Hydrogenerators

Koeketiene

Well-known member
Joined
24 Sep 2003
Messages
17,743
Location
Finistère
www.sailblogs.com
On the previous boat, I had two means of generating power: a Rutland 913 wind generator and four 100w PV solar panels mounted on the guard wire (two each side of the boat).
The solars preformed very well, though because of where they were mounted was somewhat annoying when underway (in particular as the boat could roll a fair bit when sailing downwind).

So, on the new boat, I will go for smaller solars also fitted on the guard wire, but I'll only fit them when at anchor and remove them when underway.

I found the performance of wind generators somewhat disappointing. Both the Rutland 913 on the previous boat and the Air-X on the boat before that.

So I was think about fitting a Hydrogenerator.
To be more specific a Watt and Sea.
As this is quite an expensive bit of kit I thought I'd ask around a bit first.
Anyone got any experience of these? Do they preform as advertised? How sturdy or delicate is this thing?

Many thanks.

Watt and Sea, Cruising hydro generators for your yacht!
 

MarkCX

Active member
Joined
21 May 2020
Messages
312
Location
Somewhere on the East Coast UK
Visit site
Apart from the price (!), the biggest disadvantage for any hydro system is that it’s only working while you’re moving. I know that’s stating the obvious (and I don’t know your situation), but for most people it would be sitting idle for an awful lot of the time. With that kind of money I could be very creative in finding space for solar panels.
 

Koeketiene

Well-known member
Joined
24 Sep 2003
Messages
17,743
Location
Finistère
www.sailblogs.com
Apart from the price (!), the biggest disadvantage for any hydro system is that it’s only working while you’re moving. I know that’s stating the obvious (and I don’t know your situation), but for most people it would be sitting idle for an awful lot of the time. With that kind of money I could be very creative in finding space for solar panels.

Space on the boat (36') is limited.
The narrow shape of the stern does not lend itself to having some sort of stainless gantry to place solars.

Also, internal space is not on a par with more modern boats.
Expanding the current battery bank (1 x 70 aH start and 2 x 144 aH service) is not an option.
Likewise, there is little/no room to fit a generator.
And in view of the capacity of my batterybank and my average power consumption I would need to run the engine for a couple of hours pretty much on a daily basis.

So, the thinking is to have the removable solars as power source when at anchor and the Watt and Sea when underway.
 

Neeves

Well-known member
Joined
20 Nov 2011
Messages
12,076
Location
Sydney, Australia.
Visit site
I cannot offer the answer to your specific question but add our experience with our Hydrogenerator.

We have a LVM wind gen that converts to a a trailing hydro generator. Its a bit of a faff to convert - but worth it, for us.

It obviously only works when you are actually sailing and we can power the whole catamaran, autopilot, radar, all instruments, lights, fridge and freezer and make bread, we have an invertor and bread maker and produce excess power - so when we arrive the batteries are fully charged (and we have freshly baked bread).

Now a trailing hydrogenerator is really 'old tech' and simple - but if we were starting again - we would buy a WattnSea - if they power yachts on the Vendee Globe - they are good enough for me. I do confess the price is a bit wallet squeezing.

But if you physically cruise, sail, a lot over decent distances (long day sails, or longer) we would not be without one. We have plenty of room for solar but inevitably it is covered by sails (and despite being sunny Oz) - we do have clouds, wind and rain and at anchor in the wind and rain - a wind gen is useful.

We try to sail down to Tassie annually - the trip is about 1,000nm, each way - we do lots of very long days sails and some overnights (Bass Strait). If we only pottered about - waste of money for a wind gen and a hyrogenerator.

Maybe consider the alternative, the name of which I forget (the one that more easily converts from wind to water.....Ecletic Energy???

Jonathan
 

dunedin

Well-known member
Joined
3 Feb 2004
Messages
12,525
Location
Boat (over winters in) the Clyde
Visit site
What type of sailing do you do? For short coastal hops I wouldn’t spend all that money on a hydro generator - I would find some way of fitting more solar, and keeping it out 24x7x365.

