April 28 Canada Pavilion ICOE Conference, Washington DC, 0ne-pager .pdf
HISTORY
OUR DEVELOPMENT OF A VIABLE WAVE ENERGY SYSTEM
Introduction
Beginning in 2010 it was decided to purchase a wave power system to provide clean renewable energy for our cottage on Keats Island. Waves seemed to be a better choice than wind or solar energy because we could see that the waves were active all day and all night long, most of the time. But we could not find any to buy, so we decided to make one, shouldn’t be that hard we thought . . .
After the first attempt, using the obvious point absorber pushing and pulling a linear generator, we could see that two problems needed to be solved to make electricity from wave power that was economical and more reliable than from wind and solar. First, how the deal with the change in water level due to tides approximately twice a day (up to 5 meters) and the height of largest waves at top and bottom(up to 2 m). Secondly, how to make the linear generator work more efficiently (the slow moving stop & go aspect needed to be improved). The parts that worked well & which we considered essential from the first (2010) model were the use of the float (point absorber) and the direct drive of the generator from the wave action.
2010 Neptune 0.1
2010 Neptune 0.1
Linear Generator Direct Drive with generator on top out of water
2010 - Nep 0.1
Linear Generator
We began by building a test model using the obvious approach of using a point absorber constrained inside a frame so it could only move up and down. We attached a push rod to the top of the float and extended this above the water level where the linear generator was housed.
A custom made magnet pack was attached to the moving end of the push rod (the translator) and we made a custom stator with multiple small circular coils, (using the smallest gauge wire possible), arranged in rows extending horizontally away from the translator.
We tested this in a swimming pool and found that while the moving float and the direct drive approach are keepers, the fact that we have a 5 m tide and the slow moving and stop & go movement of the generator translator needed mitigating.
2011 Neptune 0.2
2011 Neptune 0.2
2011 Nep 0.2:
Hybrid Linear Generator
We hypothesized that we could increase the slow moving aspect of the linear generator with compound levers. Sound in theory impractical in reality.
Stopping the increased speed of the Translator (now with the coils) when it came to the end of the stroke presented a physical problem. We could make it strong enough to not break but it would be prone to high maintenance and high costs.
We then hypothesized that a variation on the well know uni-directional rotating generator using a direct drive PTO may be economical and produce a greater amount of power than the stop n’ go linear generator. Our first attempt was to put two of the compound lever units together, as the image shows, turning the linear generator into a rotating generator. Of course this would require we make a custom generator that could handle variable speeds & a PTO that would convert the reciprocating motion from wave action on the float into uni-directional rotation motion.
2011 Neptune 0.2
Hybrid Linear Generator With speed increasing compound levers
2012 - Neptune 1A Generator
2012 Nep 1A:
Custom Generator Part
At this point we understood that the wave energy problem is primarily about generating the electricity from the often small waves and slow moving reciprocating motion of the float induced by the waves. We hypothesized that a large diameter axial flux permanent magnet generator (which Hugh Pigott in Scotland helped us make) would produce substantial electricity from the uni-directional rotation motion that the new PTO, we were working on at the same time, would deliver from the smaller waves.
We wound our own coils in the 30 coil by 80 magnet generator (40 on each side) of the stator coils. This generator was designed to produce 6 KW 3 phase power from 0.5 m by 4 s waves (.5 m high by 4 second period waves).
This generator coupled to the new PTO (see 2013) produced power in the Neptune 2, 3 & 4 test units all deployed in the sea.
2012 Neptune 1A Custom Generator Part
Custom Axial Flux Permanent Magnet Generator,
to handle the relatively slow and variable speeds induced by the waves on the motive float.
2013 - Neptune 1B Direct Drive PTO
2012-2013 Neptune 1
Direct Drive Wave PTO Patented: CA2808614.
Solves linear generator speed and stop & go issues while maintaining
direct drive from float to the generator.
2013 Nep 1B:
Generator Drive Wave PTO
Patent CA2808614
It was hypothesized that an endless chain driven by the reciprocation forces from floats could replace a rack and pinion drive (as a pinion can easily move a rack but a moving rack does not easily move a pinion) and that if a sprag clutch were used on one of the chain sprocket shafts it would turn on, say, the up stroke but not on the down stroke, AND, if a similar system we used opposite the first and the sprag arranged to allow the shaft to turn on the down stroke that these could be arranged to provide unidirectional motion to a generator shaft with energy from both the up and down movements of the float. We did this, patented it, and it works.
