Improving Building Energy Efficiency to Help Low-Carbon Development
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The construction sector is one of the key industries to implement energy conservation and carbon reduction.
By the end of 2020, a total of over 6.6 billion square meters of green buildings have been built nationwide, making an outstanding contribution to reducing carbon emissions.
To improve the level of building energy efficiency, it is necessary to speed up the updating of standards for building energy conservation and municipal infrastructure, raise the requirements for energy conservation and carbon reduction, and release the potential of energy conservation and carbon reduction in the building sector.
To save energy and reduce carbon, we must focus on key industries.
The "Carbon Peaking Action Plan before 2030" (hereinafter referred to as the "Action Plan") previously issued by the State Council proposed to speed up the updating of building energy conservation, municipal infrastructure and other standards, and to increase energy conservation and carbon reduction requirements.
The scale of the total number of buildings in my country is large. To improve the energy conservation standards in the building sector, what is the current progress?
What should be the focus of the next work?
The reporter interviewed relevant department heads and industry experts.
Green buildings achieve leapfrog growth
The colorful aluminum alloy grilles cross diagonally, and under the effect of light and shadow at night, they look like falling snowflakes... The Wukesong Ice Sports Center, the ice hockey training venue for the Beijing Winter Olympics, not only has a high "look", but also achieves Ultra low energy consumption.
"The venue uses carbon dioxide to make ice, which can improve the efficiency by 40% compared to conventional refrigerants. After the ice-making waste heat is recovered, it can also be used for hot water supply. Not only that, the 600-kilowatt photovoltaic power generation panel installed on the roof can achieve an annual power supply of about 700,000 kilowatt-hours.” said Feng Yanjun, project manager of the Wukesong Ice Sports Center of China Construction First Bureau, who participated in the construction of the venue.
In recent years, my country's building energy conservation standards have steadily improved.
Tian Guomin, director of the Standard Quota Department of the Ministry of Housing and Urban-Rural Development, introduced that since the first edition of the building energy efficiency design standards was promulgated in 1986, my country's building energy efficiency has experienced a "three-step process", that is, the heating energy consumption of ordinary residential buildings in the early 1980s. On the basis of building energy efficiency, the proportion of building energy saving has gradually reached 30%, 50% and 65%.
For more than 30 years, my country has promulgated standard specifications for residential building energy conservation (five climate zones), public building energy conservation, rural building energy conservation, and energy-saving products, forming a relatively systematic energy-saving technology system and standard system.
According to estimates, by the end of 2019, the newly built and completed energy-saving buildings in my country can achieve an energy-saving capacity of nearly 300 million tons of standard coal every year, and can reduce carbon dioxide emissions by 740 million tons, effectively slowing down the growth rate of total building energy consumption.
At the same time, my country's green and energy-saving buildings have achieved leapfrog growth.
By the end of 2020, the proportion of newly built green buildings in cities and towns across the country in that year reached 77%, and the cumulative green building area exceeded 6.6 billion square meters; the cumulative built energy-saving building area exceeded 23.8 billion square meters, and the energy-saving buildings accounted for more than 63% of the urban civil building area. %.
According to the Action Plan, by 2025, new urban buildings will fully implement green building standards.
"Building energy conservation has made outstanding contributions to reducing carbon emissions. Especially after the carbon peaking and carbon neutrality goals are put forward, the gradual establishment of a systematic and comprehensive carbon peaking and carbon neutral comprehensive evaluation and assessment system will help the concept of energy conservation and green development in buildings. It is more effective in the whole field." Tian Guomin said.
Building energy conservation and carbon reduction face certain challenges
According to reports, with the acceleration of urbanization and the improvement of people's living standards, coupled with the adjustment of industrial structure and the rapid development of the tertiary industry that mainly relies on buildings to provide service places, the energy intensity and carbon emission intensity of buildings in my country will also increase by a large margin. Increase.
In the future, the building sector will also release huge potential for energy conservation and carbon reduction, and the challenges and pressures to achieve carbon peaking and carbon neutrality are not small.
For example, the rising cost of construction and construction is facing certain financial pressure.