For blue water the hydro generator is ideal - eg things like ARC, where the Watt & Sea can generate a huge amount of power, and the hassle of fitting and removing is largely avoided.
Great most of the time, but Saragossa weed was a problem in some areas, which can jamb it up. Indeed it broke the bracket when hitting weed at 8 knots. Would want to find out if the bracket has been improved - eg with a breakable “fuse” to avoid damage when hitting stuff.
 

lw395

Well-known member
Joined
16 May 2007
Messages
41,951
Visit site
Neeves has a cat.
The Vendee boats are fast.
The OP has an Old Skool 36ft monohull.
There could be a lot of sailing where a hydro generator is either going to be not producing much power, or a lot of drag?

There comes a point when running the engine is better value, even accepting some cost in diesel and a shortened life?
There will always be times in late season when you're not moving and it isn't very sunny, so in the absence of shore power, most people seem to end up resorting to some engine running sometimes, even if they dress it up as moving the boat.
Or a small generator...
 

typhoonNige

Member
Joined
29 Aug 2006
Messages
445
Location
Lymington
Visit site
I used a secondhand Aquair 100 on all the long legs of my Atlantic circuit on a 37 footer. At 6 knots it produced around 6 amps and was 100% reliable. Biggest problem was fouling of the propeller by sargasso weed in the tropics. When used in wind turbine mode at anchor average Caribbean winds gave about 2 amps. With 280W of solar as well I never needed to run the engine to charge the 440Ah battery bank. Much cheaper than the Wattnsea too!
 
D

Deleted member 36384

Guest
I used a secondhand Aquair 100 on all the long legs of my Atlantic circuit on a 37 footer. At 6 knots it produced around 6 amps and was 100% reliable. Biggest problem was fouling of the propeller by sargasso weed in the tropics. When used in wind turbine mode at anchor average Caribbean winds gave about 2 amps. With 280W of solar as well I never needed to run the engine to charge the 440Ah battery bank. Much cheaper than the Wattnsea too!

I purchased a second hand one this year, £100, from a long distance sailor (Atlantic circuit and northern latitudes) and his comments were the same. I have not used it yet. It is in excellent condition. It is the version that can only be used as a towed generator.
 

Koeketiene

Well-known member
Joined
24 Sep 2003
Messages
17,743
Location
Finistère
www.sailblogs.com
Neeves has a cat.
The Vendee boats are fast.
The OP has an Old Skool 36ft monohull.

There could be a lot of sailing where a hydro generator is either going to be not producing much power, or a lot of drag?

There comes a point when running the engine is better value, even accepting some cost in diesel and a shortened life?
There will always be times in late season when you're not moving and it isn't very sunny, so in the absence of shore power, most people seem to end up resorting to some engine running sometimes, even if they dress it up as moving the boat.
Or a small generator...

She might be old skool, but that doesn't mean she's slow.
A sistership came in 2nd in the 1977 Fastnet Race. ?

My energy needs are modest - about 8aH do me fine.
According to the Watt&Sea blurb, 6kts of boat speed should give me that.
If... these figures are true.

I get your point about running the engine, but my diesel tank is only 100 liters.
Average fuel consumption 3ltr/hr. There is room on deck for a couple jerrycans extra diesel, but not many.
If I am going to be away from land and access to shore power just running the engine is not going to do it for me.
 

Red Panda

Member
Joined
3 May 2017
Messages
151
Location
Norn Iron
Visit site
I too have a small, old-school boat. I've looked extensively at ways of generating electricity, and for my sailing (mostly not long passages, but anchoring rather than staying in marinas) solar was the best answer. This year I'm moving my two 50W panels from the lifelines to be fixed flat on the deck.
 

Rappey

Well-known member
Joined
13 Dec 2019
Messages
4,264
Visit site
We have a LVM wind gen that converts to a a trailing hydro generator. Its a bit of a faff to convert - but worth it, for us.
Quite a few lvm/aerogen units still around. A decent charge controler for one is virtually impossible to get though.
How many amps at what speed can you get when towing?
Heard a few story's about sharks taking a liking to the propellors ?
 

geem

Well-known member
Joined
27 Apr 2006
Messages
7,236
Location
Caribbean
Visit site
She might be old skool, but that doesn't mean she's slow.
A sistership came in 2nd in the 1977 Fastnet Race. ?

