Trying to get further off the grid

Note:

This is another project blog for work carried out before we left in May.

Yours, Captain Procrastinator

In an attempt to reduce our dependence on shore power and running the engine, we decided to get some form of renewable energy device to compliment the solar panels that the PO installed.  I was interested in hydro as well as wind generation as an ocean crossing would hopefully be a predominantly downwind journey and wind generation would therefore be less effective as our forward speed would reduce the effective wind speed from behind.  Hydro generation also tends to be more efficient as water is a better medium for transferring its energy to a spinning blade/prop.  During my research into options I came across a company who makes a unit that combines both, i.e. their unit could be used for either wind or hydro power generation.  The company is called Eclectic Energy and they are based out of the UK.  The model is called the DuoGen3 (the 3 comes from the revision of the design).

The tower used to hold the wind blades above the bimini pivots at its base and can therefore be lowered into the water behind the boat.  This means that when you remove the blades and replace them with a propeller you can generate power based on the boats speed through the water.  The yaw arm used to orientate the blades into the wind when in wind mode is also a float and holds the propeller close to the surface when in hydro mode.  A dive plane below the propeller holds it the required amount under water.

As it does double duty from an energy generation standpoint I fully expected it would be a jack of all trades and master of none and that it would not perform as well as a dedicated unit for either wind or hydro.

As the alternator is at the base of the tower and not directly attached to the blades, the weight of the unit is at its base and so a substantial support structure is not required.  In fact the unit bolts to your stern rail directly and comes with all the support structure that is required.

One of the precursors to carrying out this installation was to move the solar panels from above the davits to over the bimini.  This was to allow the tower to be swung down from the wind mode to the hydro mode as desired.  This project was carried out and posted back in March… I know, “do your damn blogs in order, Moray”.  Here is a picture showing their old location which clearly shows why it would have been an issue as the DuoGen mounts on the transom and sticks up above the bimini.

DuoGen 004

The parts arrived from the UK after some “customs” issues.  I guess the Fedex customs person got out of the wrong side of the bed the morning this collection of packages came across their desk as they required me to fill out an importer form although the UK company had not been asked for this before.  Once I sent that to the Fedex person they asked what all the contents of the spare parts package was, I had to get this from the manufacturer.  Once they discovered that there was 2 types of silicone grease in the package I then had to fill out a toxic substance certification form on products that I had no knowledge about… bloody red tape!

The packages did finally arrive and it was Christmas all over again!

Solar0 011

I checked the contents of all the packages and took them up to the marina work bench to get an overview of the assembly process.  I had no intention of carrying out the assembly that day.  One of my neighbors at the marina, Brad, had shown interest in seeing the unit and came along for a viewing.  As happens, when guys get together, we had the unit assembled within the hour and were walking it down to the boat for a dry fit.

I had no intention of actually installing the unit on the transom that day… hmm, didn’t I basically just say that?  Must be Brads bad influence.  After 4 hours it was a done deal.  Fully installed, bar the wiring.  It must be said that the installation was relatively easy as the kit comes complete with all mounting hardware required.

The next day I installed the regulator, dump resistors (used to dissipate extra energy if the batteries are fully charged) and wiring to the batteries.  I ran the cable from the alternator through an existing clam shell vent used from the Questus radar wiring and mounted all the electrical hardware in the engine room on the wall that is the foot of the rear quarter berth.

The finished installation looks as follows.

DuoGen 001

The unit has now been installed for three months now and so I can report back on its efficiency.  Truth be told I am underwhelmed by its performance.  I have only used it in hydro mode a couple of times and it seems to perform adequately.  However in wind mode this is not the case.  The yaw arm, due to its shape and attachment method to the tower, has a lot more resistance to rotation than a typical wind generator and therefore it takes more wind to swing the unit into the wind to actually start spinning.  This means that it can miss out on power generation altogether if we are in moderate winds and the unit is not already facing the wind.  This is not typically a concern as we find ourselves anchoring more an more.  Because of this, the boat will orientate itself to the wind anyway and as the unit can be locked into a forward facing position, it automatically is facing the wind at anchor.  The blades also seem to take a little more wind to start moving in the first place.

I will take the time to carry out a more exhaustive benchmark some time in the near future.  This will involve unplugging the solar array with the engine off and turning of all electrical/electronic devices. To ensure that the alternator is able to supply current to the batteries I will first have to make sure that the batteries are not fully charged.  If I then monitor the true wind speed in front of the blades and compare that to the voltage/current produced by the unit I should be able to see if it is producing power close to its specifications.

I will also polish the tower with a silicon based polish, as recommended by the manufacturer, to ensure that the yaw arm is as free to rotate as possible.

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