Solar vs wind vs hydro

[bergius]

Originally Posted by Na Mara

If the scale to the left is both knots and amps then that doesn't look like fantastic performance from the hydro generator. Is your system clever enough to work out the average wattage over the trip? I would be interested to know as I really like the idea of the sailing gen, particularly its cost and the ease of launch and recovery.

We went sailing again today. Pretty much the perfect test setup as the morning was quite overcast. We had also run out of prepaid shore power the night before, so batteries didn't start at full.

38NM, mostly between 5 and 6kt boat speed. As you can see from below, we made as much from the hydrogenerator today as we did from 360W of solar panels. But of course the hydrogenerator would also produce at night time...



We also have LiFePO4 batteries. The SailingGen controller is behind a Victron BatteryProtect that the BMS controls.
Deployment is quite easy: just lower the prop into the water. Getting it back out is easier if you can reduce boat speed for that.

[Na Mara]

My Boat is a bit quicker than yours so I might get 80W on average our of the sailing gen. That’s 2kWh of energi per day underway. A very useful addition! About the equivalent of 400W of solar when in use.

I sail one in every 8 hours aboard, so that works out at an average of 0.25kWh per day from a hydro generator like yours, which is the equivalent of a single 50W panel. Looked at that way it’s quite an expensive energy supply (2000 euro for the same total energy input as a 50W panel)

That said, it’s constant power over the day and it’s power when solar might not be performing so well. Or in your case, when the temporary solar is down whilst sailing. Need to think about this more.

It’s encouraging that the controller copes with battery disconnect. Not all do.

[bergius]

Originally Posted by Na Mara

It’s encouraging that the controller copes with battery disconnect. Not all do.

Oh , no idea if it does. But I figured better to risk frying the controller than the batteries.

[Na Mara]

As this controller is only 230 euro and it will only be an issue underway, I think your assessment is good.

[flightlead404]

Originally Posted by Na Mara

However, if you have internally regulated batteries without ATC output, then the only safe way to do engine charging is alternator to Lead acid engine battery with DC DC chargers to LFP batteries. This is very inefficient, and if the alternator is internally regulated the best you will be able to do from a 80A alternator is 30A into the LFP bank. So do your LFP batteries have an ATC output?

My experience with an 80A internally regulated Hitachi and a Victron Orion Tr Smart 30A to 400Ahr LiTime (2 ea) house (all new) is your max output will be 20A and get degraded into the high teens quickly. Never seen 30A

[MicHughV]

Let's face it....the biggest power draw on most any boat is the fridge/icebox.

What if the boat is not moving...ie, anchored ?? No hydro available !

Speaking from experience, the power provided by the solar panels is ample to both run the fridge/icebox and charge the batteries.
At night, off course, the solar panels don't work but the batteries have ample reserve to run the boat at night.

On rare occasions, like sunny or rainy days, the power output is drastically reduced, but this is when the generator is put to use.

[Na Mara]

Compare Flightlead 404’s situation with mine where I have 90+ amps of direct charging of my LFP batteries out of my 100A WS500 regulated alternator. The engine battery is then charged off the DC-DC charger from the LFP batteries. Very much more efficient but lord alone knows that those WS500 regulators are complex things to wire up.

[Na Mara]

MicHugh V, I’m sympathetic to the argument that the best renewable generation is the kind that is always working, no matter what the boat is doing, but then many sail with power hungry instruments and autos. What makes more sense in that case, over specing static generation, relying on top up engine charging, or a hydro generator?

[fxykty]

We have lots of solar and a SW350 wind generator that the original owner installed. We would install a hydro generator in a heartbeat, but we need one that has a variable pitch prop to accommodate our usual speed range. In any sort of breeze, exacerbated by waves, we can double our average speed during gusts and/or surfs. If we’re using a prop designed for 8-12 knots, what happens when we go 15 or 20 knots?

Using the Watt and Sea range as an example, we would need to use the manual variable pitch 200mm propeller with the cruising series, which sacrifices power at speeds below 10 knots but allows for up to 30 knots. OK, so we could set it for maximum 15 knots boat speed and add lifting the hydro generator out of the water to our procedures. Or we could get the racing model with auto pitch adjustment, at double the cost.

[flightlead404]

Originally Posted by Na Mara

Compare Flightlead 404’s situation with mine where I have 90+ amps of direct charging of my LFP batteries out of my 100A WS500 regulated alternator. The engine battery is then charged off the DC-DC charger from the LFP batteries. Very much more efficient but lord alone knows that those WS500 regulators are complex things to wire up.

My intention after i crunch the numbers, now that I’m back from cruising, is to add another 200Ahr battery, upgrade the alternator and make it externally regulated, add an Argofet type device to protect against BMS load dump, and charge the house directly and start via dc-dc

[MicHughV]

For myself....I have learned to just added more battery power. Sure, batteries are heavy and require maintenance, but I find that a lot of newer boats simply don't have adequate battery power. There is the usually two house batteries and the engine start battery, and that is pretty much it.

Adding battery power also reduces the amount the batteries get drawn down, etc.

I'm a big fan of the 6v golf cart batteries. From what I've learned and read, a pair of 6v bats beats a single 12v bat. Their odd size makes situating them a challenge, but that is about their only drawback.

[bergius]

Originally Posted by MicHughV

For myself....I have learned to just added more battery power. Sure, batteries are heavy and require maintenance, but I find that a lot of newer boats simply don't have adequate battery power. There is the usually two house batteries and the engine start battery, and that is pretty much it. .

Big batteries are good, especially for winter anchoring when solar doesn’t produce much anything. But the rest of the time, you still need to charge them somehow.

We have 5kWh of house bank, which is enough for 2-3 days without renewables. That’s good enough for a for winter days. But for the summer cruise we need a way to keep it charged off the grid. For that solar, and now hydro, seems like a decent solution. Last two days, we’ve arrived to the next anchorage with battery bank about 10% more full than when we hoisted the anchor. That’s a start.

[Na Mara]

Originally Posted by bergius

Last two days, we’ve arrived to the next anchorage with battery bank about 10% more full than when we hoisted the anchor. That’s a start.

What about at anchor? Are you in deficit or credit during typical summer cruising with your solar?

[bergius]

Originally Posted by Na Mara

What about at anchor? Are you in deficit or credit during typical summer cruising with your solar?

If it isn’t too windy for the deployable panels, we’re generally in credit assuming that we stay in anchor also during daytime.

The problem is, we tend to go sailing. So being able to charge under way is a huge improvement.

[windpoweroz]

It's really hard to compare turbines. So many factors involved.

I'm thinking of pulling together a couple of charts that overlay the expected power and energy from different micro-wind turbines based on wind speed. Essentially I'll be consolidating and standardising the charts they already publish. I know it's only one of many factors but could be useful, right?