diversion load controller

woodster · Dec 28, 2014

i have a question here not an answer is your hot water heater dual voltage or is there a controller to make the solar power 110 vac if solar is only 12vdc i am not sure it would do much good

Chief RA · Dec 28, 2014

I havn't seen the term "diversion controller" used yet. All controllers could be so described as once all batterys are at full charge any DC load will draw from the panels/controller. I am only aware of using a dedicated inverter to apply excess solar amps to heat a 115AC unit. You would be able to do it in that manner. Chief

Ron20324 · Dec 28, 2014

Try : http://svhotwire.com/divert-loads/

Chief RA · Dec 28, 2014

Thanks Ron, the term is Divert Load not Controller though. Havn't studied wind much since I regard it as a poor power choice. Batteries inherently act as spike inhibitors as well with their DC filtering concept. That method still does not address the fact that his heater uses 115AC though. Chief

Bill Roosa · Dec 28, 2014

diversion controllers are only needed for wind/hydro generators. solar is fine just acting like a battery. You need a way to keep the wind generator loaded at all times. When the batteries can provide the load by needing a charge then fine but after they are charged the wind generator has no load and over speeds in the higher wind ranges. With no place for the energy harvested by the blades to go it goes into internal currents in the generator windings!!!! Then bad things start to happen. Sooooo you need a load that you can ALWAYS count on to be able to absorb the full output of the generator AND do if indefinitely (indefinitely is kinda wrong as the wind does die down, your worst case scenario of high wind for long durations will = indefinitely) . An air cooled pure resistance (toaster) fills that bill. You can use the excess output to heat water but at some point you need to ask yourself what happens when the water gets to 212F? Also will the prevailing weather (wind speed and duration) even cause this to be a problem? (think larger tank so more water to heat)
So you can indeed heat water with excess generation capacity but you need to address the following:
how will I control the charging of the batteries with both solar and wind?
If I use an 12 volt water heating element (check solar home and RV sites) will I ever get into a situation where I will be boiling water? how do I dump load from the wind generator at those times.
I'm thinking a load diverter for the12 volt water heater element AND a second thermostatically controlled load dump that turns on the "standard" air cooled pure resistance (toaster)
It all comes down to how much energy are you collecting and how much the hot water tank can absorb before it starts boiling. clearly a 1000 gallon hot water tank is not going to present a problem for the typical wind generator. 6 gallons ..... you need to do the math.
max output of the wind generator and tank size will determine how long the wind can blow (assumes the batteries are fully charged and you are dumping load) before you get to 212 F in the tank
An enterprising person could rig up a single load diverter (batteries charged and load dump begins) that just has a thermo switch (already in the AC water heating circuit) to direct the current to the correct load dump device. The actual hard part is how do you mount an additional shore power water heating element (keep looking at the RV sites they have 120/12 volt duel voltage heating elements) and then control it (and the 12 volt load dump) with a single thermo switch. It is an "I ran out of plumbing holes in the tank" problem.

Chief RA · Dec 28, 2014

gettinthere should read Rons submittal as it addresses the purchase of an appropriate element if he only has the 115AC element. Chief

Chief RA · Dec 28, 2014

Good info Ron & Bill, you guys are in an area I am not well versed in, so will learn from you guys. Thanks, Chief