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w42 · 01-07-2008, 15:07

Quote:

Originally Posted by Amgine

Electric drives: just ran across an interesting set up from Solomon, but no one talking about actually using the system. I like that it's low rpm. Should be able to let the motor freewheel to generate electricity while sailing, right?

Solomon has been around for a while. Check out these guys

E motion Hybrids Home

They are doing Nigel Calder's new D/E Malo 46.

Is electric drive a panacea? No. Is it a revolution? No. Is it an evolution? Yes.

You can install multiple means of generating electricity on a boat to power the drive:

- solar
- wind
- water (freewheel and towing generators)
- fuel cell (yes there are a couple companies trying this, powered by methyl alchohol is one source)
- generator powered by dino juice

With diesel straight drive, you need... well... diesel, to power the drive.

Electric drive gives you more flexibility and options for power sources.

Is it ready for prime time for offshore cruising yachts? Probably not yet, but there are increasing number of offshore capable boats being built with electric drives.

The jury is still out on which approach will prove itself in an offshore environment.

Trim50 · 01-07-2008, 16:55

I know nothing about this subject ;-)...who said Spinel?

dkall · 01-07-2008, 17:15

Quote:

Those run ballpark $700 delivered for a 100W panel, running 31,085 hours that's 3.1kwH delivered for $700....or $225 per kwH from the panels?? Someone please, find the error in my math, it can't be THAT bad!

Isn't it 31 kwh no not 3.1 kwh? If it's 31 kwh then it's $22.50 / kwh. Still expensive but what is it for the diesel side?

Sorry about this late entry but I was looking for some solar info and came across this thread.

Fair Winds...

Bradley · 02-07-2008, 04:27

You gave no output in your formula for solar panels. You only have hours of production times days times years. In any sunny locale a 100W solar panel will produce somewhere around 30 amps per day which equates to over 400 watts per day at 13.8 amps.

400 x 365 x 20 = 2,920,000

$700.00/2920kwh is $.24 kwh

hellosailor · 02-07-2008, 09:04

Quote:

Bradley-
"In any sunny locale a 100W solar panel will produce somewhere around 30 amps per day which equates to over 400 watts per day at 13.8 amps."

Absolutely not! You're confusing volts and amps with electrical power, which is measured only in watts. (See Ohm's Law for how they relate.)To make optimum use of the power from a solar array, you need to be using an MPPT or other pulsed-DC controller, which can boost the effective power output by 20% compared to a conventional dump regulator.
Volts don't matter, amps don't matter, they can be converted back and forth if you have the right electronics Otherwise they are wasted and the useable (effective) output is wasted. What matters is the wattage being produced--that's why I intentionally ignore volts and amps and only look at watts from the solar panel. If someone uses the wrong electronics and wastes part of that output--that only drives up the costs.
You're also totally confusing watts and watt-hours. "400 watts at 13.8 volts" is the wrong way to measure a solar panel that is putting out 17-22 volts of raw power--being truncated or converted down to 13.8 by diffferent electronics, with different effiiciencies. 400 watts for 2.5 hours is one kilowatt-hour (kwH) *irregardless* of the volts and amps producing that 400 watts.

I think Dave's right aqbout me slipping a decimal point though!

Fishspearit · 02-07-2008, 09:24

I believe Bradley is correct, by their definitions, one watt equals one amp of current flowing at a 1 volt difference of potential. Watts=current X Volts
Sure, the solar panels wattage rating is usually at 17V and the battery accepts it at a lower voltage, which is why they never put out quite what their rated wattage is.

Bradley · 02-07-2008, 09:44

By your formula

5hrs *(365*.85) * 20yrs * 100watts = 3102500watts or 3102.5kwh

$700/3102.5 = $0.2256

I said $0.23. Not much of a difference.

