Oceanvolt Hybrid Motor

[BigBeakie]

You are quite correct, maximising solar layout and efficiency is highly desireable for an EP installation. As is LFP for storage, and as is the performance of EP regen for cruising grounds/latitudes with expected multi-day cloud cover. In fact, the sizing of the solar array should take into consideration that often you WON'T have ideal solar irradiance, so, upsize your order.

Shading can be planned for in how you lay out your panels, connect your panels, and rig your boat. It's a system. On our build, we have 4.2kW recessed into ONLY the bimini on our 15 meter cat, and still have plenty of room to work along both sides of the boom for setting 3rd reef without walking on them. IMO, walk on panels are not durable enough in the medium term. They seem to breakdown over time. Ours are flexible, but we're not going to walk on them. Also you should leave a space behind them to dissipate heat, so that eliminates walking on them anyway.


Sent from my iPad using Cruisers Sailing Forum

[BigBeakie]

Correction: we have a couple of big panels on our davit also, so they are not all on our bimini.


Sent from my iPad using Cruisers Sailing Forum

[44'cruisingcat]

Originally Posted by ssmoot

Unless you have lithium batteries, have worked your salon top to minimize obstructions and shading, and you’ve got 22%+ efficient panels I’m not sure why you seem so skeptical.

I do have Lithiums.

It's pretty hard to prevent the rig from casting shadows. I've yet to see a transparent mast.... (of course I wouldn't be able to, would I?)

And is it sensible to compromise sailing ability so you can carry more solar panels? If the object is to reduce fuel consumption, surely the best way is to be able to sail well?

The reason I'm skeptical is probably just a case of real-life vs theory.

[Jim Cate]

The reason I'm skeptical is probably just a case of real-life vs theory.

those pesky realities (like shadows) sure get in the way of a good theory, don't they? And lots of windage and regen drag don't do so much for sail performance, either. So, lets just whack off the rig... no more shadows... and be a pure power boat, silently moving along with the e-drive running off theory and wishful thinking.

My cynicism is showing, but having nursed solar arrays on actual cruising boats for a long time now, these rosy pictures of electrons coursing down from above don't smack of things I've seen.

I think 44 is right in his estimation of performance.

Jim

[Q Xopa]

Originally Posted by transmitterdan

I think you missed the point. There is simply no such thing as a rotating DC generator. A rotating magnet cannot produce DC (at least not for long). So DC generators produce AC then rectify it.

The Honda people haven’t escaped the laws of physics. The EU2000 creates AC then rectifies it to DC then inverts it back to AC but with regulated voltage and frequency. The advantage is the gasoline motor doesn’t have to run constant speed. So not too different than what a boat EP system does with a so-called DC generator. They add a battery in the middle which increases the losses a little.

All these rectification and inverter steps create losses. Getting 90% efficiency at each of these steps is pretty good performance. So about 81% efficiency in the electrical stuff at full power is decent. I think Nigel said he measures something like that.

Hmm I not sure which point you think I missed. I cant remember saying anything about 'rotating magnets'. So we are as you say we are missing each others points.
The point I was talking about was sizing for usage patterns peak loads or average loads.

[Q Xopa]

Originally Posted by transmitterdan

I think you missed the point. There is simply no such thing as a rotating DC generator. A rotating magnet cannot produce DC (at least not for long). So DC generators produce AC then rectify it.

The Honda people haven’t escaped the laws of physics. The EU2000 creates AC then rectifies it to DC then inverts it back to AC but with regulated voltage and frequency. The advantage is the gasoline motor doesn’t have to run constant speed. So not too different than what a boat EP system does with a so-called DC generator. They add a battery in the middle which increases the losses a little.

All these rectification and inverter steps create losses. Getting 90% efficiency at each of these steps is pretty good performance. So about 81% efficiency in the electrical stuff at full power is decent. I think Nigel said he measures something like that.

Hmm, Im also not suggesting Honda are defying the laws of physics. Its a bit of a stretch to get that from what I said.
Indeed they, ie Yamaha and all the other generator manufacturers, are doing the same Invertor generator concept these days. They have all cottoned onto this concept.

This averaging loads is done by electricty grids, F1 cars 'KERS', etc. Thats all this is. It enables better efficiency or more power than the non Invertor gens.

No magic or defying the laws of physics. Its not a secret or complicated. I guess you could consider its defying the laws if physics if you werent aware of it. Planes have also been accused of defying the laws of physics, ie gravity. Im not going to disagree with you about that.

[ssmoot]

Originally Posted by 44'cruisingcat

The reason I'm skeptical is probably just a case of real-life vs theory.

These numbers are rules of thumb based on experiences.

