What Are The Energy Efficiency Technologies?

Energy efficiency technologies are systems, equipment, and practices that help reduce energy use while delivering the same – or greater – level of end-use service. Improving energy efficiency is a key strategy for meeting rising energy demand, reducing greenhouse gas emissions, and promoting environmental and economic sustainability. There are many mature, cost-effective technologies available today for dramatically improving energy efficiency across all sectors of the economy.

Energy efficiency delivers multiple benefits. It reduces energy costs for homes, businesses, and industry. It enhances competitiveness, increases disposable income, improves consumer welfare, and reduces the need for new energy infrastructure. It also mitigates greenhouse gas emissions and other environmental impacts associated with energy production and use. Energy efficiency is often the most cost-effective approach to addressing energy system and environmental objectives.

This article provides an overview of major energy efficiency technologies for buildings, industry, transportation, appliances, lighting, and more. It examines innovations in efficient equipment, building materials, system controls, vehicles, manufacturing processes, and behavioral change that offer significant energy savings.

Table of Contents

Lighting

Lighting improvements offer some of the most cost-effective ways to increase energy efficiency in homes and businesses. Upgrading from traditional incandescent lighting to LEDs (light emitting diodes) can reduce lighting electricity use by 75% or more. LEDs use 25–80% less energy and last up to 25 times longer than incandescent bulbs.

LEDs have become the most common and affordable lighting option. Prices have dropped dramatically in recent years, making the switch financially beneficial. LEDs give off less heat than traditional bulbs, reducing cooling costs as well. They provide excellent color quality and dimming capabilities.

Motion sensors and dimmers can further enhance energy savings. Motion sensors automatically turn lights on and off based on occupancy. Dimmers allow light levels to be adjusted as needed. Strategic use of natural lighting through skylights, windows, and light tubes is another energy saver. Proper positioning, tinting, and shading helps reduce glare and overheating while maximizing natural light.

Heating & Cooling

Advancements in heating and cooling systems provide significant opportunities for energy savings. Improved insulation in ductwork and building envelopes prevents heat loss and reduces energy consumption. Smart thermostats allow HVAC systems to operate more efficiently by optimizing temperature settings and run times throughout the day. According to the U.S. Department of Energy, ENERGY STAR certified heating and cooling equipment can yield 10-30% in annual energy savings when properly installed.

Heat pumps are one of the most energy efficient HVAC technologies available today. Air-source heat pumps transfer heat between outdoor and indoor air to provide both heating and cooling in one system. Geothermal heat pumps use shallow ground temperature as a heat source and heat sink. According to Neeco, air-source heat pumps can be over 300% more efficient than electric resistance heating.

Appliances

Energy efficient appliances offer significant savings in home energy costs. According to the U.S. Department of Energy, appliances account for about 13% of an average home’s energy use. The easiest way to identify energy efficient models is to look for the ENERGY STAR label. ENERGY STAR certified appliances meet strict energy efficiency guidelines set by the EPA and Department of Energy. For example, an ENERGY STAR refrigerator uses about 15% less energy than non-certified models.

Smart appliances take energy efficiency a step further by using technology to optimize energy use. Smart refrigerators can monitor internal temperatures and adjust cooling accordingly. Some models even integrate with smart home systems to allow remote control and monitoring. Smart dishwashers can delay cycles to run during off-peak hours when electricity rates are lower. Over the lifetime of the appliance, a smart dishwasher can save about $40 on utility bills compared to standard models, according to EnergyStar.gov.

Water Heating

Water heating accounts for nearly 18% of the average home’s energy use, making it the second largest energy expense in most homes. There are several energy efficient options when it comes to water heating that can help reduce energy usage and costs.

Tankless water heaters, also known as on-demand or instantaneous water heaters, provide hot water as needed without using a storage tank. Tankless water heaters heat water directly without storing it, which can save energy since water isn’t constantly heated in a tank. According to the U.S. Department of Energy, tankless water heaters can save up to $100 or more per year in energy costs compared to traditional storage tank water heaters (https://www.energy.gov/energysaver/selecting-new-water-heater).

Heat pump water heaters use electricity to move heat from the surrounding air into the water tank. This makes them 2-3 times more energy efficient than conventional electric water heaters, according to ENERGY STAR (https://www.energystar.gov/products/energy_star_home_upgrade/super_efficient_water_heater). Heat pump water heaters can save the average family hundreds of dollars per year on utility bills.

Insulating hot water pipes reduces heat loss as hot water travels to faucets, resulting in energy savings. The Department of Energy estimates that insulating hot water pipes can reduce heat loss by 25-45% and save 4-17% in water heating costs (https://www.energy.gov/energysaver/water-heating).

