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L’énergie dans le développement de la Nouvelle-Calédonie

 | 
Yves Le Bars
, 
Elsa Faugère
, 
Philippe Menanteau
, 
et al.

Energy management: a major challenge for New Caledonia’s sustainable development and its energy security

Energy management in the building and household equipment sector

Texte intégral

1The issue of demand side management and energy efficiency in buildings is fundamental, given the scale of the opportunities identified and, above all, the possible scope for action. Indeed, thanks to the immediate availability of mature technologies and techniques, the building sector is actually in a position to provide effective help to resolve the environmental challenges we are facing. However, this is a sector that has a reputation for changing slowly because of the long lifetimes of buildings and inertia in the building industry.

THE CURRENT SITUATION AS REGARDS DEMAND SIDE MANAGEMENT IN THE BUILDING AND HOUSEHOLD EQUIPMENT SECTOR IN NEW CALEDONIA

Climate issues

2Situated in the middle of the Pacific Ocean, New Caledonia is located at an average latitude of -21.5° and a longitude of -165°. The path of the sun (height and azimuth) is almost identical to that on the island of Reunion (-21° south latitude and 55°30’ east longitude).

3At 12 midday, an observer in New Caledonia would have the sun to his/her north for the majority of the year, and to his/her south for the rest (during the month of December). The path of the sun is relatively high throughout the year.

4Average daily solar radiation is of the order 5.4 kWh/m2/day. During the hot season (summer), it can exceed 7 kWh/m2/day whilst during the cool season (winter), it drops a little lower to around 3.5 kWh/m2/day. Diffuse radiation makes up around 40% of the overall radiation received. By way of comparison, annual sunshine levels are slightly higher than on the island of Reunion and almost identical to the West Indies.

5Temperatures are particularly mild in New Caledonia: an annual average of 23 to 24 °C, with a very slight difference between the north and south of the island, i.e. practically the perfect atmospheric temperature for human habitation.

6The annual positioning study of all external environmental conditions, plotted on the humid air diagram, enables thermal comfort in external environments to be defined. The grouping of points displays an absolute minimum temperature of the order of 16 °C, an absolute maximum temperature of 33 °C and minimum relative humidity of approximately 45%. Statistically, sources of discomfort stem from periods associated with a feeling of coolness/coldness (6% below 19 °C), heat (10% below 28 °C) or excess humidity (5% above a relative humidity of 95%). When areas of discomfort are excluded, it is clear that human beings enjoy acceptable levels of comfort for 83% of the time (in the shade).

Figure 3. Thermal comfort in external environments
The maximum enthalpy line of the point grouping is of the order of 85 kJ/kg as. This value is significant when specifying air-conditioning systems. It corresponds to a temperature/humidity ratio of 31 °C with 70% humidity.

Natural potential and options for covering a building’s requirements

Producing thermal comfort naturally

7Hygrothermal comfort is linked to the combined influence of air temperature, radiant temperature (in particular, the overheating of walls caused by solar radiation), air speed and the level of humidity in the air. Humidity is an effect that counteracts sweating, i.e. the cooling process of the human body. On the other hand, air speed facilitates this process and creates a sensation equivalent to a temperature reduction of 4 to 5 °C with an air speed of 1 m/s. It is therefore essential to look at this data when analysing the climate.

8High temperatures, naturally, have a strong correlation with solar radiation. Nevertheless, in this particular case, nature does a great job my making the hottest hours of the day the windiest. The external wind speed is 5 m/s during the hottest hours of the day: there is therefore, at the time when it is most needed, amazing potential for countering the addition of heat by natural ventilation and generating air speeds of 1 m/s within buildings. To properly mitigate the input of the sun, an air renewal rate of 10 to 15 Vol/h is desirable. Given the level of wind, this type of air renewal is relatively easy to establish. In general, a ratio of openings of 3 to 4% of the net surface area is sufficient to mitigate the internal load on buildings.

9On the other hand, in order to obtain speeds of the order of 1m/s in dwellings (to facilitate the sweating process), the challenge is more difficult. The level of porosity needed is higher - of the order of 20% for external walls. However, the fact that this criterion is not met is not critical for naturally cooling premises, because the use of fans compensates for insufficient air speed within a building. It should also be noted that the power consumption of this type of equipment (A-rated) is very low compared to an airconditioning system.

Air-conditioning: a genuine need?

10As for heating, the degree hours for air-conditioning provide an indication of the theoretical need for air-conditioning. The debate on whether airconditioning is needed or not must initially be examined sector by sector.

