4 Ways to Save Energy with EMS

VIDEO: 4 Ways to Save Energy with EMS

An energy management system (EMS) can help save money in your facility by performing four basic functions across a variety of applications.

  1. Control. An EMS controls the building environment by delivering just the right amount of conditioned air, fresh air and lighting for each type of space, always with an eye toward energy savings.
  2. Operations. An EMS will operate your building functions based on a prescribed sequence of operations and control strategies. The EMS will react to changing conditions, like occupancy or the amount of daylight.
  3. Monitoring. By monitoring performance, an EMS can implement corrective actions. All activity is shown on a screen and documented, so you know what’s happening in your facility at all times.
  4. Alerts. An EMS will also alarm and send you alerts that let you know if something needs attention in one of your systems.

By providing control, operations, monitoring and alerts, an EMS can improve efficiency, lower maintenance costs, increase productivity and enhance safety in your facility.

Best Energy Saving Opportunities for Motors

Best Energy-Saving Opportunities for Motors

Motors are major consumers of energy in industrial and commercial facilities. Equipment such as pumps, chillers and compressors all have motors performing a mechanical function. Mark Farrell, program manager and energy coach, draws on his many years of experience to provide some insights into the best opportunities for reducing motor energy use.

 

1. Turn motors off when not in use

The biggest energy-saving opportunity for motors is to turn them off where they’re not being used. There’s a perception that it costs a lot of extra energy to turn a motor on, so they’re often left on during breaks. There’s a slight bump in energy use when you turn a motor on, but it’s a lot smaller than most people think.

Starting and stopping motors isn’t just an energy issue, it’s also a wear and tear issue. There are guidelines that tell you the number of starts and stops in a motor, which takes into consideration the wear and tear. For example, a 50 horsepower (hp) motor will have fewer starts and stops allowable over a one-minute period than a 3 or 5 hp unit. Those guidelines are spelled out in NEMA Standard MG 10 and they’re set up to cover wear and tear issues.

If a motor is going to potentially be off for five minutes or more, that’s an energy-saving opportunity. If it’s a smaller (two or three hp) motor, there’s an opportunity to shut it down that’s often overlooked.

For example, a single 10 hp motor operating 25% of the time at idle would consume roughly 1.0 kWh per day at idle. That would be around 200 kWh per year, which at an electric rate of 0.08/kWh would cost about $16 annually. If the motor operated at partial load, such as running an empty conveyor belt, that number could be ten times larger or $160 per year.

 

2. Right-size your motors

Make sure your motor is sized appropriately. Often, you’ll see motors that are oversized. That’s a good opportunity; the motors are wasting a lot of energy because they’re not operating in their most efficient zone.

For more information about determining if your motors are oversized and the potential savings from downsizing, see the U.S. Department of Energy fact sheet Replacing an Oversized or Underloaded Motor.

 

3. Add variable frequency drives

Another very common opportunity is to look at the motor load. If you have a varying load in the production process, such as a fan or a pump, that may be a good opportunity to add a variable frequency drive (VFD).

For more information about the energy-saving potential of VFDs in your facility, see Adjustable Speed Drive Part-Load Efficiency from the U.S. Department of Energy.

In the end, you want to be sure that the amount of energy being consumed fits with the application.

Landscaping Your Property for Energy Efficiency

Landscaping Your Property for Energy Efficiency

Landscaping Your Property for Energy Efficiency

Good landscaping design adds beauty to your property and enhances curb appeal. While these are great benefits, did you know that properly placed trees and plants can also reduce heating and cooling costs and make your building more comfortable?

 

The shady side

Solar heat gain through windows and the roof reduces comfort on hot summer days and increases cooling costs. Leafy trees planted on the south, east and west sides of your building provides cooling shade in summer. In the autumn, the leaves fall, letting through warming sunshine all winter long.

Tree species are available in a variety of sizes and shapes for almost any shade application. Trees with high, spreading crowns (leaves and branches) on the south side provide maximum roof shading. Trees with lower crowns are more appropriate to the west, where shade from the lower afternoon sun is needed. Depending on the species and the building, a tree can provide a substantial amount of shade within five to 10 years of planting.

Shrubs and ground cover help shade the ground and pavement around the building. This reduces heat radiation and cools the air before it reaches the walls and windows.