My energy needs are modest - about 8aH do me fine.
According to the Watt&Sea blurb, 6kts of boat speed should give me that.
If... these figures are true.

I get your point about running the engine, but my diesel tank is only 100 liters.
Average fuel consumption 3ltr/hr. There is room on deck for a couple jerrycans extra diesel, but not many.
If I am going to be away from land and access to shore power just running the engine is not going to do it for me.
Are you sure its 3ltr/hr? My 4.4litre Perkins uses 2.2 ltr/hr at 5kts. 6kts costs me 3.3ltr/hr
 

lw395

Well-known member
Joined
16 May 2007
Messages
41,951
Visit site
She might be old skool, but that doesn't mean she's slow.
A sistership came in 2nd in the 1977 Fastnet Race. ?

My energy needs are modest - about 8aH do me fine.
According to the Watt&Sea blurb, 6kts of boat speed should give me that.
If... these figures are true.

I get your point about running the engine, but my diesel tank is only 100 liters.
Average fuel consumption 3ltr/hr. There is room on deck for a couple jerrycans extra diesel, but not many.
If I am going to be away from land and access to shore power just running the engine is not going to do it for me.
If you don't see the discrepancy between 6kts (which is good progress in a fair breeze) being a rate 'per unit time' and 8aH having dimensions of current . time, then I'd suggest keeping your chequebook in your pocket.
If you meant 8A, which would be consistent, that's a lot of power.

You need a clear view of how your boat will be used. Then you can estimate what a hydrogenerator might deliver and what your demand might be. Other people can only guess at how you're expecting to use your boat.
 

Koeketiene

Well-known member
Joined
24 Sep 2003
Messages
17,743
Location
Finistère
www.sailblogs.com
If you don't see the discrepancy between 6kts (which is good progress in a fair breeze) being a rate 'per unit time' and 8aH having dimensions of current . time, then I'd suggest keeping your chequebook in your pocket.
If you meant 8A, which would be consistent, that's a lot of power.

Technical symantics are not my strong suit - what I said is not what I meant. ?
8A is indeed what I meant - apologies.

Main sources of power draw are the fridge and the autopilot - neither of which I am willing/able to do without.

You need a clear view of how your boat will be used. Then you can estimate what a hydrogenerator might deliver and what your demand might be. Other people can only guess at how you're expecting to use your boat.

I realise fist impressions can be deceiving (my 8aH vs 8A clanger) but let's - for arguments sake - just assume I am not a total child.

Plans are an Atlantic circuit maybe next year or the year after at the latest.
Afterwards we will be spending 4-5 months aboard cruising - only going into marinas very rarely.
 

Koeketiene

Well-known member
Joined
24 Sep 2003
Messages
17,743
Location
Finistère
www.sailblogs.com
Are you sure its 3ltr/hr? My 4.4litre Perkins uses 2.2 ltr/hr at 5kts. 6kts costs me 3.3ltr/hr

No, I am not sure.

Previous owner said his average consumption was 3.5-4 Ltr/Hr which seems rather a lot to me.
According to the surveyor 2.5-3 Ltr/Hr would be a safe assumption.

So, at the moment I'm going by 3 Ltr/Hr.
 

Dave100456

Well-known member
Joined
11 Oct 2005
Messages
1,048
Location
Yorkshire England
Visit site
I have a W&S 300. On long passages; 24hrs plus, we deploy it at night as we have 650 watts of solar.

I have fitted the larger dia prop, 280mm which offers 25% more power generation. However, with this prop max speed is limited to 10knts I think, otherwise it would damage the unit, as we're a sail boat this isn't a problem. I find I get almost 2 amps per knt when travelling above 3 knts. This is sufficient to cope with autopilot, fridge & freezer loads during the night thereby maintaining batt charge levels.

I did have an issue with the converter within warranty and sent it back to W&S who found nothing wrong but mysteriously it worked when it came back!!!

Weed can be an issue but I not only mounted it low, its also the long leg version so the prop is at least a couple of feet below the surface and sargassum.

To sum up, good power production for loss of tiny fraction of boat speed, only useful for long passages, expensive and needs to have good deployment tackle to get it down and locked when doing anything above 2 knts.

Hope this helps.
 
Top