  • For residential buildings, the low level of internal loads (a daily average of less than 5 W/m2), combined with excellent control of the input of the sun (thanks to a good shell design according to the Ecocal system) enables the total input to be reduced to less than 40 W/m2.

  • For tertiary buildings, the internal input by office equipment and lighting is frequently higher than 20 W/m2, given the increasingly high occupancy levels of premises (1 occupant/10 m2, or even less). When climatic inputs are added, a “best case” total input of 50 to 60 W/m2 is obtained. With ventilation of around 15 Vol/h, average overheating during the day is of the order of 4 to 5 °C. For acceptable working conditions, i.e. limiting overheating to 2 °C, in addition to good bioclimatic design, it is necessary to reduce the occupancy level (which brings us into conflict with the issue of property costs), to work on natural light to limit the input of lighting, to increase the efficiency of office equipment and to make provision for greater natural ventilation. The optimum air renewal rate should preferably be between 20 and 30 Vol/h.

11Despite everything, creating an alternative to air-conditioning in the tertiary sector comes up against three obstacles: profitability for investors, the productivity of people working in the building (air-conditioning provides a constant level of comfort, whereas natural air-conditioning produces an average comfort level with the possibility of drift for a few hours a year) and behavioural stereotypes (wearing ties, the positive image of air-conditioning).

  • In the education sector, the thermal profile is mainly affected by the internal input of students: one student per 1.5 m2 in primary education and one student per 2.7 m2 in secondary education, but in a range of occupation smaller than those of tertiary buildings. With lessons taking place at the best times of day, artificial lighting is rarely used, if the building is well designed. The average input caused by occupancy during the day is of the order of 15 W/m2. With good through-ventilation (between 20 and 30 Vol/h) and good bioclimatic design, average overheating can be limited to 2 to 3 °C, creating acceptable levels of comfort.

12As energy requirements are determined by the occupancy profile depending on the time of year, it would be interesting to examine the benefits of a seasonal shift in living patterns. In tropical areas, this shift is very small, given that there is little change in the length of the day over the course of the year. However, New Caledonia is located on the very edge of the humid tropical zone and variations in daylight hours are appreciable with a difference of 2.6 hours between the shortest and the longest day.

13The main challenge when shifting time comes during the hot season ; in order to recover an hour of natural sunlight in the morning and to operate air-conditioning for one hour less at the end of the day. Given that the school year begins at the hottest time of the year, establishments are starting to equip their classrooms with air-conditioning. Giving students a positive image of air-conditioning in this way may have immediate and catastrophic consequences; triggering a desire for the same equipment at home and, ultimately, by creating a new need for future adults. The gradual spread of air-conditioning in educational establishments is a dangerous line that should not be crossed, as it would strip all credibility from awareness campaigns covering environmental issues and saving energy.

14A number of hot countries determine the level of activity/business on the basis of climatic constraints. In New Caledonia, the hottest months are also those when the days are longest. Businesses could therefore adapt their opening times to benefit from the coolest hours and take better advantage of natural lighting. Some people are advocating the return of the traditional siesta (30 minutes at the beginning of the afternoon), following the example of countries like Vietnam, where this practice is common.

15Dress codes also have a harmful influence on demand side management, in particular where they refer to European clothing (ties and jackets). The primary effect of clothing is to help “retain” the heat released by the body by increasing the ambient temperature around the body by approximately 8 °C for European mid-season clothing and between 3 and 4 °C for light-weight tropical clothing.

The benefits of cold-storage

16First of all, it is economical: removing daily peak periods characterised by brief use of maximum power. Cold storage may enable the power of a refrigerating unit to be reduced (by up to 40%), as well as reducing the contracted amount of power and enabling users to benefit from the network’s off-peak rates. Its profitability depends on the pricing system for peak power. As regards environmental audits, specifically for CO2 emissions, these depend on the nature of the resources used during peak periods to produce electrical energy.

Solar air-conditioning: the current situation

17Solar-powered air-conditioning, which does not consume fossil fuel, is now available, but the technology is far from being mature. The main benefits of air-conditioning using solar absorption are that is uses twenty times less power than traditional air-conditioning systems and that the fluids used are not harmful to the environment. New Caledonia has serious potential for development in this area as solar radiation is extremely high at the hottest times of day.

