Energy Efficiency In Hotels

Power Quality & Utilization Guide

Hotels Niki Hendrikx Laborelec November 2008

Energy Efficiency

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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.

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Application Guide for Hotels www.leonardo-energy.org Hotels and similar establishments Belgium Bulgaria Czech Republic Denmark Germany Estonia Ireland Greece Spain France Italy Cyprus Latvia Lithuania Luxembourg Hungary Malta Netherlands Austria Poland Portugal Romania Slovenia Slovakia Finland Sweden United Kingdom Croatia Macedonia Iceland Liechtenstein Norway Switzerland

2006 1955 1348 4314 473 36201 341 4296 9111 18304 18361 33768 753 321 338 277 2032 173 3099 14051 2301 2028 4125 358 922 923 1888 39107 762 150 308 46 1119 5693

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.

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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)

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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)

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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

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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

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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 2030%. 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

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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 threestar 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.

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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.

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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.

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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.

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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%).

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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

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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: Electricity price:

50 €/MWh 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.

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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.

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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. Estimated savings & investment

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: Ventilation air supply rate (is half the air flow of day mode)

: 5 500 m3/hour

Temperature

:

Ventilation operating hours

:

20 ºC 8 h/night

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

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.

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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. Estimated savings & investment

Figure 8 Power consumption of current pump (pink) and VSD pump (red) in relation to the demand in heating

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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. Estimated savings & investment

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.

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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.

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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

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