Implementation of Biogas Plants in Organic Farming, Feasibility & Technical Implementation

Anja Haupt, RENAC Frank Hofmann, Ecofys Germany GmbH

General requirements for Biogas Plants in Organic Farming

Crucial economic parameter

The SUSTAINGAS calculation model

Survey with organic farmers

Planning, constrution and running of a Biogas Plant in Organic Farming

Biogas Plants in Organic Farming: Technical and practical Implementation

Biogas Concept

Biogas as fuel

Organic vs. Conventional Biogas

Divergences in:

1. Substrates

2. Holistic approach

3. Technical Requirements

4. Sustainability

1. Substrates

Choice of Substrates in Organic Farming Farm fertilizer

Residues from livestock husbandry: slurry, manure, liquid manure, straw EEG bonus >30%

Co-substrates

Residues from crop production

Catch crops/ Clover gras

Material from conservation areas and/or uncontaminated biological residues

Additional purchases (e.g. through cooperations btw. farms)

1. Substrates

Choice of Substrates

(organic vs. Conventional) No/less cultivation of energy plants

Utilization of residues from animal husbandry and residues accumulated through organic crop rotation

Clover grass in organic farming ~20% of arable land

Possible longer transportation distances

less substrate area available than in conventional agriculture

no food/area/land use competition

2. Holistic Approach

Crucial economic parameter

Biogas plants in conventional agriculture

Biogas plants in organic agriculture

Crucial economic parameter to define the economic feasibility Costs of substrates Investment costs Operation costs

Income from the production of electricity and heat Management skills of farmer

- Higher investment and operating costs

- Biogas plant has diverse effects and impacts onto farm

- Holistic view becomes necessary

Feasibility for organic biogas production has to be considered within the context of the whole farm, and not only for the biogas plant

not an isolated view onto biogas plant

Feasibility of biogas plants in organic farming

Outputs - Digestate

Biogas digestate as fertilizer „The incentive in building a biogas plant did not lay in the production of electricity, but in the fermentation from clover gras to an organic fertilizer“ -Hubert Miller, Bioenergie Schmiechen GmbH&Co.KG

Additional nutrient source contributing to on-farm nutrient cycle, variable applicability and mobile N-source

Odor-free production of digestate

Increased fertilizer effectiveness

improved nutrient availability in digestate

Homogeinity of digestate (depending on feeding-in practices)

Increased yield and crop quality

Biogas plant as plant producing fertilizer

Catch crops

have a monetary

value as

energy plants

Feasibility of biogas plants in organic farming

Influencing factors, Biomass

Biomass: Costs and risk of delivery Dependency on biomass

Higher costs per kg DM in comparison to the conventional production of biogas

High costs, whenever biomass has to be purchased additonally

-Avoid additonal purchase of biomass – plan with realistic amounts according to plant size -Collective plants -If add. Purchases cannot be avoided: Isolation of delivery of biomass from fluctuating market prices; long-term contracts with other farmers, e.g. in exchange to fertilizer

Investment strategies according to plant size

Small plants < 100 kW

Advantages: - Few dependencies on biomass - Low transportation costs - Local utilization of heat

Disadvantages: - High particular investment costs - Management responsibility lays with farmer himself - Little electrical energy efficency of CHP

Recommended for: -Small farms -With (mainly) animal husbandry

Strategies: -„Do-it-yourself“ concept - Simple turn-key concepts

Medium-sized plants 100 - 500 kW

Advantages: - Low peticular investement and operating costs - Higher electrical energy efficiency of CHP - Generating local employment opportunities

Disadvantages: - Dependency from delivery of external biomass - Potential difficulties with the utilization of waste heat - Transportation costs

Recommended for: - Medium-sized farms - Farms with a greater size of fields - Farms with a greater horticultural production

Strategies: -Turn-key plants - Respective contracts with biomass-delivery - The import of conventional biomass for transition period

Investment strategies according to plant size

Large sized plants > 500 kW

Advantages: - Possibilities for utilization of gas: -Upgrading of biogas for grid integration -Flexible electricity production -Professional plant operator can be employed

Disadvantages: - High investment costs - Financing concept necessary - Prolonged process of approving - Transportation costs - Cooperation agreements necessary

Recommended for: - Several larger farms, neighboring organic farms - Possibility of cooperations

Strategies: - Planning and design of an individually adapted plant

Investment strategies according to plant size

The SUSTAINGAS calculator

Biogas plants should always be adapted to the local conditions and optimized in plant size and kind

The SUSTAINGAS calculator allows individual calculations

http://www.sustaingas.eu/strategy.html?&L=1

Technical Requirements

Due to special conditions of organic farming some technical adjustments become necessary

Different composition of farm fertilizer (more solid manure)

Higher amount of Lignin and fiber/cellulose in substrates due to cultivation of other crops

Substrates with higher protein content, management of higher nitrogen contents in fermenters become necessary

Generally smaller plant sizes

Practical experience: Interviews with organic farmers

What do other farmers think?

The SUSTAINGAS team questioned 40 organic farmers

Country Interviewees

AT 5

BG 5

DE 15

DK 5

ES 5

PL 5

37%

10%5%

48%

Do you run or contribute to a biogas plant?

