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Building A Low Carbon Economy with Energy Efficient Buildings

28 May

GHG emissions from building construction, reno...
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The building sector can and should play a role in achieving the deep GHG reductions that science tells us are necessary to combat the threat of global warming. The building sector contribution to GHG emissions is mainly driven by its end use of, or demand for, electricity. This is a key difference from many other sectors where the main issue is emissions from the supply of energy. The building sector as a whole could reduce its share of GHG emissions by 30-35 per cent whilst accommodating growth in the overall number of buildings by 2050. This can be achieved by using today’s technology to significantly reduce the energy needed by residential and commercial buildings to perform the same services. For example, by replacing equipment with more energy-efficient models, at the natural replacement rate, and upgrading the performance of the building shell.

Detailed ‘bottom up’ analysis of energy efficiency opportunities suggests that net cost savings can be achievable in the medium to long-term. Rather than a cost per tonne of GHG abatement, many energy efficiency options have a positive financial payback in addition to providing abatement benefits. The payback period, can vary from a matter of months to many years. This finding is consistent with a large collection of case studies within the Country and overseas. When coupled with a broad-based GHG abatement target and a supporting policy environment, additional energy efficiency investments by the buildings sector would reduce the costs of change for the building sector and the economy at large.

Despite being cost neutral in the medium to long-term, achieving the additional GHG abatement action from the building sector faces challenges as well as opportunities.

1.Adopting energy efficiency strategies requires upfront investment by businesses and households to become more energy-efficient.

2.The benefits, or payback of these investments, are gradual, accruing over the medium to long-term, as savings on energy bills.

3.The building sector will need some additional incentives to overcome the impediments to change. These need to address a range of issues, such as the need to spur behavioural change, particularly to encourage adoption, and to offset the required upfront, direct capital expenditures.

4.Essentially, there is a need to encourage the rebuilding of our current building stock to upgrade the energy efficiency of assets within buildings to deliver a more   sustainable outcome.

5.The pay-off from investing in the energy efficiency potential of the building sector would flow through the entire economy by reducing the cost that others would face to  achieve their reduction in GHG emissions.

It is vital for government and the community at large to recognize the evidence showing the valuable role that demand side management and energy efficiency in the building sector can play in GHG abatement. Significant gains are available now without the need to invent and apply new technologies. They do not involve substantial risk or uncertainty and would provide significant gains now and into the future.

THE BUILDING SECTOR

The building sector can be viewed as being comprised of two broad elements:

Residential buildings — housing the population; and

Commercial buildings — housing a range of activities including retail trade, accommodation, business services, government and government agencies, recreation and cultural services and industry, which represents around two-thirds of national employment.

Component parts of the building sector are noted in chart

Residential Building Commercial Building
Detached housesAttached dwellingsBuildings containing two or more soleoccupancy units Wholesale tradeRetailAccommodation, cafes and restaurantsCommunication servicesFinance and insuranceProperty and business servicesGovernment administration and

Defence

Education

Health and community services

Cultural and recreational services

Personal and other services

The estimate of greenhouse gas emissions due to energy consumption in the building sector takes account of:

1.  the amount of energy consumed;

2. the mix of fuels used;

3. the average greenhouse gas emissions from the different fuels (electricity is treated as a fuel); and

4.upstream emissions from transmission and other activities.

The electricity consumed within a building is only a part of the energy used to support that demand. A large amount of electricity and greenhouse gas emissions is also involved in distribution, transmission and generation. When reducing demand for electricity it is practical to eliminate the need for this upstream energy use and GHG emissions.

A larger proportion of GHG emissions are attributable to the building sector than its share of energy use because the building sector uses greenhouse gas intensive energy. Notably the building sector energy end use is dominated by electricity consumption which is dominated by coal fired generation located at the end of long transmission networks.

Emissions from the building sector are broadly of the same scale as emissions produced by the entire transport sector.

THE ABATEMENT POTENTIAL

The building sector could reduce its GHG emissions by 30–35 per cent by 2050 on an economical basis. Economic in this context means that the initial costs would be offset — and in many cases be more than offset — by subsequent energy savings over time.

The potential for increased energy efficiency in the building sector has been estimated through a bottom up analysis to identify energy efficiency opportunities in the building sector. The analysis:

1.Examine like-with-like replacement of energy inefficient appliances and building services with more energy-efficient equivalents;

2.focus on additional application of existing technologies;

3.take into account the costs of change and the expected benefits from reduced energy costs; and

4.factor in expected population growth and sustained economic growth which tends to bring pressure for increased energy use.

For the potential energy efficiency investments a much wider range of options exits. This set, however, generally represents the diversity of existing, mature technologies.

In the residential sector changes can be achieved through:

1. substitution for more energy-efficient light fittings;

2. greater use of natural light;

3.substitution for more efficient refrigeration;

4.adoption of more efficient hot water appliances with solar where possible;

5.adoption of appliances with a low standby energy use;

6. the introduction of more efficient heating and cooling mechanical systems; and better insulation.

In commercial buildings substantial savings to both costs and greenhouse gas emissions could be generated by:

1. improving air conditioning systems efficiency and including ‘economy’ cycles;

2.use of natural ventilation where possible;

3. the use of more efficient office appliances;

4.better insulation;

5.improved heating and ventilation;

6.the use of efficient light fixtures;

7.upgrading to more efficient water heating systems; and

8.where possible use of co-, and tri-generation (that is, using heat discharged from on-site power generation for water heating, and for absorption air-conditioning etc).

Energy efficiency measures would take time to be adopted by households and business. Analysis of the technical possibilities suggests the potential for GHG abatement is between 57 Mt and 66 Mt per annum by 2030. This would increase to between 86 Mt and 98 Mt by 2050.

Facts

• Buildings’ share of final energy consumption: 30-40%

• Global CO2 emissions from energy in buildings (2005): 9Gt

• Estimated growth by 2050 in all 6 EEB regions: 76%

• Growth in global population by 2050: 2.7 billion or 42%

Many energy efficiency projects are feasible with today’s energy costs. At energy prices proportionate to oil at US$ 60 per barrel, building energy efficiency investments in the six EEB regions (Brazil, China, Europe, India, Japan and the US) studied, totaling US$ 150 billion annually, will reduce related energy use and the corresponding carbon footprint in the range of 40% with five-year discounted paybacks for the owners. A further US$ 150 billion with paybacks between five and 10 years will add 12 percentage points and bring the total reduction to slightly more than half.

There are three key elements to

achieving progress:

– Use less energy

– Make more energy (locally)

– Share surplus energy (through an intelligent grid).

The most significant, long-term gains will come from using less energy.

Note: The data has been collected form various noted publications and condensed for easy understanding.

 

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