 

Breaking the wind

Properly selected, placed and maintained landscaping provides good wind protection for multifamily buildings, reducing winter heating costs. A windbreak reduces heating costs by lowering the wind chill around the building.

Dense evergreen trees planted on the north and northwest sides are the most common types of windbreaks. Trees can be planted with bushes and shrubs to block wind from the ground level to the treetops. Location is important in providing an effective windbreak. Plant trees at a distance of two to five times their mature height.

 

Stay local

Native plants are those that have adapted over time to the local climate. They provide a naturally hardy, drought-resistant and low-maintenance landscape. Landscaping with native plants offers benefits like:

  • Less watering. Native plants are accustomed to rainfall, humidity and weather of the region.
  • No fertilizer. Again, these native plants are naturally capable of thriving in the local environment.
  • No pesticides. Native plants attract native insects, helping to help keep away other insects posing a threat.

Work with local experts to determine which trees, shrubs and native plants will work best for your landscaping needs.

When planning your project, keep safety in mind. Call 811 to have all underground utility lines located and marked. It will help you avoid injury, service interruptions and costly repairs.

Charge Up Your Forklifts: Five Reasons to Go Electric

Electric forklift

Charge Up Your Forklifts: Five Reasons to Go Electric

Forklifts are critical in many industries, from material handling on shipping docks to shuffling pallets around grocery stores. Whatever your business, if investing in a new lift truck is on the horizon, consider how well electrically powered units stack up against traditional internal combustion (IC) machines.

Advances in motors, batteries and charging technology have allowed electric lift trucks to capture a larger share of the market over the last decade, and that trend is likely to continue. Modern electric forklifts are gradually replacing even some of their more powerful IC competitors.

Switching to electric forklifts can bring several benefits to your business:

  1. Reduced fuel consumption. Modern 80-volt units cost less to run than their propane counterparts. The Electric Power Research Institute (EPRI) Lift Truck Comparison calculator can be used to compare the cost of operating a liquefied petroleum gas (LPG) unit to one powered by a battery. Assuming a propane cost of $3/gallon and electricity at $0.11/kWh (kilowatt hour), running an electric lift saves over $30 per day.
  2. Lower maintenance costs. Electric motors have fewer moving parts than IC engines and don’t require regular fluid or filter changes. Also, there is no need to handle or store highly flammable fuels such as gasoline, propane or diesel.
  3. Increased workplace health and safety. Electric forklifts offer quiet, emission-free operation that complies with Occupational Safety and Health Administration (OSHA) standards for carbon monoxide and noise exposure. Electric models also eliminate most hazards associated with fuel or oil leaks.
  4. Improved motor and battery technology. Over the last decade, the introduction of AC (alternating current) motors and fast charging technologies have allowed electric units to complete most tasks formerly reserved for their IC cousins. Some newer models can support loads of 15,000 pounds while reaching the highest shelf on a pallet rack. Moreover, high frequency charging allows the battery to last all day on a single nightly charge.
  5. Outdoor capability. It’s commonly believed that only IC equipment can be used outside. Two studies by EPRI indicate that, if the lift truck can negotiate uneven terrain and operate in inclement weather, electric units work just as well as IC equipment both inside and outside the warehouse.

Although electric forklifts have significant advantages, you must decide whether they are the best choice for your business. IC units cost less upfront, but the extra fuel and maintenance can cost you more over time. Electric units, however, require OSHA-compliant charging stations and large batteries that must be regularly cleaned and charged.

Charge batteries at night to avoid adding to peak demand charges. A 24/7 operation may require additional batteries on-site to prevent downtime. Finally, the electrical capacity of your facility must meet the voltage and amperage requirements of the charging station.

Work carefully with your supplier to make sure electric units are the right fit for your application. Look for rebates at aps.com/s4b.

Energy Answers: Calculating Load Factor

Energy Answers: Calculating Load Factor

I get a lot of questions about load factor. What is it? How is it calculated? Is a high load factor good or bad?

Simply put, load factor is a ratio of your facility’s average load over your peak load. The formula is relatively simple.

First, divide your monthly electricity usage in kilowatt-hours (kWh) by the number of hours. That number is your average load.

Second, divide your average load by your peak demand, which is what your energy company charges you for every month. The result is your load factor, which is expressed as a percentage.

