
Power Consumption: Cycle Stop Valve vs. Large Hydro Tank
Using an actual flow graph from a city with 150 connections we have cut by two thirds
for a city of 50 connections. This graph is during winter so we have added in the
irrigation demand as calculated by the engineer. Flow rates for an average day are as
follows.
 Domestic Use  
 Flow Rate  Hours/Day  Gallons 
Minimum  2 GPM  5  600 
Average  14 GPM  18  11,760 
Peak  36 GPM  1  2,160

Irrigation used same time as average domestic for 6 months per year.
  300 GPM  4  72,000

Total gallons per day in summer 6 months  86,520 
Total gallons per day in winter 6 months  14,520 
Large Hydro Tank
A 350 GPM pump model 275H307 drawing 32.46 HP and a 40 GPM pump model
33GS30 drawing 3 HP are used. A pressure tank with 1900 gallons of draw down would
give 8 cycles per day if the irrigation were set up for 314 GPM without cycling. A pump
run time of 4.62 hours at 35.46 HP during summer months.
4.62 x 35.46 = 163.83 HP
1 HP = .746 Kwh
163.83 x .746 = 122.22 Kwh
Estimating 5.5 cents a Kwh x 122.22 = $6.72 per day or $1,229.76 per half year.
Using a 350 GPM pump model 275H307 and a 40 GPM pump model 33GS30 with a
pressure tank with 1900 gallons of draw down that would be 8 cycles per day and a pump
run time of 37 minutes at 35.46 HP during winter months.
.62 hrs x 35.46 = 21.99 HP
1 HP = .746 Kwh
21.99 x .746 = 16.40 Kwh
Estimating 5.5 cents a Kwh x 16.40 = $.90 per day or $164.70 per half year.
Total year electric bill $1,229.76 + $164.70 = $1,394.46
Cycle Stop Valves
Compare to a 3 HP pump model 33GS30 in one well and a 30 HP model 7WAHC3 in
another well. Both pumps have a Cycle Stop Valve and use a tank with 25 gallon draw
down. The 3 HP is shut off anytime the flow exceeds 40 GPM and the 30 HP comes on
to handle the load. For five hours during minimum flow the 3 HP pump runs 8 minutes
and is off 12 minutes making a total of 15 cycles per day. Anytime the flow is above 5
GPM the 3 HP runs continuously. There are two times during the day when irrigation is
permitted so the 30 HP pump will cycle twice per day.
 Domestic Use  
 Flow Rate  Hours/Day  Pumping Hours  HP Load  Kwh/day 
Min  2 GPM  5  3.3  2.02  4.97 
Average  14 GPM  18  14  2.56  26.74 
Peak  36 GPM  1  1  3.21  2.39

Irrigation used same time as average domestic 
Max  300+14=314 GPM  4   29.5  88.03

Total Kwh per day in summer 6 months  122.13 Kwh 
Total Kwh per day in winter 6 months  34.10 Kwh 
Summer estimating 5.5 cents a Kwh x 122.13 = $6.72 per day or $1,229.76 per year.
Winter estimating 5.5 cents a Kwh x 34.10 = $1.87 per day or $342.21 per year.
Total year electric bill $1,229.76 + $342.21 = $1,571.97
Conclusion:
Using the two pump system with Cycle Stop Valves and an 86 Gallon tank the power
consumption is $1,571.97 per year.
Using the two pump system with a 7,200 gallon pressure tank the power consumption is
$1,394.76 per year.
$0.49 difference per day or
$1,571.97  $1,394.76 = $177.21 difference per year.
At 5.5 cents a Kwh it will cost $177.21 more per year to use Cycle Stop Valves on this
system than a large Hydro Tank. The 7,200 gallon hydro tanks cost about $30,000.00
more than the 86 gallon tank and the Cycle Stop Valves.
$30,000.00 divided by $177.21 = 169 years to save enough
energy to pay for the large Hydro Tanks. (Not counting
interest, maintenance, etc..)
