Biomass Energy: A Crash Course Peter Flynn Poole Chair in Management for Engineers Dept. of Mechanical Engineering University of Alberta
U of A Energy Club: February Opening Thoughts Society will likely have limits on its willingness to spend given that the problem is in the future. What we get for the dollar spent varies widely. The head needs to help the heart get the most environmental benefit per dollar spent.
U of A Energy Club: February Biomass is Carbon Neutral The carbon it emits is taken up in regrowth of the plant. If the biomass was not converted, it would rot and make CO 2 anyway. Hence, it displaces coal or oil.
U of A Energy Club: February Alberta Has Lots of It Straw and forest harvest residues are annual crops. Straw alone could supply the next 25% of Alberta’s total power usage.
U of A Energy Club: February A. And May Have Much More
U of A Energy Club: February The Technology Exists Today: Power at Large Scale
U of A Energy Club: February The Technology Exists Today: Ethanol at Commercial Scale Grain to ethanol is long established: Whiskey Corn to fuel grade ethanol Barley and wheat in Alberta Six commercial scale lignocellulosic ethanol plants announced in the US, including Iogen
U of A Energy Club: February A. Whole Grain to Ethanol is a Poor Choice Competition between food and fuel impacts the whole world. Poor energy yield, high impact on soil and water quality.
U of A Energy Club: February A. Lignocellulosic Ethanol Lignocelluosic residues (straw/ stover and wood) are available waste products. Purpose grown crops on marginal lands are also possible.
U of A Energy Club: February Research Isn’t the Correct Prime Focus Research can be misused as a tool to postpone difficult choices. Technologies exist today. Alberta has a particular need for action.
U of A Energy Club: February Renewable Energy is not and never will be “Competitive” We have used fossil fuels because they are cheaper. Competitiveness isn’t the key question: we are paying more for an environmental gain. Someone must pay. The key objective is to buy the most greenhouse gas out of the atmosphere at the lowest extra cost.
U of A Energy Club: February Technologies are Not Equal.. The cost per unit of energy output and per tonne of avoided CO 2eq varies widely with technology and plant size. Power from straw: ~$75 per MWh Power from manure: ~$200 per MWh The minimum screen for any technology is “how much grant per tonne of CO2 avoided?
U of A Energy Club: February And Can Be Studied in Detail For each technology: What is the appropriate size of plant? How much CO 2 equivalent is avoided? Life cycle analysis need not be the complicated barrier it has morphed into. How much extra does someone pay compared to a business as usual case. Minimizing extra $ per tonne of avoided emission is the right metric.
U of A Energy Club: February There is an Optimum Size; it is Large Three elements to producing useful energy from biomass: Get the biomass Move it to site Process it Processing cost decreases with size, transport cost increases.
U of A Energy Club: February Cost Per Unit Output Plant Size, e.g. MW Cost per Unit Output, e.g. $/MWh First Cost of Biomass Can be positive (purchased) or negative (avoided cost)
U of A Energy Club: February Biomass Transportation by Truck Costs include: Loading and unloading: distance fixed. Shipping: distance (scale) variable. Typical values are $5 per tonne (distance fixed) and $0.09 per tonne km (one way) (distance variable). Increases ~ with (scale) 1/2.
U of A Energy Club: February Distance Fixed vs. Distance Variable Costs Only DVC affects scale
U of A Energy Club: February Cost Per Unit Output Plant Size, e.g. MW Cost per Unit Output, e.g. $/MWh Field cost of biomass Transportation cost Total delivered cost of biomass
U of A Energy Club: February Other Modes are Available: Pipeline (for liquid based processing only): high economy of scale, economic at sizes greater than 1 M Dry T/yr. Rail: fixed cost of trans-shipment requires minimum economic shipping distance.
U of A Energy Club: February Trans-Shipment: the Concept
U of A Energy Club: February Trans-shipment: Alberta Based Straw Power Plant Minimum economic rail shipping distance exceeds draw area: rail is not economic.
U of A Energy Club: February Biomass Processing: Use It Economy of scale in capital equipment and operating costs, typical scale factors in the range of 0.6 to 0.8. All evidence is that scale factor is valid up to very large processing sizes (>500 MW); road congestion limit is the prior constraint if delivery by truck.