We now have solved the linear generator stop and go issues, and, with increaser gears solved the slowness issues with a custom direct drive PTO.
View Videos of PTO Operation:
First test of direct drive wave energy PTO
Second test of hand powered wave energy being converted to electrical power using the direct drive Neptune PTO, 2013
2014 Neptune 2
2014 Nep 2:
Floating Wave Engine
A complete electricity producing full sized unit with the new PTO and generator was was made and tested. It produced 460 Volts, no load 3 phase power from 0.5 m waves.
The unit was made of non-corrosive polyethylene plastic tank outriggers, aluminum motive float point absorber, wooden and steel deck and a welded aluminum and ABS geodesic dome.
The unit proved to be stable in the waves, but the attachment of the polyethylene floats proved to be unstable over time and likely to wear to breaking within 6 months due to the 4 million wave duty cycle at the Keats island test site. Unit was brought back for mitigation.
2014 Neptune 2
Complete floating system producing electricity from wave actions on motive float.
Tested at 2nd Narrows Bridge, North Vancouver, BC, Canada
2015 Neptune 3
2015 Neptune 3
2015 Nep 3
Tidal Compensator
PCT Patent WO 2014/138964 Al
This, mostly steel unit, address the original issue of dealing with the 5 m tides in the test area. The tidal compensator mechanism maintains the fixedness of the floating body “vessel” to the seabed, for the point absorber to react against, while allowing the floating body to move up and down the 5 m required due to tidal flow and enables the motive float to distance of the highest waves at any time.
The operation of the electrical generator from the point absorber movement transferred through the PTO worked flawlessly, producing power as expected. In addition the unit was built to Transport Canada requirements for vessel registration which would allow it to be anchored in most parts of the world without cumbersome permits.
The fail-safe device on the tidal compensator winch proved to be unreliable and failed operationally during testing and the wave engine was brought back to land for mitigation.
2015 Neptune 3
Shown moored at Maritime Museum, Vancouver, Steel and Aluminum construction,
PCT Patented Tidal Compensator and electricity production from direct drive PTO-Generator were tested in waves at Keats Island.
2016 Neptune 4
2016 Nep 4
Dis-Harmony of 2 Floats
Harmonizing the Frequency of the point absorber movement so that it can react against the movement of the floating vessel, is known as the “attenuator problem”.
We hypothesized that a 10:1 weighted floating “vessel” would ensure that it moved in dis-harmony with the motive point absorber movement, thus providing a body for the motive float part to react against to twist the generator.
Our tests proved it is a valid hypothesis but only in small < 0.75m waves; the cost for ensuring that this would work in larger waves > 4 m rendered the wave engine not commercially viable due to associated high costs. The wave engine was brought back to land for mitigation.
2016 Neptune 4
Modified Neptune 3 shown moored at Keats Island, Strait of Georgia with 35 Tonne outrigger floats
to test the dis-harmonizing of the frequency of the motive point absorber part in waves of various sizes.
2017 Neptune 5A
Screen shot image from video record of tests, note measure stick behind float,
tug boat was used to make waves of different sizes for the tests.
2017 Nep 5A
Levered Float off a Pile
We hypothesized that a levered point absorber off a pile (different from the jetty based Wavestar and Eco Wave Power lever arm approaches) would not have the drawbacks of the dis-harmony of attenuators and be economically viable at large sizes. Testing of this concept was conducted under 4 conditions with 3 tests each for 3 wave sizes (36 tests) in Indian Arm proved successful, would be economically viable and scalable with no problems.
We then hypothesized that a full size 2 to 4 lever arm point absorber-pile system that transferred the point absorber power to the patented direct drive Neptune PTO from a point near mid way along the lever arm would solve the inefficiency problems associated with the hydraulic PTO and permit full operations at any tide level (with 5 m change) and any wave height (up to 2 m) as are found in the Georgia Strait.
2017 Neptune 5A
Test of Lever Arm point absorber attached to Pile to determine suitability of this approach under various conditions in various wave sizes (36 test runs)
Mud Flats, Indian Arm, Vancouver Harbour.
