Your energy audit should have provided you with specific energy conservation measures you can implement to cost-effectively save energy and reduce your utility bills. This section of the Building Owner’s Toolkit will give you specific information about various energy conservation measures that your audit may or may not have identified. The information in this section has been developed by technical experts, and is provided to give you a broad overview of different technologies and systems that you can install to improve the energy performance of your facility. Each section includes information on who to reach out to for more information.
STEP 3: IDENTIFY AND IMPLEMENT ENERGY-SAVING TECHNOLOGIES AND BEHAVIORS
Energy-Efficient Lighting
Did you know that lighting uses 30-40% of the electricity in your building? It’s the single largest source of electricity use in your facility, and it’s also one of the easiest to improve. Many buildings have outdated, inefficient lighting that is easily replaced with highly efficient, state-of-the-art lighting and control systems. Let’s take a moment to review the primary types of energy-efficient lighting options:
The most energy-efficient type of lighting, LEDs (light-emitting diodes, also referred to as solid-state lighting) offer quality light at a fraction of the energy use of typical lamps. These bulbs will last for an extremely long time (more than 20 years in some instances), which reduces maintenance costs. They are dimmable and can reach full brightness instantly. The lifecycle cost of LEDs is much lower than incandescent lamps.
Fluorescent lighting takes two primary forms – compact fluorescent lamps and linear fluorescent tubes – both of which are more energy-efficient than incandescent bulbs. Newer fluorescent lighting systems are more efficient than older types (T5 and T8 lamps are more efficient than T12 lamps, and electronic ballasts are more efficient than electromagnetic ballasts). While the up-front cost of fluorescent bulbs is lower than LEDs, their life expectancy is also shorter, so you’ll end up replacing them more frequently.
Primarily used for lighting stadiums, gymnasiums, parking garages, auditoriums, high bays and outdoor spaces, high-intensity discharge lamps are best used when you need to efficiently light a large area. They are also frequently used in retail applications.
Perhaps the easiest way to reduce your energy bills is to dim or turn off the lights when they are not needed. Occupancy sensors can determine when tenants are using a space and can ensure that lights are off when offices, conference rooms, and other tenant spaces are not in use. Many current technologies enable the use of advanced control strategies, such as auto-on to 50%. In addition, daylighting controls provide the ability to dim or switch lighting when daylight levels become adequate, such as midday and afternoons. This is often when demand is highest as well.
When thinking about your building’s lighting system, it’s important to think in terms of lumens, not watts. Lumens are a measure of light output, whereas watts are a measurement of energy use. A 60-watt incandescent light bulb will put out the same amount of light as a 10-watt LED bulb (approximately 800 lumens), yet the LED will use less than 20% of the power of the incandescent bulb.
It’s also important to keep in mind the color temperature of the light, that is, whether the light appears warm and yellow (3000K and below) or cool and blue (5000K and above). Higher temperatures more closely resemble sunlight in the middle of the day, while lower temperatures reflect candlelight.
Improving your building’s lighting system by installing energy-efficient LEDs and fluorescents, and by using lighting more intelligently by utilizing lighting controls and daylight management systems, you can save between 30-60% on lighting energy (or operating) costs. That works out to approximately 12-24% of your entire building’s electricity use.
The following resources will give you much more information about lighting improvements you can implement in your facility:
- Guide to New, Energy-Efficient Lighting Technologies for your Business
- LUMEN Coalition
- IES LEM-3-2013: IES Guidelines for Upgrading Lighting Systems in Commercial and Institutional Spaces
- IES LEM-7-2013: Lighting Controls for Energy Management
- Database of State Incentives for Renewables and Energy Efficiency (DSIRE)
The following companies can help you get started with your project:
Motors and Drives
Motors use approximately 40% of the electricity in a building, the same amount of electricity it takes to light a building, yet lighting is usually the first system upgraded because it’s there in plain sight. Motor-driven systems are unseen and typically the last to be upgraded; often not until they fail. The life cycle cost evaluation of motor-driven systems commonly confirms payback opportunities of less than two years. Over the life of a motor, the up-front equipment cost is just 2%, while the cost to run the motor is 97% of the total cost of ownership.
Repairing vs. Replacing Failed Motors
Electric motors used in commercial buildings are often repaired rather than being replaced when they fail. Motor repairs typically fall into two categories. The most common repair is mechanical in nature. It is estimated that over 65% of motors fail as a result of contamination or oxidation of the grease providing lubrication to the bearings. If the motor has not suffered stator damage as a result of the bearing failure it is most often a sound practice to replace the bearing(s) and re-install the motor. The second type of failure involves the motor’s stator windings. If the repair includes rewinding the motor and evaluation should be made to determine if the repair cost meets minimum life cycle cost goals. Many times motors under 200 horse power can be replaced with NEMA Premium units that use less energy over their lifetime.