Honestly it doesn’t bother me if you don’t uderstand the concept and I’m not particularly interest on arguing if the number is more appropriately 3.6, 4 or 5. If the ultimate number of excess generation ends up being 8kWh to spare, 10.8kWh or 12kWh doesn’t change much in the bigger picture.

It’s just an idea I thought other people interested in EP might find worth consideration. If you don’t, that doesn’t come as a surprise to me.

[transmitterdan]

I was pointing out that there is no such thing as a DC generator. Nothing more than that.

[john61ct]

Who cares what goes on inside the black box?

If fuel goes in and DC power comes out, afaic it's a DC generator.

Just like a DC-DC converter.

What goes in, what goes out, is it efficient?

Pedantry vs practical

[44'cruisingcat]

Originally Posted by ssmoot

These numbers are rules of thumb based on experiences.

Honestly it doesn’t bother me if you don’t uderstand the concept and I’m not particularly interest on arguing if the number is more appropriately 3.6, 4 or 5. If the ultimate number of excess generation ends up being 8kWh to spare, 10.8kWh or 12kWh doesn’t change much in the bigger picture.

It’s just an idea I thought other people interested in EP might find worth consideration. If you don’t, that doesn’t come as a surprise to me.

How about if the amount of excess generation is 2kWh or maybe 3? Make a difference you think?

These "rules of thumb based on experience", are they based on experience of solar panels on sailboats, copping shading, at best laid flat or sometimes tilted away from the sun etc, or are they solar panels used on land, ie shade free, permanentlty tilted and oriented toward the sun?

It makes a lot of difference.

[Q Xopa]

Originally Posted by transmitterdan

I was pointing out that there is no such thing as a DC generator. Nothing more than that.

Ok no argument from me. Although they are termed DC Gens. I did say the definition is murkey. But is there some relevance to that declaration?

[OldMan]

Originally Posted by ssmoot

If you replace your 16% panels with 22% panels, are you going to install fewer of them?

To me it’s nonsense to be looking at a boat approaching $600,000 like an optioned Seawind 1260, and then be worried about the price of your solar panel installation while at the same time ticking the box to drop $20K on a diesel generator.

We’ll have to agree to disagree on wether maximizing solar is a worthwhile endeavor.

Also, you’re getting ripped off on your panel pricing.

Engineer's design systems to meet requirements. If the requirements only dictate 16% panels there is nothing wrong with them. Your problem is that EP is so massively under-powered without fossil fuels, EP is looking for every watt it can find.

[ssmoot]

Originally Posted by OldMan

Engineer's design systems to meet requirements. If the requirements only dictate 16% panels there is nothing wrong with them. Your problem is that EP is so massively under-powered without fossil fuels, EP is looking for every watt it can find.

By going with 16% panels your savings are marginal and you’ve handicapped your options to expand. Wholesale prices on similar-wattage panels I can find off-hand are pretty similar unless you narrow your scope to North American branded panels. Anyways, that seems like a pretty big negative to me.

Your commentary on EP aside, I want every watt I can find. Power is luxury. Power is convenience. Power gives you flexibility. I want fresh water, hot water, laundry, an induction hob and I’ll take as much as I can get.

I’ll try to get as much as I can without having to run a noisy, polluting engine to get it. Solar panels are the gift that keeps on giving. That 3kW array, using your own estimated average output, will put out 20-megawatt-hours in 5 years time. That’d be a savings of several thousand gallons of fuel for a generator, and you’d probably not be far off from needing a new generator by the end of it. Which makes solar the lowest cost option by a mile.

[JC Reefer]

Originally Posted by ssmoot

By going with 16% panels your savings are marginal and you’ve handicapped your options to expand. Wholesale prices on similar-wattage panels I can find off-hand are pretty similar unless you narrow your scope to North American branded panels. Anyways, that seems like a pretty big negative to me.



Your commentary on EP aside, I want every watt I can find. Power is luxury. Power is convenience. Power gives you flexibility. I want fresh water, hot water, laundry, an induction hob and I’ll take as much as I can get.



I’ll try to get as much as I can without having to run a noisy, polluting engine to get it. Solar panels are the gift that keeps on giving. That 3kW array, using your own estimated average output, will put out 20-megawatt-hours in 5 years time. That’d be a savings of several thousand gallons of fuel for a generator, and you’d probably not be far off from needing a new generator by the end of it. Which makes solar the lowest cost option by a mile.

Assuming $0 spent on maintenance during those 5 years?

Not jumping in, just tossing a hand grenade.

[ssmoot]

Originally Posted by JC Reefer

Assuming $0 spent on maintenance during those 5 years?

Not jumping in, just tossing a hand grenade.

That’s fair. I’d expect the generator to cost a lot more in maintenance. Never mind that the solar panels will outlive it by years.