But what does that number mean? A high load factor — anything over 70% — is considered good. It means your peak demand curve is relatively level. It’s an indication you’re spreading out your demand, resulting in a lower peak demand charge.

A lower load factor means you have a higher peak demand compared to your average load. That sounds like an opportunity to flatten your load curve by spreading out usage more effectively throughout the day.

Simple strategies such as staggering scheduling, charging equipment during off hours and running processes at different times can all lead to higher load factors, lower peak demand charges and lower energy bills without reducing total production output.

Load factor is a good indicator of your opportunity to level peak demand, and that’s something you should factor into your planning. It can save you quite a load of money.

Tell Your Energy Efficiency Story

Tell Your Energy Efficiency Story

Tell Your Energy Efficiency Story

You’ve finished your energy efficiency project and the savings are rolling in. Don’t keep it to yourself; get the word out about your accomplishments using a variety of media channels. With such publicity, you’ll be better able to justify your next project. You’ll also be promoting your company’s commitment to sustainability.

 

Making the pitch

When selecting a publication, get to know its audience and mission statement. Visit the website and take a good look at the type of content published. In general, the trade press (business-to-business) is looking for more technical information, while a more human approach may be suitable for general-interest media.

Don’t limit your pitch to just one media type. Consider local television or radio, community publications and even national publications like the Wall Street Journal. Look outside of your geographical area for other opportunities.

Take a multi-pronged approach including social media (e.g. LinkedIn, Facebook, Twitter, YouTube). This can lead to even more publicity. Hilton Hotels, for example, shared its energy efficiency success story on social media channels, which resulted in interviews from the mainstream press.

 

Telling your tale

What makes a good energy efficiency story? Keys to a compelling narrative include:

  • The human aspect. Who are the people behind the project that made the savings possible?
  • The impact. How much energy or money did the project save and what was the return on investment?
  • The big picture How did your project positively impact the environment? Did it lower your carbon footprint? Did it improve occupant health or comfort, or worker productivity?
  • Innovative technologies or processes. Did you install state-of-the-art equipment or come up with another unique way to save energy?
  • Compelling visuals. Are your photos interesting and of high quality? Are illustrations engaging?

Don’t wait too long. Your story must be timely and to the point.

 

Getting the word out

A good success story can gain attention for your organization and inspire others. The U.S. Department of Energy’s Better Buildings Challenge is a place for innovative companies to share their energy-saving strategies and results.

A number of Challenge partners have leveraged their success to gain much wider attention. Sabey Data Centers made the local news, reaching 425,000 readers. Martin Guitar was featured on a local TV station, which has 1.4 million viewers. Shari’s Cafe & Pies was covered in a business journal with a circulation of 1.7 million.

The Better Buildings Initiative SWAP videos, where two companies in different industries do a walk-through energy audit of each other’s facility, is also a media success. The first season featuring Hilton and Whole Foods garnered 433,000 YouTube views and 45 million media impressions in 20 publications. Hilton also leveraged its internal communications, which goes to 350,000 staff. This helped increase awareness and drive results.

Sharing your success both internally and externally helps build momentum and engagement, increasing support for energy efficiency projects.

Comparing Energy Modeling Software

Comparing Energy Modeling Software

Comparing Energy Modeling Software

There are dozens of energy modeling programs to choose from, all providing a whole building comparison to a baseline. Some programs offer computational fluid dynamics (CFD), daylighting analysis, credit calculations for LEED (Leadership in Energy and Environmental Design) and other features.

Choosing the right program for your project will depend on which of these features you need. With the help of the experts at Heapy Engineering, we compared several of the most popular programs.

eQuest (U.S. Department of Energy [DOE]). This free program is simple, fast, user-friendly and template-based; extensive modeling experience is not required. However, it allows only one model per project and there are no side-by-side comparisons. eQuest v3.65, released in November 2018, added DOE-2.3 simulation capability to include a variable refrigerant flow (VRF) system, a dedicated outdoor air system (DOAS), or energy recovery ventilators in HVAC models.

DesignBuilder (DesignBuilder Software). This program combines energy analysis software with the DOE’s EnergyPlus calculation engine. From $1,353(Essentials) to $3,031(Pro) annual subscription per network, this program has template-based advanced 3D drafting, advanced daylighting, hi-fi schematics and details for visual data. It requires formal training and modules are independently priced with no free trials.