Yes, I run my own biogas plant on my farm

Yes, I run a biogas plant on another farm together with other farmers

Yes, I run a biogas plant together with other farmers on my farm

No

Negative impacts

0 1 2 3 4 5 6 7 8 9

Sale of heat

Starting problems and costs

Technology

Harvest and transport of biomass

Effeciency of CHP

Moderate power purchase

Production of feedstuff

Dry matter in plants

To convert to organic farming

Availability of biomass

Running hour of CHP

Investments

Lack of gas production

Management and process understanding

Failures and repairs

Feed in tarif for power

Price of biomass input

Number of answers

Running time of CHP

Insufficient Production of Gas

Disruptions, Interruptions and Maintenance

Practical experience: Interviews with organic farmers

Consideration of experiences of other farmers already in planning process

Practical experience: Interviews with organic farmers

Consideration of experiences of other farmers already in planning process

Practical experience: Interviews with organic farmers

Phase 1: Planning

First considerations Calculation of possible revenues

Analysis of individual requirements (e.g. compensation of power, financial resources, amount of substrate, location, utilization of heat) as basis for determining concept and size of plant and utilization of biogas

Consider effort and financial expenditures for approving process

Create a concept to keep costs for biomass as low as possible

Create a concept to keep own power consumption as low as possible

Include sufficient storage space for digestate

Phase 1: Planning

Provision of biomass: Set long-term agreements with suppliers, if there are too little resources on own farm

Organic Farmers:

Supplying surplus

biomass for biogas

plant = Access to

organic fertilizer in

high quality

Biogas-Plant

operator:

Necessity of reliable

provision of biomass:

sufficient quantity

available at fair prices

Create Win-

Win Situation

Phase 1: Planning

Implementation of Biogas Plant also means a social project!

Acceptance of suppliers, authorities, neighbours, neighbouring farms, media… necessary

Select experienced and reliable partners for planning, constrution and consulting

Phase 2: Construction

Directing substrates Consider expanded diameter and linearity of pipeline system, with short distances

Foreign material Consideration of importance of sand discharge already in planning phase

Phase 2: Construction

Digester Increased risk of floating film/layer due to higher protein content – one possibility to reduce risk is the implementation of higher digesters with a more narow diameter

Multi-phase digester: less short-circuit current, optimized substrate treatement and handling

Agitator: Correlation between costs of operation and quality

Premium agitators as a result of higher mechanical burden

Slow running process, adapted to viscious/ semifluid substrate

Phase 3: Running

Control of biological process

Due to higher protein content there are incrreased Sulfite and Ammonia values, constant controls become necessary

Phase 3: Running

Utilization of Digestate

Digestate has other characteristics than conventional liquid manure:

- Different Dry Matter Content

- Higher amount of fast available N to plants

- Lower fiber amount

- Less odor emission

Storage basin and turnout technology need to be adapted:

- Include sufficient storage capacity for digestate

- Apply turnout technology with little nutrient loss

- Separation? (Separation of the liquid and solid phase of digestate)

not yet researched.

Further technology options

Apart of the „Standardconcept“ there is a number of divergent concepts for specific implementations:

Plants with separate Hydrolyse step

Dry fermentation process

Plants without agitation technology

Analyse concept and implementation, question practical references

Best Practice Example (1/3)

Bioenergie Hallerndorf, Bavaria, Germany:

Plant on commercial property built 2011

GmbH consists of 4 organic farmers (Ø4,5km distance) and Naturstrom

~540 kW (250kWel + 290kWth)

Substrates: manure (~70%), clover grass (~30%) Electricity: 2,150,000 kWh /year (6,5% used for biogas plant, rest fed-in

through EEG)

Heat: 2,400,000 kWh/year (75% of heat is utilized (goal: 90%): 30% used for heating digesters, part of the rest also for drying units)

Digestate: 5,900t/year (divided among providers - shareholders and neighbouring farms that feed-in)

Best Practice Example (2/3)

Sophienhof, Brandenburg, Germany:

Plant built in 2011

Farm size: 510 ha Crops: Greenland, cereal, fodder production

Livestock: Dairy cows, pigs

195kW

Substrates: Farm fertilizer (manure, slurry + cooperation with chicken farm in neighborhood), grass silage

Electricity: 1.570.500 kWhel/a (100% fed-into national grid (EEG), plant demands high amount of energy, electricity needed

for the plant still bought externally but provided by wind mill from 2014)

Heat: 92% utilization of heat (in summer): Average per year: 50-60% heating of barn, 15-20% heat tanks of biogas plant

Digestate: Utilization on areas that served as biogas substrate

Best Practice Example(3/3) Hofgut Räder, Bavaria, Germany:

Plant built in 2009

Farm size: 105 ha Crop production: brewing barley, radish, mustard,

buckwheat rest grassland Livestock: pigs

~510 kW (250kWel + 260kWth)

Substrates: clover grass (~60%), manure (~35%), maize/cereal (~5%)

Electricity: 2,150,000 kWh/a (10% own usage of biogas plant, rest fed-in through EEG)

Heat: 2,000,000 kWh/a (100% utilization of heat: 5-10% own use (Biogas plant, housing,

stalls, drying units), rest sale to local heat grid

Digestate: Yield increase in amount and quality through digestate of about app. 20% (subjective impression)

Summary

Biogas plants in organic farming should be seen within the system of organic agriculture

Besides energy production, the increment of yield is another important part of the financial efficiency

Biogas plants in organic farming need adapted technical concepts, that are accessible in a standardized way

Thank you for your

attention!

Frank Hofmann, Ecofys Germany GmbH

f.hofmann@ecofys.com