I use that same type of water heater on my 60V array which also has my MPPT charge controller. At that voltage, it is 1/4 power. I run off a custom power point controller which only diverts excess energy, 1W to 400W. This system looks at array voltage and when that voltage exceeds the natural power point only enough power is diverted to bring the voltage back to power point. This is the ideal cheap method for efficient off grid water heating and it is quite cheap to build. I have three tanks. Two are in series and both can come on when there is enough power. One is only for laundry and the washer uses hot water for all cycles. The clothes come out steaming. No extra panels were needed to get this extra power to heat water. Every successful PV system has excess power. No charge controller, battery or inverter capacity is needed making this the most cost effective method for water heating.
Two of the busted panels wired in series would be 6.4 ohms, which would provide more power than 24v from the battery. I have 3/320w panels wired in series directly to a 240v 4500w lower element in a 50 USG heater. Has been working great for 6 years. Sun is out water is heating.
What if you just applied wattage to a lower element without a thermostat? Keep the wattage fairly low and in a worse case scenario the relief valve would release excess heat or pressure, but would probably never happen if you were to keep the wattage low.
I use that same type of water heater on my 60V array which also has my MPPT charge controller. At that voltage, it is 1/4 power. I run off a custom power point controller which only diverts excess energy, 1W to 400W. This system looks at array voltage and when that voltage exceeds the natural power point only enough power is diverted to bring the voltage back to power point. This is the ideal cheap method for efficient off grid water heating and it is quite cheap to build. I have three tanks. Two are in series and both can come on when there is enough power. One is only for laundry and the washer uses hot water for all cycles. The clothes come out steaming. No extra panels were needed to get this extra power to heat water. Every successful PV system has excess power. No charge controller, battery or inverter capacity is needed making this the most cost effective method for water heating.
Good work!!!!! Good thinking! Keep it up!
Two of the busted panels wired in series would be 6.4 ohms, which would provide more power than 24v from the battery. I have 3/320w panels wired in series directly to a 240v 4500w lower element in a 50 USG heater. Has been working great for 6 years. Sun is out water is heating.
Remember that you get DC from the solar panels, and there will be sparking in the thermostat in the water heater as it is made for AC.
Could lead to a 🔥 😮
What if you just applied wattage to a lower element without a thermostat? Keep the wattage fairly low and in a worse case scenario the relief valve would release excess heat or pressure, but would probably never happen if you were to keep the wattage low.
Split up the load to multiple resistors
Great experiment
This could be good for keeping a cistern from freezing in the Winter. Maybe i will try this.
You could at least pour some clean water into the bucket