Hybrid Car – More Fun with Less Gas

Problems combining wind and solar

register ::  Login Password  :: Lost Password?
Posted by Solar Flare on July 30, 2005, 7:05 pm
Has anyone had problems combining a windmill controller and a PV controller?

Is the best place to parallel at the battery?

Is there a special technique to avoid conflict or misfiring solid state
devices by interaction?

Has anybody done this?

Posted by wmbjk on July 30, 2005, 7:44 pm

On ours (2000W PV, 1300W wind), the solar controller
(mercury-contactor type) cuts out first. The wind controller
(diversion type) is set about a half-volt higher. If it was set up the
other way around, then the wind controller would be diverting the
excess from both sources.

In good winds, things work pretty smoothly. Once the solar controller
disconnects the PV, and if wind power is sufficient to raise the
voltage, then the wind controller diverts excess wind power to
maintain the preset voltage. In lighter winds there's some occasional
conflict, but it doesn't cause any trouble. At least not with the
contactor-type controller (10 years old).

All of our supplies come together on a bus bar inside a junction box,
which also has a master pull-out fuse holder between the bus bar and
the batteries.


Posted by nicksanspam on July 30, 2005, 8:14 pm

Why waste wind power?


Posted by Anthony Matonak on July 30, 2005, 9:16 pm
 nicksanspam@ece.villanova.edu wrote:

Why waste solar PV power? What would you suggest that he do with
the power once his batteries are full?


Posted by wmbjk on July 31, 2005, 12:58 am
 On 30 Jul 2005 16:14:04 -0400, nicksanspam@ece.villanova.edu wrote:

We try hard not to waste capacity. When the batteries are full (or we
know they will eventually be full at the current rate of
charge/consumption, which might be at 8am), then that's the perfect
time to do laundry, baking, run AC, etc. Nevertheless, every system
*has* to have a failsafe way of disconnecting or diverting excess when
there's either no place to put it, or there's nobody home to redirect
it. If your next question is "why not have it automatically redirected
to do useful work", then my answer is that the only practical thing
left at our place is water heating. For the few days per year that the
solar water-heating system doesn't fill that need, but that there
might be excess energy available, it's really not worth the trouble.
Besides, the controllers would be still be needed if the water got too

Perhaps you haven't noticed, but I've been um, outspoken, on this
subject whenever the Ghinius has tried to convince people that making
good use of excess capacity is somehow an indication of bad design.


This Thread
Bookmark this thread:
  • Subject
  • Author
  • Date
please rate this thread