Retrofit vs. New Equipment
Building operators and maintenance staff should make an effort to ask contractors and motor suppliers to include new technologies in their retrofit and new equipment options. The motors and controls available today are significantly improved from only a few years ago, offering improved control of system speeds and flow that can dramatically reduce power requirements.
For More Information:
- NEMA Premium Motors
- NEMA General Motor Specification for Consultants, Industrial, and Municipal Applications
- NEMA Energy Management Guide for Selection and Use of Fixed Frequency Medium AC Squirrel-Cage Polyphase Induction Motors
The following companies can help you get started with your project:
Heating, Cooling, and Ventilation Systems
Space conditioning (heating and cooling) accounts for roughly 15% of electricity used in commercial buildings – second only to lighting. ENERGY STAR-qualified commercial heating, ventilation, and air-conditioning (HVAC) equipment is designed to reduce energy waste and save money on utility bills. ENERGY STAR-qualified equipment can use 7-10% less energy than standard equipment.
According to ENERGY STAR, approximately 25% of all rooftop HVAC units are unnecessarily oversized, resulting in increased energy costs and equipment wear. Properly sized equipment dramatically cuts energy costs, increases the life of the equipment, and reduces pollution.
ENERGY STAR-qualified commercial HVAC products can save your business approximately $1.70 per square foot over the life of the equipment. For example, a 12,000 square foot building using ENERGY STAR qualified HVAC products could save more than $21,000 over its lifetime and avoid more than 40,000 pounds of greenhouse gas emissions.
When you include energy performance and the lifecycle cost of owning a specific product as part of your typical planning process, the results can be very rewarding. There are many HVAC products that you can choose from, so remember to look for the ENERGY STAR logo to ensure that you’re choosing one that limits the life cycle cost of operating your building. Specific technologies that you should consider include:
Programming your thermostat to adjust the temperature based on occupancy at a given time of day or year can significantly reduce energy waste in your facility. Thermostats for commercial buildings can also integrate into building energy management systems to give building operators full control of your building’s HVAC system and can help you optimize the energy performance of your building and maximize occupant comfort.
Variable frequency drives (sometimes referred to as variable speed drives) control the speed of a motor by moderating the incoming frequency of the electricity supplied to a motor. This can significantly reduce energy consumption by running a motor at the appropriate speed to meet airflow needs instead of running the motor at its maximum speed and controlling airflow with dampers. The latter is a very inefficient way to control a motor, akin to driving a car with the accelerator all the way down and controlling the vehicle’s speed using only the brake.
An economizer uses outside air or a cooling tower to cool indoor air, using less energy than a traditional air-conditioning system would. Typically, economizers work best in cooler climates. For more information on economizers, read this fact sheet from ENERGY STAR.
Heat pumps can either heat or cool a building by extracting heat from the air (i.e., air-source heat pump) or the ground (i.e., geothermal or ground-source heat pump) and releasing it into the air or into the ground where it is not needed. For example, in warmer months, a heat pump can extract indoor heat, cooling your buildings, and releasing that heat into the ground or outside air. In the winter, heat can be extracted from the ground (where temperatures are relatively constant year-round) or outside air and deposit it into your building, warming the inside air. Heat pumps typically work best in more temperate climates. For more information on heat pumps, read this fact sheet from Oak Ridge National Laboratory.
Building Envelope and Daylighting
The building envelope determines to a large extent how energy efficient the building is. A poor building envelope design cannot be fixed by the HVAC or lighting equipment. The function of the building envelope is multifold. It insulates the building from the elements, it provides occupants views to the outside, and it allows daylight to enter the building to take advantage of the energy and human benefits of daylight.
Changes to the building envelope in existing buildings are typically expensive. Properly designed interior shading systems are the most cost effective way to improve both energy performance and human comfort in existing buildings.
For new buildings, and when renovations are extensive enough to involve the building envelope, several options exist that provide superior performance in energy efficiency and human comfort.
Electrochromic glass is becoming commercially available for building exteriors. It offers a wide range of control of its visual transmittance as well as solar heat gain, making the building highly energy efficient and providing reasonable glare control to occupants. Buildings with electrochromic glass especially on the East, South and West facing orientations may be able to reduce the size of their HVAC equipment.
Exterior shading systems have been used in buildings for several decades, especially in Germany. They are effective in blocking solar heat gain from entering the building. The down side is that they may interfere with the view from the inside. However, they are not suitable for all climate zones, such as those that have severe storms.
Interior shading systems are the most economical solution for providing thermal and visual comfort to occupants near the perimeter of a building. They should be motorized and automated, otherwise they tend to get pulled the first time the occupants experience sun glare – and never opened again. Automated shades offer some energy efficiency gains, although not as much as controllable glass or exterior shades. They also provide benefits that the other two do not: privacy to occupants, thermal comfort by shielding the occupant from the hot or cold glass, additional thermal insulation, and an aesthetic look to the interior.
