Solar panels
 

Larry wrote in news:Xns98109EBC3AAC7noonehomecom@
208.49.80.253:

Geoff Schultz wrote in
6:

What you need is a regulator that runs in diverter mode.

Naw.....What you need is a TOWEL to throw over the panel to keep it in the
shade at the dock. What's that cost? $1.39?....(c;


That's a good plan until you forget to do so or they blow off and you cook
your batteries. Hey, those batteries only cost you...oh a lot, lot more than
a controller. Send the bill to Larry! He told you that you don't need
one...that's your choice. You're the captain and pay the bills.

My water heater accepts 2 heating elements. Ones 120V and the other is 12V.
I know other people who have large resistors that they divert power to. Of
course they get hot, but it works.

-- eoff

Solar panels
 

"Glenn Ashmore" wrote

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com


I like the idea of diverting to the water heater, but most of us do not have
the option to add a second 12V element to our existing heaters.

One thought, would be to add a second heater in an external loop around the
water heater - something like the add-on heaters that are sold for cars in
lieu of a block heater. This site has the elements:

http://www.realgoods.com/renew/shop/...204/ts/1025078

But, if the solar panels put out, say 150 watts for 8 hours, what happens
when the water becomes too hot? With a small boat type water heater say 6 or
10 gal, this could happen quite quickly. Maybe then we throw the towel?

GBM

Solar panels
 

"GBM" wrote in
:


"Glenn Ashmore" wrote

I'm building a 45' cutter in strip/composite. Watch my progress (or
lack there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com


I like the idea of diverting to the water heater, but most of us do not
have the option to add a second 12V element to our existing heaters.

One thought, would be to add a second heater in an external loop around
the water heater - something like the add-on heaters that are sold for
cars in lieu of a block heater. This site has the elements:

http://www.realgoods.com/renew/shop/...1204/ts/102507
8

But, if the solar panels put out, say 150 watts for 8 hours, what
happens when the water becomes too hot? With a small boat type water
heater say 6 or 10 gal, this could happen quite quickly. Maybe then we
throw the towel?

GBM

You can get elements that have both 120V AC and 12V DC feeds. See
http://www.svhotwire.com/divert_loads.html

-- Geoff

Solar panels
 

I used diverted power from my solar regulator to run fans throughout the
boat.


"Geoff Schultz" wrote in message
6...
"GBM" wrote in
:


"Glenn Ashmore" wrote

I'm building a 45' cutter in strip/composite. Watch my progress (or
lack there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com


I like the idea of diverting to the water heater, but most of us do not
have the option to add a second 12V element to our existing heaters.

One thought, would be to add a second heater in an external loop around
the water heater - something like the add-on heaters that are sold for
cars in lieu of a block heater. This site has the elements:

http://www.realgoods.com/renew/shop/...1204/ts/102507
8

But, if the solar panels put out, say 150 watts for 8 hours, what
happens when the water becomes too hot? With a small boat type water
heater say 6 or 10 gal, this could happen quite quickly. Maybe then we
throw the towel?

GBM

You can get elements that have both 120V AC and 12V DC feeds. See
http://www.svhotwire.com/divert_loads.html

-- Geoff

Solar panels
 

"Gerald" wrote in
:

I used diverted power from my solar regulator to run fans throughout the
boat.

Just how many watts do your fans draw?

-- Geoff

Solar panels
 

At initial outfitting time, I had a separate 12V fan curcuit installed with
outlets throughout over bunks, heads, galley, eating area, chart table. I
installed HELLA fans primarilly because they would give a reasonable breeze
..... for a 12 V fan and have minimal current draw --- for an electric fan..
So when I wanted to operate on the cheap (electrically cheap) I could have
my breeze without eating the batteries. When I installed solar panels, I
discovered the controller I selected(morningstar) had the ability to divert
as the batteries topped off. Rather than do nothng with all the free
electrons, I hooked it up to the fan circuit.


