Waste not, want not

Waste not, want not

Increasingly we are facing the effects of climate change and the rapid growth of urban living. Our everyday living is laden with consumption. This is very difficult to avoid and carries a huge environmental cost. Among other things, sea levels are rising and plastics are polluting our oceans.

Proven Energy from Waste (EfW) technology generates clean resources from residual waste.

It is the vital piece of the waste treatment puzzle for New Zealand to achieve a long term sustainable green solution to waste management.

Clean and green?
New Zealand is lagging behind other developed countries when it comes to waste management practices, putting our clean green reputation at stake.
Compared to other OECD countries, we are 1.7 times the average for total annual greenhouse gas emissions; 1.4 times for municipal waste generation and 1.3 times for municipal waste to landfills. In 2015, we collected 1.5 million tonnes of domestic kerbside waste. Of this, 1.1 million tonnes of untreated waste was landfilled. And only 25% of domestic kerbside waste was recovered.

Landfilling is unsustainable
Landfilling our waste is a short-term solution. It is recognised as the least preferred disposal method for waste in terms of risk to human health and the environent. It contaminates rangi (air), whenua (land), and wai (water) due to methane emissions and leachate discharge. Although methane can be captured, landfills are not a closed system and pollution cannot be controlled for the entire lifetime of a landfill. None of the materials sent to landfills are converted into re-usable material, and little energy is produced.

EfW - creating energy from waste
To achieve New Zealand’s zero waste aspirations, the lifespan of resources must be maximised and then recycled and repurposed at the end of each service life. While there will always be a percentage of waste that is not recyclable, this can be used to generate energy in the form of electricity and heat.

EfW provides a solution to the limitations set on recycling complex materials. It eliminates the need for landfill and the export of inferior plastics to emerging countries, where it often ends up polluting the environment or being incorrectly incinerated. Adopting this approach would enable New Zealand to take responsibility for its waste by managing it domestically, simultaneously converting it to clean energy.

What is EfW?
EfW plants are controlled, closed systems enabling complete monitoring and treatment of by-products. Energy, heat, precious metals, CO2, inert ash, and aggregate can be captured from this process. EfW is a well-developed and established technology in many developed countries. Air pollutant emissions are less than that of road traffic.

EfW is ‘fed’ by residual waste, which no other technology can sustainability treat. This is material which is either contaminated, or has reached the end of its service life (plastic significantly degrades each time it is recycled and has a finite life time). With the aid of EfW technology, what is perceived as waste can be utilised and converted into beneficial resources.

The Swiss example
Switzerland has a well-established resource management system with 100 per cent recovery of all waste material. Combustible waste landfilling was banned in 2000. Of the total waste produced, 52 percent is sustainably repurposed and the residual 48 per cent is recovered through EfW.

Tangata whenua believe that everything and everyone is interconnected, and therefore should be valued and cared for. The wellbeing of the people is directly related to the wellbeing of all natural resources. Using residual waste and converting it into beneficial resources sustainably, aligns with this culture. Adopting the EfW approach would enable New Zealand to take responsibility for all our waste by managing it domestically, simultaneously converting to clean energy. It would ensure we are living in a country where we know exactly what is happening to the waste we create, and where we can honestly say we are doing everything in our power to deal with it sustainably.

Holger Zipfel is the Engineering Solutions Manager at Harrison Grierson, leading the Building Services and Mechanical and Electrical teams. Having lived in Germany and Switzerland, Holger has experienced an integrated waste management system in action, where waste reduction, reuse, recycling and energy recovery are common practice.

Hana Kirk is a Mechanical Engineering Graduate at Harrison Grierson. Hana has a passion for creating sustainable living environments, and utilising what is perceived waste as a resource.

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