EnCurrent Operating Results
(Pointe du Bois)
The project at Pointe du Bois has included the installation of both a 5 kW and a 25 kW EnCurrent
Power Generation System. The site has been utilized to gather significant data on the operation of the
systems with five graduate students, four from the University Manitoba and one from the University of
Calgary, basing their Thesis on operations at the site. As this is an operating site, the range of flows is
limited by the operation of Manitoba Hydro’s downstream hydroelectric generating facility. However,
the data measured at the site shows a strong correlation with the expected performance of the
equipment.
The 5 kW System is equipped with a rectifier and an inverter which converts the variable frequency
AC power signal from the permanent magnet generator into the 60 Hz signal provided to the Manitoba
Hydro grid. The inverter utilizes Maximum Power Point Tracking (MPPT) capability that controls the
operating point of the system. As the MPPT algorithm uses simple interpolation between the points
entered, the power curve for the MPPT is set at a slightly lower power output than the predicted power
curve for the turbine in order to maintain stability.
Highlighted in the graph above are the predicted power output, the MPPT configuration and the actual
power output measurements for the 5 kW System using different support arm configurations. Support
arms provide the connection between the center shaft of the turbine and the hydrofoils which generate
the lift to drive the system. They introduce a parasitic loss on the performance of the system and as

shown in the graph, the choice of support arm shapes greatly
influences overall system performance. Profiled steel support arms
were used during the development of the EnCurrent Turbine,
however, a decision was made to substitute these with steel flat bar
to decrease manufacturing costs. This decision reduced overall
performance and the system was retrofitted with profiled steel and
hydrofoil support arms. Based on the results of both of these options
all EnCurrent Power Generation Systems now ship with hydrofoil
support arms.
Similar to the 5 kW System, the 25 kW System makes use of the inverter’s MPPT algorithm to
control the power output from the system. However, the values entered into the MPPT table are closer
to the predicted values than for the 5 kW System, as is highlighted in the graph below.
The graph also provides the power output for the 25 kW System utilizing profiled steel support arms
over a range of velocities from 1.7 to 2.4 m/s. Over this range the power outputs track very closely to
both the predicted values and those that have been provided in the MPPT table. New Energy plans to
retrofit the system at Pointe du Bois with hydrofoil arms and take additional measurements to validate
the performance of the system. It is anticipated that performance improvements will be seen similar to
that of the 5 kW System, in which case it is expected that performance will exceed originally predicted
levels.