The potential for energy savings range from about 10% using interior shades to about 20% using controllable glass or exterior shading systems compared to buildings that use standard glazing solutions and no interior shades.
The following companies can help you get started with your project:
Plug-Load Management
With the increased adoption of energy-efficient lighting and HVAC systems, the most rapidly growing electrical load in today’s commercial buildings is plug-load. The New Buildings Institute (NBI) reports that in 2004, plug-loads consumed just 14% of a commercial building’s electrical energy, but that amount has now risen to 28% – 48%. In a commercial building, plug-loads include computers, printers, networking equipment, video projectors, desk lamps, cafeteria equipment, and more. These plug-loads could be costing you almost half your electricity bill. The range of plug-loads in most buildings can be staggering, but often they can be classified into two main types:
These loads can be easily controlled without adverse consequences to most users. Typically consisting of discretionary use devices, such as small heaters and fans, speakers, personal charging stations and other similar devices, these loads lend themselves to a variety of control strategies to reduce the amount of time they are running while not actually being used.
Uncontrollable plug loads include load types where automatic shutoff might be harmful to the device or the user. Typical examples will be desktop computers, computer servers, and emergency standby equipment that must remain on at all times.
The energy savings potential from implementing automatic shutoff of some plug-loads can be as much as 20-50%. Research conducted under the California Public Interest Energy Research (PIER) program in 2011 revealed possible savings of up to 40%. When thinking about the best approach to controlling plug-loads in existing buildings, it’s important to consider the current state of electrical wiring, the best way to tackle automatic shutoff of these loads, and local electric codes. The ASHRAE 90.1 energy standard covers existing buildings and requires offices and classrooms to have 50% switched receptacles. California Title 24 is for all new buildings in California and for renovations and is prescriptive regarding implementation of plug-load control. In general, few local building codes that are not covered by ASHRAE 90.1 or California Title 24 have requirements for plug-load control. Buildings owners in unregulated locations may implement plug-load control in any fashion they choose, but may want to consider aligning with these codes to avoid extra cost of future compliance
You can meet these requirements without rewiring your building by installing a wireless network (e.g., ZigBee) connecting a 24/7 on-off scheduler plus remotely controllable receptacles, switches and occupancy sensors. Smart strip outlets with built-in occupancy sensors can help reduce your energy consumption, but do not meet the building code requirements for new buildings and significant renovations. To also get electricity cost reductions per kilowatt-hour, many utility companies offer Demand Response programs that typically require some industry standard communication protocol, such as ZigBee Smart Energy, within load controllers.
For new buildings, however, it may not only make sense to wire specific receptacles separately from others to manage plug-loads, it may be mandated by the local building energy code. In these types of projects, half the receptacles in a specific space would be wired separately from the other half, either by split wiring individual outlets or clustering controllable outlets together in a space. Then, the controlled outlets can be automatically shut off with an occupancy-based signal or a timer.
Tips for Reducing Energy Waste from Appliances
Appliances waste energy by operating when not needed and from phantom or “vampire” power draw. Phantom power draw refers to the fact that many appliances continue to consume power when turned off. You can reduce this energy waste from idle appliances in three ways:
By unplugging an appliance, you have turned it off completely, eliminating any phantom power draw. Unplugging also helps prevent fires ignited by overloaded appliance wires or components or bad wire junction in the branch circuit.
Some newer appliances have reduced phantom power draw and higher efficiency ratings than old appliances. Payback depends on improved efficiency, price of electricity and price of the new appliance, but some appliance replacements will pay back in less than 2 years.
Perhaps the easiest way to reduce your energy bills is to automatically disconnect power from appliances when they are not is use. 24/7 control schedules can shut off receptacle during off hours and on weekends. Occupancy sensors can over-ride these schedules for occasional extended usage hours. Payback depends on the price of electricity, number of “off” hours, and size of load, but some automated plug-load control can pay back in months.
The following companies can help you get started with your project:
Data Centers
The U.S. Department of Energy (DOE) estimates that the energy consumption of a data center can be as much as 100 times greater than a standard office building. Because almost all organizations rely on information technology equipment (ITE), most office buildings have one or more data centers. More energy is typically provided to the support equipment (e.g., chiller, humidifier, air-conditioning, and power supply) than to the IT equipment itself, as shown in this figure.
