A little help calculating savings please?

Neemer

Gold Supporter
Oct 10, 2017
178
Mid-Atlantic
I'm thinking of upgrading my SWCG from T-3 to T-15. I ran into some hefty electric bills last summer and would like to know how long it would take for electric savings to pay for the upgrade. Anyone?
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,533
Pleasanton, CA
I'm thinking of upgrading my SWCG from T-3 to T-15. I ran into some hefty electric bills last summer and would like to know how long it would take for electric savings to pay for the upgrade. Anyone?
Are you talking about the pump run time savings? The cell itself won't save anything. But because the T-15 produces more chlorine, you can run the pump less. But if you just change the % setting to a lower value for the T-15, there are no savings.

The T-3 produces about 64% less chlorine than the T-15 so if the % setting is the same, the T-15 run time would be 64% less time. The Superpump 1.5 HP uses about 1500 watts. To determine cost savings, I would need to know your current run time and electricity costs.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
22,052
San Dimas, CA (LA County)
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.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
22,052
San Dimas, CA (LA County)

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,533
Pleasanton, CA
Their method simply uses the motor maximum power rating which is at full load. In most cases, a pump motor will use much less power than the rating. In general, it isn't a very good method of determining actual power usage. The number I quoted is from the Energy Star data set (i.e. measured data).

Energy Star Database
 
Last edited:

Neemer

Gold Supporter
Oct 10, 2017
178
Mid-Atlantic
I haven’t given much thought to a VSP pump, but that’s a good point. I’ll look into it. I have a season that’s about 5 months long here and at summer’s peak, I was running the pump 14 hr/day.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,533
Pleasanton, CA
14 hrs a day is probably way more than what you really need. Most pools can get away with 2-4 hrs of run time. Unless of course you have run a heater or need the extra run time for the SWG.