18It would be particularly interesting to set up a number of pilot schemes in order to better assess the actual performance of this type of system under the climatic conditions for the territory in question. The additional cost, of the order of 50% compared to a classic system, varies depending on the output, and its physical limit is the building’s collection area in relation to the area to be air-conditioned.

Natural lighting

19Lighting is a major energy expenditure item, specifically in the tertiary sector where requirements are high. In New Caledonia, the need for lighting can be largely met by natural light, the resources of which are endless, provided that the design is good in terms of coverage.

Producing hot water

20Heating 1m3 of cold water to 55 °C requires a quantity of energy of the order of 37 kWh per cubic metre per day in New Caledonia, which is roughly 30% less than systems in mainland France. The New Caledonian cli-mate allows the majority of demand for hot water to be satisfied using a solar-powered system. This is why, where the area for producing hot water is sufficiently exposed, heat pumps are less efficient than a well-dimensioned solar-powered system, in particular for private homes. The only reason for possibly using heat pumps would be where solar panels cannot be sited in a sufficiently well exposed location.

Other domestic requirements

21Apart from cooking, the majority of domestic tasks require electrical power: lights, cookers, fans/ventilation, refrigerators, televisions, computers, washing machines and dishwashers, etc. For these last two items, most water can be heated by solar-powered heating. Excluding cooking and heating domestic hot water, overall consumption, in mainland France, is of the order of 3,000 kWh a year per household. With efficient equipment, which is suited to sustainable development, consumption could be reduced to less than 2,000 kWh a year.

22In order to make-up for fossil fuel consumption by this electrical equipment, it is possible to envisage the equivalent production of solar power in a photovoltaic form. The optimum orientation for solar panels in New Caledonia is facing north and tilting 20°.

23Another way of making up for fossil fuel energy: wind power generation in an urban environment. With an average wind speed of the order of 5.5 m/s in Nouméa, it is possible to envisage considerable productivity of around 1,500 to 2,000 kWh/kW (this varies depending on the brand and the technology).

24The technologies that are most suited to the blustery conditions in towns and cities are vertical axis wind turbines, which capture turbulent energy. Nevertheless, in order to develop, this sector has a number of obstacles to overcome:

  • the products are not mature in terms of safety, certification procedures and standardisation,

  • the economic profitability (financial return) is low (the cost of each kWh produced is more than 15 c€/kWh),

  • on a local level, this assumes that buy-back prices per kWh will adjusted for the network and that a network of professionals will be developed.

Cooking

25Classic hobs and ovens traditionally use gas or electricity. The current power source, electricity, being a heavy polluter, it is easy to envisage the use of solar power for some of these tasks. In all events, cooking with gas should be preferred to electricity, given the primary energy content of each kWh of electricity (1 kWh of electricity is equivalent to 3 kWhep). The issue of organising genuine competition for distribution - or market regulation by the public authorities - is a fundamental challenge in this case.

26Initially seen as a gadget, solar-powered cooking is no longer the province of a small number of self-build disciples. The range of commercial products for private homes is beginning to expand around the world and there are also a number of major mass-catering projects, in India in particular, which have demonstrated the effectiveness of the process. The basic principle – concentrating solar power – applies to different types of equipment: ovens, barbecues, pressure cookers, steamers, etc. The space needed for this type of system is approximately 1 m2 oriented horizontally and tilting slightly to the north, depending on the season.

Using solar power for transport?

27For short urban journeys, electric bicycles are the perfect mode of transport. With power consumption of 10 Wh/km and recharged by the sun, for an average journey of 30 km a bicycle requires a quantity of power of 300 Wh, i.e. the production for a photovoltaic panel measuring 1 m2.

28With an electric car recharged by a photovoltaic system, based on daily mileage of 40 km and consumption of 0.15 kWh/km, average daily consumption is 6 kWh. A well-aligned 13 m2 unit, facing around 15° north, will be capable of recharging an electric car using solar power. The fossil fuel saved in this way would be around 3 litres of petrol a day, based on theoretical fuel consumption of 7 litres/100 km.

How large a collector area is needed to create energy positive buildings?

In the residential sector

29The feasibility of solar power coverage for the various energy requirements of a New Caledonian household (4 people, 100 m2), with well-designed bioclimatic accommodation, amounts to a solar collector area measuring approximately 60 m2 for a heavily equipped household (air-conditioning, 2 cars). An identical household, which is “aware of sustainable development”, with a single car and natural air-conditioning, needs a solar collector area half the size.

