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Renewable energy solutions combat climate change
Methane gas from the former Burwood landfill heats
the Queen Elizabeth II pool complex in Christchurch.
Renewable energy sources, such as hydro, wind, solar, geothermal, biomass and cogeneration, are playing an increasingly important role in reducing our greenhouse gas emissions and ensuring New Zealand’s environmental sustainability and energy security.
The Christchurch City Council-Burwood landfill gas initiative is a good example of what being sustainable is all about.
The Council is using methane gas from decaying organic matter at the former Burwood landfill to heat the Queen Elizabeth II Park swimming pool complex, a move that is saving it money and reducing its greenhouse gas emissions. Previously, the methane gas – which is 22 times more harmful to the atmosphere than carbon dioxide – was released into the atmosphere.
How it works
Fifteen wells up to 20 metres deep have been sunk at the landfill. A fan draws the gas from the wells at a rate of 1000 cubic metres per hour. The gas is then chilled to remove any condensate and make it dry. It is then compressed and sent by pipe 3.7km to Queen Elizabeth II Park where a boiler turns it into heat for the pool, showers and air conditioning.
The project will result in some 200,000 tonnes of carbon dioxide emissions reductions over the first commitment period of the Kyoto Protocol and save the Council more than $500,000 per year by replacing liquid petroleum gas currently used to heat the pool complex.
“The availability of saleable carbon credits was the decisive factor in pushing ahead with this project,” said the Council’s Water and Waste Manager Mark Christison.
“Without this mechanism, the project was likely to have been stalled because it would not have met threshold economic criteria.”
Projects to Reduce Emissions
Burwood is one of five landfill gas initiatives in the Projects to Reduce Emissions (PRE) programme funded by the Ministry for the Environment. PRE projects use renewable energy sources – landfill gas, wind, hydro, biomass, geothermal and cogeneration – to reduce carbon dioxide emissions in exchange for emissions units, or carbon credits.
Christchurch City Council has forward-sold carbon credits from the PRE project to British Gas for about $3 million.
Another similar initiative is Palmerston North City Council’s Awapuni landfill gas project which will receive up to 149,000 emissions units under PRE. The Council has an agreement with the Austrian Government which will purchase the units for $1.2 million.
Wind farms
The fastest growing form of renewable energy generation is wind because wind farms are relatively easy to build and bring online. Wind is also one of the cheapest forms of electricity generation. A recent player in the wind turbine-based electricity generation market is NZ Windfarms. Its first wind farm, Te Rere Hau, on the Tarurua Ranges near Palmerston North, is another PRE project. The $80 million farm will have 97 turbines which will be constructed in stages and generate 48.5 MW.
A review of wind potential in New Zealand carried out by the Energy Efficiency and Conservation Authority, states that the physical potential for wind energy is around 100,000 GWh per annum.
Other renewable energy sources
Unlike other forms of renewable energy, hydro electricity is a well-established technology and a major contributor to energy supplies both in New Zealand and overseas. New Zealand’s large hydro power schemes generate more than 60 per cent of our national electricity supply.
As well as wind and hydro, renewable energy sources include solar, geothermal, cogeneration and bioenergy. Bioenergy currently provides about five per cent of New Zealand’s primary energy supply but it is forecast that this will rise to 10 per cent of supply by 2010. Most of this is derived from woody biomass (domestic firewood and waste products from wood processing).
Looking ahead
The Government is investigating options for further cross-sector incentive schemes like the PRE programme to encourage use of renewable energy sources. It is also considering a national policy statement (NPS) on electricity generation to provide guidance on renewable energy generation projects that reduce emissions.
In 2005, hydro, geothermal and wind made up about 64 per cent of total electricity generation. The Energy Outlook projects electricity demand will increase 40 per cent by 2030 and energy-related greenhouse gases will increase by 35 per cent under a business-as-usual infrastructure (MED, 2006).
If the draft New Zealand Energy Strategy’s proposal that all new electricity generation should come from renewable sources is adopted, then projects like the Burwood gas landfill will become the norm rather than the exception.
For further information on Projects to Reduce Emissions visit www.mfe.govt.nz/issues/climate/policies-initiatives/projects/ or email projects@mfe.govt.nz
For further information on renewable energy visit www.eeca.govt.nz or www.med.govt.nz
