energy efficiency in hotels

Energy Effic

iency

Power Quality & Utilization Guide

Niki Hendrikx Laborelec

November 2008

Hotels

2

Energy Efficiency

www.leonardo-energy.org

1. Introduction : general description of the hotel sector

This application guide aims at describing the use of energy and the potential

energy savings in the hotel sector, on the basis of theory and practical case

studies. Hotels and restaurants represent some 9% of total energy consumption

in the utility buildings sector. Utility buildings are offices, shops, hotels,

restaurants, educational establishments and care institutions.

Before going into detail on the energy consumption of a hotel, it is best to get a

clear view on the utility sector, the part hotels play in the sector, the number of

hotels in Europe and the different types of hotels.

Hotels as part of the utility sector

The hotel trade has gone through a serious evolution and expansion over the

recent decades. Tourism is the most important industry in the world economy,

both on the employment side as on the consumer side. Around 35% of the total

world hotel capacity is available in Europe (the European Union and Northern

and Eastern Europe). In Table 1 below, the total number of hotels in the different

European countries in 2006 is shown.

3

Application Guide for Hotels


Table 1 : Number of hotels in Europe (2006) (source : Eurostat)

The grand total for the EU (of 27 countries) amounts up to some 201 168 hotels

and similar establishments (like motels, roadside inns, beach hotels, rooming

and boarding houses, etc).

In order to get an idea of the energy use in hotels as part of the utility sector, the

example is taken of the utility sector in Flanders. The breakdown for this sector is

shown in Figure 1 below. Of course, Flanders is only a part of Belgium and a

small part of the EU, but the numbers are indicative for the rest.

Hotels and similar establishments 2006

Belgium 1955

Bulgaria 1348

Czech Republic 4314

Denmark 473

Germany 36201

Estonia 341

Ireland 4296

Greece 9111

Spain 18304

France 18361

Italy 33768

Cyprus 753

Latvia 321

Lithuania 338

Luxembourg 277

Hungary 2032

Malta 173

Netherlands 3099

Austria 14051

Poland 2301

Portugal 2028

Romania 4125

Slovenia 358

Slovakia 922

Finland 923

Sweden 1888

United Kingdom 39107

Croatia 762

Macedonia 150

Iceland 308

Liechtenstein 46

Norway 1119

Switzerland 5693

4

Energy Efficiency


Figure 1 : Energy use in Utility Sector (source : VITO)

Energy use and the different types of hotels

This application guide will describe the energy use in hotels, which is only part of

the ‘hotels and restaurants’ sector of the utility sector. Analysis of the energy

consumption in a hotel must take into account what kind of hotel it is.

There are several ways of categorising hotels. For example there are hotels,

apartment hotels, motels, roadside inns, beach hotels, residential clubs, rooming

and boarding houses, tourist residences,... But a different way to look at hotels is

the size by numbers of rooms (small hotels, medium hotels, large hotels, hotels

that are part of a chain of hotels eg Accor), or the luxury they provide (air

conditioning or not, number of square meters per room – depending on the type

of room or suite, inside or outside swimming pool or no swimming pool, ... ), the

number of stars a hotel has (related to luxury), etc

The location, the local environment and the architecture of the building play an

important role in the energy consumption of a hotel. These factors determine the

design of the hotel and many of the characteristics affecting energy use.

The location is important : distance from the sea, is it a rural, urban, mountain or

industrial area ?

The specific energy consumption of a hotel is strongly related to the type of hotel.

Clearly, there is a huge variety of types of hotel, but hotels are generally

classified by number of rooms and category. The division is thus :

• Small hotels (those with less than 50 rooms)

• Medium hotels (those with 50 to 150 rooms)

• Large hotels (those with more than 150 rooms)

5



The division by category also gives an idea of the size of the rooms :

• One and two stars hotels with an average of 22 square meter per room

• Three stars hotels with an average of 32 square meters per room

• Four stars and luxury hotels (5 stars) with an average of 42 square meters

per room

The space of a hotel can be divided into 3 areas with different purposes. First of

all, there is the guest room area (bedrooms, toilets, bathrooms, etc). Second,

there is the public general service area (reception hall, bar, restaurant, meeting

rooms, swimming pool, etc). And third there is the service area (kitchen, offices,

store rooms, laundry, etc). For energy savings, these three areas have to be

looked at separately, with different requirements. Comfort is more important in

the guest room area than in the service area, for example.