In the tertiary sector

30The possibilities for reducing the input of the sun as part of good climatic design are set at around 40 W/m2. The main problem resides in the compromise between allowing light in, in order to maximise light, and limiting the input of the sun. Major progress in terms of sun blinds (shading devices) and glass designed to filter infrared radiation offer the prospect of considerable light transmission with a low solar protection factor.

31For premises designed without air-conditioning, the greatest difficulty is to ventilate them well, in particular to obtain sufficient air speeds by through-ventilation. It is easier to envisage adequate mitigation of the input of the sun using through-ventilation and to rely on fans to generate the required air speeds.

THE CURRENT SITUATION AS REGARDS DEMAND SIDE MANAGEMENT IN THE BUILDING AND HOUSEHOLD EQUIPMENT SECTOR OUTSIDE NEW CALEDONIA

Thermal regulations in the intertropical convergence zone

The example of Australia

32In 1999, a national strategy for combating the greenhouse effect set the goal of producing improved energy efficient buildings, by encouraging voluntary “good practice” in the design, construction and operation of buildings, and by incorporating a simple minimum efficiency requirements standard in the Building code of Australia (BCA).

33According to this standard, the thermal efficiency of dwellings is primarily obtained by means of heat transfers resulting from the shell, whereas the priority, for other categories of buildings, is internal loads, which can alter the recommended level of insulation.

34Efficiency levels are defined by the consumption of energy, the cost of the latter and CO2 emissions, and relate to the unit values of floor area, number of occupants and number of rooms. Finally, a three-stage programme was proposed to establish the required efficiency levels:

  • the compilation of a list of locally appropriate measures by consensus between experts,

  • the selection of measures, which are economically efficient,

  • the determination of efficiency levels on the basis of examples, which include these measures.

The example of ASEAN countries

35The standard ASHRAE method is also used by and adapted for various ASEAN countries, which need to meet the requirements of thermal regulations based on global shell heat transfer coefficients known as the Overall Thermal Transfer Value (OTTV). The air-conditioning load is subsequently estimated on the basis of degree days.

The example of overseas departments

36In April 2009, following ten or so years of development, thermal regulations for overseas departments finally formed the subject of a ministerial decree. These regulations specifically make provision for the modification of building and housing legislation (CCH) for new homes, with the creation of a chapter entitled “Special provisions for the departments of Guadeloupe, Guyana, Martinique and Reunion”, which sets out the principles and guidelines and reflects decrees adapting the regulations to the specific aspects of overseas departments, in terms of heat, ventilation and acoustics. The primary aim is to improve the thermal efficiency and energy ratings of new homes within the limits of acceptable costs.

37The planned adaptation defines, at an initial regulatory stage, standardised levels of requirements for the four departments, adapted to suit specific local climate-related aspects (specific climatic zoning for the island of Reunion). The requirements are expressed as performances by structural elements (roofs, external walls, bays, sunshades) in order to facilitate use by professionals and to verify compliance with established levels (with little or no calculation).

Minimum thermal properties of walls

38The level of solar protection provided by the shell is evaluated on the basis of a solar protection factor (S), which expresses the ability of a wall to limit solar energy in the form of heat. The S factor is calculated using the following formula: S = (0.074 x Cm x α) / (Rth + 0.20), where Cm is the reduction coefficient for the sunshade, α is the absorption coefficient for the wall, the values for which depend on the colour and Rth – the thermal resistance of the wall.

Minimum thermal properties of bays

39With the exception of residential buildings built on the island of Reunion at an altitude of above 800 metres, transparent or translucent bays in homes in contact with the exterior are prohibited in the plan for horizontal walls.

40The level of solar protection provided by bays is evaluated on the basis of the solar protection factor (S), which expresses the bay’s ability to limit solar energy. The factor is calculated in accordance with the type of bay (louvre windows, glazed), the colour of the slats, where these exist, and the presence of a sunshade. The solar protection factor (S) for all the bays in contact with the exterior should confirm: S ″ Smax. Bays in service-rooms, with areas of less than 0.5m2, are excluded.

Comfort ventilation and hygiene ventilation

41In order to guarantee a minimum air speed, homes are designed in such a way that one or more air flows coming from the outside the home pass through the main rooms. These air flows should be able to pass through external and internal walls via bays that can remain open and which therefore help to provide natural comfort ventilation.

42In a home, openings should be planned in at least two external walls, which face in different directions. In premises, openings are made in facing or lateral walls.

