Powering LEDs in a container farm
Ok so you are talking about 12x &quot;100W&quot; active loads in series at 240V?
First of all if you turn some of them off, the extra voltage has to get dropped by the remaining ones, which means they'll be seeing not just 27V but 30 or 40 or 50V or even 210V, at the same current. Where will that heat go?
Secondly, while putting them in series is great for thing like bulbs, PWM LED controllers produce a constant power output and high efficiency. That means input is also constant power, which means negative impedance on the input (i.e. if you feed it with a higher voltage, it will pull less current). Negative impedance can make things unstable, so you'll have to work that out. However simply adding positive resistance will ruin your efficiency.
Have you considered the old fashioned solution, a transformer? Reduce the 240V to, say, 30V-36V, which your controllers can hopefully tolerate and leave breathing room for the ripple. 240V x 10 Amps will get you in the ideal case 30V x 80 amps = 2400W You'll want to have plenty of margin there, and might want a transformer even bigger than that, if load is switched suddenly / has inrush. You can get you into pretty good trouble, i.e. produce big voltage spike, trip breakers etc, switching loads suddenly in decent sized transformers.
On the plus side, you won't have line voltages on every part of the system.