An Analysis on the Economics of Power Generation Using Wood Wastes from Scrapped Houses in Japan

Transcription

1 An Analysis on the Economics of Power Generation Using Wood Wastes from Scrapped Houses in Japan Yoshiki Ogawa and Hiroto Nakajima Toyo University, Japan The 10th IAEE European Conference, Vienna, Austria September 7-10, 2009

2 Contents of Presentation Present situations on wood wastes recycling in Japan Simulation methods on economics of biogas generation using wood wastes How to consider gathering cost of wood wastes Simulation results (1) : Base case - No subsidy Simulation results (2) : Reasonable supports Concluding remarks

3 Generation of Biomass Wastes in Japan and Positioning of House Wood Wastes Generated Amount (mil. Ton) Utilized Not utilized Livestock excreta % 10% Food Wastes % 80% Disposed papers % 40% Pulp effluents % Sawing wood wastes % 5% House wood wa stes % 40% Forest wood wastes 3.4 2% 98% (1,000 mil. t) ton) Generated amount Drain sludge % 30% Farming wastes % 70% 4.0 FY1995 FY2000 FY2002 FY2005

4 Recycling of Wood Wastes from Scrapped Houses (%) Landfill Reduce Particle board about 420,000 ton Mulching wood tips about 80,000 ton Paper making about 440,000 ton Fuel use about 1,200,000 ton Recycle FY1995 FY2000 FY2002 FY2005 Compost about 400,000 ton Covering wood tips about 260,000 ton Other recycle about 290,000 ton Material recycle Thermal recycle

5 of Wood Wastes Recycling The following problems are crucial for wood waste uses. Weak competitiveness to cheaper woods imported from overseas. Share of imported woods reaches to 80%. Quality control in separation of wood wastes from scrapped houses for material recycling of wood wastes Necessity to reduce simple burning (22%) and landfill treatment (9%) Thus the thermal recycling of wood wastes from scrapped houses is expected to increase more and more. Further strengthened programs for recycling of wood wastes are required by construction recycling law. In this study, the fuel use of wood wastes randomly generated by scrapping of houses. We adopt power generation by direct burning because initial investment is lower than other methods.

6 Simulation Methods on Economics of Power Generation from Wood Wastes <Purpose of simulation> In this study, we would like to analyze the economics and suitable size of plant for wood wastes. <Structure of economic simulation> First, each item on construction and operating cost is estimated based on preceding researches. Second, the cost required for gathering of wood wastes is estimated by the separate model dealing with dispersed random generation points and gathering routes. Third, we presumed the selling revenue of generated electricity and gathering revenue of wood wastes.

7 Simulation Structure of Biomass Expense Estimation Power Plant Economics Construction cost Operating cost Gathering cost Utilization rate Subsidy for initial cost Outlet model of food wastes Gathering Price Selling Price Disribution of gathering points Net Profit Estimation Wood Food wastes Wastes gathering revenue Electricity sellinng revenue Revenue Estimation The economics is evaluated by obtaining net profit calculated from the balance between revenues and costs piled up from the respective items of each sector.

8 Construction Cost, Number of Workers etc. Depending on Input-size Construction cost (billions Ye n) Number of workers Generation efficiency (%) ! Number of workers Ge ne ration e fficie ncy " !Construction cost Input size of wood waste s (ton/day) 10

9 Model Structure for Gathering of Wood Wastes Item Value Case 1 Number of area 1,801 (High Radius of area (d) 500 m density) Ring road interval (X) 1 km Case 2 Number of are a 1,801 (Middle Radius of area (d) 1,000 m density) Ring road interval (X) 2 km Case 3 Number of area 469 (Low Radius of area (d) 2,000 m density) Ring road interval (X) 4 km X d Case 1: Region within 24 km-radius, Case 2: Region within 48 km-radius Case 3: Region within 50 km-radius (restricted by construction recycling low guideline Case / km 2 Tokyo Pref. 1,226.4 / km 2 Kanagawa Pref / km 2 Osaka Pref / km 2 Case / km 2 Hyogo Pref / k m2 Fukuoka Pref / km2 Hiroshima Pref / km2 Case / km 2 Kochi Pref / km 2 Aomori Pref / km 2 Hokkaido Pref / km 2

