Sustainability of Biogas Plants in Organic Farming

SUSTAINGAS Workshop, Austria

Frank Hofmann Ecofys Germany GmbH

Sustainability of Biogas Plants in Organic Farming

Sustainability criteria

Life Cycle Assessment for 12 model biogas plants

Further Sustainability aspects Soil quality

Food vs Feed

Water quality

Biodiversity

Independence from fossile energy

Socioeconomic effects

Sustainability Criteria

RED: Biomass for utilization as fuel and bioliquids are subject to sustainability criteria

Less GHG-effects to fossil fuel reference

Land use requirements must not have negative impacts to biodiversity or carbon stocks

Sustainable agricultural practice

Introduction of sustainability criteria for biomass and biogas is under discussion, at EU-level

Organic biogas can be produced sustainably

Sustainability Criteria

Sustainability is mainly influenced through the use of input material

GHG

Balance

Envir.

Aspects

Social

AspectsLUC

Biodiv.

ILUC + Food

competition

Food industry

and municipal

residues

Catch crops

Animal

excrements

Existing agricultural

land

Idle and marginal

land

Cascading &

Recycling

Energy crops

Feedstock Sustainability issues

Harvesting

residues

© ECOFYS

LCA/ GHG-Emission Accounting

Definition of 12 biogas plant models

LCA Methodology Calculation according to „typical German“ Methodologies

Calculation corresponding to RED and COM(2010)11

SUSTAINGAS GHG-tool based on BioGrace tool (www.biograce.net)

Adaptations in the SUSTAINGAS calculation to RED/COM Methodology:

GHG emissions are attributed to electricity. Emission reductions from substituting fossil based heat are included as credit.

GHG-emission savings conneted to manure treatment are quantified

Additional Information: Impacts of plant production to humus content

LCA Impact Parameter

Biomass cultivation (Pesticides, fertilizer, diesel consumption)

Transport

Running of plant, diffuse emissions

Utilization of biogas, CHP

Impacts to Manure efficiency

Humus content

Result: LCA I

Overview of 12 biogas plant models

-1,300

-1,100

-900

-700

-500

-300

-100

100

300

500

700

900

g C

O2

,eq/k

Wh

el

Fossil comparator

Cultivation

Transport and distribution (including storage ofraw material)

Diffuse emissions

Methane leakage in the CHP generator

Externally used heat

Avoiding methane emissions from manure

Net emissions

Key findings, GHG

Avoided methane emissions due to manure treatment as most relevent effect

Substitution of fossil heat second most influencing factor

Biogas process is dominated by diffuse methane emissions; based on CHP operation

The cultivation of energy crops is connected to emissions

The more energy crops are used the higher CO2 emissions exist

The difference between biogas plants in organic and conventional farms is determined highly through use of substrates

Emissions associated with transport are of minor importance

Scenario: Methane emissions

15 % diffuse Methane emissions (before 1 %)

Energy crops are located around the fossile comparator!

Manure treatment plants mitigate GHG

-1300

-1100

-900

-700

-500

-300

-100

100

300

500

700

900

1100

g C

O2

,eq/k

Wh

el

Fossil comparator

Cultivation

Transport and distribution (including storage ofraw material)

Diffuse emissions and storage

Methane leakage in the CHP generator

Externally used heat

Avoiding methane emissions from manure

Net emissions

Further environmental aspects

Two comparisons of operation methods are analysed: Organic Farms with and without a biogas plant

Biogas plants in organic and conventional farming

Generalization: Whole Europe

Individual situations are crucial (climate, soil quality, crop rotation, regime) => Generalization critical

Soil quality It has to be distinguished between crop cultivation and effect of digestate.

Impacts of a biogas plant onto organic farm Differences in farms with and without livestock

Catch crops are cultivated more often

Increased N fixation, less N-leaching (in comparison to mulching), reduction of N2O-emissions

Flexible utilization of fertilizer

Humus balance, individual reconsideration, C-removal vs root growth

Phytosanitary effects; Deaktivation of weed seeds, promotion of N-availability

The influence onto soil quality is dominated through substrates and their cultivation .

Biogas in organic in comparison to conventional farming More catch crops, less renewable resources

Pesticides, mineral fertilizer

Food vs Feed

Effects of biogas on food security in organic farming depends on the substrates and the use of the land associated with it:

Substrate Positive Effects Negative Effects

Enery crops Area competition Soil quality

Catch crops Increased yield Higher protein content in plants

Livestock production: competition

Harvesting residues

Increased yield Higher protein content in plants

Livestock production: competition

Manure Increased yield Higher protein content in plants

Water quality

Organic farm with and without Biogas plant Catch crops, decreased N-leaching in comparison to mulching

Manure, N-leaching can be increased; Dung, N-leaching reduced

Disasters have high negative potential

Organic vs conventional farm Correlation of regions with high density of animal husbandry, density of biogas and pollution of ground water with Nitrate

Intensification of conventional farms can additionally lead to higher N-loads

N often is a limiting factor vs higher N-inputs

Biodiversity

Organic Farming

Correlation with Biodiversity With soil fertility, with N-charge (digestate)

Expension of cultivation and harvest period

Seeds of foreign kinds are deactivated

Negative impacts of over-fertilization, eutrophication

Erosion of Biomass (Manure, straw, harvest residues) has complex impacts

Losses of habitats

Yield increase

Better control (especially N)

Cultivation of energy crops Higher competition and pressure on agricultural areas

Reduction of closure sites

LUC

Impact onto biodiversity dependend on plant type

Independence of fossile energy

Biogas can be used in many ways Electricity

Heating and cooling

Heating of buildings

Processes (Breeding of piglets, cooling dairy products,….)

Drying

Selling

Fuels

As biomethan, as a substitute for natural gas

As biogas directly

Biogas can hence lead to a substitution and independence of fossile energy

Socioeconomic effects

Few differences btw organic and conventional biogas

General impacts of operating with biogas

Social effects Development of rural areas

Creating a network, exchange of information

Cooperation

Acceptance

Negative: Odor, transport, noise, fear

Employment opportunities 45.000 jobs in biogas sector (source: FVBG, Germany), 10.000 farms

App. 12 people per Mwel that is installed

Revenue Investment biomass electricity (solid & gaseous): 1,5 Mia € in 2012

Turnover biomass (Electricity and heat, without fuels): 6,8 Mia. € in 2012 (AGEEStat); (Biogas kanns: 6 Mia. €, German sources)

Regional turnovers increase

Summary I

GHG balance:

Biogas plants in organic farming can improve the LCA of a farm and further produce renewable energies

Manure treatement is a crucial part

Utilization of heat

Avoid methane emissions

Limit cultivation of energy crops

Summary II

Soil fertility can be improved through a biogas plant.

Production of organic biogas does not (or in a reduced way) mean a competition to food production

Water quality: Reduced N-leaching

Biodiversity: Biogas can expand crop rotation cycle

Biogas offers the possibility to become independent of fossile resources

Biogas is socio economically feasible Acceptance, (local) employment opportunities, revenues

Thank you for your attention!

Frank Hofmann Ecofys Germany GmbH f.hofmann@ecofys.com