"Geoff Schultz" wrote in message
6...
"Gerald" wrote in
:

I used diverted power from my solar regulator to run fans throughout the
boat.

Just how many watts do your fans draw?

-- Geoff

Solar panels
 

"Geoff Schultz" wrote

You can get elements that have both 120V AC and 12V DC feeds. See
http://www.svhotwire.com/divert_loads.html


That's great, but:
- how is the water temperature controlled? Temperature should not exceed
49C to prevent scalding (used to be 60C)
- Once water reaches maximum temperature, what do you do then?

Seems to be of limited value if engine is also used to heat water. Our hot
water gets up to about 45C after an hour of motoring at low speed. It is
self limiting because of engine thermostat.

GBM

Solar panels
 

"Geoff Schultz" wrote

You can get elements that have both 120V AC and 12V DC feeds. See
http://www.svhotwire.com/divert_loads.html


GBM wrote:
That's great, but:
- how is the water temperature controlled? Temperature should not
exceed
49C to prevent scalding (used to be 60C)
- Once water reaches maximum temperature, what do you do then?

Seems to be of limited value if engine is also used to heat water. Our
hot water gets up to about 45C after an hour of motoring at low speed.
It is self limiting because of engine thermostat.

Just curious because I'm not familiar that with them - do marine water
heaters have any sort of provision whereby you can insert a temperature
sensor, which can then be hooked up to a limiting circuit?

Solar panels
 

Sailaway wrote:
"Geoff Schultz" wrote

You can get elements that have both 120V AC and 12V DC feeds. See
http://www.svhotwire.com/divert_loads.html


GBM wrote:
That's great, but:
- how is the water temperature controlled? Temperature should not
exceed
49C to prevent scalding (used to be 60C)
- Once water reaches maximum temperature, what do you do then?

Seems to be of limited value if engine is also used to heat water. Our
hot water gets up to about 45C after an hour of motoring at low speed.
It is self limiting because of engine thermostat.

Just curious because I'm not familiar that with them - do marine water
heaters have any sort of provision whereby you can insert a temperature
sensor, which can then be hooked up to a limiting circuit?

Marine water heaters typically have two heating devices in one package.

The first is a standard 110V electrical heating element, connected thru
a thermostat mounted on the tank, more or less just like your standard
domestic water heater.

The second heating device is a coil of tubing inside the tank thru which
you can circulate your engine coolant. There is no thermostat in the
water heater for this circuit. But the engine has a thermostat which
controls the temperature of the engine coolant which is circulating in
it. This means that the hot water temperature will approach the engine
thermostat set temperature with prolonged engine run times.

bob

Solar panels
 

"GBM" wrote in news:5vvzg.53527$Uy1.48756
@read1.cgocable.net:


"Geoff Schultz" wrote

You can get elements that have both 120V AC and 12V DC feeds. See
http://www.svhotwire.com/divert_loads.html


That's great, but:
- how is the water temperature controlled? Temperature should not exceed
49C to prevent scalding (used to be 60C)
- Once water reaches maximum temperature, what do you do then?

Seems to be of limited value if engine is also used to heat water. Our hot
water gets up to about 45C after an hour of motoring at low speed. It is
self limiting because of engine thermostat.

GBM

I would say that if you have large enough panels to worry about this, then
you should use the controller in PWM mode. Solar panels don't require a
load. Wind generators do. I use 1 controller for both.

In real life I rarely have problems with the batteries being completely
charged while cruising. I only have 2 panels that output 68W *peak* each.
The only time that I have the luxary of fully charged batteries is when it's
been blowing 15-20+ for a day or two and my wind generator is cranking.

Remember, this is a boat and there's no one-size-fits-all solution. You can
always buy a resistive load such as the one at
http://www.svhotwire.com/divert_loads.html, but then you have to do something
with all of that heat. I can always find something to do with my "extra"
power such as making more water and washing down something on the boat.
Don't go crazy solving a problem that probably doesn't exist in real world.

-- Geoff