Building Materials

Energy efficient building materials play a key role in reducing heat loss/gain and improving the energy efficiency of buildings. Some key technologies include:

High R-value insulation materials like fiberglass, cellulose, and spray foam insulate buildings from temperature extremes and reduce heating and cooling costs. The higher the R-value, the better the insulating effectiveness.¹

ENERGY STAR certified windows incorporate advanced materials like low-emissivity (Low-E) coatings that reflect heat. They let in light while blocking UV rays and improving insulation.²

Cool roof technologies use reflective paints and membranes to reflect sunlight and heat away from a building, decreasing cooling costs. Options like reflective tiles and metal roofing keep attics and interiors cooler.³

Smart Equipment

Smart equipment utilizes advanced technology and connectivity to help optimize energy efficiency. Some key technologies include:

Smart meters – These advanced meters monitor energy usage in real-time and send the information back to utility companies. This allows for more accurate billing, outage detection, and analytics on usage patterns to find savings opportunities. Smart meters also enable innovative time-of-use pricing to incentivize off-peak energy use.

Programmable controllers – These embedded devices regulate systems like HVAC based on pre-programmed settings and sensor data. Advanced programmable controllers employ machine learning algorithms to continuously optimize settings and identify faults or opportunities to improve efficiency.

Sensors and controls – Motion sensors, occupancy sensors, and light sensors allow lighting, HVAC, and other systems to dynamically adjust based on real-time needs. Smart sensors provide data to automatically dim lights, change temperatures, and take other actions to reduce energy waste.

Electric Vehicles

Electric vehicles (EVs) are becoming an increasingly popular energy efficiency technology. According to the U.S. Department of Energy, EVs convert over 77% of the electrical energy from the grid to power at the wheels, whereas conventional gasoline vehicles only convert about 12%–30% (https://www.fueleconomy.gov/feg/evtech.shtml). This makes EVs much more energy efficient than traditional internal combustion engine vehicles.

Some key benefits of electric vehicles include:

Dramatically lower fuel costs because of the efficiency of electric drive components (https://afdc.energy.gov/fuels/electricity_benefits.html)
Reduced greenhouse gas emissions since most emissions happen at the power plant instead of from the tailpipe

Lower maintenance costs with fewer fluids and moving parts
Potentially lower total cost of ownership over the lifetime of the vehicle

Two challenges for wider EV adoption are availability of charging stations and improvements in energy storage technology. More public charging infrastructure is needed to alleviate range anxiety. Advances in battery technology will continue to increase range capabilities and lower costs.

Industry

The industrial sector is responsible for about 32% of all energy consumption in the United States (NAS). There are several ways that industrial facilities can improve their energy efficiency:

Process optimization involves analyzing industrial processes to identify inefficiencies and opportunities for energy savings. This can be achieved through heat integration, wherein waste heat from one process is captured and reused in another process that requires heating. Process optimization also entails upgrading equipment, modifying processes, and improving maintenance practices to reduce energy waste (DOE).

Waste heat recovery involves capturing heat exhausted from industrial processes and using it for heating applications instead of wasting it. This recovered heat can potentially replace a significant amount of the energy normally supplied from conventional sources. Waste heat can be used for generating steam, preheating boiler feeds, and heating air or water (DOE).

Cogeneration, also called combined heat and power (CHP), generates electricity while also capturing usable heat. Conventional power plants waste the heat produced when generating electricity. By capturing and utilizing this wasted heat onsite, CHP systems can achieve efficiency levels of up to 80%, compared to about 45% for conventional separate heat and power (DOE).

By implementing process optimizations, waste heat recovery, and cogeneration, industrial facilities can significantly improve their energy efficiency and reduce energy costs.

Conclusion

In looking at the various energy efficiency technologies available, several key themes emerge. First, upgrading lighting to LED bulbs offers one of the simplest and most effective ways to reduce energy usage in homes and businesses. Second, improvements in heating, cooling, appliances, water heating, and building materials all provide additional energy savings through better insulation, waste heat recovery, and smart controls.

Third, smart equipment and sensors allow for real-time monitoring and adjustment of energy systems, optimizing efficiency. Fourth, electric vehicles are radically improving transportation efficiency when charged with renewable electricity. Finally, industrial processes are tapping into energy efficiency opportunities through co-generation, waste heat recovery, and optimized motor systems.

The benefits of these energy efficiency technologies are lowered energy bills, reduced greenhouse gas emissions, improved air quality, increased competitiveness, and enhanced sustainability. As costs continue to decline and capabilities improve, the future outlook is bright for wider adoption across homes, businesses, utilities, and transportation.

In summary, energy efficiency is a critical tool for combating climate change, saving money, strengthening energy security, and building a cleaner economy. The technologies explored in this article showcase the myriad options available today to dramatically reduce energy waste while maintaining or improving quality of life.