Decription:

This publication is available in two volumes. Volume 1, Buildings and Transportation, deals with domestic, commercial and industrial buildings and transport. Volume 2, Primary Production and Industry, deals with primary production, food processing, forestry processing and manufacturing and minerals. Volume 2 also includes a section on general energy efficiency technologies.

Volume 1 was published on April 30 and Volume 2 was published on August 21. Both volumes can now be purchased (separately or as a set) from CAE (for details on how to order, see the order form). The books had their official launch at the Beehive (part of New Zealand's Parliamentry buildings) on August 21 at a function addressed by New Zealand's Minister of Energy. Also launched at the same function was New and Emerging Renewable Energy Opportunities , a joint publication between the Centre for Advanced Engineering and the Energy Efficiency and Conservation Authority.

Volume 1

Part 1: Domestic Buildings

In the domestic buildings sector, the main uses of energy are for space heating and hot water heating, which together account for 75% of the total energy use in a house. The main type of energy used is electricity (71%), although wood (14%), coal (7%) and gas (7%) are also used. Forecasts suggest that the electricity and gas shares of residential energy use will continue to rise, while coal's share will decline.

There are three major factors that affect the energy efficiency of a house: the design, the appliances in the house and how the homeowner uses the house. For New Zealand homes to become more energy efficient, all three factors will have to be considered at a national level. However, little is known about how much a change in behavioural habits will reduce the amount of energy used in a household.

Because people are often unaware of what can be done in their home to save energy, better access to information about energy efficiency for all New Zealanders is required before behavioural changes can be made.

Part 2: Commercial and Institutional Buildings

The operation of commercial and institutional buildings accounts for the direct use of about 18% of New Zealand's electricity and 5% of its fossil fuels. In 1990, the sector contained over 42,000 buildings totalling some 40 million square metres of floor space. However, the commercial sector's floor area and energy use is concentrated in larger buildings Ñ just 345 buildings over 10,000 square metres in the health, education and office subsectors account for a quarter of the sector's floor area and probably about 30% of its electricity use.

Lighting and airconditioning (including heating, cooling and distribution equipment) are the major end uses in offices. Heating water is a major use only in hospitals and residential institutions. Energy efficiency in buildings can be increased by attention to building design, use of new technologies and the practice of sound management techniques. In the short term, refurbishments, retrofits and improved management of existing buildings will offer the greatest opportunity for increasing energy efficiency in the sector. In the longer term, energy efficient design will become increasingly important. The use of energy efficiency design assistance prior to construction can yield savings of up to 75%. Where energy efficiency measures are incorporated into a major retrofit or a refurbishment that is being carried out for other reasons, the potential for cost-effective energy savings can approach that for new buildings.

Part 3: Transport

Increasing energy efficiency in transportation is an important issue worldwide. Transportation is primarily a consumer of fossil fuels, and as fossil fuel prices rise and concern about global warming increases, renewable energy sources could offer an alternative to fossil fuels.

Transport covers the movement of goods and people by vehicles of various sorts rather than via conveyors, lifts or pipelines. Internal transport consumes about 34% of consumer energy in New Zealand, a proportion higher than in most European countries and on a par with Australia and the USA.

Road transport is the predominant user of energy within New Zealand and accounts for 90% of total transport energy demand. The next largest energy user is domestic air transport (7%), and rail and coastal shipping account for the remaining 3%. Around half the transport energy is used in motor cars.

Ways transport can be made more energy efficient include vehicle technology advances, improved load factors, substitution of one vehicle type with another and modification of the demand for transport.

Volume 2

Part 4: Primary Production

The primary production sector's total energy demand is a small fraction of the national total, around 4% to 5%, but energy efficiency in the sector is important to maintaining a competitive advantage and the clean, green image of New Zealand's exports. Most of New Zealand's primary production is not energy intensive, and where it is (such as dairying), it generally compares favourably with overseas countries.

