Solar powered electric water heating using spare solar capacity?

[puiumeu]

Hi all,

As our truck is air cooled we will have no residual hot water for heating and washing. I would like to configure 'the system' to channel solar power to a immersion heater one the charging circuits are complete to provide a soak heating.

Does anyone have any experience or similar setups. We are still to purchase our solution so are flexible but as a starter we were aiming for a 600-1000 watt solar system, with diesil/electric heating and lithium batteries with 24v.

Thanks in advance....

Al.

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[john61ct]

See solar/wind combined controllers.

Load shedding is required for wind and hydro.

Can also be done with voltage sensing relays, or SoC meters even better.

 

[john61ct]

See also eutectic holding plates for marine refrigerators.

Also ice making.

 

[dwh]

Small wind turbines require a "dump load" to be hooked up to keep a load on the turbine so it doesn't freewheel and overspeed after the batteries are full.

Dump loads are not required for solar.

The Midnite Solar Classic charge controller can do solar or wind, and has a dump load relay. You could use that to switch on an electric heating element in the hot water tank when the batteries are full.

 

[msiminoff]

Like you I wanted to use my surplus solar power to heat my water. I couldn't find any suitable solutions off the shelf so I built my own dual voltage (12Vdc & 110Vac) immersion heater that fits into the drain/anode port on my Suburban 6-gallon water heater tank. The 12V heater is 150W and is powered by the diversion load output of my MorningStar solar charge controller (can also be switched on manually). The 110V heater is 500W and can be powered by shore power, generator, or the inverter. Each of the heating elements has its own thermostat.
Below are some pics. Let me know if you have any questions.
Cheers,
-Mark

 

[javajoe79]

Beautiful work!! ^^^

As to the OP. If you are planning on diesel heat, you can easily have that system heat water too. But I guess if you plan on that much solar power, you should have plenty of excess power.

 

[Joe917]

We have an Isotemp Spa water heater with calorifier(no use with air cooled engine) and a 12 volt immersion heater we chose the 750 watt element (instead of 1500 watt) specifically for running off our excess solar. It works very well.