2. Energy data of a Hotel

2.1 Energetics, or the energy balance of hotels

About 40% of the energy used in a hotel is electricity, 60% comes from natural

gas and oil fuels. These energy bearers are bought in by the hotel. The energy is

converted by a number of conversion systems into the most important internal

flows of energy, namely heat, cold and electricity. These energy flows are used

for among others the following applications:

Heat is used in the form of hot water or in the form of steam. Steam is rarely

used in hotels. Hot water is used in the form of central heating and hot tap water.

Central heating can be done by radiators in the rooms, or by heating installation

in the HVAC units. Gas-fired boilers or cogeneration systems generate the heat.

Electricity is used for a wide variety of purposes. The largest electricity

consumers in a hotel are lighting, HVAC fans, cooling machines, circulation

pumps, some water heating, food service and office equipment.

Cold is used mainly in HVAC systems, for cooling and drying the ventilation air.

Mostly, cold is produced in the form of ice water.

In many cases cold is generated centrally by means of compression coolers. In

combination with cogeneration, absorption-cooling machines are used to

supplement compression coolers.

The breakdown of the typical energy flows is shown in Figure 2 below. (source :

National Action Plan for energy efficiency – US EPA)

6

Energy Efficiency


Figure 2 Typical Total Energy Consumption by End Use in Hotels

Figure 2 shows that heating (both of space and water), cooling and lighting

account for a large part of the energy consumption.

The thermal energy consumption is mainly for space heating and water heating.

The typical electrical energy consumption is shown in Figure 3 (source : National

Action Plan for energy efficiency – US EPA)

Figure 3 Electric Consumption by End Use in Hotels

7



2.2 The major energy users in a hotel

In the following paragraphs the main energy consuming systems of a hotel are

discussed. These are :

• Space Heating

• Air conditioning and ventilation

• Hot water production

• Lighting

• Other applications

For each of these areas we give a general explanation, followed by an inventory of

opportunities for efficiency improvement. Some practical examples taken from

various studies carried out in the Netherlands, Belgium and Germany follow in

Chapter 3 Case studies.

The competition, the importance of reducing costs and the growing sensitivity to

environmental factors in hotel design, are a challenge for the hotel managers.

These factors are leading to the introduction of elements with reduced

environmental impact and energy saving measures. The importance of energy

saving is underlined by the fact that, after staff, it makes up the largest proportion

of hotel running costs.

Space Heating

Figure 2 shows that space heating accounts for 1/3rd of the energy consumption of

many hotels.

Rising energy costs have forced the design of modern hotels to take energy

efficiency into account, without touching the comfort level and aesthetics that are

vital for the hotel business.

Space heating should preferably be done using a directly fired gas boiler. Heating

oil boilers can also be found, but the efficiency of today’s gas boilers is much

higher than that of heating oil boilers.

Following rules of thumb have to be taken into account for heating :

Ensure good pipe insulation. The losses from a non-insulated pipe are huge.

Fittings such as valves and flanges must also be well insulated.

Flue gas losses must be kept as low as possible. This is done by keeping the flue

gas temperature as low as possible, using economisers on the flue gasses.

Today’s directly fired gas boilers work strongly on this principle (condensing gas

boilers).