43This system also defines the minimum acceptable sizes for openings in external walls. These “clear span areas”, expressed as a percentage of the room’s wall area, may not be less than 1m2. The size of openings in internal walls must be greater than the smaller of the two areas for openings in external walls.

44In order to be able to add to “natural ventilation”, where it is ineffective or inadequate, the system includes provisions relating to fans. In terms of hygiene ventilation, ventilation may be provided room-by-room. In all cases, the kitchen has an opening to the outside. For other service rooms, should they not have adequate openings to the outside, minimum extraction rates are guaranteed by means of mechanical ventilation. In the case of air-conditioned homes, an extraction system is required for all service rooms.

Facilities

45Domestic hot water being mandatory for all new homes, the system specifies the use of renewable energies (solar-power systems in particular) and, in the absence of this, it outlines the principles for saving energy, excluding, specifically, instant generation systems. It also proposes the installation of thermostats on equipment in each air-conditioned room in order to limit energy consumption.

Demand side management and/or environmental programmes for building

The BREEAM method (Building Research Establishment’s Environmental Assessment Method) in the United Kingdom

46This method for evaluating projects consists of recording credits based on a certain number of criteria, including CO2 emissions connected with energy consumption, ozone depletion, the ecological value of the site, the protection of natural resources, etc.

47The aim of the Green Globes Design programme, derived from the BREEAM Green Leaf method, is to incorporate a certain number of ecological principles into architecture, by means of an assessment protocol in the form of a questionnaire. This enables buildings, which are efficient in terms of energy management and are healthier, to be designed.

The LEED method (Leadership in Energy and Environmental Design) in the United States

48This method is based on five key principals: sustainable development of the site, water management, energy efficiency, the choice of materials and the quality of the internal environment. It has given rise to several offshoots, including the Indian method, Teri’s Green Building Rating System (TGBRS), which pays particular attention to transport links for sites, external lighting, water and waste management and the quality of the internal environment.

The High Quality Environmental Standard (HQE®®) in France

49The HQE requirements frame of reference sets 14 targets, 7 of which relate to managing external impacts and 7 to managing internal impacts. Furthermore, three other frames of reference provide in-depth details on an operational level:

  • an explicit definition of environmental quality (the aims and corresponding indicators used to define and prioritise requirements for clients),

  • an environmental management system (the entire organisation, procedures and practices specific to a construction operation),

  • certification: two certification procedures put in place for tertiary buildings and the residential sector. Tertiary certification (certified by Certivea) may apply to tropical zones subject to adaptation, relating specifically to energy targets.

Environmental and demand side management programmes in overseas departments

50Until 2009, the absence of thermal regulations, restrictions on acoustic regulations in mainland France and the concept of HQE resulted in the creation of a number of operational tools, programmes and labels, developed within overseas departments as part of the Regional Energy Management Programme (PRME) for the overseas region. A common goal guided these programmes: to improve the quality of design, in particular of the shell, in order to increase comfort, reduce air-conditioning costs and lay the foundations for future thermal regulations.

51In terms of demand side management, the predominant theme is managing the increase in air-conditioning, where the level of growth is worrying. A series of programmes and tools has been launched in order to trigger the involvement of professional networks and to better dimension systems (NDLR: the CD-ROM enclosed with the report includes a table containing all these tools).

