Untapped savings for your car wash

by Jim Belanger

A flat economy and rising energy costs[1] have put tremendous pressure on car washes to find ways to lower variable costs. Implementing energy-optimizing initiatives is no longer an option. Proven methods for car washers to reduce energy consumption are already at hand. These cost-effective solutions promise substantial return-on-investment now and in the future, without sacrificing performance or quality. For almost all car washes, the answers to maintaining a competitive edge in this era of rising energy costs are readily available. By applying several cost-effective power and automation solutions, car washers can achieve substantial energy savings today.

Hidden in Plain View

So where should operators look find these vast untapped energy savings?  The crazy thing is that they are hidden in plain view—motor driven equipment systems.

Motor driven systems consume approximately 80 percent of car wash energy, which means auditing them is the most logical starting point to find ways to conserve energy and reduce costs.  Centrifugal loads, such as fans and pumps, offer the greatest energy savings potential. Fortunately for us, our car washes are chock full of centrifugal loads. In fact, centrifugal loads represent the vast majority of our motor horsepower; dryer fan motors, water pump motors, vacuum pump motors and air compressor pump motors.

Start at the Beginning

When discussing energy efficiency, the beginning for car washers is the local power company. As everyone knows, electric rates vary by state and utility company. Utilities have different tariffs for different types of customers (users).  Larger users tend to get more favorable rates than small users. Some utilities offer different rate periods based on time of day or calendar

periods. Others charge flat rates regardless of the time or the days.  Before you seek out efficiency strategies you need to know how your utility company rate is structured.

Educate Yourself

Utility company terminology and billing structures are confusing. Take a little time to learn their language; see, www.carwashcmi.com/resource-center for Energy Management for Motor Driven Systems, Chapter 2, under White Papers. It describes in layman language how to understand your utility bill.

Know How You are Billed

Call your utility company and make an appointment with a representative to review your bill in person. Electrical utilities usually charge commercial customers like car washes for both consumption (kWh) and demand (kWd or kVa). Consumption is a measurement of total electricity used for a period of time called a kilowatt hour or kWh. Electric demand refers to the maximum amount of electrical energy that is being consumed at a given time.  It is measured in both kilowatts and kilovolt amperes, depending on the rate tariff. In most parts of the country car washers have demand penalties built into their rates. Demand charges can exceed 50 percent of your total electric bill. As such, a good strategy should consider consumption reduction and demand side control.

Select the Best Rate Plan for Your Car Wash

In reviewing and selecting the best rate plan for your facility, you may achieve significant savings without any capital expenditure. Now that you know how you are billed, you know how various efficiency strategies will impact your bottom line.

Pick the Low Hanging Fruit

We already mentioned that centrifugal loads are the best place to gain efficiencies and savings. Because electrical contractors aren’t car washers, and car washers are not electrical engineers, our equipment systems are typically controlled with inexpensive across the line motor starters. The starter devices on centrifugal loads need to be changed to variable frequency drives. These types of loads offer big opportunities for savings by moderating their speed according to their load. For example, reducing a fan’s speed by only 10 percent with a VFD can reduce energy consumption by almost 25 percent. Centrifugal fans and pumps follow a variable torque load profile, which has horsepower proportional to the cube of speed and torque varying proportional to the square of speed.  In other words, use VFDs to run your systems slightly slower and generate huge savings. “More than ever, power optimization tools, like variable frequency drives, have an immediate, measurable impact on a car wash’s bottom line;” says Eric Dettling of Rockwell Automation. “The optimization goal of car wash automation companies, including Car Wash Management Integrators, is to help customers manage and minimize energy consumption with products and solutions focused on maintaining or exceeding current performance and quality levels while providing a return on capital investment.” Typically, energy savings from VFDs can be sufficient enough to pay back the capitalized cost in a matter of a couple of years depending on the size and runtime of the motors.

Application is Everything

Slowing down motors to save power seems contrary to optimizing performance and quality; we know, but it works. It’s all about the proper application of the VFD technology to the car wash environment. The greater number of VFD application strategies you implement and how aggressively you deploy them is up to you with each having a direct impact on savings, payback time and performance.

VFD for Dryers (tunnels and automatics )

Dryers are the mother lode of power savings. Often times they are 50 percent or more of the horsepower at a car wash. The good news is that there are a number of proven VFD applications that drive big savings in power use. Check it out.

Use the VFD’s to tune the top speed of the drying system. Not unlike dialing in your chemicals, with a VFD you can walk down the speed of the dryer motors until you achieve satisfactory drying with the lowest acceptable speed. In most cases, an excellent top package dry is achieved between 83 percent and 90 percent motor speed for 25 percent to 40 percent electrical consumption savings.

We all sell Good-Better-Best wash packages … right?  Then why don’t we match them with Good-Better-Best drying?  Go figure!  Use your controller to provide inputs to the VFD’s to change the drying system performance to match your wash packages. Like other merchandised services, a confirmation sign is used to communicate dryer performance to the customer. Common savings range from a nickel per car on the top package to 15 cents per car on the base package—depending on horsepower and runtime.

All car washers know that it is easier to dry cars when it’s hot out. Then why do we run the dryers full tilt during the summer? Integrate an outdoor temperature sensor with the VFDs to automatically slow the dryer motor speeds down when it is warm out. Savings range up from a penny per car depending on what other measures are also being used.

Eliminate “look back” by slowing the motor speed between cars. Program the VFDs to an idle speed of 50 percent and save 85 percent power use between cars.

Enhance quality by programming the VFDs to reduce motor speed over pickup truck beds to reduce water blowback.

