EcoRenovator - View Single Post - Alternative Energy Water Heater in Series?

Xringer · 10-28-10, 06:00 PM

A 3500 watt heater / 220 volts = 16 amps.. Means the heating element will warm up
and drift to a resistance of about 13.75 ohms..

12vdc / 13.75 = 0.9 amps.. Or, about 10.5 watts of heating.. Not good enough..

Now, if you had about 600watts of PV, and wanted to deliver it into a load
resistance of 14 ohms, you could use about 6.5 amps at 91 volts...

Anyways, you need to match your load to your PV power source..

~~~

If you have one of these, (or a few of these wired in parallel),
Micromorph Tandem Thin Film Solar Module 130w, Micromorph Tandem Thin Film Solar Panel 130w

Spec:
* Pmax: 130W
* Vmp: 101V

101 volts at the max power point (doing 1.3A) means you need a load
resistance of 77.7 ohms, if you wanted that 130w..

Just remember, any time you start using DC over 48 volts, you can get shocked.
Just one mistake with a 101v panel could KILL you..

Holding your VOM lead tips with your thumbs and forefingers
to measure the panel output, will (even in weak sunshine) stop your heart..

On the plus side, (pun intended) you can use smaller diameter wire at these voltages..
And not suffer big line losses.. That's why I'm using 70volts these days..

10-28-10, 06:00 PM	#10
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	A 3500 watt heater / 220 volts = 16 amps.. Means the heating element will warm up and drift to a resistance of about 13.75 ohms.. 12vdc / 13.75 = 0.9 amps.. Or, about 10.5 watts of heating.. Not good enough.. Now, if you had about 600watts of PV, and wanted to deliver it into a load resistance of 14 ohms, you could use about 6.5 amps at 91 volts... Anyways, you need to match your load to your PV power source.. ~~~ If you have one of these, (or a few of these wired in parallel), Micromorph Tandem Thin Film Solar Module 130w, Micromorph Tandem Thin Film Solar Panel 130w Spec: * Pmax: 130W * Vmp: 101V 101 volts at the max power point (doing 1.3A) means you need a load resistance of 77.7 ohms, if you wanted that 130w.. Just remember, any time you start using DC over 48 volts, you can get shocked. Just one mistake with a 101v panel could KILL you.. Holding your VOM lead tips with your thumbs and forefingers to measure the panel output, will (even in weak sunshine) stop your heart.. On the plus side, (pun intended) you can use smaller diameter wire at these voltages.. And not suffer big line losses.. That's why I'm using 70volts these days..