10 Estimation of Gathering Cost of Necessary Food Wastes Area assignment by generating random number s!area " Data on area (gathering cost) Calling gathering information on the assigned area Repeating this procedure fo r necessary input amount and estimating total gathering time of house wood waste Repeating this estimation necessary times for estimating fluctuations of total gathering time Estimation on fluctuation of total gathering time # Average ( AVE ) : average of all total gathering times # Maximum ( MAX): lo nger times 20% average # Minimum ( MIN) : shorter times 20% average

11 Gathering time (hour/ton) Estimation of MAX Case 3 Gathering Cost of Necessary MIN AVE AVE MAX MIN Case 2 Food Wastes Gathering time (hour/ton) MAX Case AVE 1.65 MIN

12 Base Case Simulation Results on the Economics of Biogas Power Plant Cost (1,000 Yen/t) 18 Case 3: Gathering cost Max 16 Min Case 2: Gathering cost Cost Max Min Net benefit (1,000 Yen/t) 8 6 Case 1 Net Benefit GC Min GC Max GC Min 10 Case 1: Gathering cost Max 0 Case 2 GC Max 8 Min Operation cost -4-6 GC Min GC Max (Note) GC: Gathering cost 2 Depreciation cost Case Util. rate: 70%, No subsidy for inv., Gath. charge: 15,829 Yen/ton, Elec. price 7.8 Yen/kWh

13 Base Case Simulation Results on the Economics of Biogas Power Plant Net profit difference (Yen/ton) Case 1 Case 2 Case Gathering Cost: Minimum! Net profit: Maximum Net profit (Maximum) - Net profit (Average) Gathering Cost: Maximum! Net profit: Minimum Net profit (Minimum) - Net profit (Average)

14 Simulation Result (1) Base Case No Subsidy First, the economics of biomass generation using wood wastes is better in the high density region than in the middle density or low density region. Second, in the high density region, the biomass power plant more than 75 ton showed a good economics because of the balance between the scale merit of plant size. Third, in the high density region, the economics of biomass power plant is almost secured without special supports. Forth, in the middle density region, the biomass power plant more than 405 ton showed a positive economics, but in the low density region, always negative.

15 Improvement of Profitability by External Supports in Case 2 (1) Net benefit ( 1,000 Yen/ton) 6 Net benefit ( 1,000 Yen/ton) 6 Construction cost support Operation rate change Base 30% -2 Base 60% 50% 80% -4 70% -4 90%

16 Improvement of Profitability by External Supports in Case 2 (2) Net benefit ( 1,000 Yen/ton) Net benefit ( 1,000 Yen/ton) 6 6 Gatering price support Power price support Base ,000Yen +2,000Yen +4,000Yen -4 Base +1.5Yen/kWh +3.0Yen/kWh +4.5Yen/kWh

17 Simulation Result (2) Reasonable Supports Net benefit ( 1,000 Yen/ton) !"#$% &%'%()*+%,$-#)./%% !"#$% 0%'%1),,2$%,$-#)./%% $, "-,%? &BC%@$-DEF+%$2$A.9)A)./%79)A$ 0.0 HC%.8- &:C%.8- G;C% !"#$% 0%'%1),,2$%,$-#)./%% 3 4"#$

18 Concluding Remarks First, Japan need to establish the effective recycling methods for wood wastes from scrapped houses. Thus, the biomass power generation is an important option for house wood wastes as a potential pass. Second, especially in the high density region, we can expect the good economics of a larger scale of biogas plant. But in the middle density region, the plant size more than 405 ton is required to have positive economics. We need to consider some supports. The balance between the scale of plant and the secure procurement of input wood wastes is important. Third, Japan also needs to consider the elimination of several barriers and problems in order to improve the economics of biomass plant and to expand the effective use of wood wastes from scrapped houses.