Faculty of Energy and Fuels

Faculty of Energy and Fuels Research Needs in Optimisation of Energy Use of Biomass Authors: Adam Guła1,2, Adam Hempel2, Paweł Wajss2 • International Forum of R&D for Eco-innovation • Katowice, 22-23 October 2009 • 1) 1. AGH – University of Science and Technology in Krakow, Poland • 2) 2. The Krakow Institute for Sustainable Energy

BUT we cannot satisfy all those needs at least in short or medium term, because CONTRARY TO WHAT SOME PEOPLE SEEM TO ASSUME BIOMASS is a LIMITED RESOURCE (available harvest area, soil quality, climate ... but also financial resources for investment) we need it also for food !!

Biomass can be used for energy purposes in a variety of ways: • as • gas • liquid fuel • solid (logs, chips, briquettes, pellets) • for • heat production • electricity generation • motive power (motor biofuels)

Hence we are faced with a typical optimisation Problem The function to be maximised (or minimised) can be, e.g. GHG emissions reduction Total final energy (solid, liquid, gaseous...H2) Total revenue (e.g. for farmers) Mix of the above

TWO LEVELS OF OPTIMIZATION NEEDS COGENERATION GAS AGRO- TECHNOLOGY MOTORS ELECTRICITY HEAT BOTANY DISTRIBUTED GENERATION COGENERATION ELECTRICITY HEAT ELECTRICITY DIRECTCOMBUSTION SOLID HEAT CONVERSION LIQUID R&D LEVEL 2 R&D LEVEL 1 BIOTECHNOLOGY TRANSPORT HABITAT

The task can (should) be considered • at two levels: • Supply of biomass • Conversion  final applications • LEVEL 1  boundary conditions for LEVEL 2 • (simulation mode)

An appropriate tool (mathematical model) is needed to support decision-making it can be universal as an algorithm (only requiring appropriate input data) and it must be sufficiently user-friendly, because its main users should be local decision-makers such model still remains to be developed

This, of course, applies in particular to solid biomasswhere some factors are of particular importance Eg. for minimisation of GHG emissions Minimising embedded energy (pellets: 20% energy is lost) Minimising energy lost in transportation Minimising energy losses in energy conversion (electricity generation in thermal power plants – ca. 40% efficiency)

Poland provides an example of misuse (or largely sub-optimal use) of solid biomass resources (and of public money for supporting it)This example is: using solid biomass for power generation (mostly in pulverised coal boilers

This trend has been driven by the requirement to fulfill the obligations following from the European Directive2001/77/EC

Polish targets for the 2001/77/EC Directive(requried fraction of renewable electricity)

Poland is • A flat country - small hydro potential • Not much wind either • Biomass is abundant (BUT LIMITED !) • co-firing of biomass with coal

Howeverincreasingly many experts believe that cofiring of biomass with coal for power generation is WASTE of money and of the biomass resources

Examples of technical problems:

Slagging of ash at higher (red) and cooler (blue) temperature pipesfrom left-to-right:: hard coal (hc), (hc)+10%WP, brown coal (bc), bc+10%WP WP= wood pelletsdramatic increase with addition of WP is observed especially for brown coal

fractional remainder of the ground material on the seaves of the grinding mill for different pure coals and coal+20% biomass (right-most green column)

remainder of pure coal (left) and coal +biomass (right) on the seaves of the grinding mill after grinding 100 t of the input mass

POWER GENERATORSWOULD NEVER DO THAT IF THEY WERE NOT HEAVILY COMPENSATEDHOW?

FOR EACH MWh of GREEN ELECTRICITYPOWER GENERATORSGET ABOUT3 TIMES MORE THAN they get for a coal-based MWhpaid by ALL electricity consumerswhich is a „hidden subsidy”

for 10 TWh of „Green Electricity” ‘’Hidden Subsidy’’70 €/MWh • 10 TWh/year = 700 mln €/year !!

is there an alternative ?let us make some very roughORDER OF MAGNITUDE ESTIMATES

In Polish climate conditions Thisbiomass energy would be enough to heat about 150 000 rural households 10 TWh of electicity (36 PJ of heat)

According to the aforementioned targets, The annual green electricity production should be roughly:17 – 18 TWh Of this amount wind and hydro can cover only about:6 TWh Hence, biomass(co-fired with coal) must give10 – 12 TWh !

those 10 TWh of electicity translate to 36 PJ of heat At the same time a Polish farm requires on average 30 kW for heating which gives about 240 GJ / year i.e. 10 TWh of heat would feed about 150 000 rural households

This would giveAT LEASTTHE SAME CO2EMISSION REDUCTION EFFECT in fact MUCH LARGER ! EMBEDDED ENERGY LOSSES IN FUEL TRANSPORATION AND PREPARATION THERMODYNAMIC CYCLE EFFICIENCY

It is then natural to assume that once: biomass is a local resource, it should be used first of all where it is produced i.e. for heating farmers’ houses and farm premises

However, the farmers as a rule, do not have enough money to buy and install a modern biomass boiler. Financial support is needed WHERE FROM?

Instead of subsidising burning biomassfor „Green Electricity”we should subsidise biomass heating in RURAL AREAS

How much subsidy togreen heat would we would needto achieve the same environmental effect ? (in terms of reduction of CO2 emissions)To have an idea some estimates obtained using a economic model INVERT are presented below

INVERTInvesting in RES & RUE Technologies:Model for Saving Public MoneySimulation tool to support the design of efficient promotion schemes Developed under the EU ALTENER Programme by the consortium of: TUWIEN (AT) FHG (D) AGH & FEWE (PL) RISOE (DK) CEEETA (PT) ACE (UK) DuTh (GR)

Forecasted installation of domestic biomass boilers (blue) replacing the existing coal boilers (red and green) with the assumed subsidy of 30%

Forecasted number of new biomass boilersfor 40% subsidy level(the blue line reflects the in-country production capacity)

A 40% subsidy to a typical conversion invesment in the range 20-40 kW WOULD BE 2000 EURO 2000 EUR x 150 000 units = 300 mln EUR ONLY ! This is less than the 700 mln to be collected as the „hidden subsidy” from all electricity consumers in one year alone Over 20 years of boiler life-time this gives : 20 x 700mln = 14bln EUR(!) which is the proper number for the comparison

i.e. for ca 2%of this hidden subsidy we would achieve the same(in fact much larger) GHG emission reductionand at the same time we would:create local jobsenhance local economydecrease energy povertyimprove living standarsimprove local environment

This simple example only illustrates how important is the analytical support to decision-making in properly targeting the public subsidy money to achieve the assumed goals. Prior to promoting the use of biomass for energy purposes one should first ask the question what should be promoted first and if some applications should be promoted at all

Thank you for your attention

Faculty of Energy and Fuels