Because of the sites variable steam demand and the high cost of wood‐fired boilers per kilowatt, the most cost‐effective approach to steam supply at the Nelson site would involve utilising a relatively small woodfired boiler as a “Base Load” boiler. Modelling shows that a boiler capable of 2.2T of steam per hour (1.5MW) would be optimal, producing about 11,000 tonnes of steam per year, and displacing about 55% of the light fuel oil needed by the site. Download Report [4.75Mb]

The Dunedin City Council (DCC) in partnership with City Forests Ltd (CFL) and Otago Polytechnic (OP) received funding from the Energy Efficiency and Conservation Authority's (EECA) Wood Energy Grant Scheme (WEGS). The fund was used to investigate the opportunity of creating a locally owned and sourced wood fuel using local energy consultant, Transitionz Group Ltd, and land management consultant, Forest Environments Ltd.

The project is separated into demand (end user) and supply side (forest supply) components and reporting will be completed according to partner reporting requirements. This report, "Wood energy supply options for City Forests Limited" addresses the requirements of the supply chain, from forest floor to point of sale. From a forest owner's perspective it is important to understand the security of demand for the woody bioenergy product, the cost of production of the product, and any barriers that may limit the potential of this new business stream.

This report follows on from the study completed by Transitionz Group Ltd, which considered the potential demand for wood energy in Dunedin. The recommendations from these two reports, "Wood Biomass Options for the Dunedin City Council" (July, 2009) and "Wood Biomass Options for the Otago Polytechnic" (July, 2009) have directed this study to analyse wood chip as the preferred product of supply for CFL.

This report begins by assessing the volume of usable woody residue that is available within the CFL estate. It then discusses the operational considerations of a potential bioenergy business; evaluates these considerations with due applicability to the CFL estate, and provides recommendations for a CFL supply chain. The profitability of a bioenergy business is explored, with the potential risks of a CFL bioenergy business also discussed.

Finally, recommendations for the next steps in the development of a bioenergy business are made.

Download Report [2.56Mb]

An opportunity has arisen for the NZDF/RNZAF to improve the economics surrounding the operation of the Woodbourne Air Base heating system.

This two-part report evaluates the opportunity to convert or replace coal fired boilers to woody biomass. Part one of the report refers to the feasibility of the conversion of the current coal fired boilers, and part two will discuss the feasibility of a new boiler or boilers to replace the current two coal fired boilers.

Download Report [678 kb]

An opportunity has arisen for the New Zealand Defence Force to improve the economics surrounding the operation of the Burnham site heating system.

An opportunity has arisen for the New Zealand Defence Force to improve the economics surrounding the operation of the Waiouru site heating system.

This report details the commissioning and some financials of a moisture meter used by HA Foote Haulage supplying wood chips to Tahuna Intermediate School in Dunedin. A specialist wood chip moisture metering device is used to define the energy content of wood chips HA Foote Haulage delivers.

Download report [3.8 MB]

 
In any system for delivering wood residue as bio-fuels from forests or wood processing sites, transport is a key factor and contributes significant cost. Transport cost as a percentage of delivered cost can vary from ~12% (5 km haul) to ~60% (150 km haul) depending on the transport distance. Optimising transport systems on medium (50 km) to long (100 km) haul transport is therefore critical to minimising costs.Download full report [1.83 MB]

One of the energy forms that biomass can be converted into is electricity. In response to a call to the Bioenergy Hotline, bioenergy experts have completed a quick survey of the feasibility of a number of methods of converting biomass into electricity. The options for generation electricity were: 1) via a two-step process of first converting the biomass to ethanol and then to electricity via jet turbine; 2) via a steam turbine; 3) via a two step process of gasifing the biomass and then converting the gas to electricity via a gas turbine; 4) via an organic Rankine cycle.

Download the short report (4 pages)  for more details.

Options for generating biomass [86 KB PDF]