The real cost of solar power?

[rossir]

What if you could factor in federal and state tax credits for purchasing solar panels? While I am not aware of these credits being available for boat installations (though perhas a "second home" may be worth exploring), why can't you either purchase the panels for a home, get the credit, then put them on your boat. Or, for liveaboards, set up an arrangement for a friend or someone to buy them for their home, get the credits, then re-sell them to you. I understand that there are some very good creits available out there right now. See the link below:
http://www.forbes.com/taxes/free_for...ml?partner=rss

Rick

[Jon D]

We have been having the genset, wind, solar debate all summer while cruising Maine.

At this point we have a genset and wind generator. When there is wind the KISS makes at least 10 usually 12 to 15+ amp per hour, at that rate keeping up with our daily burn of about 120 amp hours/day is feasible. If no wind the genset runs the inverter charger which puts out 100 amps max which means if we run every day for an hour or two we keep ahead as the smart charge feature scales back output. The genset burns about 1 quart/hr. Both of those are fairly efficient, the debate is do I add solar to the mix.

I need at least 2 75 watt panels minimum probably will do 2 120 watts if I do it. That's about 2000 - 2500 in costs just for the equipment. Right now the conclusion is wait till after this winter and see how the wind generator does in the Bahamas where we will be. If it keeps me to running the genset every few days just to catch up then will go that way. If we need to run the genset every day to catch up then will probably put some solar on next year.

This energy stuff adds up the boat units quickly. That's the only thing I can say for certain.

[senormechanico]

The argument of solar companies knowing about ROI etc may be true, but solar panels don't need to be started or shut down like a genset, don't have any moving parts, need only an occasional rinse to remove bird poop, and are COMPLETELY NOISLESS. IMHO with decent care, they'll last forever.

I've never had another boater move because of my solar panels, but many times I've moved (when there was anchoring space) because of some guy's genset. The worst experience I ever had was in the mid '90's in Marina Mazatlan before there was any dock power. Some cruiser about 6 slips away from us with a big cheap sailboat had a Honda portable gas generator which he ran every morning on his foredeck for about 3 hours. (It seemed like forever.) One afternoon I went over to his boat to ask him how he could deal with all that racket. His answer? "I don't! I just go to town!
NO problem!"

AAGGGHHHhhhh!!!!

Steve B.

[Strygaldwir]

Sailor;

I only saw full rated output for about 3 hours a day in the Bahamas. Outside of those ranges, the power fell off. What I found the most amazing was that with an MPPT, I was getting 1-2 amps as early as 7:30am and as late as 6:00 pm. So, it is definately a bell shaped curve with a moderately high standard deviation.

They tell me output increases as the temperature goes down. I have been turning off my charger during the day, I'll have to start observing the output now, and as it gets colder!

My point with Sean is his numbers are better than I observed. I absolutely believe his observations! It does indicate that diesel is probably a more efficient conversion source than gas. he is seeing a cost of $10 a week. It take a lot longer to recover the cost of the original investment. Given the nature of the discounted cash flow, it takes even longer with his numbers. The only way it could be justified given a variable cost approach is by perhaps comparing initial investment cost. But, I think having an aux generator provides needed flexibility. That's why I was trying to look at it in terms of cost offset. So, ideally one could justify both panels and auxillary generators.

I don't think I could begin to justify the financial cost of solar if I had readily available shore power. It is just too cheap to plug in and too much for a complete solar system. I am not sure how homes justify the cost, if they have a grid available! Credits certainly, but otherwise?

Solar make a lot more sense if we in the States didn't have an overcapacity of electrical energy. If we could displace our dependancy on imported oil by solar. But, I don't see that as the case. Until we start running our transportation with more electricity, we're still stuck. We still have to care about the stability of world oil producers!

Sigh...

Keith

[Strygaldwir]

The problem with the Bahamas is it is too pleasant!! Most of the places you pick to anchor, you do so because you're shielded from the wind. So, we rarely saw 10 knots of wind.

If I had it to do over again, I'd probably go with a 4 Winds generator. The standard blades on the Air X just don't put out much at under 10 knots. At 10 knots we saw 1 amp. Other wind generators are better! I'll see what bigger blades and more of them will do for the Air X. That might change my opinion. So far, the 3 bigger blades I am using are giving me about 1 am at 9 knots. A 10% difference, but not enough to call the farm on. I'll see when I go to 6 blades.

