We need to be speaking the same language in order to communicate. I know there is a lot of confusion on this, so please allow me to attempt to clarify; amp-hours is energy, amps is power (when both are referenced at the same voltage). You can think of amps as “instantaneous”, that is, the number of electrons flowing. Amp-hours is power times time, which equals energy. We usually talk in terms of amp-hours per day, in order to determine the overall energy used, generated, or stored.
An electrical engineer will point out that this is not correct, that watts is the way to measure power and watt-hours is energy, and they would be technically correct, but we use amp-hours because it is more convenient and plenty close enough.
Wind Generators – AC v. DC Output and Blade Design Effects
Thank you for the mostly accurate article about wind generators in the
Feb, “All At Sea”. I do want to point out some things you said which
are generally accepted as true, but like many urban myths, are not.
First was your statement that the generators with A/C output are more
expensive (“because more components are necessary”). It’s the same
number of components. The KISS is the only one that makes the
conversion to D/C in a remote location, and it is less expensive than the other high-output wind generators..
The smaller bladed wind generators do not start turning in lower wind
speeds. The Air X, for example, needs 12 knots to start turning. The
generators with more than three blades start turning in lower wind
speeds, not because because the “blades are lighter”, but because there
is more torque placed on the shaft by the multiple blades. As usual,
compromises must be made, and the generators with more than three
blades (GWMTTB) are not as efficient in higher wind speeds. The big
advantage to GWMTTB is the effect of surface area and drag. In higher
wind speeds, GWMTTB have more drag due to larger surface area, which
tends to limit the maximum speed (RPM), a big advantage for generators
designed for use on farms in England, which is where most of them come
from. They also do not “cut in” at lower wind speed. They (generally)
start turning at lower wind speed. Generator voltage is a function of
RPM and load. “Cut in”, sometimes called “start up” speed is the wind
speed where generator RPM produces voltage above battery voltage to
start charging, and some manufacturers use 12 volts (which in my
opinion is too low).
The amount of energy a wind generator can produce is a function of
blade swept area, with a slightly larger diameter significantly
increasing swept area. If you look at the power curves, you will see
that “generators with smaller blades” do not produce more power in “10
to 15 mph”.
102 W. Fulton St.
Tarpon Springs, FL 34689
Hand-Operated Clothes Washer
This washer uses a technique of pushing and pulling the water through the clothes. This reduces much of the wear that would come from the friction method.
Due to the agitation motion, much like a mechanical washing machine, less soap is required to do an effective job. Minimal water is required to have this washer work effectively. In fact, four inches in a five-gallon bucket is ample water (one and a half gallons).
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I was talking to a KISS owner the other day. He had recently purchased a boat with a KISS wind generator installed. He said that there were three other KISSes in his marina, and that all the owners had told him that it was necessary to turn the generator out of the wind and tie it down when the winds get over 25 knots and the generator goes into freewheel. Apparently, this rumor has become common knowledge, and like much common knowledge, is untrue.
Why and How
All wind generators have to have some way of preventing overheating. Most modern marine wind generators use rare earth magnets, which are sensitive to overheating. Even older generators with earlier magnets can loose their magnetism if they get hot enough. Manufacturers use a lot of different techniques to prevent overheating. On the KISS, we use two thermal sensors inside the housing that are bi-metalic discs that open the circuits, stop energy production, and allow the generator to cool. When both are open, the output drops to zero, and the generator turns much faster than normal, causing additional noise and vibration. When one opens, the output is unbalanced, and the generator vibrates more than normal and the output drops by 2/3.
The on-off switch on the KISS connects the coil windings in the stator (shorts them out), creating a very large electrical (and thereby mechanical) load. When the circuits are opened by the thermal sensors, the coils cannot be shorted, and so the on-off switch will not turn the generator off when it is freewheeling.
What to do
There are more than one way to deal with this;
1) Do Nothing. When the KISS cools, it will start making power again. It will be making more noise and vibration while freewheeling. It will not be damaged. The thermal sensors we use are rated for something like 500,000 on-off cycles. We were stuck in 30 – 50 knots winds off shore with no engine or useable sails (it’s a long story). The KISS kept the SSB/ham, all the deck lights, and VHF radio going all night, cycling on and off it averaged 11 amps.
2) Turn the switch off and wait. The KISS will cool, and when the thermal sensors close, it will shut off.
3) When the winds get up to a steady or average 25 knots, pull the generator part way out of the wind with a tether attached to the tailfin. In order to avoid approaching rapidly spinning blades, the tether should be set up before hand. We sat in the Tobago Keys for a few days with nothing but a submerged reef and 3000 miles between us and Africa. Winds were well above 25 knots. As the boat sailed around on the anchor, the wind generator (pulled part way out of the wind) would speed up or slow down, but it never went into freewheel. On a dark and stormy night, alone in the cockpit, without the additional tether rigged, I would probably go for options one or two.
Sanyo HIT Double
Note: As of now (spring 2012) the double is out of stock.