Part 4 outlines technologies that can make energy use more efficient in the various divisions of the primary production sector, including dairying, livestock and poultry production, arable farming, horticulture (including greenhouse enterprises), forestry and fishing. Part 4 includes a chapter on remote area power schemes.

Part 5: Food Processing

The total energy use in the New Zealand food system is made up of production (28%), processing (32%), distribution (18%) and preparation (23%). The 32% used in food processing is the focus of Part 5. Food processing uses over 31,000 TJ or approximately 9.5% of the national primary energy requirements. Producing heat is the main energy use in the food processing industry. The dominant use of heat is for drying. Oil was once the dominant source of this heat, but has been replaced by natural gas.

The dominant energy consumers in the food sector are the dairy and meat industries, which together account for around 70% of the total sector energy demand.

The main technologies and methodologies for improving the use of energy in the food processing industry are:

• considering the fundamental technological requirements of processes and matching these to the energy supply (e.g. variable speed fans in meat freezing);
• using efficient heat transfer and reuse such as direct firing of driers, adopting mechanical recompression in evaporators and applying pinch technology;
• optimising insulation in both hot and cold applications and paying attention to other well understood but easily neglected practices; and
• exploring new technologies such as electro-technologies, the use of superheated steam and low-temperature heat pump dehumidifier drying.

Part 6: Forestry Processing

The New Zealand annual log harvest is slightly less than 16 million m3. Approximately one-third of the wood volume goes into pulp and paper manufacture, and log and chip exports account for another third. The next major use of wood is for sawn timber (about 2.5 million m3). Plywood and reconstituted panel board manufacture make up the balance.

Forest processing uses almost 10% of New Zealand's total power generation, which makes this sector the second largest industrial electricity user after aluminium production. Pulp and paper manufacture uses over 80% of the electricity (and heat) consumed in forest processing.

New Zealand kraft mills compare favourably with overseas mills of the same era. There is a trend for increased energy use in paper manufacture due to faster production rates and higher product quality. In a modern mill, this can be countered by energy efficiency in the pulp and paper mill using technologies such as extended delignification, increased tree utilization, reduced evaporation, the use of biomass in the lime kiln and greater cogeneration. There is also a wide range of retrofit technologies that could improve energy use in New Zealand kraft mills.

Mechanical refiner mills should be largely self sufficient in heat via energy recovery from refiner flash steam. In general, New Zealand mills do not take full advantage of the technical potential for refiner energy recovery. A variety of technologies are under development to reduce the electrical input to the refiner pulping process.

Energy efficiency in sawmilling can be improved via better saw design and operation to increase timber yield, and the use of low temperature heat pump drying, mechanical vapour recompression and better fan systems can make kiln drying more energy efficient.

Part 7: Manufacturing and Minerals

The manufacturing and minerals sector uses around 20% of New Zealand's total consumer energy. Aluminium and steel refining account for nearly 60% of the total energy use by the manufacturing and minerals sector. Steel and cement use almost all of the sectorÕs coal supply and about 40% of the total fuel supply. Aluminium smelting accounts for two-thirds of the sectorÕs electricity supply.

Heat is the main energy need for the manufacturing group and natural gas is the dominant fuel source. Most of the energy consumed in the chemical industries and in metal fabrication is used to produce high grade heat (e.g. in kilns). The textile and leather industries mainly use fuels for intermediate grade heat (e.g. steam from boilers). Electricity use makes up about 25% of the manufacturing groupÕs energy supply and nearly all of it is used for motors driving pumps, fans and other machinery.

Part 7 concentrates on a number of general principles relating to targeting and monitoring and good housekeeping. It also provides some case studies covering the energy intensive minerals group.

Part 8: General Energy Efficiency Technologies

Part 8 is not specifically linked to any economic sector, but instead outlines a range of energy efficiency technologies that are applicable to buildings, transport, and primary and secondary industries.

Topics covered in Part 8 include heat recovery technologies; kilns, ovens and furnaces; heat pumps and heat transformers; cogeneration; pinch technology; efficient motor technologies; pumps, fans and compressors; variable speed drives; and electro-technologies.