Autonomous temperature control systems should be used to enable the

temperature in a room to be lowered when it is not occupied, keeping it at a

8

Energy Efficiency


standby level so that it can be quickly restored to the normal level. As the

different

areas in a hotel (guest rooms, meeting rooms, etc) have variable, and not

simultaneous, periods of occupation, the time during which they are in use is the

most important factor with regards to energy consumption. When occupied, a

guest room can be heated to 20°C (+/- 2°C), but when unoccupied, the standby

heating should be lower. Then, temperatures of 16 to 18°C are more than

sufficient, for quick restoration to be possible. In winter, it is even recommended

that rooms that are unoccupied for a longer period of time, are on minimum

heating at 12 to 14°C. Autonomous control systems can save energy up to 20-

30%.

Air conditioning and Ventilation

For the air conditioning and ventilation of the hotel areas there are usually

various units available. As the occupation of the various hotel areas is different,

the comfort level required in each zone is different and the load (decorative

lighting, heat losses, solar gains, etc) is variable, the HVAC installation has to be

engineered to answer these different needs.

Depending on the conditions, the air may be heated, cooled, humidified and/or

filtered. Cooling, heating and humidification are generally done by a central

generating station of heat and cold.

Some typical applications in a hotel and their particular characteristics are :

• Guest rooms: depending on the type of hotel and the environment, guest

rooms are generally only used to relax and sleep in. Comfort level

requirements at night are lower than by daytime, so this has to be taken

into account in setting the HVAC parameters.

• Meeting rooms: used only during “office hours” with HVAC to suit the

comfort of people in these areas.

• Restaurant: almost continuously occupied, except during the night. HVAC

set to suit the comfort of the people there.

• Inside swimming pool, sauna and wellness area: HVAC to control the

conditions of higher humidity. Comfort level is at a higher temperature than

guest rooms, but occupancy hours are different. Outside opening hours, it

is important to set HVAC to a lower level to reduce energy consumption.

The energy consumption within an HVAC unit is accounted for by the following

main applications:

• Heat, for heating the air

• Cold, for cooling and drying the air

• Electricity, to drive the fans

• Steam, to humidify the air

9



Steam is a very expensive form of energy, so for HVAC installations it is very

important to check the need for humidification of the air before steam is

produced. Mostly, the vapour is electrically produced for this application.

Some energy saving measures for HVAC systems in hotels are (excluding

building design considerations):

• Installing frequency controllers on the fans

• Recovering heat from the extraction air

• Optimising the running hours

• Optimising the temperature and humidity

Domestic Hot Water

The energy required to produce domestic hot water can account for up to 17% of

the total energy consumption of a hotel (see Figure 2). Domestic hot water

requirements in hotels are very different from category to category. For example,

a five-star hotel requires around 150 litres per guest per day, while for a three-

star hotel only 90 litres per guest per day are used. Hot water is mainly used for

baths and showers in the guest rooms, for services (cleaning ao) and in the

kitchens.

The principal hot water production systems are:

• Accumulation systems, where water at the required temperature is stored

ready for use in insulated tanks. The water is heated using a directly fired

gas boiler or a heating oil boiler, and then stored in an insulated tank.

Limitation here is the response time when the demand for hot water is high

and the storage tank is emptied to quickly.

• Instant heating systems, where hot water is not stored, but is produced

when and where required. Such systems require great instant power to

cope with peak demand periods. Limitation here is that the installation has

to be designed for maximum demand of hot water. Most of the time there is

no over-dimensioning done for cost reasons, so when the hot water

demand peaks, the system is working at its limit.

• Mixed systems where there is limited hot water storage so as to reduce

power demand during periods of large consumption. Hot water is normally

stored at a temperature of 60°C. With this system the limitations of

accumulation systems and instant heating systems are somewhat reduced.

The production of hot water using solar energy can give important energy

savings. The efficiency of solar panels depends on the intensity of solar

radiation, and the sunshine hours per year. In Southern Europe, where there are

many sunshine hours, solar energy systems are a viable solution.

10

Energy Efficiency


Some measures for energy savings in the production of hot water without

compromising the comfort level, are:

• Insulation of piping and storage tanks.

• Installation of low consumption systems in showers and baths without

reducing quality of supply.