One of the issues facing cruising sailboaters is having enough room for all the solar panels needed to run the boat. The Sanyo HIT Double, a bifacial panel, makes the most energy per square inch of any solar panel available. It does this by gathering light energy from the bottom as well as from the top. So, if you are installing the panels on an arch or on davits, sunlight reflected from the water and/or from a white dinghy can be made into electricity. These panels are rated at 195 watts, but that does not include the power that comes from the bottom because of the standard used to test panels. The back face of a HIT Double panel generates electricity from ambient light reflected off surrounding surfaces, and combines with power from the front face of the panel. Depending upon system design and amount of reflected light, this results in up to 30% higher power generation (more kWh) per square foot.
HIT bifacial solar cells are hybrids of single crystalline silicon surrounded by ultra-thin amorphous silicon layers, available solely from SANYO. The crystalline silicon is the most energy-efficient, and the amorphous is more shade tolerant, so this is a combination of the best of both worlds.
As temperatures rise, HIT Double solar panels produce more electricity than conventional solar panels at the same temperature, due to their low temperature coefficient. So they work very well for tropical and subtropical areas!
Technical Info BUY NOW
Here’s our story:
When we met in January ’94, John said, “I’m leaving in 9 months to cruise the Caribbean on my sailboat, and I’m looking for crew.” Within a month, Libbie was buying her foul weather gear! We spent 4 years cruising in the Caribbean aboard s/v HOTWIRE, our steel Bruce Roberts 36′, and continued to live aboard in the Tampa Bay area for another 8 years while we were growing the business.
When we started cruising, our energy needs were very basic. The longer we were out, the more comforts and conveniences we added. By the time we decided to sail home on business, we were using lots of electrical gadgets, keeping the batteries charged with a KISS High Output wind generator and a solar panel, rarely having to start the engine.
Since we returned to the U.S. in late 1998, we’ve been using our education backgrounds and cruising experience to help other cruisers put together energy systems that will make life easier and more comfortable for them, sticking to the KISS principal: Keep It Simple, Sailor! We know we’re doing something right because so many of our customers have become our good friends and our best referral sources! (You guys are GREAT! Thank you!)
Our knowledge and experience with small systems evolved into consultation, design and installation of the larger residential and commercial solar electric systems as well.
John has extensive experience with power-related systems and is available for FREE consultation, helping you to design a working system to meet your energy needs. (But even Libbie has learned more than she ever thought she’d want to know about alternative energy and is now able to guide customers on basic issues.) Please feel free to contact us with your alternative energy questions or use us as a sounding board for your ideas. We’d love to hear from you!
Mage Power of Germany now in the USA with very attractive warranty and pricing
Reliability is at the core of all of our solar energy systems. So is power. To that end,
MAGE POWERTEC PLUS modules use mono- and polycrystalline cell technologies. They keep the energy flowing and operate with an electrical cell efficiency of up to 17.3%. And it’s important to note that our modules boast allowable tolerances of up to +5 watts. Which guarantees maximum power without compromise. In fact, nominal power is always obtained and often exceeded. This gives us a distinct advantage over our competitors, whose modules may actually deliver less than the wattage they claim.
on the subject of superiority, our 10-year product warranty is also in a league of its own, and easily surpasses those required by law. And MAGE POWERTEC Plus modules go far beyond competitors´standards with the the added guarantee that they’ll produce 90 % of their nominal power for 12 years and 80 % for 30 years. That´s three full decades of reassurance. In order to certify such high quality, we insist that our products meet or exceed the most rigorous North American and international standards. What’s more, every MAGE POWERTEC Plus module must pass stringent optical, mechanical and electrical quality controls.
It’s comforting to know that MAGE POWERTEC Plus modules can handle the toughest demands with regard to stability and corrision resistance. This is due to their engineered hollow-section frame and 3,2 mm (0,13 in) special solar glass. We also use high-quality EVA foil, which is ideal for embedding solar cells, while the weatherproof foil on the back of the modules protects against humidity. As a final security measure, we place a junction box with bypass diodes on the back of the module to avoid overheating of the individual solar cells (hot-spot effect). Our extremely robust modules resist a maximum pressure of 5,400 Pa (= 113 psf).
Kaneka Solar modules
60 watts, 92 volts open circuit, 37.8 in. X 39.0 in., 30.1 lbs
A new low:
$1.25 per watt/$75 per panel. Pick them up in Tarpon Springs, no taxes in FLorida on solar. Limited quantities.
You might also be interested in our led lights…
Thin, Walk-On Solar for your Boat
• Efficient – monocrystalline silicon provides twice the power of thin film panels
• Ultrathin – All models are only 3/16″ (4.5 mm) thick
• Light-weight – ideal for racing, or for mounting on a bimini, dodger or other light structure
• Flat front – there is NOTHING protruding from the surface that can catch sheets, sails or your feet
• Snug-fit back – wires are recessed and protected in grooves, either mounted hidden through tiny holes to interior or without holes on top
• Rugged – sealed with a durable UV-resistant surface, salt water proof to IP67
• Step-on – you can step on the textured surface and add optional anti-skid strips
• Mount on curved surface – the narrow Bluewater modules are slightly flexible and can be installed to follow a curved cabin roof or deck
• Temporary use at anchor – mount on boom with bungee cords, then store under bunk or cushion while underway
• Partial shade resistance – an array of modules is less sensitive to major power loss from boom, mast and sail shadow than a large single panel
• Beautiful – not an eyesore on the boat you are so proud of
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