Wind vs Solar

[NoTies]

OK,
The budget isn't going to allow for a big wind system as well as a big solar array until 2007. I can buy a 400 watt air X for around NZ$1200 and a 125 watt solar setup for around the same price. I have a 1000watt Honda portable for the days the sun don't shine and the wind don't blow. Our electrical reuirements are going to be quite low as lighting will be LED, pilot consumes around 1 amp at 25% duty cycle, fridge is gas and apart from that it's simple navigation and radio demand. Given my plans for coastal cruising what would you do? We plan to fit a 200 amp/hour battery to give us some leeway for days when charging isn't so great (I've done all the calcs but decided to go much bigger than I need). I've read a lot of stuff on both but not a lot of comparison. From my experience fishing the coast of NZ around 15 knots is reliable wind speed but of course we weren't searching for sheltered anchorages every night. At this speed the air X pokes out around 100 amps.

[Talbot]

Surely the correct question is what do you want to have as a final fit. If it is a higher number of solar panel and a larger wind turbine. You need to decide whether having two wind turbines of the air X are what you want or whether you will consider replacement.

If the Air X does meet your final requirements, it is obviously the better initial buy cause it will provide a much higher power than the solar panel.

If it doesnt meet your final requirements, and you can manage initially with the solar panel, then go the solar panel route, cause it is easier to join up several panels (and a better solution.

[NoTies]

Oops. Re read my post and realised I didn't express myself too well. At present I have neither solar nor wind so I have a blank canvas so to speak. I can't afford both for the first year but intend to eventually fit both when we go offshore in April 07 as well as upgrading electronics, fitting watermaker etc.

[Strygaldwir]

I installed the Air X marine about 2 months ago. I like many features of the unit, but I think someone overstated its output. It does not start generating appreciable output until you get up to about 8 kts of wind. At 15 knots, mine appears to generate about 7 amps at about 12.7 volts. At 20 knots I see significant amounts of energy. But, at 20 knots, it is starting to get unpleasant. I would absolutely install one again, but, its output is less than I hope. Over an extended period of time, it will keep up with my DC usage with the exclussion of Freezer. I have a seperate freezer and refrigerator. It will supply enough energy for running the refrigerator. My lights are not LED, they are hallogen. I do keep my anchor light on at night. I do have a pretty extensive array of electronics, but nothing to energy consumptive, on the DC side.

Having said that, I also have just purchased a 170 watt solar panel. I intend to get 2 or 3 additional panels. I expect that this will be able to provide both my DC and AC needs without having to utilize external generators.

If I had to sequence my purschase, I'd pick the solar panel first. They are quiet and pretty much maintenace free. I think the energy output is mosre consistant over a widder range of times and conditions. My 170 watt solar set up is going to cost more than my Air X setup. I have an MPT solar controller that allows me to run 24 volt panels in my 12 volt system. So my set up may be more expensive. But, given the output, I think the additional cost is worth while.

I'll know what kind of longer term output I get from the solar panel in a month or so.

Good luck

Keith

[BC Mike]

Not wind or solar but a generator.
My 1000 watt Honda generator connected to an automatic battery charger puts 10 amps in with very little fuel used, and very little noise. The Honda was $1000- plus taxes, and the charger was $60- A larger charger could be used. I will use solar panels, and run the diesel as required and use the Honda as back up. At least that is the plan. The Honda weighs 26 pounds so is easy to carry.
Michael

pwedderell, I agree with Talbot. You can always add to the solar array, but to upgrade the wind generater will require replacement, or addition of another unit.
As for practicality, when there is no wind, you will be more likely to run your engine, therefore charging your batteries, so wind generation is a more practical solution in the long term IMHO.
As for a genset, the small unit mentioned is a good option, and can be set up to run off your outboard fuel tank for the dinghy. If you have a 4 stroke outboard.
I am curious if anyone has set up a 12 volt genset as opposed to 110. These units are easy to build, and inexpensive. With sufficient house bank sizing, and an inverter, I would think it would work well for generating all the power you would need. I am considering building one for my boat, but have not heard any of the downsides yet.

[sv_makai]

On Makai we did the research and added solar first. Even in the caribe where the trades supposedly blow all the time we found that we had more sun than overall wind. Many nights anchored out the wind is near dead or very low. This is generally due to the anchorage, island blocking or altering the local wind pattern.

Bonaire for example has many dead calm nights and or light wind days. When you sail southeast around the end of the island the winds will go to 18-20 knots. The ground and the wall made by rising heat will block the wind. The first 2 weeks we had the wind gen up it didn't make a single amp while our solar kept the battery bank (680amps) fully charge and floating by 10AM.

We have 480 watts 4 * 120 kyroceas with the goal of adding more. After 2 years we decided add a wind generator, a KISS. Overall it is a lower producer of power, but our decsion to add was predominately to cover days of little sunshine and passage making.

There is a second benefit to Solar. Our bimini is almost completely shaded and the cockpit is much cooler. We are heavy users of electirc power and do not like to camp. We also don't spend much time in marinas and avoid running the genset when ever possible. Or best was 6 weeks with only solar. This includes making water, tv, computers, radios, ssb, etc.