• Installation of hot water consumption meters in order to monitor

performance of services.

• Installation of programmed taps in toilets and services in general service

area.

• Minimisation of hot water leaks through correct maintenance of pipes and

taps in showers, baths and hand basins.

Lighting

Lighting is one of the largest electrical energy consumers in hotels, as in many

other kinds of utility buildings. Figure 2 shows that some 12% of the total energy

consumption in hotels goes to lighting.

Lighting installations must provide adequate levels of illumination for each

activity. Aesthetics and comfort level are also important for lighting inside hotels,

depending on the area where lighting is required.

Lighting levels necessary for each zone are established in the lighting regulations

of each particular country. These levels should be reached by the most suitable

lamps for each application. When it comes to the energy savings that can be

made on lighting, there are two main ways.

EFFICIENT LIGHTING

Required lighting is supplied by light sources, which are made up of lamp and

luminaries. The choice of light source depends on various criteria, ao : efficiency,

colour temperature, colour rendering index, lamp life, emission mode, ... Lighting

in the different areas of the hotels have different requirements, but it is very

important that the most efficient lamp and armature is chosen for each

application. For corridors in large hotels for example, with many guests using the

same corridor, the lights stay on 24/7 all year long, so here the CFLs (compact

fluorescent lights) are the way to save energy. For corridors in small hotels on

the other hand, where less guests use the corridor, a motion detector with

incandescent lamps could be better. For more information on lighting, please

refer to the Energy Efficiency Application Guide on Lighting.

Fluorescent tube lighting (TL) is a very efficient way of lighting, but it isn’t always

aesthetically the right choice. For parts of the hotel were the atmosphere should

be warm and comfortable, a fluorescent tube is not the right choice. Accent

lighting is also very difficult using tube lighting.

11



However, where possible, compact fluorescent lamps should be used instead of

light bulbs. (remark : replacing an incandescent lamp with a CFL improves

efficiency drastically, see AG Lighting).

Luminaries direct artificial light towards the zone to be illuminated, avoiding

lighting spaces where it is not required and distributing light in a balanced way.

Use of localised lighting instead of global lighting can also be a form of energy

saving (less spoiling of Watts over a whole area and only lighting where it is

needed).

SMART SWITCHING

Another savings can be achieved with “smart switching” of the lighting. Lighting is

frequently switched on unnecessarily when e.g. there is sufficient daylight or

there is nobody in the room. With manual operated systems especially, lights

tend to be left burning needlessly. The advice is therefore to make the greatest

possible use of automatic light regulating equipment. Examples include:

• Daylight sensors

• Presence sensors

• Connection to the building management system (BMS)

• Timers

For example, in some hotels the lighting inside the guest rooms can only be

switched on when the guests are inside the room using a key card, and are

switched off automatically when the guests leave the room taking the key card

with him.

Other applications

Figure 3 shows that also cooking (food preparation) and other equipment use an

important amount of energy in a hotel.

Depending on the equipment in a hotel, it is important to use the adequate

technologies for the specific applications. For example, some hotels have a

kitchen that only support the preparation of breakfast, which has other

requirements than a kitchen for a large number of meals per day.

Other possible equipment are lifts and service lifts, office equipment, laundry

equipment (when this is not outsourced), etc.

2.3 Specific consumption for hotels

Energy consumption in hotels accounts for up to 6% of the total running costs.

Due to the huge variations which exist regarding types of establishment, number

of rooms, category, geographical location, etc., it is difficult to arrive at a standard

classification of energy consumption in hotels. However, it is possible to define a

range for energy consumption in a hotel, see Figure 4 below.

12

Energy Efficiency


Figure 4 Energy benchmarks for the Hotel sector

There are multiple ways to do benchmarking in the hotel sector, but the

difficulties are numerous. Some hotels have their own laundry service, which

implicitly means a higher energy consumption. Other hotels outsource their

laundry. Some hotels have an indoor swimming pool, others don’t. Depending on

the influence of the seasons, the occupancy level of the guest rooms can vary

throughout the year. This is why there is a spread for the energy consumption of

hotels, and not just an average number.

