Hey electronics experts.......PV cells

First of all I want to say that I have very much enjoyed the debates here about various energy supplies and uses. I disagree with almost all of it about cars and sometimes think some folks need to take off the tin foil hats. That said, it is obvious there is a lot of knowledge here,and I really respect how everyone is civil. I really enjoy Darrell's comments, and I don't agree with him much, but he certainly knows his stuff and puts the $ where the mouth is, so I want to thank him in paticular.

Back in 91 I went back to school and got a degree in mechanical engineering. I was obsessed with self reliance in all of its facets. Energy, food, shelter - all of it. I was also a diesel mechanic during the day and was making a form of bio diesel back then. I even lived for two years without electricity or running water, part of that time on a boat, grew most of my own food and hunted for meat. My point is I am a kindred spirit when it comes to cheaper, cleaner, efficient energy.

Back then, I attended lots of trade shows and the like, and was told that PV cells that were affordable and powerful were a year or so away. I am still waiting. When I think about what can be done right now when I rig out my boat that I am going to live on in terms of LED lighting and its power sipping qualities, I can't believe other things haven't come along.

Here are my questions and specific needs.

Where is PV today?

Why are PV prices seeming to go up?

How can I find an efficient way to cool my boat? My AC unit zaps my 6.5 Onan generator almost to the max, and I can't run it on batts at all.

Why haven't PV become more efficient, from what I have seen the gains have only been minimal?


Elaborate as much as possible. Thanks.

I wish I could tell you why PV hasn't advanced that much in the last 15 years.

As far as prices go when I bought my first 2 panels about 8 years ago, the 2 Solarex 43w were about $7 a watt, now you can get panels for just under $4 a watt so I do think price is coming down.

Also the size of the panels is getting smaller for the same wattage, I can get a 140w panel that is physically the same size and weight as my old 43w panels.

As for the AC on you boat I am not sure, they usually run about 1.5kw, so it shouldn't be dragging down a 6.5kw genset. I assume it is a water to air heat pump taking in cool water and ejecting warm water to cool the boat. In the past I have found that if the intake strainer is at all plugged they run a LOT longer then they should, but if you can see the output side of the AC water pump and it has a good flow you should be set.

Darell would appreciate this, I run 2 marine 5000 btu heat pumps in the summer in my house. It heats my pool water and cools my house, a 2 for 1 deal /ubbthreads/images/graemlins/smile.gif Darell they make them for household water heaters now. If you need the cooling it is the way to go.

Wind Generators! I just purchased another Air/Wind X 403
400watts at 20 mph wind!Blows my Solar away!
For cooling how about a heat exchanger?
Closed circuit,sea water to fresh?

Laser,
do you have a link for that wind turbine. I have an old non-x 403 and it's rated at 400 watts at 28 mph..

Big,
Have you checked the solar energy websites?

http://www.altenergystore.com/

http://www.gotsolar.com/

<added> Southwest Wind Power's Air-X, specs;

https://www.altenergystore.com/cart/1008.html?oFNkksXA;

etc...

Oh if only I could install a windgen here, not allowed without about $2500 in variances and then it still has to go to a vote with the town board. I can get a lot of solar for $2500.

Some more interesting articles on solar energy development.

http://www.lbl.gov/Science-Articles/Archive/MSD-full-spectrum-solar-cell.html

http://www.lbl.gov/msd/PIs/Walukiewicz/02/02_8_Full_Solar_Spectrum.html

I have to apologize for my lack of electrical knowledge, just was never around it and now have to deal with it.


Thanks for the help. My air unit is a conventional RV/Marine type overhead cooling unit, just like a window unit but waterproof housing and sits on top. I think it is around 9K-10K BTU, believe it is a Coleman and I don't know what it draws power wise. The guy next to me has a HUGE Hatteras ($$$$!!!!) and has two very large AC/Heat units. A 220 from shore will only run one unit, but he has a giant diesel Westerberke genset that will run both like it is boring to it. The AC unit on my boat will pull the Onan hard and it is clearly laboring. Other than the fridge, everything else draws very little. I usually heat water with onboard propane, as well as cooking and heat. My boat is in freshwater, forgot to mention that.

The boat is in one of two places, Little Rock Ark and Memphis Tenn on the Arkansas or the Miss. The heat will be in the upper 90's -100's everyday for months with 100% humidity. Without AC it would be almost impossible to sleep. I have checked out what everyone else has, the live aboards rip the factory gensets and install huge ones to run their upgraded AC units. The AC unit I have will smoke the batts almost instantly, and it barely makes it possible to stand the heat.

I would like PV for things like charging the batts for lights, TV, Radios, and running the water pumps and head. During the cold or mild seasons, which is not often, I could go without running the genset. I don't like running it because it is unholy loud and is subject to all kinds of mechanical problems, mostly the impeller. I have talked to other boaters, some use PV for charging small things, all that tried windpower called it useless.

Please, all thoughts welcome.....

Bigcozy,

Among things to look at in terms of needing more power to your a/c unit, make sure that the wiring conductor size is above the minimum size suggested for your unit. With 120V a/c power, a #12 gauge wire is rated for 20 amps for THHN or THWN insulation. Typically conductors should not be loaded over 80% of their capacity,thus for the #12 gauge, 16 amps would be acceptable. I'm not sure what insulation type you have on your boat, so am unable to find more particulars on it. Another consideration is voltage drop and overall circuit conductor length. How far is it, as the wire runs from source to load? What is the Full Load Amperage of your a/c unit? Watts? Input voltage? What are the power ratings for your genset? Watts? Amps? Kilowatts? Kilovolt Amps?

Lighthouse

Yup, that type of AC is an air to air, about 1/2 as efficient as a water to air unit, that is if the water is the same temp as the air. The beauty of the water to air is when it's 90+ outside the water is still usually 70-80, way cooler then the air. I bought both my units on ebay and regularly see them there. Just do a search for "Marine airconditioner" or "boat airconditioner". The trick would be finding a place with enough space to install it and the know-how to do it, or paying someone to do it. I bet it would use about 2/3 less then the air to air one your currently using and would draw the same power or less.

I used to deliver boats when I was in college so I was on everything up 48 Grand Banks and worked on them all. What size/type do you have?

In any case I personally would add maybe 100w to 200w of solar with a controller. Again the trick is where to mount it. On one sailboat I was on they used that flexible type PV and put it right on the deck, we literally walked around on it. I can't imagine the $ he put in to that, but we never ran the genset on that boat, I think it was about 1000w of solar.

Lighthouse, I will have to look that stuff up, but I know that the boats I am around all have similar situations.

I don't know anyone that has a water to air unit. My guess here is that is do to expense and simplicity. The air to air unit is fairly inexpensive and easy to replace and plentiful. I want to check that out, if I can make it work I would use it.

The boat I have now is a very old 47' Chris Craft Commander. 100% Hunduran Mahogany. It has been a project, but it is not a practical live aboard. I think I have it sold. The boat I am trying to buy is a 1987 39' Marinette Marquis. Much better boat, aft cabin, gas Crusaders, V drive, Onan Genset. The big thing is it has an aluminum hull, which is just about perfect for the river, and very few boats have them. The river forces you have very stout hulls and tons of horsepower, there is no getting around those two requirements.

I am going to by some PV and start playing with it, I still think it is the way to go, I will let you now how it works out.