"Improving energy-saving standards means reducing the heat transfer coefficient of windows, thickening thermal insulation materials, etc., and the cost will increase. In addition, there is a large stock of existing residential buildings in my country, and energy-saving renovations require sufficient financial support." Tian Guomin said At present, the government still plays a major role in promoting building energy efficiency. Market-oriented promotion mechanisms such as contract energy management, carbon trading, and comprehensive energy efficiency services have yet to be improved, and green financial support is also being explored.
At the same time, technical research still needs to continue to advance.
"For example, the thickness of the external wall insulation material for building energy-saving renovation has reached 15 cm to 18 cm. If the energy-saving standard is further improved, the 'padded jacket' worn on the wall may be thicker. In this way, the risk of the insulation layer falling off and flammability will also be reduced. Will increase. In the future, we will actively develop external thermal insulation materials with the same thermal insulation effect but lighter and thinner, with better fire performance and longer service life." Tian Guomin told reporters.
Not only that, high-efficiency energy-saving doors and windows, high-performance concrete, high-strength steel and other building materials, waterproof technology for prefabricated building joints, etc., all need to rely on stronger technical support to improve the energy efficiency of buildings.
In addition, the promotion of building energy efficiency still faces some bottlenecks: the society still does not pay much attention to building energy efficiency; the extensive construction method of “mass construction, massive consumption, and massive emissions” in the field of urban and rural construction needs to be transformed; The development is unbalanced between urban and rural areas, between the eastern coastal areas and the central and western areas, and policies, standards, technologies and systems that adapt to the characteristics of rural areas need to be improved.
The "Action Plan" mentioned that to accelerate the green and low-carbon development of urban and rural construction, urban renewal and rural revitalization must implement green and low-carbon requirements.
Accelerate the promotion of green and low-carbon development of urban and rural construction
410 steel structural components, 197 roofing unit panels, and 170 photovoltaic curtain wall units have been used for only 7 days and nights. The building area of the National Energy Group's 1063-square-meter photovoltaic building integration center wall is like "building blocks" Assembled.
Compared with the traditional cast-in-place method, prefabricated construction is not only fast, but also can effectively reduce the emission of construction waste during the construction process, and can reduce environmental pollution such as dust and noise.
Data show that in 2020, 31 provinces (autonomous regions and municipalities) and the Xinjiang Production and Construction Corps will start construction of 630 million square meters of prefabricated buildings, an increase of 50% over 2019, accounting for about 20.5% of the new construction area.
In addition to promoting new construction methods and reducing material waste and energy consumption on construction sites, how will we further promote energy conservation and carbon reduction in the building sector?
The "Action Plan" proposes to promote urban group development, scientifically determine the scale of construction, and control the excessive growth of new construction land.
Build high-quality green buildings, further improve the energy-saving level of new buildings, strengthen energy-saving renovation of existing buildings, and strengthen building operation management.
In terms of improving building energy conservation standards, Xu Wei, professional chief engineer of the China Academy of Building Research, suggested that the construction of "zero carbon building technical standards" should be accelerated, and the building energy conservation work should be gradually moved towards the "double control" of energy consumption, total carbon emission and intensity. .
In addition, it is necessary to speed up the optimization of building energy structure.
For example, deepen the application of renewable energy in buildings, actively promote clean heating in severe and cold areas, and improve the electrification level of building terminals.
The "Action Plan" proposes that by 2025, the renewable energy replacement rate of urban buildings will reach 8%, and the roof photovoltaic coverage rate of new public institutions and new factory buildings will reach 50%.
Nowadays, corresponding policies have been introduced in many places to encourage building energy conservation: Hebei's special funds for high-quality development of key industries give preference to manufacturers of ultra-low energy-consumption building special parts and components such as high-performance doors and windows and special special materials; Heilongjiang proposes that in land supply, Substantive preferential policies have been introduced in terms of industry management, taxes and fees to guide the construction of affordable housing in various regions to adopt the prefabricated construction method; Guangdong has issued financial support for the construction, purchase, operation of green buildings or green transformation of existing civil buildings Incentives such as plot ratio incentives, tax incentives...
Next, the Ministry of Housing and Urban-Rural Development will work with relevant departments to promote local governments to further consolidate their responsibility for green development in urban and rural construction, improve relevant working mechanisms, and gradually form a legal system and policy system for green development of urban and rural construction. Neutralize the goal to make a positive contribution.
Graphics for this edition: Wang Zheping