The best available technology and labels for equipment

Lighting

Improving street lighting
Street lighting represents around 50% of electricity consumption for local authorities. This power, generated using fossil fuels in New Caledonia, produces high levels of greenhouse gas emissions.
The environmental impact of street lighting
Street lighting helps to make public spaces safe and contributes to the social and economic development of society. It is not, of course, a matter of questioning these undeniable benefits, but of examining its impact, in order to better manage environmental pollution.
What are the environmental impacts of street lighting in New Caledonia?
The impact on fauna and flora: the fragmentation of ecosystems with the creation of permanent light barriers, a reproductive imbalance for certain species, a change in the balance between predators and prey, altered migration patterns for birds that usually fly at night, fish migrations ceasing as a result of lights on bridges, etc.
The impact on human health: a failure to observe the day/night pattern imbalances the circadian cycle and may adversely affect the quality of sleep, hormonal functions and even be the cause of more serious illnesses.
Development of a halo of light, which prevents us seeing a starry sky.
Greenhouse gas emissions of up to 800 g of CO2 per kWh consumed, as lighting needs electricity.
Demand side management, an appropriate response in the quest for sustainable development
Only a programme of demand side management (MDE) and energy conservation will enable both energy consumption and environmental pollution to be reduced at the same time. Current technologies easily allow for twice the level of development offered by standard practices.
The use of street lighting based on renewable energies is also extremely promising, above all in New Caledonia, where sun and wind are available all year round. These technologies, which are highly competitive in non-electrified areas, still require full economic development in electrified urban areas.
The potential for energy savings on existing networks is considerable. These savings could even reach 48%; by replacing mercury lamps with sodium lamps (14%), by controlling the voltage and by improving the cos phi (9%), by replacing “old” sodium lamps (5%) and installing power regulators (20%).
By way of an example, following the complete renovation of street lighting, this type of action has resulted in energy savings of 42% for the city of Lille. It is possible to go still further by adopting new technologies; as in Biarritz, with its pilot operation for the remote management of innovative light sources.
What should we do in practice?
A town council or local authority wishing to take action regarding its street lighting systems should first set out a lighting development plan, incorporating energy consumption management and environmental protection. Examination of lighting development provides the perfect opportunity to clarify the local authority’s expertise in terms of street lighting, by creating a steering committee and thematic working groups, covering the topics of sustainable development and demand side management. The involvement of users and consultation on a clear definition of lighting requirements are both important factors in the success of a development project. A requirements analysis should be complemented by a technical and town planning assessment of street lighting.
In order to conduct this technical assessment, a local authority may call in specialist and properly equipped service providers, who will draw up a complete inventory of the condition of lighting stock – spots, equipment, bulbs, reflectors, ballast, control boxes, time clocks, remote management systems, etc. The inventory should be rounded off by street illumination and energy efficiency measurements.
Once the requirements have been defined, the establishment of a specification in order to define the scope and order of work is a vital stage, during the course of which demand side management and environmental aspects must be explicitly and firmly detailed. Monitoring of energy efficiency and environ-mental targets, in particular, should be based on verifiable and quantifiable indicators. At this delicate stage, the assistance of a street lighting expert as well as a demand side management and environmental expert provides a guarantee of success in conducting operations.

52In the residential sector, low-energy light bulbs are slowly and gradually replacing incandescent light bulbs. The hot climate is perfect for their use, as demonstrated by the success of low-energy light bulb distribution campaigns in overseas departments.

53In offices, T8 fluorescent tubes are gradually being replaced by more efficient T5 tubes. Good design should result in installed power of less than 10 W/m2. However, it is progress in terms of dimming and presence detection that will generate considerable energy savings. It is actually vital to correct the behaviour of users, who fail to switch off artificial lights when there is sufficient natural light or when they leave a room.

54The range of commercial products for the residential sector is beginning to expand and, in the tertiary sector, sizeable office projects are starting to be fully equipped with LEDs; this future technology, which is currently equivalent to the best compact fluorescent light bulbs, has the added advantage of lasting five times longer. This development is also far from being complete, all the more so since another revolution involving OLEDs (Organic light-emitting diodes) is on the horizon.

Office equipment

55In terms of office equipment, flat screens have made enormous progress, consuming 4 times less power than previous cathode tubes. The industry is also making progress in terms of the consumption of microprocessors and power supplies. However, it is primarily management of “stand-by” modes that is vital, specifically by encouraging energy management (the energy star label). What is more, like other equipment – photocopiers, printers, fax machines – the greatest potential for saving energy relates to operation in “stand-by” mode.

Domestic electrical equipment

56The EU energy label, which is mandatory for certain pieces of equipment, displays energy efficiency classes, but also provides the customer with other useful information, helping him/her to choose between different models. This label could serve as a valuable resource in terms of demand side management regulations or operations.

57In terms of improving performances, the European proposal for standbys on domestic televisions, video recorders and hi-fis, which consume the most power when they are not in use, will enable a quantitative leap to be made in terms of energy efficiency. The new constraints will mean, for example, that the consumption of equipment in stand-by mode must no longer exceed 1 Watt between now and 2010 (2 Watts, if the equipment in question has an information display system, such as an LCD screen). This permitted level of electricity consumption will subsequently be reduced to 0.5 W in 2013 – measures that will generate a saving of 73% of the energy used in stand-by mode.

Air-conditioning

58Following a long period of stagnation, the efficiency of centralised cooling units is improving (EER). Terminal equipment, specifically fan coil units, are actually benefiting from new technologies for motors with electronic switching, which is enabling power consumption to be cut by a 3rd. To demonstrate the actual efficiency of a piece of equipment, the Eurovent association certifies the efficiency of air-conditioners, cooling units and air-purification units.

