Local Biogas Grids - improving the economics of biogas plants

SERVICE MIT ENERGIE.

© KWA EVIVA GMBH 2010 VOGELSANGER STRASSE 250 I 50825 KÖLN I GERMANY

Development of local biogas grids in Germany

Oldenburger Gastage, 1. Dezember 2010



Development of local biogas grids in Germany

Oldenburger Gastage, 1. Dezember 2010


© KWA EVIVA GMBH 2010 Eviva – nachhaltige Energiedienstleistungen

Content

• Biogas in Germany• Motivation for local biogas grids• Best-practice examples• Outlook



Biogas plants in Germany

Amount of newly built plantsTotal amount in previous yearAverage size of plant (kWel.)Additional capacity (MWel)Installed capacity (MWel)

Source: German Biogas Association

Amou

nt

Elec

tric

alca

paci

ty


Source: KWA Contracting AG

Source: KWA Eviva GmbH

Agricultural Biogas Plants



Digestion

HydrolysisBio filter Heat exchangerTransformer station

CHP-plant + stack Storage tank

Treatment hall

Thermal treatment

Desulphurisation

Fat tank

Industrial Biogas Plants

BGP WTE

SoccerStadium

BGP WTE

SoccerStadium

Source: BioWerk Hamburg

Source: HSV

Source: BioWerk Hamburg



Market Development in Germany

• More than 1,000 enterprises working in the sector• About 5000 biogas plants in operation• Technologies for upgrading to biomethane (23

projects) and biogas as transport fuel (2 projects) • Technologies for efficient use of thermal energy• Advanced technologies for treatment of digestate

and its application as fertilizer


Feedstock for Biogasproduction in Germany

Source: IBBK



Overview on biogas utilisation applications

• Slightly pre-treated biogas– Combustion in CHP’s for electricity, heat and cold

generation– Flare (only back-up)

• Upgrading to natural gas quality– Feeding into the natural gas grid– Vehicle fuel



Combined Heat and Power (CHP)

Application in Co-generation units for electricity, heat and cold production

Source: Econcern



Co-gen unit with district heating grid



Upgraded Biogas

Upgrading and injection into natural gas grid or utilisation as vehicle fuel

Source: Deutsches BiomasseForschungsZentrum gGmbH / Econcern



Why biogas grids?



Motivation

• >5000 biogas plants with 2200 MWe installed electricalcapacity in Germany à ~2300 MWth capacity potential

• Current degree of heat utilisation: ~50%, often „only“ to a small degree and/or to heat some buildings

• Using the heat– Increased degree of utilisation– improved economics– Relating the heat sales price to market prices of fossile

energy carriersà Improved hedging of economic risks

– Fixed EEG-tarifs + market volatile heat revenuesà hedging of substrate market prices



Biogas and efficient resource utilisation

• Prime energy: biogas à 6 kWh/Nm3• Biogas in co-gen unità2,5 kWhe per Nm3 of biogas used + 2,4 kWhth per Nm3 of biogas used…but how to use the heat?



Heat usage options

• Heating of buildings• Heat supply via district heating grids• Drying systems• Heating greenhouses• Cold supply to cooling applications• Heat supply to large cleaning businesses• Process heat for (e.g.)

– Food industry processes• biogas pipelines and satellite CHP units



Co-gen unit with biogas pipeline

Nahwärmenetz



Solution: local biogas grids

• less thermal losses• more economic for small/medium size biogas plants (<1000 kWe)

when heat off-take can be increased significantly and distances <3 km– Biogas grid costs 1/3 compared to heating grid– Additional costs for compressor and auxiliary material– Operational costs higher

• Versatile: possibility to connect more biogas plants on one biogaspipeline

• Safety important– Pipeline must be errected und operated according to DVGW-rules– Construction by DVGW-enterprises– Operation with 24 h availability– DVGW materials (PE)



Best-practice examples in Germany



Germany‘s 1st Biogas grid Braunschweig/Lower Saxony, 2007

• Biogas CHP unit500 kWe

• Biogasleitung 20km• satellite-CHP units

2 x 1 MWe• Heat injection into

district heating grid of the local utilityof BS Energy (16 Mio kWh/a)

• Details• Under large canal• under motorway

• Savings: 7200 t CO2/a

Source: Abwasserverband Braunschweig



Biogas grid Braunschweig - ecocnomics

• Investment costs– Biogas plant: 6.6 Mio. €– Biogas pipeline + CHP unit: 4.8 Mio. €

• Annual costs– O&M: 560 k€/a– Substrate: ~1.04 Mio. €/a– Financing: 645 k€/a

• Revenues – Heat & electricity: 2,62 Mio, €/a• P&L: + 375 k€/a



Biogasgrid Schwäbisch Hall/Baden-Württemberg, 2010

• Biogas CHP unit100 kWe, 120 kWth

• Biogasleitung 7km• Satellite-CHP unit

300 kWe, 330 kWth• Heat injection into

district heating grid of the local utilityofSchwäbisch Hall

• Savings: 2.500 t CO2/a

Source: Energiepflanzen, 4/2010



Biogas grid Bad Bevensen/Lower Saxony, 2010

• Biogas pipeline 5,5 km• satellite-CHP unit

600 kWe• Heat utilisation by public

thermal baths (4 Mio kWh/a)

• Heat off-take contract• to be always

„cheape“ than heatfrom gas/oil

• Details• Under little river

• Savings• 400000 l/a fueloil• 2700 t CO2/a

Source: KWA Contracting AG



Ins & outs

• External heat supply for fermenter necessary• Safety regulations for gas grids (e.g. 24h support)• Often additional CHP unit needed • Versatile – connect several biogas plants to one

grid• Q: Selling biogas or electricity and heat?



Summary and Conclusions

• Many biogas plants utilise the available heatinsufficiently

• Large economic potential to make use of „waste“ heatfrom CHP units

• EEG and prices of fossile energy carriers call forbiogas heat solutions

• Biogas grids can be an economically attractive optionto increase the degree of utilisation of the energycontent of biogas with less haet losses compared toheating grids



Questions?

Frank Schillig

e: [email protected]: +49-221-78946910w: www.eviva-energie.de

Eviva Strives for a Proper and Straight Support of Your Sustainable Energy Supply

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Local Biogas Grids - improving the economics of biogas plants