Lighting

Lighting is the second largest energy-using system in a hotel, and is probably the easiest and most cost-effective area for reducing energy costs (Alexander 2002). Options for lighting energy savings include (Bohdanowicz):

• Maximising the use of daylight by designing large windows, regular window cleaning and reducing light-blocks (with consideration to heat gain).
• Adjusting lighting levels to the demand and types of fixtures used for the purpose.
• Switching off lights in unoccupied areas.
• Keeping bulbs, reflecting surfaces and diffusers clean at all times for maximum efficiency.
• Comparing lumens per watt for the most efficient purchase of lighting equipment.
• Replacing inefficient fluorescent ballasts with new energy-efficient, high-frequency electronic ballasts and inefficient electromagnetic ballasts with new high-frequency ones.
• Using time and motion sensors for turning lights on and off where appropriate  (the installation of occupancy sensors can lead to 35­‐45% savings on the lighting cost – IMPIVA, 1994).
• Using a photo-cell or time clock control together with high-efficiency lighting, for outdoor and parking lights.
• Using dimmer controls in dining areas and meeting rooms.
• Installing PV-powered outdoor lighting where feasible.

And....

• Replacing inefficient incandescent lighting fixtures with efficient fluorescent, sodium or metal halide fixtures; tungsten lamps with compact fluorescent lamps, and old fluorescent tubes with new efficient ones.

The installation of low energy lighting is presumably one of the easiest and more adequate solution for an energy saving program, since it reduces not only energy costs, but working costs in bulb changing as well. 

Notes: 

- Cost of electricity will vary. The figures used above are for comparison only, and are not exact. Residential energy costs among the various states range from 28.53 cents (Hawaii) to 6.34 cents (Idaho) per KWH. 

- The cost per bulb for LEDs may vary. We used the figure of $35.95 (for a 60 watt equivalent LED bulb) as an average among lighting retailers.

- Estimates of bulb lifespan are projected, since it would take about 6 years of continuous lighting to test. Some manufacturers claim the new LED bulbs will last up to 25 years under normal household use, but this is not proven.

- Bulb breakage and bulb replacement costs have not been factored into this comparison chart. Incandescent bulbs and CFL bulbs are more easily broken than LEDs, which increases their cost of use.- Most LEDs come with a minimum 2-year guarantee. Any defective LED bulb will usually fail within this time.

This comparison demonstrates that Light-emitting diode (LED) and Compact fluorescent lights (CFLs) last much longer than than incandescent lights, using significantly less energy for the same light output. Both generate less heat than incandescent bulbs thereby reducing the cooling load. Another advantage of investing in lighting is the payback time, which is relatively short.


According to the Alliance to Save Energy, a compact fluorescent light used in place of an incandescent light that is left on continuously for 12 months, all 8,760 hours of the year, will pay for itself in less than one year.


However, to make an appropriate choice for lighting, not only costs and energy should be compared, but also durability, the usage of hazardous materials, replacement frequency and sensitivity amongst others (see table below).

It is clear that incandescent light bulbs are much less efficient that both CFLs and LEDs. But what about comfort? It is difficult to give up on comfortable, warm lighting. So, how do this lights perform?


Compared to the average incandescent bulb, a LED 17/75-watt bulb is much less fragile, uses less energy, can match that familiar yellow glow of incandescents, and lasts far longer. Compared to many CFLs on the market, it gives off a warmer light if that's what you're looking for. The LED is slightly dimmer than the average incandescent, which can be quite pleasant for bedrooms where you want a cozy light. But several LEDs from the market, are still only available at early-adopter prices. It is expected that they come down in price shortly. Therefore, it is a good idea to start planning those replacements!

CASE STUDY
The Sheraton Tacoma Hotel developed a project to transition to compact fluorescent light fixtures. The staff replaced 2,000 incandescent light fixtures with quadruple-tube compact fluorescent light (CFL) bulbs in various areas of the hotel such as the guest rooms and the lobby. The cost saving was calculated at up to $15,000 with a payback rate of 18 months. (Alexander 2002)

CONCLUSION
To encourage hoteliers to really invest in environmental measures (including energy conservation measures such as the mentioned above), a pro-­‐active French hotelier interviewed by the Hotel Energy Solutions (2009),  recommended highlighting the fact that investment in energy conservation measures can improve the overall performance of the hotel.
He adds that it is a way to motivate the staff and an opportunity to re­‐evaluate guests’ needs and the services provided by the hotel, while getting more visibility on the market and maintaining (or achieving) good economic performance. 

TO THINK ABOUT
Setting goals and targets and monitoring results are great tools for observing your progress in energy use as well as your declining energy costs. So... why not setting a goal for a Net-Zero Hotel? Switch to more energy efficient bulbs, adopt more responsible attitudes, invest in clean energies and (very important) keep monitoring results!

ELECTRICITY DEFINITIONS

Watts: A unit of power (i.e., 100-watt incandescent bulb). Power used by an appliance multiplied by the time it’s in use, expressed as watt-hours. For example, running a 100-watt light bulb for one hour uses 100 watt-hours. Power is the product of current (amperes, or amps) times voltage (or volts), i.e., 1 watt = 1 amp x 1 volt.

Kilowatt-hours: Often expressed as kWh, this is how most companies buy electricity; 1 kilowatt-hour is 1,000 watt-hours (i.e., 1 kWh = 1,000 Wh).