59In terms of cooling fluids, the most widely used are HFCs, which are not harmful to the ozone layer, but which contribute to the greenhouse effect (GWP, Global Warming Potential). Traditional systems using chilled water limit the quantity of fluids being transferred, however, the same does not apply to rapidly developing VRV technologies, which have major potential for leaks. What is more, individual air-conditioning poses the problem of dispersing and recycling these fluids at the end of the system’s life. Faced with this problem, “new” zero ODP and zero or low GWP fluids are emerging; these include water (R-718 in the language of an air-con specialist) and CO2.

60As regards solar air-conditioning, despite considerable potential for development, we have to admit that all the current developments are, as yet, experimental and heavily subsidised. Three technologies are emerging: absorption systems (efficiency/primary energy ratio: 0.6 to 0.65; cost 1,400 and 600 €/kW depending on the size), single-effect absorption systems (ratio: 0.6 to 0.7) and double-effect absorption systems (ratio: 1 to 1.1; cost 600 and 300 €/kW depending on the size).

61The initial investment cost and the lack of a professional network are barriers that need to be overcome in order for this sector to develop. However, it should be noted that the climate in New Caledonia clearly lends itself to the use of this type of technology, trials of which would be beneficial.

Ventilation

62The thermal regulations of 2005 limit the consumption of fans/ventilators to 0.25 W/(m3/h) of air volume delivered. The best technologies currently allow fans to drop below 0.13 W/(m3/h), using switched motors equipped with optimised flywheels and transmission. The design of the aeraulic network (limiting pressure losses) and the management of leaks (13% on average) are also decisive. Finally, the modulation of flow rates thanks to variations in speed allows flow rates to be precisely tailored to requirements detected by the appropriate sensors (humidity sensors, CO2 sensors, presence sensors, level of activity). Installation of a timer also allows substantial savings to be made when using existing systems.

Circulation pumps

63Water circulation pumps, specifically for the circulation of chilled water, are also a major electrical expenditure item. They are frequently over-dimensioned and operate constantly. Replacing asynchronous motors with switched motors, combined with optimised blades, enables the annual electricity consumption of circulation pumps to be reduced by around 60% or more.

Urban environmental programmes

64There is no real methodology developed specifically for insular tropical zones, but two tools can nevertheless be applied in relation to environmental audits and sustainable design on an urban level.

The Urban Environmental Analysis (UEA)

65This is a method that the ADEME has been developing since 1996, it enables environmental and energy concerns to be incorporated into regional planning projects and operational town planning. It is based on a global analysis of the region on the basis of various themes - energy, the climate, transport/travel, noise, polluted sites and land, biodiversity and the landscape, waste, water and drainage/sanitation.

66It comprises a multidisciplinary diagnostic followed by recommendations enabling the aims of the project to be met, whilst also taking account of the potential and constraints of the particular site. This method is an excellent decision-making support tool and clearly enables the various challenges to be identified before deciding on a future development project.

The Maximisation Method for Sustainable Urban Design

67This design method, which was developed in the Netherlands, can be applied to tropical climates. It is an approach that begins by analysing the design, based on a number of key themes including the landscape, soil, nature, water, transport/travel, energy and archaeology.

The Carbon Audit™ or measuring decarbonisation

68The ADEME’s Carbon Audit™ method, adapted for local authorities, evaluates direct and indirect emissions of greenhouse gases generated by activities in the area, in relation to inhabitants, companies and authorities.

69The sectors in question include industry, tertiary activity, residential, agriculture and fishing, and transport. The results obtained enable actions relating to the organisation of activities within the area in question to be identified: relocation of production units, organisation of trade networks, regional development, etc.

The Sustainable Built Environment, SB Tool

70The SB Tool is the result of a Canadian initiative dating from 1996, which consists of a method based on a spreadsheet comprising three modules: definition of the context and weightings inherit to the project, information on the site and the characteristics of the project, and self-assessments based on data from the first two modules. Account is taken of a certain number of requirements, in particular when selecting a site, such as the proximity of public transport routes, respect for development densities and functional diversity, or the possibility of alternative solutions for managing water and renewable energy resources.

71The system provides a framework of ratings based on a toolbox, which is only transformed into credits when the user calibrates it for the region in question, by weighting the various criteria. This modular method is seen as flexible, as it enables reference data to be incorporated on the basis of regional values and can therefore be applied on a local level.