Later

Keith

[ssullivan]

Originally Posted by Strygaldwir

How much you need? how much you'll get out of them? They are all variables you'll have to play with. One thing that is probably sure, you're ROI on saving energy is probably better than any energy production method.

Keith

Keith hits on the best point of the whole conversation. It is in the conserving of energy that one really wins. This is why we only use about $10 (to $15) worth of deisel per week when at anchor. The genset isn't putting out that peak output I mentioned, but far less and running time is reduced.

For numbers, my Italian diesel Pramac genset with Yanmar engine was $3000 USD.

Sorry... my previous post wasn't well written because I had people coming on board to look at buying the boat. I had to go quickly. I have another set in 10 mins, so here I am again. I'll try to get some hard numbers up here shortly. We did an Excel sheet (or it may have been on paper) that costed it all out. It was definitely equal over 10 years mostly due to the huge hit it takes to get the solar up and running in the first place.

[Sandero]

Solar panels are a great means to top off your batts... of course depending on your power use and the size of the panels.

They are damn quiet too which appeals to me cos I almost shot that fella "xxx" with his noisy generator who was anchored 500 feet from me.

The ROI and so forth seems hard to asses.. but my 2 - 55w panels have been producing juice for almost 2 decades and can run the autopilot and electronics on a sunny day.

If I were to live aboard I would add wind too because unlike most other boat expenses... energy resources like wind and solar DO literally create something of value.. WATTS.

To get oodles of watts you need lots of direct sun and a large footprint for the panels.... therein lies the rub... but for keeping the batts floated whilst you are away... they are the cat's meow. I love em.

Jef
sv Shiva
Contest 36s

[ssullivan]

Jef... you can name names.. it's ok.

I can't afford the inboard fancy gensets. I have a loud one out on deck, and I think when I ran into Jef, I had a problem where I had to have the genset on for like 2 hours one afternoon. Not ideal at all, but a solar array wouldn't have been able to power the tools I was using either, so I would have had to shell out for a dock or gone without the repair if I hadn't had a genset.

I guess a lot of this really does depend how much you are on shore power. I wasn't plugged in between April and a week ago or so.
My electrical demands were very high due to charter guests, which was also a factor in our calculations. What really surprised me was the $10-$15/wk we were spending while at anchor for normal 45min to 1hr daily runs, which I started doing at noon, thanks to Kai Nui's wisdom: He mentioned that at noon, most people are off doing something, working on the boat, or underway. He was right. We only really had a noise problem that one time with Jef. (It was kind of him not to open fire)

It was because we were in a very tight area - Newport Harbor. There were boats everywhere and we had a charter guest coming, so we had to get everything ready for the guests. Ideally, we anchor in less crowded places and don't have repairs before guest coming that night.


My main point though on this thread has been that they have priced solar to be equivalent to gensets as a power generation source. I think wind might be one of the best alternatives, but have not run numbers. I see those things quietly making a reasonable amount of power on many occasions.

The other rub with solar is that you typically need a genset anyway, which completely defeats the purpose. If you still have to fire that thing up and make noise when it's too cloudy or you are too far north, my reasoning is that you might as well just get a good genset. That is definitely cheaper than going solar AND genset.

Sorry... can't find my numbers. We did them on paper, not in Excel.

[roverhi]

Other than the fact they aren't the most reliable beasts in the world, you can use an inverter to generate needed A/C. In our house, the 2500 watt inverter would run one major appliance like a washing machine plus the house lights. Equate that to tools and it's no less than running something like a table saw or other large draw item. Actually less of a draw 'cause a table saw will be cycled way less frequently than a washing machine. If you are only running hand tools, a smaller inverter would suffice and even less current draw.

Our problem with the inverter was that the house was wired AC so the inverter was on constantly when the sun went down and any time we needed juice. Inverters are good for short use items like power tools, microwaves, coffee makers, etc. as they are relatively efficient when putting out large amperage. Unfortunately, inverters have inordinately large current draws even when they aren't producing much in the way of AC amperage. As long as you have the solar generating capacity, you can make up for that draw, easily. It's when the inverter is on for long periods that you will be hard pressed to replace the juice via a reasonable sized solar array.

As has been mentioned before, the secret is using high efficiency DC systems for those things that have high cycle current draw.