13



Figure 5 Electrical energy use of a hotel (+/- 17 000 m²) on a typical

summer day, before energy saving measures

Figure 6 Electrical energy use of the same hotel, after energy saving

measures

Figure 5 and Figure 6 show a typical hotel load profile before and after energy saving

measures. Energy measures taken here, include optimising temperature set points in

common areas, optimising HVAC set points (schedule and ventilation demand) in

common areas, optimising chiller settings, power management for office equipment and

optimised use of laundry programs. The investment for these measures is minimal, and

the energy saving can go up to 4-8%. Other energy saving measures (like more efficient

lighting, occupancy sensors, high efficiency chillers, etc), ask for an investment, but

depending on the acceptance of the payback time, can further reduce the energy

consumption drastically (sometimes up to 30-40%).

14

Energy Efficiency


2.4 The relationship between degree days and energy consumption

When looking for factors that influence the energy use, analysis shows that the electrical

energy use is more or less constant. The thermal energy use is influenced by the degree

of occupancy (if the allocation of rooms is done properly) and by the outside temperature.

The influence of the outside temperature can be analysed by checking for a possible

correlation between the degree days and the thermal energy consumption. For more

information on degree days, refer to http://www.degreedays.net

In Figure 7 this analysis is shown for a typical Amsterdam hotel. This figure shows that

there is a very strong relation between thermal energy use and degree days.

Figure 7 Correlation between natural gas use of a hotel and degree days

per month for an Amsterdam hotel

15



3. Case studies

In Chapter 2.2 the major energy users in a hotel were discussed. In the following

paragraphs we look at a number of case studies for energy saving options.

The hotel sector in all its guises is faced with a number with a number of energy

savings solutions with payback periods ranging from immediate to up to 3-4

years. The following cases illustrate how different hotels have applied some of

them.

These case studies are taken from various studies carried out in the

Netherlands, Belgium and Germany.

In the calculations the following rates are used for gas and electricity:

• Gas price: 50 €/MWh

• Electricity price: 120 €/MWh

The profitability calculations are done on the basis of the energy savings

achieved, without taking into account any government subsidies or maintenance

savings that could further reduce the payback period, since government

subsidies vary greatly from one country to the other.

The underlying formulas and calculations are not presented in this guide; only

the results are given. Further details can be found in the application specific

guides, issued in this series.

Case 1: Heating – changing the setpoint of the heating and

changing the way of allocating the guest rooms

Introduction

The hotel in this case is a medium sized seaside hotel, and has full air

conditioning. The heating of the non-occupied rooms is off when there are no

guests. There seems to be no relation between the occupancy of the rooms and

the natural gas consumption. The cause of this can be found in the fact that in

periods of low occupancy of the hotel, the allocation of the rooms is random.

16

Energy Efficiency


Present situation

In periods of low occupancy, the allocation of rooms is random. This way, it is

possible that several corridors are heated indirectly, with only a few rooms per

corridor that are occupied. Also, when the room is occupied, the heating has a

setpoint of 20°C, all throughout the year.

Proposal

A better allocation of the rooms in periods of low occupancy, can save energy.

When corridors are left empty (as is the case in many hotels), energy is saved

and a direct relation will show between natural gas consumption and the degree

of occupancy.

Also when the heating set point is set to 18°C in winter, instead of 20°C, also a

great deal of energy will be saved. Of course the guests can change the heating

according to their needs, but 18°C is used is most hotels for wintertime.

Estimated savings & investment

The savings in a better allocation of the guest rooms can amount up to 4% of the

natural gas use of this hotel. In this case, this means an annual saving of 80 000

kWhth or € 4 000. This way a direct relation between natural gas use and the

occupancy of the guest rooms will show.

