APS load controller

Frequently Asked Questions:
What is a load controller?
A load controller is an outdoor mounted computer that measures your power usage and controls peak demand by load shedding. Loads (A/C, Dryer, Water Heater), are not allowed to run at the same time which causes high demand charges.
Load controllers work in conjunction with electrical rates that have a demand charge. Since the demand charge on most energy bills can be as much as the consumption, controlling demand significantly reduces your electric bill. Think of it as a cruise control for your APS bill. You set it where you want it. The lower you set it, the more you save.

What is Demand?
Demand is the highest usage of electrical power during a given period. For APS residential users, this time period is one hour. You are charged for the highest demand reached during any sixty minute period. Demand is measured in time and in amount. The typical measurement used 1000 watts or 1KW. The current charge is $11.85 per KW. Simple math dictates a demand of 10KW would equate to $118.50 for one hour usage of power! Cutting this in half (easy to accomplish with a load controller), would reduce your bill by almost $60 per month.

Examples of KW loads in a residence:

Electric Clothes Dryer: 6KW
Electric Water Heater: 4.5KW
3 Ton Heat Pump: 5.6KW (1.6 KW/ton)
5 Ton Heat Pump: 8KW (15 year old heat pump: 11KW)
Range: 2.5KW per burner
Oven: 5KW
Pool pump (per pump) 2KW
Electric Spa Heater: 10-20KW

Since the meter measures an average of power usage, adding the KW values above would not be how the meter reads your usage. Example: Let's say a 5 ton heat pump consuming 8KW runs 10 minutes on, 10 minutes off. The average demand that the meter (and the load controller), "sees and reads" is a 4KW load. A water heater uses 4.5KW but can run for a full 60 minutes (the APS demand time window), after a load of clothes and therefore would contribute 4.5KW to the months bill. Our APS load controller has a built-in timer to keep the water heater from running during on peak hours.

What Does a Load Controller Connect To?
On most all electric homes, the load controller is connected to the heat pump(s), the clothes dryer heating element (so the tumbler keeps spinning), and the electric hot water heater. Years of experience has shown that pools should run at night during off peak periods and ranges/ovens do not need to be connected. Since the microprocessor in the load controller is aware of all loads being used, (not just the ones connected to it), when the demand needs to be controlled the load controller will shed loads to allow the use of the range or oven. If set correctly and programmed you won't even know the load controller is working until you open your Arizona Public Service bill each month and see the reductions.

What is a KVAR box?
The unit marketed as "KVAR" is marketed as a "power conditioner" and claims to make appliances with motors run more efficiently. This is true on 3 phase commercial applications but has little to no savings on residential single phase applications. There is a warning to consumers on the Arizona Public Service Company web site who, along with the US Environmental Protection Agency (EPA), that installing a KVAR power conditioner is of little value. Click here for more information before you have one installed.

I Have Natural Gas, Can a Load Controller Help?
Absolutely. Your savings won't be as high as an all electric home but you will be able to lower your demand more because of less appliances using 220v to operate. Lower demands means lower bills. The recently introduced APS rate is one of the lowest in the country and compatible with our load controllers. We know, we have been doing this since 1981 and have helped hundreds of APS customers lower their monthly bills.

Do Load Controllers Need To Be Maintained?
No, once installed it is very rare to have a problem with them and they do not require maintenance or check ups.

How does a load controller work?

Quite simply, a load controller is like a cruise control for your electric system. You set the level of savings, you reap the benefits. A load controller constantly measures the usage of power in your home with sensors (current transformers), on your main power line and directs power to a pre-set priority which lowers your demand and thus your bill. As the demand level rises towards your set point (demand limit), the load controller "sheds" (shuts off), lower priority appliances to maintain a user pre-set demand level for several minutes. Cutting demand by 50% is very typical and at $11.85/KW, this adds up quickly in your favor!

Current Transformers (seen in photo at left on main buss bars), measure your power usage the same as your APS electric meter and gives the computer in the load controller the information needed to make decsions on control strategy.

