Implementation of biogas plants in organic farming
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Transcript of Implementation of biogas plants in organic farming
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