Todays video is from our forum member B. Kelly and he is testing 2 DM Solar 145 watt panels today in 93-99 degree heat. They are wired in series to get 24 volts nominal and the battery bank is a simple DC27 marine 12 volt battery. Maximum watts that he caught while checking on it was 210 watts at 93 degrees at 10:25 am and 174-179 watts at 12:05 pm at 98-99 degrees. Not bad for a HOT day.
The charge controller is a Midnite Solar Classic 150 MPPT. The wiring is 15' of 10AWG PV wire to simulate a real wire run.
Keep in mind the controller was out in the heat also so output would be lowered as well as you not supposed to do this. The controller needs to be in doors and are tested at 25'C which is 77'F.. the controller internals were at 53'C (per the meter) which is way above the 40'C derating.
Everything You Need to Produce Your Own Solar Energy.....Check Out New World Solar Power!
Showing posts with label MPPT. Show all posts
Showing posts with label MPPT. Show all posts
Friday, July 20, 2012
Thursday, February 23, 2012
Are MPPT Charge Controllers Really Worth the Cost?
From guest blogger Dale Marshall......
I would say that MPPT charge controllers are really worth the cost. The overall gain of harvesting more power with MPPT will make up for extra panels you would have to buy to make up for the losses. So far my gain has been around an average of 40%. I would have have had to spend twice the money to make up for those losses in extra harvesting power.
Once you get past the 250 watt mark MPPT is your best friend when it comes to power harvesting. I will give you an example. I have been doing some testing.
I used just 1 of my 125 watt panels. I used a regular PWM controller full sun, I was lucky to pull 4.3 amps. Voltage of course stayed at battery level. Max power at top charge charge was 14.4 volt at 4.27 amps. Rounded off math say 61.5 Watts, half of the panels rated output.
Now with MPPT I have a Solid 18 volts even coming in at 6.1 amps. MPPT Boost amps because it tracks voltage at VMP. But because of the way MPPT works I am getting a 14.4 volt charge at 7.5 amps at 109 watts. That's a gain of 3+ amps going into your battery bank. And it would take another 125 watt panel to make up for those losses. This is where MPPT shines like a star.
I hope this helps, take the time and weigh the cost. I do use a MPPT charge controller it is a Rouge MPT-3024. But there is other models out there. You just have to be careful on which ones to buy.
Everything You Need to Produce Your Own Solar Energy.....Check Out New World Solar Power!
I would say that MPPT charge controllers are really worth the cost. The overall gain of harvesting more power with MPPT will make up for extra panels you would have to buy to make up for the losses. So far my gain has been around an average of 40%. I would have have had to spend twice the money to make up for those losses in extra harvesting power.
Once you get past the 250 watt mark MPPT is your best friend when it comes to power harvesting. I will give you an example. I have been doing some testing.
I used just 1 of my 125 watt panels. I used a regular PWM controller full sun, I was lucky to pull 4.3 amps. Voltage of course stayed at battery level. Max power at top charge charge was 14.4 volt at 4.27 amps. Rounded off math say 61.5 Watts, half of the panels rated output.
Now with MPPT I have a Solid 18 volts even coming in at 6.1 amps. MPPT Boost amps because it tracks voltage at VMP. But because of the way MPPT works I am getting a 14.4 volt charge at 7.5 amps at 109 watts. That's a gain of 3+ amps going into your battery bank. And it would take another 125 watt panel to make up for those losses. This is where MPPT shines like a star.
I hope this helps, take the time and weigh the cost. I do use a MPPT charge controller it is a Rouge MPT-3024. But there is other models out there. You just have to be careful on which ones to buy.
Everything You Need to Produce Your Own Solar Energy.....Check Out New World Solar Power!
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