Hot Water First Thing in the Morning

[GordMay]

Originally Posted by ColdFusion

Why has there been no mention of diverting the power from solar panels too ... So why not use solar panels to power the heating element too?

It's not necessary with solar cells, which can be open circuited.
Other than the very small return (you’ll need a minimum of 300 Watts to be of any appreciable use), there’s no reason you couldn’t switch the PV output to water heating, when not needed for charging.

[ColdFusion]

I appreciate that PV solar panels can be open circuited, I was just curious why they hadn't been mentioned, along with the wind gen, for heating water.

...OK, so maybe one or two solar panels and a wind gen might not be able to power a 300watt heating element directly (depending on sizes and weather) but most cruising boats have several hundred amp-hours of battery capacity. In the example you gave, 300watts at 12volts for 2 hours = 50amps. This could easily be put back into the batteries during the course of a day by solar and wind. A 12volt timer could be used to direct power to the heating element early each morning.

[Not Sure]

Originally Posted by ColdFusion

Why has there been no mention of diverting the power from solar panels too, as well as a wind gen, once the batteries are charged, or have I missed something? I appreciate they'll only work during the day but with enough insulation on the calorifier/hot water tank the water should still be hot in the morning. So why not use solar panels to power the heating element too?

Because as a rule solar panels don't generate the kind and amount of power necessary to efficiently power items such as hot water heater elements. That type of power is commonly found coming from an alternator or generator of some type, which is essentially what windmills are, i.e. a 'wind generator'.

[ColdFusion]

The OP has 520 watts of solar panels. Easily enough to power the 300 watt heating element, as per the post above.

[MarkJ]

Originally Posted by mvthankful

Water First Thing in the Morning

What else is there if I'm on the hook for a month? .

Deboarah,

One of the woonderful things about being at anchor for a month is there is nothing to do. Absolutly nothing!
You can laze in bed till 10am!
You can get up early and lay in the moring sun
You can get up late and swim off the back
You can rise with the sun and take the dinghy for a row.
You can sleep in then read a book...


....... theres so many things that you will discover you can or don't have to do.

Perhaps after a few days you will be able to change your whole morning rythm to one of relaxation.

You might find the dishes don't need to be done in the morning
A shower can be taken in the afternoon after swiming & before Sundowners.

You will find there is always hot water when you need it. But on a boat at anchor for a month you may never need it!

Mark

[lorenzo b]

I keep a water tank on the roof and let the sun heat it
paint it black
simple
works

[Cheechako]

yea, much of the world does it that way in warmer climes. Can probably buy a black plastic tank. How about a night blanket for insulation?
Here's a question: If I wanted to use a dark tank up top, the water would get too hot in the FL sun I'm sure. If I gravity feed the hot water to a faucet/mixing valve, will the cold pressure side push up into the tank ? or will the hot mix in properly?????

[lorenzo b]

You keep the water a perfect temperature by moving the boat to a perfect temperature.
That way you don't need a mixing valve.

[Pelagic]

My ER is large enough to hold a 20 gal electric HW tank.

Very fast recovery when the Gen is running and the ambient Temp in the ER keeps it warm all night. Safe and simple

[rusky]

We have a 10L instant heater which works either by heat exchange or by shore power. We use water saving shower nozzles so always plenty of hot water - in fact more than enough.