The savings in changing the set point of the heating in wintertime to 18°C instead

of 20°C : in many hotels, the set point of the heating in wintertime is between 16°

C and 18°C. Per degree of lowering the set point, 3 to 5% of the natural gas used

can be saved. As this measure is only concern part of the year, and because the

hotel has heat recovery systems on their HVAC installation, the savings by

lowering the set point in wintertime are estimated to be around 3% of the natural

gas consumption. For this hotel this means an annual saving of € 3 000.

The required investment is nil.

However, the policy of some hotel chains can be in conflict with this measure. If

the policy states that the guest rooms have to be heated to 20°C throughout the

year, then it will be more difficult to implement this energy savings measure.

Case 2: HVAC – Turning off the HVAC in the restaurant and

conference rooms during night time

Introduction

The hotel in this case is a large hotel. In the hotel there are various HVAC

systems. For the restaurant and conference rooms, the HVAC installation also

has a heat recovery installation.

17



Present situation

At present, the night mode of the air conditioning for the restaurant and

conference rooms is tuning down the air flow to 50%.

Proposal

The proposal is to turn off the air conditioning for the restaurant and conference

rooms all together at night.


The savings are achieved in terms of electrical energy (the fans can be turned

off) and in terms of gas consumption (no more heating of the air). The gain in gas

consumption is lower than it would be for a system with no heat recovery, but is

still significant.

The HVAC settings are currently as follows for the night mode:

On the basis of the above parameters, the saving can be calculated as follows:

The annual energy savings amount to 3 MWhe/year and 60 MWhth/year, or a

financial saving of € 3 626 per year.

The investment needed for this measure is very low : only a new setting in the

Building Control System, setting the night mode to ‘OFF’ instead of to half the air

flow of day mode. Payback time is less than 1 month.

Ventilation air supply rate (is half the air flow of day mode) : 5 500 m3/hour

Temperature : 20 ºC

Ventilation operating hours : 8 h/night

Present gas consumption (heating) during night mode : 60 MWhth/yr

Present electrical energy consumption (ventilators) : 3 MWh/yr

Degree-hours on basis of 20°C (+1°C with respect to ventilator) : 27 674 hK/year

Economical saving : 3 626 €/year

18

Energy Efficiency


Case 3: HVAC – Installation of a VSD pump for hot water

circulation to HVAC installation

Introduction

The hotel in this case is a large hotel, with hot water generated centrally for

heating application in the HVAC installation.

Present situation

The hot water is centrally produced. The circulation of this hot water for heating

application in the HVAC installation is currently done by a regular, non-VSD

pump. The current pump is constantly running, independent of the degree of

occupancy in the hotel. The circulation pump can be manually adjusted from 100

W to 1 750 W. At the time of the audit, the pump was set to 1 000 W.

Proposal

The installation of a VSD (Variable Speed Drive) pump. Depending on the

demand, the flow is regulated by the VSD pump, which results in energy savings.


Figure 8 Power consumption of current pump (pink) and VSD pump (red)

in relation to the demand in heating

19



Figure 8 shows the power consumption of pumps depending on the heat

demand. The pink line shows the power consumption of the current pump, the

red line shows the power consumption of a VSD pump. For example, at a flow of

60%, which occurs about 600 hours per year, the VSD pump only uses about 0,5

kWh per hour, whereas the current pump uses 0,9 kWh per hour, or for this case

240 kWh per year more. For the hotel in this audit, the annual savings amount to

3 MWh of electrical energy, which is € 360 per year.

The investment comprises in installation of a VSD pump, which amounts to € 1

250. This give a payback time of 3,5 years.

However, when the current pump breaks down and has to be replaced, the

investment of a new pump is necessary, and the advantage of a VSD pump is

much more easily accounted for. The price difference is about € 400, so the

investment in a (bit more expensive) VSD pump will have a payback time in that

case of a little bit more than 1 year.

Case 4 : Maintenance of condenser coils

Introduction

The hotel in this case is a large hotel. In the hotel there are various HVAC

systems.

