Height (VH) = __4.0__ft.

            8:         Point Load Circumference = PLC

            9:         Deflector = __0.33_____ft.

           10:        Radius = R

           11:        Point Load Circumference (PLC) = 3.14( 0.5 VW__0.75_ft +0.5 Deflector  __0.165___ ft. + Drum Diameter ___3___ft.)  = _12.2931___ ft.

           12:        Unit RPM = WV per min. ___150___ft./min. ÷ unit PLC_12.2931__ft. =12.2 at 100% efficiency 

           13:         __11____rpm (Validated by field test) /12.2 = 0.89 or 89% Turbine efficiency. Therefore momentum would be 2.5 x 0.89= 2.225 at 11 rpm [Theoretical Information for prototype design]

           14:     [Prototype Information for stall calculations field tests]  

Force = 2.5’/sec x 62.5 lbs/ft3 x 3.33’ (vane width +r) x 2.5’ (vane height) = 1300.78

 Force= 1300.78 x 0.72(vane efficiency) = 936.56

 Torque = 936.56 x 2.225 (Point Load) = 2083.85

           15:  The Gear Box (1950’/lbs + generator unknown + Turbine Unknown)


This assumption appears to be approximately correct. From this information of the prototype testing, the GEM Engineer determined the accurate point load location which takes into consideration the turbine efficiency but, not the vane efficiency. From the testing of this prototype an accurate point load location was determined for this prototype at 2.143. This will remain consistent to this design and it accounts for the turbine efficiency of 89%.


This prototype will generate –


A 3.33’x4’x2.5’x62.5lbs/ft3 x0.72=1498.50lbs

B Mass = 1498.50lbs

C Momentum =mvr=1498.50lbsx2.5’/secx2.143=8028.21lbs’/sec

D 8028.21lbs’/sec/550’lbs/sec=14.60 HP at 11 RPM


The prototype will operate under load at 11 RPM and produce 14.60 HP or 14.60x0.74= 10.80kw


The prototype generated adequate HP but failed to provide the RPM required; as it was designed to be installed in 1.5m/sec or 5ft/sec water flow as was advertised by the CTTC but was installed in 0.75 m/sec or 2.5’ft/sec water flow, as the higher flow was not available during our testing.


GEM Assumptions and Evaluations

  1. The Momentum at the stall in the prototype has no effect on the rotation of 7RPM. If there is an effect it will be minimized by the average of water force over 2.5 feet of immersion of the turbine.
  2. The point load or PL remains constant once established. The PL will maintain a ratio to the vane force regardless of the turbine size if the vane width is equal to the radius or r.
  3. The prototype under load began to rotate to 7RPM when immersed in 2.5’ or 5x6” of water. Therefore 6” of emersion represents 7RPM/5=1.4RPM every 6” of emersion.
  4. At Stall or 7RPM no momentum is considered therefore when the turbine is immersed in an additional 6” or 3’ of water the turbine rotated at 10RPM.
  5. The water force represented 7RPM + 1.4RPM or 8.4RPM therefore the momentum represents (10-7) = 3RPM-1.4RPM Therefore 1.4xmomemtum = 3 or momentum =2.143 x Force Therefore the PL is 2.143 on the turbine from the axis.
  6. The point load will be constant to a turbine of various sizes relative to the prototype therefore 2.143/r or 2.143/1.5=1.43 Therefore the PL is located 43%of the vane width distance from the vane hinge or r+0.43(vane width) will determine the momentum ratio or 1.43rxVxM.
  7. Example – This is a small to mid-sized example turbine. The durable design will accommodate much larger turbines.

5’ vane x 10’ high
10’ drum x 10’ high
Water Weight- 62.5 lbs/ft3
Water Velocity- 10’/sec or 600’/min
Radius of drum-5’


Water volume #1= 10’x10’x10’x62.5lbs/ft3

Velocity =10’/sec

Momentum= MxVxr

Peak HP=4,468,750/550=8,125HP @600’/min ÷ (2x7.15x3.14) =13.4RPM

Vane Efficiency @ 72%= 4,468,750 x0.72 = 3,217,500

HP=3,217,500/550=5850HP or 4329Kilowatts


  1. The prototype operating turbine would have considered the 89% and included the efficiency and determined the PL position. 
  2. The vane will operate at between 72-89% efficiency and maintain a 13.4 RPM.
  3. The vanes determine the efficiency of the turbine therefore at no load the vane will operate at approximately 89% and as the load is applied the vane efficiency will drop to a minimum of 72% efficiency. This feature will allow the turbine to maintain a constant RPM with a minimum HP relative to the vane efficiency.
  4. The PL position has to take into consideration the normal directional flow of energy as well as the high and low pressure effect(substantial), the direction of flow and turbulence off of the drum or cylinder. Fluctuation water flows with their many variables the point load location can only be determined off of a prototype with a load as the GEM Engineering Team identified.  The prototype identified a point load of 2.143ft from axis or r+0.43r=1.43r.
  5. If the turbine efficiency is calculated as having 89% efficiency only the vanes will have an influence therefore the vanes are operating at 89% efficiency for a maximum and a minimum of 72%. The turbine will operate between 72-89% under load and RPM will be constant as identified by the prototype.



Solar Energy:

Assuming a solar panel site is installed at $900,000 per Megawatt., and it operates at 10 to 15% efficiency.  Using the highest efficiency of 15%, an installed Megawatt of electrical output would be $6,000,000., per Megawatt of production.  The installation price is a low estimate and the output efficiency is a high estimate. New solar farms near the equator can operate at a 22% efficiency, but a decrease in efficiency occurs as installations move away from the equator.  Solar panels use approximately 4 acres of valuable land per installed megawatt when located close to market.