Roy M · 02-07-2008, 10:29

Maybe another way to evaluate this issue of petrochemical costs is to look at how they do their job versus other options for the $$. I built my West System trimaran in the late 70's when the oil embargo took place. That hurt, but I'm glad I chose epoxy over polyester resins, for the long run. For builders facing similar problems today, I offer the consideration that, if one chooses a good design, builds it solidly with materials that hold up to time, and FINISHES the boat (sadly, not all get that far), then they will have an investment that will pay off handsomely in the future. In the meantime, that polyurethane foam, epoxy or vinylester resin, LPU paint, synthetic rigging is never going to be cheaper than today. When the market recovers, people are going to be looking around for boating options. A fast, responsive, and commodious modern design (see, I didn't say multihulls at all!) will have greater allure than a maintenance-heavy, gasoline or diesel guzzling, megamonster. And there will be a whole bunch of those waiting at the broker's docks for perusal. My conclusion is: try out as many designs as you can before making a decision to purchase or build. Look at what the future maintenance issues might entail, including simple use of the vessel. Try to buy or build the best boat you can. Don't fall into the trap of buying a real fixer-upper, expecting to pass it on to a neophyte for a lot of bucks, and keeping up the charade until you can get the boat of your dreams. Build or buy the basic hull(s) today. Rig and equip it later, when the technology will be better (and more expensive, oh well), and you can start using it at its most elemental stages, gaining confidence in it as a primal sailing machine.

slomotion · 02-07-2008, 10:36

When we went cruising 8 years ago one of our goals was to be as energy self sufficient as possible. And we pretty much succeeded with the use of solar, wind, mega AGM batteries, smart charger, inverter, etc. This had nothing to do with saving the planet or even saving money (it was expensive). It was all about convenience and comfort. The Admiral announced that she had done all the boat camping she cared to do. There would be no more daily trips ashore for ice and water, no more noisy/smelly generator, no more running the engine every day to charge the batteries and make hot water, etc.

Yes, we had a diesel engine, but we hardly ever used it to charge batteries. Yes, we had to buy propane for cooking, but we had lights, fans, refrigeration, communications, fresh water and hot water all from batteries. The truth is that at least in sunny windy places reasonable energy self sufficiency to support some reasonable level of comfort and amenities has been available to cruisers for years. The cost is high, but in the context of yacht ownership it is "affordable." Does it somehow pay for itself? Yes, it pays for itself in comfort and convenience. Advances in technology may well make this easier to achieve; they may or may not make it less expensive.

hellosailor · 02-07-2008, 10:47

Bradley, you say I gave no "output" number for the solar panels.

But I clearly posted "that's 3.1kwH delivered" and yes, kilowatt-hours is output.

You are saying " ..solar panel will produce somewhere around 30 amps per day which equates to over 400 watts per day at 13.8 amps."
That's very much the same as saying "My boat speed is six knots per hour". No, it is not. You don't produce "watts per day" you produce "watthours" per day. You don't produce "amps per day" you produce "amphours" per day.

If you want to look at how much power a device produces over a finite lifetime, to analyze the cost of that power from that device, you must look at kilowattHOURS, not kilowatts. And not the raw amps or volts that a particular regulator may produce--but the kilowatt hours available from the device itself.

You didn't say 23 cents, you said 24 cents. still not much of a difference, but did you say either before I broke out the numbers? No that I can see. You only compared unrated panels at $2000/20 years, to an unrated diesel at $9/day. That's way different from comparing the cost of kilowatthours. What are you comparing, nine dollars per day for twenty years versus your solar panels? Without looking at the outputs from either? Hardly fair, especially if you are not using the full power output from either one.

Brent Swain · 02-07-2008, 12:31

So where are our tax exemptions for solar panels, wind generators, sails and sailboats.
Even if we motor everywhere, it still takes a fraction the amount of fuel to get a sailboat from A to B compared to powerboats.
Politicoes who claim to be green without giving us tax exemptions for making greener choices have a credibility problem.
A friend said " When the oil runs out, who are going to be the only people who can move goods around? Us guys with little sailboats. Sounds like a good lifestyle."

w42 · 02-07-2008, 15:12

Quote:

Originally Posted by Louis Riel

So where are our tax exemptions for solar panels, wind generators, sails and sailboats.
Even if we motor everywhere, it still takes a fraction the amount of fuel to get a sailboat from A to B compared to powerboats.
Politicoes who claim to be green without giving us tax exemptions for making greener choices have a credibility problem.

Good question.

You know, years ago, just after the arab oil embargo in the seventies, the state of California (governed by Jerry Brown, Democrat) gave tax incentives that helped create the window power farm on Altamont Pass. A move that wasnt that popular with Dems at the time (what? give tax breaks?)

Those original tax incentives are now long gone, but the wind farm has continued to grow and produce a lot of electricity.

Now, I just read in Forbes (right leaning conservative magazine) an editorial slamming this particular wind farm because of all the birds that have been killed. WTF? Conservatives concerned about the environment??

Some of these political pundits really dont have a clue.

But dont get me started...