VFD for Central Vacuums

Not the same savings potential as dryers, but still an awesome place to go next. The typical vacuum motor in today’s car wash is operated by an across the line motor starter. The vacuum is either on at full speed or off. Using a VFD control system, a pressure transducer measures vacuum pressure and feeds this information back to the VFD. A PI algorithm dynamically controls vacuum motor speed to maintain proper vacuum pressure based on demand. No longer will your vacuum motors be full on when only one customer is vacuuming. The application is straight forward, proven and easy to setup. Savings range from 30 percent to 50 percent.

VFD for Pumps

Like vacuums, pump motors in today’s car wash are typically controlled with across the line motor starters. Similar to vacuum’s dynamic control, pump systems can use an in line pressure transducer to feed pressure information back the VFD. Pump volume and pressure can be programmed by package so power and water savings can be realized for basic packages. Moreover, dynamic VFD control from a pressure transducer can also be used to optimize chemical dispensing equipment and water reclaim equipment to maintain constant water pressure without going over unloader valves or through bypass valves saving power and enhancing performance.

Collateral VFD Savings & Benefits

If big savings, enhanced control and optimized performance weren’t enough, here are some other motivating reasons to design VFDs into your car wash operation.

VFD’s Mitigate Peak Demand Penalties

VFDs are the best way to mitigate demand penalties in your electric bill. VFD’s control the inrush current peaks 80 percent better than cross the line motor starters and 50 percent better than soft start motor starters. If you are getting nailed with demand penalties, then you may have all the reason you need to convert to VFD motor control.

VFD’s Reduce Wear, Tear & Repair

Starting a motor using an across the line starter increases stress on the mechanical system. Belts slip and squeal, chains jump, and high pressure develops in pipes. VFD motor control inherently offers soft starts and soft stops which reduce mechanical stress on systems and lengthens their productive lives, helping to reduce the overall long-term cost of equipment ownership.

VFDs Usually Qualify for Government &/or Utility Company Incentives & Rebates

There has never been a better time to retrofit or design and install Green. The passage of the American Recovery and Reinvestment Act (ARRA) has appropriated billions of dollars to support Green energy-efficiency and renewable-energy programs. In short, the federal government and many local utilities are offering incentives and rebates to install energy efficient devices like VFDs which take some of the sting out of the capital expenditure required upgrading your facility or new project design. VFDs are also known as adjustable speed drives (ASDs) or variable speed drives (VSDs), so don’t overlook them when you peruse the DSIRE Web site, which is a comprehensive source of information on state, local, utility and federal incentives and policies that promote renewable energy and energy efficiency; www.dsireusa.org

Other No Brainers to Get Efficient

I feel a little like the late Billy Mays, going on and on about VFDs; “they can do everything including slice, dice and make julienne  fries.” Focusing so much on smart motor control makes it easy to lose sight of a couple of other no brainer efficiency strategies that can’t miss. Like VFDs, both of the following efficiency strategies offer government and utility rebates that make continued use of old technology quite short sighted

Energy Efficient Motors

When you are replacing an existing motor, or when specifying new equipment, don’t settle for anything less than a premium efficiency motor with at least an EFF1 rating > 90.  High-efficiency motors use better quality materials and are manufactured to higher quality specifications than standard-efficiency motors. They are 5 percent to 10 percent more efficient on average than standard motors in the smaller sizes (25 horsepower or less) which mean $70 to $110 in power savings annually per motor for a two year payback on the upgrade cost. Federal efficiency standards now require minimum efficiencies for electric motors so the older motors in your facility are likely to be less efficient than the lowest efficiency motors of that size you can buy now. Some well known, large end item equipment manufacturers of components like dryers, pump stations, etc, are designing to the minimum nominal efficiency rating allowed by law; see NEMA Design table.  It’s bad enough if you are running old, inefficient motors, but don’t let poorly designed new equipment saddle you with profit sucking motors.

Energy Efficient Fixtures

Offering up something as pedestrian as compact fluorescent lights (CFLs) and  high efficiency fluorescent tubes seems disproportionate to the huge savings available from VFDs or high efficiency motors; that is until you do the math for such an easy fix. For example, CFLs produce approximately four times more light output per watt than incandescent lamps. This means a 100 watt incandescent lamp can be replaced with about 25 watts of CFL saving 75 percent energy per bulb. Simple paybacks are usually less than three years. Many CFLs have an expected operating life of 10,000 hours, which is five to 13 times longer than incandescent lamps. This can save a great deal on the maintenance labor for lamp replacement and maintain brand image having all of the lights lit in signs. T-8 and T-5 fluorescent tubes are 10 percent to 20 percent less money use than outdated T-12 fixtures making their adoption easy to justify as well.

Wrap Up

Given the potential for easy access to such tremendous savings it’s no wonder that energy efficiency, power management and VFDs are such hot topics around the industry. Now that the secret of how to tap that potential is out, it should be easy for you to stop waiting for alternative fuels to help save the planet and your profit margins.  What are you waiting for?  Put some green in your bank account by tapping into energy efficiency strategies that are proven effective and ready to be deployed at your wash.

Jim Belanger is president of Car Wash Management Integrators (CMI). CMI is at the forefront of integrating advanced technologies and solutions into car wash applications that reduce power consumption, enhance operational readiness, process control and quality, and lower the variable cost of chemistry, water and gas. CMI brings the world’s best automation technology to car wash. www.carwashcmi.com call toll free 866.868.5312.

References:

[1] The national average cost per kWH in 2010 is 11.5 cents with a 1.4% increase forecast for 2011

2 NEMA Design B, Single Speed 1200, 1800, 3600 RPM. Open Drip Proof (ODP) or Total92.4ly Enclosed Fan Cooled (TEFC) motors 1 hp and larger that operate more than 500 hours per year.