Does Arizona Public Service Co. Have Incentives For Load Controllers?
Currently there are no credits or incentives for this device.   However, during the rapid growth of the mid 80's, Arizona Public Service initiated a program where either a credit was issued or a zero interest finance plan was available for the installation of a load controller. Thousands of Valley residents found themselves with lower bills after using a load controller. Once the Palo Verde Nuclear Plant was completed there was sufficient energy to meet peak demand so all incentive programs for load controllers were ended.
The best rate to use a load controller with is the APS "Combined Advantage Rate (click here for details)

The rates below from the APS web site 7/1/11:
Winter (November - April billing cycles) Cents per kWh
On-peak kWh used (Mon. - Fri., noon - 7 p.m.) $0.05815
Off-peak kWh used (Mon. - Fri., 7 p.m.- noon and all day Sat. & Sun., 6 holidays) $0.04273
Cost per kW Demand charge $9.203

Summer ( May - October billing cycles) Cents per kWh
On-peak kWh used (Mon. - Fri., noon - 7 p.m.) $0.08845
Off-peak kWh used (Mon. - Fri., 7 p.m.- noon and all day Sat. & Sun., 6 holidays) $0.04363
   Cost per kW Demand charge $13.404

Can a Load Controller Help Me?
D. Marrzella in Scottsdale has a four bedroom ranch with a pool and has saved $16,000 in twelve years on her APS bill! Although this figure is on the high end of most of our customers, you can expect at least a 30% drop in your monthly bill with little or no change in lifestyle, many save as much as 40%. Remember, you have control of the load controller, you set where you want it to be.

JW Flint in Scottsdale writes:
"I purchased a home in Scottsdale over three years ago; 3500 Sq ft with two 5-ton A/C units, two water heaters, pool, etc. A beautiful home with an enormous electric bill. We were on the APS Time Advantage rate plan (suggested by APS). We were paying $330/month (every month on the APS equalizer plan even with programmable thermostats with the actual peak summer bill exceeding $400.
Four years ago you installed the load controller. On the averaging plan our monthly bill is now $154 and our highest single monthly bill has been $225 over the the past two years. A savings of $3700 in this time! The load controller has been well worth the investment. I just wanted to thank you and let everyone know the savings are real."
JW Flint.

Alex Johnson of Moon Valley:
We had Thermal Control Membrane installed in our attic along with a German attic fan and by pre-cooling our home to 72 degrees until noon, we can turn off our heat pump and coast through the on peak hours on the Combined Advantage Rate and have our Pensar System 1000 set at 2kw! Our home is more comfortable and our consumption and demand are down over 40% before having this package installed. I highly recommend this system, it works as planned and we are very happy with results. My neighbors are amazed at how low my APS bills are!

D. Kalt of Glendale:
We had a Pensar System 1000 installed in March of 2009 by Horizon Energy Systems who also installed TCM in the attic, wrapped and sealed our duct system. The effects have been nothing short of amazing! Previously, on days over 105 degrees, our A/C units ran non stop and could not get the house below 81 degrees and our APS equalizer payment was near $400. We also had an 18" tubular skylight installed which just made my kitchen incredibly bright and cheery, I LOVE my "new" kitchen! The granite counters look amazing with the natural light. Below is a video of our savings after nine months with this package. To say we are happy would be an understatement, "amazed" would be more appropriate!

What does a Load Controller look like?
Below is the Pensar System 1000 (outdoor display)

This unit is mounted next to your existing electrical breaker box outside and houses the control module where you set the demand levels. There are modes on the display which shows your demand set point (where you set the maximum demand level), current demand (what the home is currently using), past hourly average (this is what the APS meter measures from), highest demand peak (what the highest peak reached was during last billing cycle), time, date and alarm settings.
Typically you would interface with this display to set the demand where it best fits your lifestyle. It may take a full year to know just how low you can set it as the seasons and demand levels change and we encourage our customers to check it more often than not during the first year. Demand adjustments should reflect the load on the home, for example: one setting to accommodate the summer load, a lower setting for Fall and Spring, and one setting to insure your home is warm during the winter. Key point to remember: the lower you set the demand level, the lower your APS bill.

Ok, I'm Interested, What's The Next Step?
Your first call is going to be to Arizona Public Service Company: 602 371 7171 and ask for customer service. Assuming you have been in your home for a year, request your consumption history for last year including demand levels. Having the demand levels on this history is very important for our energy experts to determine accurately how much we can save you. This is free to all APS customers. Again: Last years consumption history with demand levels. You will be asked for your APS account number, your address and the last for digits of your social security number for security purposes.
Once you receive this document call us and schedule an energy audit and we will come out to your home and show you how to save. It's simple and understand this: If you are not completely satisfied with the savings or how we accomplish this we will remove the unit and give you a full refund. How can we be so sure you will cut your APS bill? We have been doing this since 1982, longer than any other company in the valley and have hundreds of satisfied, comfortable customers.

DON'T DELAY! The longer you wait, the more you will be needlessly paying high electric bills.

Residential Load Controllers Lower APS Bills