HAP (Carrier). At $1,495 per network, this template-based energy analysis and system design program is based on algorithms developed by ASHRAE. Hourly Analysis Program (HAP) requires little modeling experience and includes side-by-side performance and economics evaluation and load simulations. However, it is proprietary and has no support for thermal storage. Also, it is limited to Carrier systems.

Trace 700 (Trane). At $4,000 per network, this program compares up to four alternatives for a single project and includes life-cycle cost and payback, weather profiles for 500 locations, as well as ASHRAE 90.1 analysis and sizing of mechanical systems. Users can now import a model from Autodesk’s Revit (or another BIM program) to make energy modeling of a building design much easier. However, the program requires formal training and only includes one HVAC system per zone. Trane recently re-architected TRACE, incorporating DOE’s whole-building energy modeling engine EnergyPlus, and is calling it TRACE 3D Plus for improved visualization.

Features and costs vary, so do your homework before selecting a program. If a program is frequently updated, results may differ for each version. Other programs on the market include EnergyPro from Elite Software, OpenBuildings Energy Simulator from Bentley Systems and IES Virtual Environment (IESVE).

To find out more about these programs, visit the online forum Energy-Models.com.

Ask an Engineer: VFD Phase Conversion

Ask an Engineer: VFD Phase Conversion

Ask an Engineer: VFD Phase Conversion

How do you convert variable frequency drives from single-phase to three-phase power?

Phase converters convert a single-phase supply to three-phase power. If you’ll be using the phase converter device to create a three-phase output from single-phase input, you should know that variable frequency drives (VFDs) typically require a more balanced voltage than off-the-shelf phase converters can provide. VFDs may also create harmonics, and this could potentially create problems with the operation of the phase converter.

To use a VFD with single-phase power the VFD should be oversized by a factor of roughly double the drive’s horsepower (hp) capacity. If you need to run a 10 hp, 230 volt three-phase motor from single-phase power, purchase a 20 hp VFD to do the job. This is because only half of the input rectifiers are available to energize the direct current (DC) bus.

VFDs provide single-phase to three-phase conversion as a part of the speed control process. To use single-phase power, simply connect the voltage source wires to the L1 and L2 terminals on the VFD. To use three-phase power, connect the input voltage wires to L1, L2 and L3 terminals on the VFD. The output (load) voltage is always three-phase regardless of the input voltage source.

There are specially designed phase converters which can serve sensitive loads, such as CNC machines and VFDs. An isolation transformer is included to change the typical output, three-phase delta high leg to a balanced wye configuration. A delta high leg taps one of the three-phase legs to supply single-phase voltage, resulting in an unbalanced transformer. A VFD requires a more balanced three-phase supply voltage.

There are also phase converters with automatic adjusting circuitry that help keep the voltage in balance so three-phase VFDs can be supplied equal voltage on all three input phases. In most cases, these units must also be derated, but this depends on the type of load being served. Because VFDs can create harmonics, line reactors are sometimes used to avoid this problem.

Phase converters that serve mostly motor loads will need to be sized larger than those that serve non-motor loads. If you have an existing phase converter, contact the manufacturer to see if that unit can serve a VFD.

Then & Now Air Conditioning

Then & Now Air Conditioning

Willis Carrier invented air conditioning in 1902. Let’s take a look at how it has changed since then.

In 1914, the first residential air conditioning units took up 840 cubic feet of space. Today, standard home HVAC units only occupy about 36 cubic feet.

In 1932, the first room air conditioners cost about $50,000 — $860,000 in today’s dollars. Prices dropped quickly; by 1938, the average cost of a window unit was only $416 — $7,250 in today’s dollars. In 2019, the average window unit cost $200.

In 1939, Packard became the first manufacturer to offer air conditioning in cars. The option cost $274 — about $5,000 today. Now, air conditioning is standard equipment in most new vehicles.

Air conditioning has become much more common through the decades. Before 1940, only about 50% of homes had central air conditioning. These days, about 91% of homes are equipped with central air conditioning.

Today’s central air conditioning systems are much more efficient, using about 30% to 50% less energy to produce the same amount of cooling. In the mid-1970s, the average home used about 40 kilowatt-hours (kWh) a day for cooling. In 2019, that number had dropped to 28 kWh a day.