Spring time: more solar and wind experiments anyone?

[txlibdem]

Does anyone have any plans to try:

Solar heated air?

Solar hot water?

Concentrated solar?

Geothermal heating and/or cooling?

Hydronic heating (in-floor heating)?

Passive solar additions or improvements?

[cbayer]

1. We have installed two more solar panels and are considering a wind generator.

The total of 4 panels are running everything, including the refrigerator, very well during the day (unless it is overcast all day). Our hope is that the wind generator could run things at night, as the wind tends to pick up then.

The solar panels do keep a charge in the batteries but don't really supply the amount of power needed to really charge them.

:hi:

[txlibdem]

2. Question about your setup

You have a bank of batteries but you said the solar doesn't really charge them so is your house also connected to the grid also? I'd hate to think you're in the dark all night long.

A couple of suggestions:
1. Look for a wind turbine with a low startup wind speed. Most of the ones on the market start at 8 or 10 mph wind speeds yet the average wind speed in all but a few areas is less than that, which means the turbine will spend most of its time sitting there generating zero power.

I've been looking into wind turbines (but can't use them where I live now, :mad:) and found the following:
Honeywell "WT6500" http://www.earthtronics.com/honeywell.aspx
and...
Missouri Wind and Solar "Missouri General" on eBay at http://cgi.ebay.com/General-1500-Watt-Wind-Turbine-Generator-24volt-11Blade_W0QQitemZ290546913062QQcategoryZ121837QQcmdZViewItemQQ_trksidZp4340.m263QQ_trkparmsZalgo%3DSIC%26its%3DI%252BC%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D10%26pmod%3D280631870786%26ps%3D63%26clkid%3D7903731091837527746
... these start up at 7mph but are far less expensive, usually sell on ebay for less than $800 (so you can buy a couple of them if your wind speeds aren't above 7mph often)

2. Depending on your solar panel watts output, you may want to look into a different charge controller for the batteries. Some are less efficient and basically waste 15% of the energy you put into them,

3. If you haven't exceeded the watts or amps rating of your existing charge controller it might be cheaper to add another solar panel or two.

Look into the costs and weigh the options that seem right for you.

[cbayer]

3. I am on a boat so my set up may be somewhat different. We are not connected to the grid at all.

We have a bank of 6 6 volt batteries (basically 3 12 volts, in practice). The solar panels keep them charged, but they really need higher input to get them completely full. The batteries can generally run the "house" all night, but we have (imo) too many 110 items, requiring use of the inverter. The inverter is a huge energy hog. We are trying to switch everything we can (TV, dvd player, router, computer chargers) to 12 volt, so we can draw directly off the batteries. This would probably allow us to run pretty completely off the solar panels. Almost all of our lighting and all of our refrigeration runs off 12 volt, so we don't sit in the dark, lol.

We have lots and lots of wind, being on the water. We had a storm yesterday with gusts to 50 knots and steady winds between 25 and 30. My biggest gripe about them is the noise, so I am adamant about getting the quietest unit I can get. When sailing, our average speed is about 7 knots.

I think (but am not sure) that our controller is extremely efficient. We have over 13 watts going into the batteries when the sun is out. Two of the panels are fixed, but two we are able to move during the day to maximize the input. The two fixed ones are Kyocera 130's and the two new ones are 135's. I am very, very happy with them. The problem with getting more is where to put them. They can't interfere with wind when we are sailing.

As the water heater is probably the biggest hog on the boat, I am very interested in solar water heating. We don't heat water unless we are going to use it, but absolutely have to run the generator to do so. If we have to run the engine when out at sea, we have a heat exchanger that runs through the water heater and heats the water really well.

Thanks for all the great info. It is wonderful to exchange information with others interested in this.

What kind of system(s) do you have in place?

[trud]

4. wandering down the free association path

I live right next to the water. I didn't realize how strong and almost constant the wind would be. I grew up here, but what I didn't notice at 16, when I moved away, I notice at nearly 70 :-)

I am planting shrubs as a windbreak, but I'll probably be dead by the time they are high enough to be useful. I don't want to have larger shrubbery installed, because this is a tiny lot and the ground will have to be torn up sometime in the next five years when we get a sewer connection, hopefully.

What do you do to be comfortable? Just wrap up like a mummy? I do find this a problem when I want to work in the garden when it is hot.

[cbayer]

5. Layers! That way you can adjust easily.

It's often much colder on the water. I like the wind, in general, except for days like over this past weekend when it is screeching with gusts up to 50 knots!

The boat itself is very tight (hopefully) and we generally just turn on the propane burner that is under a heavy griddle plate. We have an ecofan that sits on there and heats the whole place up in about 15 minutes.

:hi:

[txlibdem]

6. Anyone understand passive versus active solar water heating systems?

I'm planning for a future system, our HOA will not allow solar hot water systems (Texas, go figure). This is for our "downsized" retirement home in a few years. I'll be making a DIY system due to the high cost of the "commercially available" systems so I can design it any way I want.

I've seen a number of youtube videos that show a grid of connected tubes with no set path from inlet at the bottom (the low end) to the outlet at the top (the high end). These videos show the water (or heat transfer fluid if a coil system) flowing from bottom to top by heat convection only. I'd always thought that there had to be a pump involved to push the water through the system, an active system, where the water travels through a single loop from inlet to output.

Here's an example of a passive system, showing the thermosiphon effect with red dye in the water:
http://www.youtube.com/watch?v=haXK_-rmzFY&feature=related
...takes about 2 minutes for the water to cycle from the cold inlet to the hot outlet (at 2:30 in the timeline).

Compare that to an active system which uses a water pump to circulate the heat transfer fluid:
http://www.youtube.com/watch?v=YBfOfcaOFWw&NR=1
... or: http://www.youtube.com/watch?v=D-ZpzDntsZ0&NR=1
...solar panel powers the water pump so any of these systems are "off the grid" as far as that goes.

My question is: which way is better? Which one heats the water fastest or gets it hottest?

PS, here in Dallas we get plenty of sun during the day even in the dead of winter and I'll have plenty of roof space to put the solar collectors so if one doesn't do the trick I can put up two, three, four, however many I'll need. Also, the water will be from a well, filtered first and then pumped into an underground cistern or a very well insulated water tower (I'm uncertain how much water pressure I can get with a solar powered pump, thus the tower). If I go the tower route, the solar water collectors will be bolted onto the tower with solar collectors/wind turbine atop the whole thing to power the water pumps and sensors (which will wirelessly report water temperature, water level in the tank, etc.)