PROPOSALS FOR IMPROVING DEMAND SIDE MANAGEMENT IN THE BUILDING AND HOUSEHOLD EQUIPMENT SECTOR IN NEW CALEDONIA

Energy efficiency tools1

Spread the word, raise awareness

72Various communication channels can be used: public campaigns (advertisements, for example), raising awareness in schools, tax incentives, the organisation of energy saving seminars and exhibitions, awareness campaigns aimed at certain sectors or clients, visits to existing model operations, study visits, etc.

Persuade/Convince

73A second level of information consists of entering the sphere of evidence-based reasoning. This is a question of demonstrating, supported by evidence, that the interests of the local authority and the final decisionmaker actually coincide, where the latter proposes solutions enabling savings to be made in terms of investment and operation, or solutions with a lower operating cost, but which require higher initial investment.

74This type of information can be spread by means of leaflets or brochures, economic and technical sales pitches, design guides, demonstration operations, topic-based audiovisual broadcasts or documentaries, etc.

Encourage/Incentivise

75In order to trigger a real movement within the market and to create competitive conditions for new systems, it is initially necessary to make up all or some of the additional cost of energy management actions. Incentives may be finance-related, to aid decision making or bear some of the additional investment cost, price-related or indirect, by establishing labels that may possibly allow compensation to be obtained. These incentives are generally not designed to continue beyond the point at which the market achieves a certain maturity in terms of competitiveness.

Oblige

76Public authorities may impose an obligation to comply with precise design rules, prohibit certain categories of equipment and dictate certain behaviours (air-conditioning directives) on building designers. This is the most effective course of action as it applies to everyone. This type of approach needs to pro-vide evidence of the economic relevance of any rules imposed and requires a consensus of the stakeholders involved: it is often a case of ratifying good practice and imposing it on the majority. It is also possible to encourage clients to invest in demand side management actions, by means of an energy labelling system, borne out by energy efficiency diagnostics.

Thermal regulations2: a vital step

  • 2 A table demonstrating the various stages for compiling regulations appears on the CD-ROM: “Energy m (...)

77The backbone of any energy management policy is based on putting thermal regulations in place. The compilation of regulations requires a precise understanding of all aspects, i.e. climate, consumption, consumers and stakeholders. This detailed understanding, translated into indicators and standards to be achieved, constitutes a frame of reference for all actions to be undertaken, including for labelling or certification. For example, the lowconsumption building label (LCB) is defined as a level of consumption that is 50% less than the standard imposed by regulations. It is therefore an essential instrument, which obliges clear and precise long term targets to be set.

Across-the-board actions

Action on an urban level

78The majority of global energy challenges are played out on an urban level. Urban design, which does not pay any attention to demand side management and environmental issues, may considerably hamper the development of environmental solutions. Specialists must be involved in defining global town planning schedules (GTPS), determining master plans and defining morphologies and volumes.

79In order not to conceal any challenges and to deal with issues in their entirety, we recommend two courses of action:

  • the compilation of a guide identifying specific environmental issues in New Caledonia on an urban level,

  • the creation of standard specifications, in order to better take account of environmental issues on an urban level and the preliminary studies to be carried out: carbon audit, wind simulation in urban surroundings in order to optimise through-ventilation, sunlight simulation, optimisation of collector areas for photovoltaic systems, simulation for the development of urban wind power.

Educate/Train

80The size of New Caledonia means that it does not have cutting-edge technical skills in all the areas involved in demand side management or the environmental approach to building. In order to remove this barrier to the development of energy efficiency, an evaluation of education/training needs in terms of energy management and renewable energies should be undertaken. A lack of expertise in certain areas can be swiftly made up for when demand becomes apparent (for energy audits, for example). Once this need is identified, ad hoc and partly subsidised training can be organised in partnership with the CTME and major stakeholders in the sector (HQE training, for example).

Notes

1 For actions designed to improve energy efficiency, please refer to the summary tables on the CD-ROM: “Energy management in New Caledonia.”

2 A table demonstrating the various stages for compiling regulations appears on the CD-ROM: “Energy management in New Caledonia.”

Table des illustrations

Légende Figure 3. Thermal comfort in external environmentsThe maximum enthalpy line of the point grouping is of the order of 85 kJ/kg as. This value is significant when specifying air-conditioning systems. It corresponds to a temperature/humidity ratio of 31 °C with 70% humidity.
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