1. Biomass GEM assumptions Erwan Hemery 12 May 2009

2. Existing assumptions NameCapacity (MW) FOF ( %) Implied maximum energy (GWh) LocationHeatrate (GJ/GWh) Variable O&M, $/MWh Fixed O&M, $/kW Capital cost, $/kW Earliest commissioning year BioCog130 184.0Kawerau12000106028002014 BioCog230 184.0Central12000106028502015 BioCog330 184.0Whirinaki12000106028002016 BioCog430 184.0Kinleith12000106029002030 BioCog530 184.0Ashley12000106028002020 Total: 150 MW

3. Flow chart The parameters that were randomly selected are the: biomass resource available in New Zealand; share of the energy production used as direct heat; efficiency of the plant; and capacity factor of the plant. MC simulation How the maximum installed capacity has been derived from the estimated total biomass resource

4. MC assumptions New Zealand Biomass resource 2008 biomass resources is in the order of 47 PJ; 83 PJ per annum (pa) in 2030 and 90PJ pa in 2050 will be available (Scion); Derating factor to account to the proportion which is technically and economically available leading to 67 and 72 PJ pa; Biomass resource range between 67 and 90 PJ. Share to direct heat In 2007, around 23 % of the total biomass energy production was consumed by the electricity generation sector; The share of energy used for electricity generation could be anywhere between 23 and 33 %. Plant efficiency In the energy data file biomass efficiency of 30 %; In the future, the plants efficiency will improve as new technologies become available; Efficiencies ranging from 30 to 40 %. Capacity factor The Kinleith power station over the last couple has averaged a capacity factor of 0.78; Capacity factor ranging from 0.7 and 0.8.

5. Installed capacity

6. Delayed earliest commissioning year There are still a number of barriers and issues (Scion, 2008) that would limit the use of wood resource in New Zealand over the shorter term such as: forest harvest operational issues and integrating wood residues with the conventional harvest system; the need for the development of standards. Wood residues represent a large proportion of the energy and a classification of the different type of wood residues (e.g. water content) will be required; and the need to guaranty security of supply by having better information on the actual volume available and the impact of log harvest driven by overseas markets.

7. Yearly installed capacity

8. New assumptions NameCapacity (MW) FOF (%) Implied maximum energy (GWh) LocationHeatrate (GJ/GWh) Variable O&M, $/MWh Fixed O&M, $/kW Capital cost, $/kW Earliest commissioning year BioCog1 3120217Kawerau 12000 11.8100 28502020 BioCog2 6320441Central 11400 11.8100 28002024 BioCog3 6320441Whirinaki 10800 11.8100 29002028 BioCog4 3120217Kinleith 10200 11.8100 29002032 BioCog5 2120147Ashley 9600 11.8100 28002036 BioCog6 2120147Nelson 9000 11.8100 28502040 Total potential installed capacity 150 MW to 230 MW FOF i.e. capacity factor for baseload – Kinleith 22 %; 6 th power plant in Nelson; Heatrate was changed from 12000 GJ/GWh (~30%) to values ranging from 30 to 40 %. The heatrate has been decreased by 600 GJ/GWh every 4 years in order to reach 9000 GJ/GWh (~40%) by 2040; Variable, fixed and capex from the EnergyScape.