Critical Power Infrastructure
24/7 operation is typical for most data centers. In order to achieve or approach zero down time, redundant power distribution paths are the norm. Levels of redundancy are ranked by the Building Industry Consulting Service International (BICSI) as levels F0 through F4, with F4 being the highest, even including dual utility feeds into the building. That means that critical power infrastructure, such as uninterruptible power supply (UPS) systems, power distribution units/transformers, and switchboards are often operating between 20-50% of rated capacity. Older equipment would often run at efficiency levels in the low 80% range at such loading, but today’s equipment is designed for operation in the high 90% range. To maximize the energy efficiency of your data center, you should look for:
- ENERGY STAR-certified and labeled equipment;
- Multi-mode operation: energy saving operating modes when higher operation is not needed;
- High-efficiency transformers, or elimination of transformers wherever possible; and
- Pre-configured, scalable modules or performance-optimized datacenters (PODs).
Cooling and Environmental Control
Temperature and air quality management represent the greatest area of energy consumption, and therefore the greatest potential for energy efficiency improvement. It starts with a few simple concepts:
- Align equipment to create hot aisles and cold aisles;
- Keep hot and cold aisles contained;
- Use blanking panels in cabinets to prevent mixing of hot and cold air;
- Use point of use cooling systems (e.g., in-row, ceiling mount) rather than whole-room cooling systems; and
- Use economizer mode (“free cooling”) when outdoor air temperature and quality are suitable.
Data Center Infrastructure Management (DCIM)
Software to manage everything in a data center requires a holistic approach, because all elements of the data center (power, cooling, lighting, IT equipment, etc.) are interconnected. A change in one element can cause a change in another element. Intelligent management prevents “fighting” between different equipment. DCIM should integrate easily with a building information management system. The common metric for defining data center efficiency, developed by the Green Grid, is Power Utilization Efficiency (PUE). While very effective for tracking trends in a data center, PUE is not easily used for comparison with similar data centers. The method of calculation must be identified.
Information Technology Equipment (ITE)
Because the ITE is the single largest consumer of energy in a data center, it should be a primary target for energy savings. Owners of data centers should:
- Use ITE with multiple operating modes – cease power draw when not needed;
- Use ITE with high efficiency power supplies; and
- Discontinue use of “stranded capacity” (i.e., decommission or consolidate servers and other devices that are under-utilized).
Low-Hanging Fruit
As recommended in Step 1 and Step 2 of this Toolkit, the first thing you should do is conduct an energy audit to find out where and how energy is being used and wasted. Consider engaging an organization that specializes in vendor-neutral data center infrastructure management services including:
- Data center life cycle services;
- Project management services;
- Vendor management services;
- Maintenance management services; and
- Facility operations management services.
Electric Vehicles and Electric Vehicle Charging Equipment
By providing electric vehicle (EV) charging stations or making your building EV-ready, you can promote and enable the use of electric vehicles, reducing dependence on foreign fuel, and also reduce the carbon footprint of your facility.
According to the U.S. Department of Energy, hybrid and plug-in electric vehicles can help increase energy security, improve fuel economy, lower fuel costs and reduce emissions. In 2012, the U.S. imported about 40% of the oil it consumed, and transportation was responsible for nearly 75% of the total U.S. oil consumption. About 33% of the nation’s greenhouse gas emissions come from transportation and 60% of that is from personal vehicle use. By installing EV charging equipment in your facility, you’re signaling to your tenants that your facility is sustainable and able to accommodate a rapidly changing vehicle fleet.
There are three methods for charging an electric vehicle, referred to as Level 1, Level 2 and Level 3 or DC Fast charge:
In the United States, standard outlets supply power at 120 volts. All Level 1 charging is done at this voltage. Depending on the car and the level of charge on the battery, Level 1 charging can take up to 16 hours to fully charge a battery. New electric vehicles come equipped with Level 1 equipment, which looks similar to an extension cord.
Level 2 charging uses 208 or 240 volts and is able to fully charge a battery in 4-6 hours or less, depending on the car and level of battery charge. This is the preferred EV charging method for both public and private facilities. These units are fastened in place and are not intended to be portable. Most Level 1 and Level 2 units use a connector that conforms to the SAE J1772 standard. This enables vehicles from different manufacturers to connect to all standard EV charging stations.
Level 3, DC Fast Charge equipment can provide 80% of a full charge in fewer than 30 minutes; it is the EV equivalent of a commercial gas station. The exact voltage and amperage requirements have not been standardized. They are typically 3-phase 480 volt. There is no standard connector yet for the Level 3, DC Fast Charge and most current vehicles have no provision for this type of charging.
Is your Building EV-Ready?
Being “EV-ready” means having the infrastructure in place to facilitate the installation of EV charging equipment. It is more economical to do this at the time of initial construction, but you can also retrofit an existing building to be EV-ready. The simplest approach would be to run conduit from the electrical distribution panel to the designated parking locations. The conduit should be of sufficient size to supply the equipment. To find out the specific requirements to make your facility EV-ready, visit http://evseready.org/