2018 Neptune 5B
2018 Nep 5B
Floats on Lever Arms have been required mitigation due to high 2.6 m/s (5 knot) currents at test location. After several failures a stable “lateral force bearing” with a “bridge-like” lever arm was built to provide a stable float system for all currents and waves at the test location.
This has allowed us to test various solutions to the “Last Wave Energy Problem” which is to produce continuous output electrical power from waves a that are 3 to 10 seconds apart.
Continuous power test results are reported on the Test Results Page.
Development Stage 3 (TRL 5-6)
2018 Neptune 5B
Deployment of levered floats off pile under IUL license 800 m off Point Grey Strait of Georgia to test full size system and experiment with various ways to achieve continuous power output from waves that are 3 to 10 seconds apart.
2018 Neptune 5B
2018 Nep 5B
Floats on Lever Arms
These point absorbers on lever arms have required mitigation due to high 2.6 m/s (5 knot) currents at test location and 6 m/s horizontal wave transfer forces.
After several failures a stable “lateral force” bearing with a “bridge-like” lever arm was built to provide a stable point absorber system for all currents and waves at the test location, however this system would not be economically viable at larger scales and would require constant maintenance. Mitigation was required, see 2019.
This Neptune 5B engine is deployed under a 5 year Investigative Use License issued by the MLRNRO, BC Government, 800 m off Point Grey in the Georgia Strait
2018 Neptune 5B
Deployment of levered point absorbers off pile under 5 year IUL license 800 m off Point Grey Strait of Georgia
to test full size system and experiment with various ways to achieve continuous power output from waves that are 2 to 10 seconds apart.
2019 Neptune 6
2019 Nep 6
Float on a pile and 3rd party testing
station is being deployed, expected completion date is end of 2019.
This complete wave engine uses the ‘float on a pile” and the modified PTO with custom generator connected to a heater bank at sea. It will use the existing pile framework and domed enclosure built for Neptune 5 and include a new Testing Station on piles 50 m away.
Allowing potential business partners to test and verify the continuous electrical output claims with their own people and their own equipment.
Development Stage 4 (TRL 7)
2019 Neptune 6 (3rd quarter 2019)
Float on Pile and Test Station, under IUL license 800 m off Point Grey Strait of Georgia, providing 3rd party verification by interested commercial joint venture partners to visit with their people and their testing equipment to verify continuous power and hourly power output claims from verifiable wave sizes.
2019 Neptune 6
2019 Nep 6
Testing Full size Unit
This complete wave engine uses the ‘point absorber on a pile” and the modified PTO with custom generator connected to a 20 kW resistor bank at sea. It will use the existing pile framework and domed enclosure built for Neptune 5 and include a testing station on piles approximately 10 – 20 m away.
We hypothesize that this point absorber on a pile with reducer gearing will enable the power from the float in all tides (5 m) and wave heights (up to 2 m) levels will be transferred to the direct drive PTO, and that modifications to the PTO will produce continuous power from waves as small as 0.1 m high as well as other hypotheses.
The testing station will allow 3rd parties to verify the amount of power produced from waves of various sizes. See: https://www.neptunewave.ca/test-results
2019 Neptune 6 (3rd quarter 2019)
Point absorber on Pile and Test Station, under IUL license 800 m off Point Grey Strait of Georgia,
providing 3rd party verification by interested commercial joint venture partners to visit
with their people and their testing equipment to verify continuous power and hourly power
output from various verifiable wave sizes.
2020 Nep 7
Add-on to Offshore Wind Turbine
This concept for a 24 piston-point absorber wave engine add-on to offshore wind turbine was made for a feasibility study for Otary,be
The Neptune wave engine add-on is for offshore wind turbines that have a 6 + m mono-pile, are 106 + m high with a rotor diameter of 154+ m.
The Wave Engine is 25 m high by 30 m diameter.
Scatter chart below shows projected, not verified, power values.
2020 Neptune 7 Wave Engine Add-on to Offshore Wind Turbine Mono-pile
Concept drawing and projected (not verified) kWh power scatter chart for a location in the English channel off Belgium
Combining proven test units backed by decades of government-funded wave energy research with a
revolutionary wave engine technology to add a new commercial method for firm base load electricity
production that is carbon emission free and competitively priced