[s/v 'Faith']

BC Mike C once whispered in the wind:
Not wind or solar but a generator.
My 1000 watt Honda generator connected to an automatic battery charger puts 10 amps in with very little fuel used, and very little noise. The Honda was $1000- plus taxes, and the charger was $60- A larger charger could be used. I will use solar panels, and run the diesel as required and use the Honda as back up. At least that is the plan. The Honda weighs 26 pounds so is easy to carry.
Michael

Mike,

That generator comes with a 12v tap for charging batteries. Why did you elect to purchase a seperate charger? The Honda makes 12vdc, then uses an inverter to produce 110AC. If you are running an ac battery charger, you will be losing quite a bit of the overall output to heat.

Just a thought.

[sv_makai]

Makai also carries a Honda 2kw as a backup. I have mentioned this unit before and is great. We use the 110 through the charger and will see about 80amps/hr charing to the battery bank. If you have read other posts from us we are power users and our boat is configured to generate the maximun output across several sources. But, we don't like to rely on the gen for several reasons

1) It uses fuel. we are weeks and months away from fuel sources. Though it is cheap in Venezuela to refuel, you have to carry it. In Bequia it is 5 dollars US a gallon and that was 7 months ago. Hate to think what it cost now.

2) They break down. As noted above we are out alot and for long periods. We have had several failures from carb gasket blowouts to salt water playing havoc with parts, cords breaking, this could leave you with out an adaquete means to recharge.

3) In the long run they cost more to operate (fuel, oil, repairs) and in inconvience. While passagemaking or at anchor the sun charges our bank automatically.

We will always carry one as the 2kw gen are great, but I think for long term cruising they are not the greatest choice as primary power.

[BC Mike]

I need a charger for the other batteries on the farm so it was a test. The Honda produces 7 1/2 amps using its 12 volt charging system. I will not take the 110 volt charger with me cruising. I also have a smart charger inverter on the way courtesy of another contributor to this site. The Honda is for backup only is case the other systems have failed. It is handy to have around the farm, easier to run than it is to get a long heavy extension cord. Next time I go down to the boat I will test the 12 volt side of the generator.
Michael

[windthief]

One on either side of my hard dodger. I sailed for 8 hours today, not motor sailing, with the following running and partly cloudy conditions.

C.D. player with two remote controls going
Simrad TP20 autopilot
Icom m420 with the Command mic scanning
Windex
Knot log

When I got into my fairway and fired up the engine there were 13.5volts.

[NoTies]

I hate to think how much unnecessary money I would spend if the internet didn't exist. Thanks for the advice and it is taken on board. Yep, I said 100 amps when I meant 100 watts Strygaldwir
10 hours into a 12 hour nightshift and the brain gets a bit addled.

[Euro Cruiser]

It's interesting how opposite recommendations can come out of the same thread, isn't it. My take is that you should start with *your* givens and then make a decision based on our input where it lines up with your circumstances. Those seem to be:

-- you have about 60 amp/hrs of usable battery capacity; if the reasoning for this isn't clear, you might want to revisit the battery side of things; if you don't feel this is enough, you probably should revisit your planned bank capacity
-- you will be coastal sailing in New Zealand, a far cry from the Caribbean's wx & sun; especially if trying to do some local cruising off-season, you'll have sufficient rain & cloud - and your latitude is high enough - that a solar array is going to give you far less amp/hrs of charging than the wind gen will in your sometimes blustery conditions with repeated frontal systems
-- you are 'ramping up' re: outfitting your boat, and plan longer term cruising; inevitably, this means bringing more power-hungry systems aboard and, sure enough, you already mentioned a watermaker. I can imagine that, prior to the 'real' cruising beginning, your DC power needs will incrementally increase so initially picking a higher amp/hr charging source would seem better than a lower one, even if solar and wind could both work for you at the moment.

The only downside I can picture when choosing wind over solar is that a wind gen will work for some years before needing servicing, while a solar panel will work for some decades (assuming it doesn't suffer a winch handle assault). So...you'll be eating into your shorter lifecycle sooner if going wind gen. However, that wouldn't push me in the direction of solar if I were in your shoes.

Jack

[Talbot]

An earlier post talked about charging a battery from the 12v output on the charger. Provided it is a true 12v output - it is designed to run 12v equipment and not charge a battery. The voltage is too low to achieve anything really worthwhile as a battery charge. Normally if you are charging hard, the voltage will rise to 14.4volts (maybe even higher with some chargers and specific battery technology). Even a float charge will be running at abt 13.6v. Thus a 12v outlet will not achieve much.

My little generator has a 14.4v outlet - specifically designed for putting power into a battery and it cost less than £50 from B&Q stores in UK.

[BC Mike]

The manual for the EU1000 Honda generator has this to say.
" The DC receptacle may be used for charging 12 volt automotive-type batteries only. The generator cannot be used for both AC and DC simultaneously. Maximum charging output = 6.5 A "
At 1000 watts there are up to 65 amps available using AC, so an efficient 110 volt automatic charger should be better than the built in system. Also using a 110 volt charger a small heater can be used at the same time. My intension is to use solar panels to charge the batteries, backed up by the engine if there is no sun. I will have a dedicated starting battery. The Honda is a back up system in the event of a system problem. In the winter I do not run the engine and I do not have the solar panel in place, reason, freezin. The Honda is used to charge the batteries and warm the boat a few times during December January and February.
Another issue I found was that the boat gets too heavy for the races with all the extra junk. I fixed this problem by purchasing a smaller boat just for the races. It will be bare with only sailing and safety gear on board.
Michael