Controller questions

[Dutch John]

Got a 10 feet Piggott style running. 24 Volt, Tristar TS-60 controller, 325 Ah forkliftpack, feeding our living room. It's a hobby, we are connected to the grid. I want to add 800 Wp solar panels, also feeding the battery pack. But I am stuck about what to take for additional power control.

I could take another TS-60 and put it in solar mode. On the Morningstar site I can't find out if both of them can, or need to be connected in order to work synchronized. Do they need to be connected? Or could I set the equalize settings in manual mode and set the PWM absorption voltage of the solar controller one step lower? Thus the controllers do not interfere and solar shuts off before the wind controller starts dumping?

I could also take a controller that dumps all excess power to the grid. Anyone knowing an affordable one? Does such a thing even exsist?

Regards, DJ

[ghurd]

If someone knows how they should speak up!

I do not see if they can be connected together and behave synchronously.

Do you have a use for the extra power?
800W of solar will be a big leap in daily production, and the battery will not hold it all most days.
Might be worth considering a water preheater sized to nearly max out the 1st TS-60...
Add a second TS-60 (with a 2nd load) set a bit higher to take up any slack?

It would be worth considering adding a bit more battery capacity.
Fuzzy brain at the moment.
G-

[dave ames]

never saw any kind of interconnect/sync, there are some interconnect abilities for system monitoring thru a meter hub using a remote display meter. also some more advanced stuff available with the morningstar pc based software..hope to have a chance to try that some day, some neat options including monitoring your system on line.

sounds like a "plan" to have that dump load (diversion mode charge control) set just a tad higher than the solar controller. we really don't see many reports of folks having problems with controllers "playing well" together..

with that 2nd TS-60 in solar charge control and 800wp of pv we have a chance of maybe 200Ahs of production a day in the summer?  as ghurd mentioned we need battery capacity to put it in.

some of the guys here are running some nice grid tie inverters with an interconnect agreement with their utility. something like the GTFX2524 or the GVFX3524. might end up costing less than adding batteries? could even think of going with a separate gird tie only inverter..something like the sunnyboy sb700. lots of options. gotta start working the numbers to see what works for your case.

hope others may have more to offer.
cheers, dave

[ghurd]

sounds like a "plan" to have that dump load (diversion mode charge control) set just a tad higher than the solar controller. hope others may have more to offer.

That would work, and be the simplest.

When the controller set up for solar sees the battery reach regulation voltage, which will not take a long time with that battery, the 800W of solar will not be 'making' any power.
Seems a shame to have 800W of solar pretty much not doing much.

Send the excess to a water heater sounds pretty good to me.  It would add some cost and a bit of complexity.
For an idea of the power that would be 'not made', the lower element in a typical electric water heater is around 1600W?  Seems a shame to have nearly half that much power available to be made, but not made or used.

Usually I am fairly anti water heater, but this system will have enough spare power to make it feasible, IMHO.
G-

[Dutch John]

I see. I'll need to think this over. It's a shame to shut off the panels because of a battery pack too small. Making hot water is not really an option, because I already have a solar heater. Want to buy the panels anyway, because it's subsidised. Panels, controller and mounting system will cost me less than 1 euro/Wp. Guess it will leave me some money to enlarge the battery pack.

I now use a salvaged manual three way switch between grid, wind system and living room. If I could find a special double relay, it could switch automatically and more parts of our home to wind/solar power when the controller starts dumping for a longer time. This relay commanded by the dump load temperature? And automatically switching back to grid power when the battery voltage gets too low. Just another possibility. 

Dave,

That are nice grid tie inverters, just what I need. Unfortunately my wallet does not allow them to join me    Adding battery capacity is affordable, because I can lay hands on cheap outdated forklift batteries. Although waking them old batteries up is another long winded story....

Regards,
DJ

[ghurd]

"1 euro/Wp"?
Might be worth looking into a MPPT controller with 800W. 
FM-80 can give quite a power boost, and with the cost of solar in places that use Euros, it may be a very wise investment.  Under the right conditions (often when it is needed most), it could gain about 240W.

I would be a little concerned about automatically switching between inverter and grid with relays.
I believe it would be safer to connect a grid powered battery charger to automatically come on when the battery got low.  It would be easier.  It would not be very efficient.
G-

[Dutch John]

An MPPT controller will add to the 1 euro/Wp total. Besides that, I come to like the fact to have two identical controllers. If one fries, the other can do the most profitable job.

The relays I would use are the same type used in automatic backup generator sets. Twin relays with a mechanical seesaw rod between them. Without that connection there is the danger that grid and inverter get connected when one of the relays sticks.

Regards,
DJ