Once again, the rated panel output is an ideal situation with the sun directly overhead on a cloudless day, panel aimed at the sun in a low humidity atmosphere. We never came close to realizing the advertizeed amperage output of the panels. They seldom put out more than 80% of what they were rated at and then only for short periods. Before 10:00 and after 2:00 output fell off significantly. A slight haze would cut output by as much as 50% and an overcast dropped output below 20%. that was at 20 degrees latitude so we had the sun passed directly overhead or close to it, most of the year. Start heading north and the output will suffer even if angled to the sun. Simply put, you cannot analyze panel output based on rated power. Probably a 50% reduction in peek output would be a more likely result on a 8 hour day assuming good sun.

The beauty of solar panels is they are quiet and reliable as long as the weather cooperates. Their non use of petro products and non polluting nature are a light frosting on the cake.

Aloha
Peter O.

[hellosailor]

Rossir-
It's probably tax fraud to move the panels, I'd expect the rebates to require the installation of the panels and to say something about not promptly selling them off or removing them. You'd have to read rebate terms to see what any of them say, but if they require installation on your "home", a boat legally can be a home. If they require a tie-back into the grid that's a little harder afloat.<G>

Keith-
"I only saw full rated output for about 3 hours a day in the Bahamas." WOW. Only three hours?!

Defjef-
"They are damn quiet too which appeals to me cos I almost shot that fella "xxx" with his noisy generator who was anchored 500 feet from me." What, you and senormechanico didn't bring enough to share, and then you complain when the other guy isn't playing nice?<G> You could have paddled over and dropped off a few panels to show him the Shining Path.<G>

I'm gonna have to call Reddy KiloWatt and ask him how much longer my nuclear pile is goona take. Or maybe just buy one black market from the old USSR.<G>

[sluissa]

If you think about it one way, humans lived without electricity for thousands of years very comfortably. In that sense any amount of electricity at all(other than safety devices, like radios and nav lights) could be considered a luxury and could be done without. I'm not saying people should go without it, I'm just saying that many people could probably cut down their electricity needs to what could be supplied by a reasonably priced set of solar panels without too much discomfort or inconvenience.

[ssullivan]

Sluissa - again, this is the answer. I couldn't agree more. I think this is why we were down to only $10-$15/wk. Essentially, the genset ran to do the fridge and charged up the batteries at the same time (AC fridge). We keep thinking how nice it would be if we could grow our own food and preserve it using methods used prior to the invention of refrigeration. Power requirements would drop to just about nothing.

[Sandero]

I am not sure why people who need power don't run their main engine... charge the batts, make hot water... and run the frig... and you can do a little trip to ablate some bottom paint to keep the bottom smooth and run the diesel a bit more load than just the high output alt and the frig (compressor).

Our solar panels could not sustain 4 adults or charter guests... But at .5gal / hr and running 2 hrs a day... at anchor... is like $3.50/day or $25 per week... we would have juice and cold and hot water... The diesel IS noisy so we do showering when the engine running at on the hook... or more likely I up the hook and do a harbor spin and set it down in a new location. I like to change spots a lot... change the scenery.

We have been assalted too many times by gensets and I have a severe alergy to them and the disturb my naps and my dinner and the quiet of the harbor. I think they should be prohibited or required to meet a sound limit. They do make insulated enclosures for them too.

I can't stand those leaf blowers either... nor noisy motorcycles...but I don't run into them at anchor... usually. My diesel is too loud and I hate it too for that reason...

One of the sweetest things about sailing is the quiet and the sound of wind and waves ONLY. And this is why solar assist is perfect..no moving parts and no noise. if they could only get more juice outta them things.

Jef
sv Shiva
Contest 36s

[hellosailor]

Defjef-
"I am not sure why people who need power don't run their main engine..." All the engine companies and "the usual suspects" of authors seem to agree that a main engine makes a lousy genset, mainly because it is running at fractional loads so it is inefficient, and because diesels running at light loads coke up.
Someone with a Ford diesel pickup tells me that Ford claims this is no longer the case, they have some models with multiple AC outlets in the rear and supposedly there's no harm to the engine using it as the genset, so to speak. But that's not the typical old marine diesel.
I'd think using the main engine as a genset would be perfectly feasible--if there was room to add a second alternator with a clutch on it, to really load the beast up. And, assuming that would turn it into a genset of the "right" size for the boat.

[Alan Wheeler]

It depends on size of engine for fuel usage and cost of replacment/repair when it expires. For me, it is a BIG engine which uses a good quantity of fuel and EXPENSIVE, so I will run a cheap genset when ever I can.