Tagged with carbon emissions

Opera House Goes Carbon Neutral Five Years Ahead of Schedule

The Sydney Opera House was notoriously behind schedule on most things during the 14 years it took to build but will be five years ahead of schedule when it meets its target to reduce emissions and become carbon neutral.

This move puts it up there with New York’s Empire State building and Paris’s Eiffel Tower as global architectural icons which are actively working to become world symbols of energy efficiency, its Environmental Sustainability Manager Emma Bombonato said.

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Officials at the Sydney Opera House have been working to increase its energy efficiency and decrease its waste for the past decade. In 2014 it replaced incandescent bulbs in the Concert Hall with custom LED lights to achieve a 75 per cent reduction in the venue’s electricity consumption. In 2017 it introduced a new building management control system to monitor energy and water use and manage climate control. It also optimised the heating and cooling of the building by replacing chiller units connected to the Opera House’s pioneering seawater cooling system in that same year, resulting in a 9 per cent energy reduction.

“One of the biggest benefits of changing the incandescent bulbs to LEDs, means that instead of changing them in the Concert Hall once a year, now it is needed only once every nine years,” she said.

By becoming more energy efficient and streamlining day-to-day operations, it reduced its carbon dioxide (CO2) emissions, and offset its remaining emissions for the year 2017-2018 with help from its major partner EnergyAustralia. To reduce its carbon footprint, Australia’s most recognisable building invested in renewables, tree planting and biodiversity projects to offset its greenhouse emissions. The 2015 Paris Agreement set a goal of limiting a rise in world surface temperatures, and last month the mayors of 19 cities, including Sydney, put in place regulations requiring all new buildings to be carbon neutral by 2030 and all existing ones to reach the same goal by 2050.

Each year the Sydney Opera House hosts 1800 events, serves 2.6 million food and beverage orders – producing 5000 cubic metres of waste and uses electricity equivalent to 2500 households (16 gigawatts). A new waste management program, including the introduction of new recycling streams and transferring food waste that would have otherwise gone to landfill to an organics facility to be turned into energy last year, improved the waste recycling rate from 25 per cent to 60 per cent. An educational program on waste management for staff and contractors also helped reduce waste.

This article was originally published by the Sydney Morning Herald. Click here to continue reading entire article.

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Greening the Concrete Jungle: How to Make Environmentally Friendly Cement

Cement is the world’s most widely used material apart from water, largely because it is the key ingredient in concrete, the world’s favourite building material.

But with cement’s success comes a huge amount of greenhouse emissions. For every tonne of cement produced in Australia, 0.82 tonnes of CO₂ is released. That might not sound like much, especially when compared with the 1.8 tonnes emitted in making a tonne of steel. But with a global production of more than 4 billion tonnes a year, cement accounts for about 8% of the world’s CO₂ emissions.

Photo: article supplied

The electricity and heat demands of cement production are responsible for around 50% the CO₂ emissions. But the other 50% comes from the process of “calcination” – a crucial step in cement manufacture in which limestone (calcium carbonate) is heated to transform it into quicklime (calcium oxide), giving off CO₂ in the process.

A report published by Beyond Zero Emissions (BZE) (on which I was a consultant) outlines several ways in which the sector can improve this situation, and perhaps even one day create a zero-carbon cement industry.

Better recipes

The cement industry has already begun to reduce its footprint by improving equipment and reducing energy use. But energy efficiency can only get us so far because the chemical process itself emits so much CO₂. Not many cement firms are prepared to cut their production to reduce emissions, so they will have to embrace less carbon-intensive recipes instead.

The BZE report calculates that 50% of the conventional concrete used in construction can be replaced with another kind, called geopolymer concrete. This contains cement made from other products rather than limestone, such as fly ash, slag or clay.

Making this transition would be relatively easy in Australia, which has more than 400 million tonnes of fly ash readily available as stockpiled waste from the coal industry, which represents already about 20 years of stocks.

These types of concrete are readily available in Australia, although they are not widely used because they have not been included in supply chains, and large construction firms have not yet put their faith in them.

Another option more widely known by construction firm is to use the so-called “high blend” cements containing a mixture of slag, fly ash and other compounds blended with cement. These blends have been used in concrete structures all over the world, such as the BAPS Shri Swaminarayan Mandir Hindu temple in Chicago, the foundation slab of which contains 65% fly ash cement. These blends are available everywhere in Australia but their usage is not as high as it should due to the lack of trust from the industry.

This article was originally published by The Conversation.

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