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rlg · 26-12-2018, 18:26

Solar is great when living aboard at anchor or mooring.
Nobody regrets a well designed solar setup.

GRIT · 26-12-2018, 18:42

Quote:

Originally Posted by SailingPNW

Unless you are running your engine at high RPMs you should avoid using it to charge your batteries. Diesels do not like to run at low RPMs and doing that for lengthy periods should be avoided, it can actually damage the engine.

If you are sitting on hook nothing beats solar, if the initial cost is to high, get a Honda, my guess is in a year if you spend much time at anchor you will be wanting solar, having both is never bad.

The bit about running your engine at high rpm is a myth. It's a shame that the engine manufacturers have such poorly written manuals, but that's the way it is when English isn't your first language.

I've been beating this drum, on this forum, for years. A diesel runs "best" at about 80% LOAD, not 80% RPM.

My 60hp engine produces about 40hp at 2600 rpm, and 60hp at 3600 rpm. If I want to run it at 2600 rpm, at about 80% LOAD, I'd want to absorb just over 30hp. At 1600, it produces somewhere around 20hp (by memory), which means that I'd want to be using about 15hp, for what is considered "Optimum" load. However, it doesn't take 15hp, at 1600 rpm to keep the engine at operating temperature, which is what you should be aiming for.

If you keep your light duty, marine engine at operating temperature, it'll live a long and productive life. Slightly less long than running it constantly at an 80% load, but longer than running it constantly at 80% of maximum rpm.

Automotive engines, and pleasurecraft engines, (3600 rpm to 5000rpm) are rated at a higher rpm than you find in commercial engines 600rpm-2200rpm, and they don't tend to last as long. So, unless you've got a ship engine, tractor/trailer engine, or train engine in your boat... your goal should be 80% of LOAD, not rated RPM.

If you run it hard enough to keep the engine at operating temperature, you'll be fine.

Fleet maintenance/repair of Diesel engines was, at one time, my job.

And, to reinforce my previous post. I vote for solar.

Cheers.
Paul.

leftbrainstuff · 26-12-2018, 21:22

Solar is awesome when the sun is bright.

We even heat hot water with our 1kW solar. The only maintenance is a hose off and fuel cost is zero. But our generator makes up when the sun is absent.

If you can only pick one then a generator is probably the choice.

GRIT · 29-12-2018, 06:13

To aid your calculations, it is generally assumed that a given size panel will produce about half of it's value, in AH, on a clear day.

For example: a 100 watt panel can be expected to replenish about 50 AH (12v) on a clear day.

This is a helpful generalization, used to calculate your solar needs.

Cheers.
Paul.

**a64pilot** · 29-12-2018, 06:16

I have a kilowatt of Solar, and often need supplemental charging to get to fully charged.
Ideal is both, but if you can only have one, go with the Honda. It will provide way more power and doesn’t care about the weather conditions.
I wait until at least 8 AM to start mine, unless I’m alone in an anchorage, then I will start of shortly after Dawn, and only run it for an hour or two then Solar takes over.
But on a 33’ Boat, my bet is you will need to have a generator or you will often be running your Diesel to charge batteries/

From what I see Solar only makes about 1/3 of rated power, and often less. Meaning at most I can get is 330 AH from my 1000W of panels.
Even then what has me running my generator is not output, but usable Solar hours. It takes 6 hours to completely fully charge my AGM bank, and I don’t get y hours of Solar in December

gmakhs · 29-12-2018, 06:39

Quote:

Originally Posted by GRIT

To aid your calculations, it is generally assumed that a given size panel will produce about half of it's value, in AH, on a clear day.

For example: a 100 watt panel can be expected to replenish about 50 AH (12v) on a clear day.

This is a helpful generalization, used to calculate your solar needs.

Cheers.
Paul.

100 watt solar will give you 25 to 30 ah a good day in the tropics, if you want to be accurate .

mako · 29-12-2018, 07:05

Quote:

Originally Posted by gmakhs

With the price of solar to 1 € per watt I really don't see how solar is expensive compared to 1000 generator .

Try 25-28 cents per watt is you buy a bulk load... put some on your house... take a tax deduction if available... then grab a few extra panels for your boat.

gmakhs · 29-12-2018, 07:12

Quote:

Originally Posted by makobuilders

Try 25-28 cents per watt is you buy a bulk load... put some on your house... take a tax deduction if available... then grab a few extra panels for your boat.

Back home ,I added solars to remove my house from the electric company , a wise decision back then if you think that most of the extra taxes in Greece during the last year's are added in your electricity bill

Now I am not paying those fees neither electricity bills.

It's bad I didn't have the boat back then

sailorboy1 · 29-12-2018, 07:24

I feel people waste too much time and money thinking that it is important to get to 100% SOC every day. Sure that's great for your batteries, but the extra cost doesn't justify it.

I feel, and have, enough solar to get to greater than 95% SOC on "most" days by around 2pm. I write down the date the batteries got to full 100%, and if it has been a week or so I just run the engine/generator some in morning to slow it to happen that day.

The best battery/power solution on a boat is a multi-source approach

BTW - even though I try not to, I still spend waaaay too much time and energy serving the lead acid gods :-( , hell just 9 days ago I had to spend 10 minute to add water to them (not really because I got my wife to do it)

FlyingScot · 29-12-2018, 12:30

Fit as much solar as you can. Keep a small generator for backup. I think if I could do it again, I would have gone with a Honda 1k instead of 2.2k. Smaller, lighter, 1/2 the price. I can't imagine wanting or having to start a generator everyday. There are enough other things to do that are better than dragging out a generator, trying to minimize noise, have the exhaust not flow back in the boat, etc. Napping sounds much better. Solar is silent.