Let's see. 14,600 gallons and a loss of 2 FC per day means 3.9 oz. Chlorine gas. I'm going to round that to 4, which is .25 Lbs.
T3 output is .56 Lbs per day. T15 is 1.45. (From
SWG Cell Sizing)
So at 100% t3 runs 10.7 hr. T15 will only need 4.1 hours.
.
Your pump draws about 2.139kw (
How To Calculate the Cost of Running A Pool Pump - INYOPools.com)
So... 10.7 hr @ 2.138 kw is 22.87 kwh for the T3. T15 is 8.77 kwh
So the savings is 14.1 kwh per day Call the season 6 months, or 180 days for simplicity. A total of 2,538 kwh
$600/2538 = .236
Check your electric bill and see how much you pay. If electricity is more than $23.6 per kwh, you'll save. If less, you won't. That number will change depending on how many days per year you actually run the pump and where the water is warm enough that the SWG is producing.
Most likely you CAN save money by switching out the motor to a two speed or variable speed. The SWG doesn't need full flow to work. Nor does your filter. You might also get substantial rebates from the power company that will reduce the expense.