The life expectancy appears to be 20 to 25 years, with an 80% production near the end of the life expectancy.  The efficiency when taken over one year could be less than the 15% efficiency, this would increase the installation cost, with a maintenance cost of 1% to 3% of the installation cost per year depending on location and age.  Therefore the capitalization and maintenance of the installation will be between 5% and 8% of the installation costs per annum, or $300,000., to $480,000., per year.  Concentrators of solar rays to increase efficiency are known to kill or injure wildlife such as birds and insects, and are under scrutiny and subject to restrictions in California.

Three solar farms are approved for installation in southern Alberta, Canada totalling 94 megawatts, costing over 100 million dollars. This will supply power for 20,000 Alberta homes using 7200 kilowatts per year (Alberta Average) (20,000 homes x 7200 kilowatt hours/year) = 144000 megawatt hours per year or (144000 megawatts per year/365days/24hrs)= 16.4 megawatts per hour average. The efficiency will be (100%/94 mega watts x16.4 megawatts) or 17.45% efficiency. The average power production for Alberta is 1292 kilowatt hours/ year on a 1 kilowatt solar panel  therefore one kilowatt solar panel at (1292 kilowatt hours per year/365days per year/24 hours per day)= 0.1475 or 14.75% average efficiency.  The 2019 southern Alberta installation operates at 17.45% efficiency as compared to the Alberta average of 14.75% because it is located further south in the province. The cost of one megawatt of solar installation will be $100,000,000.00/16.4 Megawatts = $6,097,560.97 per Megawatt or approximately $6,000,000.00 per megawatt.

Decommissioning costs of solar is $200,000.00 per Megawatt of installation.  At a 15% efficiency or ($200,000.00/15%)100= $1,300,000 per Megawatt of production. (Heavy Metals costly to dispose of)

Windmill Energy:

Assuming a windmill is installed at $2,000,000., and it operates at 34% to 37% efficiency.  Using the highest efficiency of 37%, an installed Megawatt of electrical output would be approximately $5,400,000., per Megawatt of production.  The installation price is a low estimated installed price, and the output efficiency is a high estimate.   The operating and maintenance costs are extremely high. The maintenance costs fluctuate by age, location and year therefore view government operations and maintenance website for wind turbine operations and maintenance. Due to these high costs the Alberta Government appears to be moving towards solar energy by not renewing some of the wind energy contracts.  


Wind turbines are known to kill and injure a substantial number of wildlife, such as large and small birds and bats every year.

Decommissioning of windmills is $200,000.00 for 1 Megawatt of installation.  At 37% efficiency or ($200,000.00/37%)100=$540,000.00 per production Megawatt.

GEM Turbine:

The GEM Turbine is installed at an estimated cost of approximately $1,500.000. to $2,000,000., per Megawatt of power output, site dependant. Low maintenance costs are due to the use of a limited number of 20 to 40 year environmentally friendly bearings with non polluting heavy gauge metal (stainless steel or aluminum) components in the GEM Turbine construction. 

The GEM Turbine will require new bearings every 20 to 25 years as per bearing manufactures claims.  The easily accessed generators will require regular maintenance according to manufacturer specifications as in all generators.  This results in very low operating and maintenance costs as the generators operate above the water and the turbine is easily accessed. The various efficiencies in constructing the GEM Turbine are taken into consideration so the output is 1 megawatt per hour as designed for this competition.

The GEM Turbine has built-in design protection to accommodate aquatic life and is environmentally friendly, with low noise pollution, slow speed, high torque, durable design.  GEM does not anticipate the mortality of any wildlife, while producing substantial amounts of dependable predictable power due to its high efficiency. The GEM Turbine will produce power 24 hours 7 days a week unlike solar or wind turbines that are dependent on weather conditions.  The environment is paramount in the GEM Turbine design.    

The capitalization costs on the solar and wind installations per megawatt hour of production will be ($6,000,000/25 years) = $240,000 per year or ($6,000,000/20 years) =$300,000 per year. The GEM Turbine anticipated capitalization costs over 40 to 50 years will be ($2,000,000/40 years) =$50,000 per year or ($2,000,000/50 years) =$40,000 per year per megawatt hour of production with substantially lower operation and maintenance costs and zero to low environmental impact.

After 50 years of use the decommissioning of the GEM Turbine, if nessesary, there will be a net profit per Megawatt of production. (Salvage of stainless steel or aluminum components) 

GEM Services Provided

Project Assessment

  • Project Costing
  • Budget Estimating
  • Project Consulting

Site Assessment

  • Energy Production 
  • River/Channel Velocities Measurements 
  • Site Location

Engineering Designs & Service

  • Site Safety Appraisals
  • Site Mooring/ Anchoring
  • Calculating Hydro flows
  • Calculating Hydro Kinetic Turbine Size
  • Power Output
  • Stress & Dynamic Analysis on Models with Software
  • Fluid Flow Analysis Optimization with Software
  • Environmental Impacts 

Environmental Assessment

  • Wildlife Survival Including Birds & Fish
  • Low Noise Impact
  • No Water Reservoir Required
  • All Components are Environmentally Friendly


  • Site Installation
  • Transportation
  • Site Assembly

Power Distribution

  • On-Shore grid
  • Off-shore grid
  • Micro grid 

This is a prototype concept turbine.


For any clarification please contact GEM Holdings Ltd.