Present situation

The maintenance of the condenser coils is very poor, so these are very dirty.

Proposal

Cleaning and regular visual inspection of the condenser coils. Replacing filters

on a regular basis.


A dirty evaporator coil or condenser coil will reduce cooling capacity and degrade

equipment efficiency. Exposed to unfiltered outdoor air, condenser coils easily

trap dust and debris, which raises the condensing temperature and reduces the

cooling capacity. A clogged evaporator coil reduces air flow through the coil, thus

causing the compressor motor to consume more energy.

Studies have shown that a dirty condenser coil can increase compressor energy

consumption by 30 percent (ref. Pacific Gas & Electric). Visual inspection and

yearly cleaning can avoid this. Replacing filters on a regular basis will keep the

evaporator coil fairly clean.

20

Energy Efficiency


For the hotel in this case, the estimated savings amount to 10% of the energy

consumption for cooling, meaning a yearly savings of 40 MWh or € 4 800.

The cost for cleaning of the condenser coils is only the man days, which amounts

to some € 1 000 or so. Payback time is less than 4 months.

Cogeneration

Cogeneration is combined generation of heat and electricity. An important factor

for the viability of a cogeneration unit for a hotel, is the continuous demand for

heat and electricity..

The installation of a cogeneration system is only viable for hotels of a certain size

and system of functioning. Hotels should be medium-sized or large and not

seasonal in type. The number of hours functioning decides whether a

cogeneration unit will be viable or not.

Cogeneration systems generate both electricity and thermal energy from one

single fuel (such as natural gas). Exhaust gases from combustion are used to

heat water for domestic use or heating. This heat can also be used by absorption

machines to produce cold for refrigeration purposes.

An important factor for the economic potential is that good use has to be made

not only of the electricity but also of the heat. This means that there has to be a

continuous demand for heat as well as electricity. It is important for the

investment to be optimal, that the cogen-plant should supply electrical energy

over the greater part of the day, but when demand is high during peak

consumption periods, the grid covers for the shortfall of electricity.

For maximum energy saving, the engine should be sized according to the

thermal demand of the hotel.

Solar energy in hotels

One of the most commonly used methods of the utilisation of solar energy in

hotels is for the production of hot water.

Since energy consumption in a hotel for hot water consumption can amount up to

40% of total consumption, it is clear that thermal solar equipment has high

potential in this sector.

The viability of the solar energy system depends on the number of sunshine

hours per year. This means that in the southern countries the investment in solar

energy will pay back much quicker than in other parts of Europe.

An interesting application of solar energy in hotels is the heating of swimming

pools. Investment costs for such systems is lower, as the required water

temperature is lower than for domestic hot water.

21



Application of solar energy for electricity has not been viable for a long time, but

because of the rising energy prices, this solution starts to be interesting for

hotels. Depending on subsidies and legislation, the investment can have a

payback time of 5-10 years.

4. Conclusion

Because of the high diversity in the hotel sector, it’s not easy to do benchmarking

or to talk about ‘the standard hotel’. There are several types of hotels where the

energy use is comparable, but depending on the environmental influences, the

government rulings and the attractiveness for tourists, the energy savings can

easily pay back the investments or not. The installations as they are designed

and installed, aren’t always used in an optimal way. Adjusting settings and better

maintenance already can save energy.

The use of energy in the hotel sector is mainly for application in heating, air

conditioning and ventilation and lighting. There are several possible measures to

save energy for each of these applications, but the quantitative saving potential

depends on external factors (hours of sunshine, occupancy, subsidies, etc).

Important things to look at for a hotel manager who wants to save energy, are

• For heating: the insulation of piping and the flue gas losses (gas fired

boilers), ...

• For HVAC: frequency controllers on the fans, optimising running hours/

temperature/humidity, ...

• For DHW: the insulation of piping, low consumption systems in showers

and baths, ...

• Lighting: smart & efficient lighting

energy efficiency in hotels

Documents