Hotels and motels make great candidates for commercial and industrial (C&I) demand-response (DR) programs for a couple of reasons. Participating allows owners to bolster their “green” image in the marketplace, which gives them an edge in attracting event organizers who are looking for environmentally minded venues to host an event. In addition, incentive payments for participating in a DR program can offset some of their operating costs and make a positive difference in hotel operations even when there’s no DR event taking place. For example, a DR program can be used to educate staff about simple ways to save money every day, such as turning off lights in guest rooms or closing shades to reduce air-conditioning loads.
Hotels and motels are occupied around the clock. In general, occupancy levels tend to be highest at night. Hotels and motels that have conference rooms or restaurants, on the other hand, can be highly occupied throughout the day. Regardless of occupancy pattern, hotel electric loads, such as lighting and HVAC, tend to run at full capacity throughout the day—providing multiple opportunities to curtail loads. Additionally, because guests are typically not in the hotel in the mid-afternoon, guests will generally not notice the effects of load reductions. This gives hotels more flexibility when reducing loads.
Hotels and motels have several large loads that facility operators can curtail during DR events. The largest electricity users in hotels and motels are, in decreasing order: space cooling, lighting, space heating, office equipment, refrigeration, and water heating. As a result, facility operators typically reduce HVAC and lighting loads during curtailment events. Hotels and motels may also shut down kitchen and laundry facilities to reduce water-heating loads. In some larger hotels, swimming pool heaters and pool pumps have large demands and can also be curtailed. Lastly, some hotels can shift their loads onto backup generators, depending on local environmental regulations.
A hotel in San Francisco achieved a noticeable load reduction by participating in a DR program (Figure 1). During an event, the hotel’s facility manager dims or turns off lights in unused areas of the hotel, such as conference rooms, and increases thermostat setpoints by 2° Fahrenheit (F).
Depending on local building codes, hotels and motels may have mandatory indoor air quality requirements, such as ASHRAE Standard 62, “Ventilation for Acceptable Indoor Air Quality,” which must be considered when enrolling in a DR program. Also, due to the nature of the hospitality business, it can sometimes be difficult to reduce certain loads, especially in guest rooms. However, hotels and motels can still reduce loads by adjusting cooling setpoints and reducing lighting in common areas, such as atriums and empty conference and meeting rooms. Lastly, about one-quarter of hotels and motels in the U.S. have backup generators, which, depending on local environmental regulations, may be used to offset the building’s load during a DR event.
Many load reduction strategies can be used in hotels and motels. These include curtailing lighting, air conditioning, and equipment operation; shifting to backup generators; and employing a building automation system (BAS).
Curtailing lighting. Hotels and motels typically have discretionary lighting loads or decorative lighting in the atrium, conference rooms, and meeting rooms that hotel staff can turn off during a DR event. Staff can also turn off lighting in special-purpose rooms like restaurants, conference rooms, and exercise facilities. On the morning of a DR event, facility managers can also remind staff to turn off lights in unoccupied areas and guest rooms. On DR event days, the staff can reiterate that policy to the housekeeping staff. Turning off lights can reduce a hotel’s total peak load by up to 5 percent (Table 1).
Reducing air conditioning. Air-conditioning systems are typically running at full capacity throughout the day in summer. During a DR event, facility managers can raise thermostat setpoints to decrease cooling demand. Some DR programs offer day-ahead notification of events, allowing facility operators to warn hotel guests that indoor temperatures may be somewhat higher on the day of the event. Staff can also be reminded in advance to draw the blinds in guest rooms to reduce cooling loads and turn off room air conditioners in unoccupied rooms. Curtailing air-conditioning loads can typically reduce a hotel’s total peak load by 8 to 10 percent.
Manually reducing or eliminating key equipment loads. There are a couple of key equipment loads that can be shut down in the mid-afternoon when most guests are not in the hotel. First, hotels can turn settings in the swimming pool, kitchen facilities, and laundry facilities down or off if these systems aren’t in use. Kitchen and laundry activities can also be shifted to off-peak times. This strategy requires that management effectively communicate these activities to hotel staff because these loads must be turned off by hand.
Turning off fountain pumps. Interior fountains in some hotels provide aesthetic appeal as well as evaporative cooling. However, shutting down fountains during DR events will not cause much discomfort to the occupants. Potential demand savings vary from 3 to 10 kilowatts (kW) for most fountain pumps.
Shutting down elevators and escalators. If a hotel has multiple elevators and escalators, facility managers can shut down a portion of these loads if there is low demand from guests. Generally speaking, shutting down an elevator can reduce demand by 30 kW, while turning off an escalator can reduce demand by 7 kW.
Switching to on-site generation. Some hotels and motels have on-site backup generation. Such customers are good candidates for DR programs that allow shifting building loads onto these generation sources. Switching to backup generation is usually immediate, so it causes no interruptions to service. Hotel generators typically have capacities ranging from 250 to 500 kW.
Using a building automation system. Although less than 10 percent of all lodging facilities in the U.S. have BASs, many modern hotel and motel facilities have BASs that use sensors and controllers to monitor and optimize lighting, temperature, pressure, humidity, and flow rates—while minimizing lighting and HVAC energy use in common areas (the guest rooms are typically not controlled by the BAS). If the BAS can communicate directly with the DR facilitator, the BAS can automatically adjust thermostat setpoints and reduce discretionary lighting loads upon DR notification—eliminating the need to manually adjust equipment. If a hotel doesn’t have an automatic DR system, the staff or a facility manager will need to manually switch the BAS into DR mode whenever a curtailment event occurs.
A large, full-service hotel in central California has 654 rooms, a kitchen/restaurant, large conference spaces, and a small laundry service. Its peak demand during summer is about 1.7 megawatts. The cooling system, which accounts for around 50 percent, is the most intensive electricity load, followed by lighting at 30 percent. Other large electric loads include water heating, office equipment, ventilation, and refrigeration. Load fluctuations throughout the day are tied closely to air conditioning and tend to increase gradually between 11:00 a.m. and 6:00 p.m.
The hotel has been enrolled in the Pacific Gas and Electric Co. Demand Bidding Program since 2006. There are no penalties for not participating, the hotel receives notification one day prior, and the hotel gets a refund based on its actual load reduction during an event. The motivation for enrolling in the program stems from a corporate philosophy that emphasizes energy savings.
To create a DR action plan, the hotel identified everything that it could turn off without affecting guest comfort. For example, it turns off the large fountain in front of the hotel, turns off bathroom exhaust fans, increases thermostat setpoints by 2°F, and postpones laundry and dishwasher operations. In addition, when the senior director of engineering receives notification of a bidding opportunity, he sends an e-mail to all employees asking them to do whatever they can—listing all the ways they can help. He also mentions it again at the morning meeting on the day of an event.
This hotel typically reduces its demand by about 1.2 megawatts (by about 70 percent) during an event for a direct savings of about $300 per event. In addition, the DR program has refocused the hotel’s overall practices regarding energy conservation. For example, the program serves as a daily reminder for staff to close the blackout shades, turn off lights, and turn off kitchen ovens when not in use.
Facility Type: Hotels and Motels, Energy Star Building Upgrade Manual, U.S. Environmental Protection Agency and U.S. Department of Energy
Managing Energy Costs in Hotels and Motels, E Source Business Energy Advisor