There are close to 50,000 hotels and motels in the United States, and they spend around 6 percent of their operating costs on energy each year, according to Energy Star.

Most of that is used for lighting and climate control. Because hotels and motels operate 24 hours per day, those two things run almost constantly. Making a few energy-efficient changes can make a big difference.

Energy consumption at hotels also accounts for 60 percent of its carbon footprint.

Upgrade your lighting

Most of the changes to lighting can be done inexpensively while cutting a hotel’s energy bill by as much as 20 percent, according to Carbon Trust.

Carbon Trust is a nonprofit established in 2001 between UK businesses and government. They regularly advise businesses on energy improving efficiency.

They recommend the following tips to improve lighting efficiency:

  • Install occupancy sensors. These can dim or turn off lights when no one is in the room and reduce electricity usage by 30 percent.
  • Install daylight sensors. These adjust the artificial light in the room to the amount of natural light in a room. It can reduce electricity usage by 40-percent.

Lighting alone consumes about 35 percent of the electricity used in a hotel and 18 percent of the total energy generated in the U.S.

Another 4 to 5 percent of energy is used to remove the heat generated by those lights through climate control.

Upgrading the lighting improves HVAC efficiency, but also the power quality in general by freeing up electrical capacity. Energy Star highlighted Columbia University as an example of this. The school upgraded lighting in two adjacent buildings and freed up enough electrical capacity to allow the wiring of the lighting circuits into one building’s electric service.

Purchasing the transformers for that one system became a cost-effective way to put both on high-tension service, which saved 29 percent off the two buildings’ electric bills.

The simple act of switching to LED lighting can make a big difference, too. GreenTree Inn & Suites in Phoenix, Arizona, swapped out 65 watt BR30 bulbs for 9 watt LEDs in 2013. The lights had a lifespan 10 times longer than the previously used bulbs. The change resulted in a savings of 80 percent on lighting-related energy costs.

Another type of lamp you can install is the compact fluorescent lamps, which use about two-thirds less energy than standard incandescent bulbs and can be swapped out easily in guest rooms. These bulbs are more expensive to buy, but save about $25 to $30 in electricity costs over the lifetime of one bulb.

Lodging magazine, however, recommends LED lights as the superior option. They generate little to no heat, don’t attract bugs and have a smaller environmental impact than halogen or fluorescent bulbs.

Evaluate your heating and cooling systems

Heating and cooling a hotel uses even more energy than lighting — 40 percent of the total electrical usage, and half of the natural gas. Many hotels heat and cool rooms whether a guest is in them or not.

Energy Star recommends linking the hotel’s reservation system and energy management system to an automated check-out system to keep an unsold room ventilated but with minimal heating and cooling.

That can reduce energy costs by 35-45 percent, with a utility savings of 50-75 percent.

Other simple solutions include sealing cracks around windows and doors, weather-stripping doors and windows and changing air filters regularly. It’s also important to have the HVAC equipment serviced yearly.

You can also retrofit a new HVAC system that is Energy Star certified for increased savings over the life of the system. Look into rebates and incentives for businesses that install energy efficient equipment to offset the initial investment. The U.S. Department of Energy offers a searchable map to see rebates available in your state.

Energy Star recommends the following to make sure your HVAC units are running as efficiently as possible:

  • Optimize performance by recalibrating the thermostats. They need recalibration every six to 12 months.
  • Inspect the dampers, linkage and actuator if your system has zone dampers.
  • Hotels with electric reheat systems can shut off the reheat coils at the breaker during cooling system for significant energy savings.

Consider converting to a Variable Air Volume System if you currently have a Constant Volume System. Airflow requirements for VAV systems are about 60 percent of CV systems, according to Energy Star. An HVAC contractor or the local energy utility can help you discover what type of system you have if you don’t have the original design plans. They can also help you decide if replacing the system is a cost-effective decision.

Saving on hot water

Water heating is another major load for hotels. Commercial heat pump waters are up to four times more efficient than typical water heaters and can cut costs up to 50 percent.

According to Energy Star, hotels can get “free” hot water from the cooling and refrigeration equipment by using double-bundled heat exchangers in the chillers or a plate heat exchanger in the condenser-cooling loop.

For showers, hotels can use gray water heat-recovery equipment to save 50 to 60 percent of water-heating energy. The payback period is about two years.

For hot water used for hotel laundry, Energy Star recommends the following:

  • Efficient tunnel washers
  • Ozone laundering systems that use cooler water and much less of it
  • Covers on heated pools and hot tubs
  • Solar water heaters for pools to save 50 to 70 percent of the pool’s energy use while it’s not in use

More ways to reduce the electrical load

In many hotels, office equipment sucks up a lot of electricity. The equipment is often left on when it isn’t being used and also generates heat in the space. Making sure the equipment — including computers, copiers, fax machines, laptops, printers and scanners — have a sleep mode can help offset that use.

Turning other energy consumers off or unplugging them can make a difference in your utility bill, too. That includes coffee pots, fans, heaters and audio equipment.

Encouraging staff to use the power-management settings on their computers can result in cost savings as well.

Other than purchasing energy-efficient models, there isn’t much you can do about the energy use of things like refrigerators, vending machines or stoves.

Controlling heat flow in the building with insulation, good sealing materials and maintenance is another step hotel owners can take to improve energy efficiency and reduce utility bills. Seal or caulk small cracks around windows, install more installation between the roof and top floor and install energy efficient windows to reduce solar radiation.

Windows can also have a film fitted onto them to reduce heat gain.

A less traditional approach to reduced energy consumption is green roofs. These have been popular in Europe for a few decades and involve adding layers of soil on top of the roof for gardens. The soil provides additional insulation, the trees and other plants provide shade, and a green roof doesn’t absorb much heat.

The plants also transpire, which cools the rooftops.

Simple maintenance on most things like boilers, HVAC units, water heaters and even refrigerators can help improve energy efficiency, which has a direct impact on your utility bills’ bottom line.