Solar controllers

Does anyone use the Bluesky 2000E controller? Supposedly MPPT technology improves the draw from the solar panel(s). I wonder if this is real or if it's hype.

I'm thinking about one 110 Mitsubishi panel with the Bluesky controller and two Trojan 105 batteries. I just want the lights and the furnace fan to work as needed. Not much more than that.

[Bill]

Tonopah -

I am an electrical engineer, and I also went through a time when I was really interested in solar power. I investigated MPPT from an engineering perspective (not "does it work?", but "how does it work and why does it work?") If I recall correctly, MPPT is real and it works, and it can get maybe 15% more power from your panels. But this isn't worthwhile on small solar installations because MPPT is expensive. For example, if you have a 100 watt system, it may produce 15 extra watts - but it would be cheaper to buy an extra 15-watt panel than to buy MPPT capablity for your controller. On the other hand, if you have a 1000 watt system, the MPPT (which produces an extra 150 watts) is less expensive than an extra 150-watt panel. Does that make sense?

So for TM use, the answer is probably no, don't buy MPPT. Get a good PWM controller and be done with it.

There is some real good information available on the Arizona Wind-Sun website. They sell both kinds of controllers, so they are reasonably unbiased. Try

http://www.windsun.com/ChargeControls/ChargeCont.htm and
http://www.windsun.com/ChargeControls/MPPT.htm .

Bill

[Caver]

Originally Posted by Tonopah

Does anyone use the Bluesky 2000E controller? Supposedly MPPT technology improves the draw from the solar panel(s). I wonder if this is real or if it's hype.

I'm thinking about one 110 Mitsubishi panel with the Bluesky controller and two Trojan 105 batteries. I just want the lights and the furnace fan to work as needed. Not much more than that.

Tonopah, I've been using a BZ Product MPPT controller but I'm disappointed with the performance and plan to purchase the Morningstar MPPT controller that should be available in March. You can see my installation on the solar section. If you go with the Mitsubishi solar panels they produce the maximum power at a voltage of 17.1 volts. To get the maximum charge current out of these panels you need an MPPT controller that can accept the higher voltage. The Bluesky 2000E can take 30 volts and the Mitsubishi has an open circuit voltage of 21.2 volts so that would be OK.

The Morningstar SunSaver MPPT controller is only rated for 200 watts but with it's 75 volt rating will allow me to operate my two 90 watt panels in series to reduce loss in the wiring. I'll probably try both parallel and series wiring and figure out which is the best. If one panel is shaded then the parallel wiring would probably be best. See: http://solar-guppy.com/downloads/SS-MPPT_data_sheet.pdf

Since I already have a Trimetric meter I just need an efficient charge controller without meters. I'll mount the charge controller out of site.

Good luck with your installation. Ray

Bill and Ray,
Thank you for your replies. I understand much better now. By the way, I no longer have the TM and moved to a different trailer for several reasons but I continue to read this forum because the information available and the community itself is just the best. I will continue to contribute to the maintenance of this forum and remain a member.