BIOENERGY PRODUCTION IN NEW ZEALAND AGRICULTURAL RESOURCES

1
BIOENERGY PRODUCTION IN NEW ZEALAND
AGRICULTURAL RESOURCES

• Donna Giltrap1, Surinder Saggar1, Vicky Forgie2,
  Rocky Renquist3
• 1Landcare Research Limited, Palmerston North
• 2New Zealand Centre for Ecological Economics,
  Palmerston North
• 3Crop and Food Research, Palmerston North

2
ISSUES?

• Current levels of energy consumption and
  production not sustainable.
• Fossil fuel security and prices.
• Stronger emphasis on the development of cleaner
  and more efficient technologies.
• Environmental sustainability
• reduction of greenhouse gas emission
• minimising other environmental impacts

3
Why bioenergy?

• Is renewable energy
• A key focus of government policy
• Potential to reduce GHG emissions
• Substitute for diminishing global oil supplies
  that NZ is dependent on
• Potential to leverage NZs existing strength in
  agriculture.

4
Potential Feedstock and Conversion Technologies
Technology not yet commercially available
5
Agricultural Crops

• Crops with high sugar or starch content (e.g.
  maize) - ethanol
• Oil crops (e.g. canola, soy) - biodiesel
• Perennial grasses - ethanol (cellulose conversion
  technology) or combustion.

Current Production (2005)
6
Crop Residues (Straw)

• Straw heat power (future ethanol?)
• Assumed to have zero economic value.
• Collection, storage and transport are the main
  costs.
• Some straws incorporated into the soil to
  maintain soil quality.

Current Production (2005)
Assuming that 50 of the residue is returned to
the soil
7
Horticultural wastes

• Combined heat and power
• Large volumes located at processing plants
• High moisture contents, making transport
  expensive
• Co-location of energy and plant processing
  facilities minimises transport costs
• Some wastes already used for process energy and
  others have competing uses (e.g. stock food).

• Gisborne
• Sweetcorn
• Squash

Current Production

• Hawkes Bay
• Orchard prunings
• Fruit and vegetable culls and processing

• Canterbury
• Green pea vines
• Vegetable culls and processing

8
Animal Manures

• Anaerobic digestion to produce heat and power.
• May avoid economic and environmental costs of
  disposal.
• Increased use of herd homes and feed pads for
  dairy could increase the amount of FDE available.
• Animal manures contain nutrients and have some
  value as fertilisers.
• FDE are widely distributed and expensive to
  transport. So most suited to energy conversion
  methods that can be operated at farm (or small
  co-operative) scale.

Current Production
9
Land use change
Scenario Land-use change to growing energy crops
Land area suitable for cropping 2.4 million ha
Some sheep and beef farms might be able to
economically switch to grain production.
Current sheep and beef area suitable for
cropping 0.9 million ha
10
Considerations

• Producing bioenergy requires resources (e.g.
  energy, fertilisers, water) for feedstock
  production, transport and conversion.
• Bioenergy needs to be produced in an
  environmentally sustainable manner (water
  quality, soil quality, greenhouse gas emissions
  and biodiversity).
• Bioenergy has opportunity costs (e.g. alternative
  uses for feedstock, alternative land use).
• Is bioenergy competitive with alternative energy
  sources (including imported biofuels)?
• Social impacts jobs created in bioenergy sector,
  but possible job losses in other sectors (e.g.
  freezing works).
• Impacts on other parts of the economy (e.g. food
  prices)

11
Conclusions

• Bioenergy could help reduce New Zealands
  greenhouse gas emissions and improve energy
  security.
• Currently a large amount of waste biomass is
  produced that could be used for bioenergy.
• Large land areas that could be converted but has
  an opportunity cost.
• The full social, economic and environmental
  impacts of any proposed bioenergy system needs to
  be assessed.