U of A Energy Club: February Scale factor for Manure AD Plants
U of A Energy Club: February Data Consistency Varies Direct Combustion to power has been widely applied including very large scale plants.
U of A Energy Club: February Hence Good Fit for Processing Cost Estimate: Direct Combustion
U of A Energy Club: February Wide Scatter in Other Processes Fischer Tropsch estimates show wide scatter only partly due to configuration options
U of A Energy Club: February Cost Per Unit Output Plant Size, e.g. MW Cost per Unit Output, e.g. $/MWh Field cost of biomass Transportation cost Total delivered cost of biomass Operating cost Capital cost Total plant processing cost
U of A Energy Club: February Cost Per Unit Output Plant Size, e.g. MW Cost per Unit Output, e.g. $/MWh Field cost of biomass Transportation cost Total delivered cost of biomass Operating cost Capital cost Total unit output cost Total plant processing cost
U of A Energy Club: February Power from Field Sourced Biomass in Alberta
U of A Energy Club: February Optimum Size Increases with increasing processing cost Increases with increasing biomass availability Is neutral to the field cost of biomass
U of A Energy Club: February Optimum Size Depends on Biomass Gross Yield and Processing Cost
U of A Energy Club: February The Optimum is “Flat” A 3% relaxation in the criterion of minimum cost drops plant size sharply.
U of A Energy Club: February % of Optimum Size Has Minimal Impact, But the Cost Climbs Sharply Thereafter Power from straw in Alberta: $75 per MWh at optimum (330 MW net) $77 per MWh at 50% of optimum $100 per MWh at 25% of optimum $125 per MWh at 10% of optimum $145 per MWh at 5% of optimum
U of A Energy Club: February Power from Field Sourced Biomass in Alberta Straw to Power: >150 MW FHR to Power: >100 MW Lignocellulosic Ethanol: >3000 TPD Power from Manure: county wide plant.
U of A Energy Club: February Life Cycle Analysis of Emissions For most biomass plants the replacement of fossil fuel is the overwhelming contributor. Processing related emissions tend to equalize. Transport and refining are relatively small and estimates vary widely.
U of A Energy Club: February LCA Values, CO 2 eq Base load power vs. coal: 830 g/hWh, 1350 g/dry tonne of biomass. Ethanol or diesel: 2000 – 2400 g/l, 600 g/dry tonne of biomass. Power from manure (methane avoidance a factor): 900 g/kWh.
U of A Energy Club: February Put Cost and Avoided Emissions Together How much extra does someone (the consumer or taxpayer) pay? How much emission is avoided. Pick the most cost effective process.
U of A Energy Club: February Two key technology questions For a given end form of energy, e.g. power or transportation fuel, what is the most efficient technology. (This will depend on the abundance of biomass, since low availability = higher delivered cost). Between two end forms of energy, what should I pick.
U of A Energy Club: February Gasification vs. Direct Combustion As straw availability drops, the required carbon credit increases faster for direct combustion than BIGCC. The crossover is beyond any point of real interest. ~ Current power price in Alberta
U of A Energy Club: February Ethanol vs. FT Diesel Oil price range, 2008 to 2009 As straw availability drops, the required carbon credit increases faster for ethanol than FT diesel.
U of A Energy Club: February Picking the End Energy Form
U of A Energy Club: February Some Cautions Some technologies are far better demonstrated than others, hence more confidence in cost. All cost estimates rely on pre 2006 references, and hence miss the upswing in equipment and labor cost. The future of these costs is uncertain.
U of A Energy Club: February Policy Comes in Good and Bad Flavors Jurisdictions around the world are wrestling with how to integrate a more expensive form of energy into an existing energy economy. Some do it better than others.
U of A Energy Club: February Bad Policy “Man on the moon” targets obscure social costs. Short term “up front” payments. Higher payment to small scale projects. Doing everything with every source (makes as much sense as making electricity from gasoline).
U of A Energy Club: February Good Policy Does not, for a global warming target, specify the end product of bioenergy. Is long term Allows competition between projects to meet a social goal at the lowest cost. Identifies the cost per tonne of avoided CO 2eq.
U of A Energy Club: February For Biomass Energy to Grow: Drayton Valley, AB: 12 MW Alholmens, Finland: 240 MW