Availability and viability of small on-farm biogas plants

Transcription

1 IEA Bioenergy Conference Vienna, Austria - November 14 th 2012 Availability and viability of small on-farm biogas plants Nathalie BACHMANN Task 37 Energy from biogas EREP SA Chemin du Coteau Aclens Switzerland nathalie.bachmann@erep.ch

2 Context Estimated feedstock potential for biogas production EU 27: (Based on AEBIOM, 2009) Nathalie Bachmann Task 37 Availability and viability of small on-farm biogas plants 2

3 Context Investment costs for biogas plants /kw kwel installed Nathalie Bachmann Task 37 Availability and viability of small on-farm biogas plants 3

4 Objectives Availability and viability of small on-farm biogas plants Nathalie Bachmann Clare Lukehurst - Illustrate existing technologies for small-scale plants & possibilities to reduce investment costs - Necessary and favourable framework conditions - Management and operation to improve economic viability More successful small-scale biogas projects - new agricultural branch, rural development, improved waste and fertiliser management Renewable energy production and reduction of GHG emission - exploitation of the huge agricultural potential Nathalie Bachmann Task 37 Availability and viability of small on-farm biogas plants 4

5 Principal small-scale concepts CSTR Continuously Stirred Tank Reactors Nathalie Bachmann Task 37 Availability and viability of small on-farm biogas plants 5

6 Principal small-scale concepts Garage reactors Nathalie Bachmann Task 37 Availability and viability of small on-farm biogas plants 6

7 Principal small-scale concepts Plug-flow reactors (Source: schmack-biogas.viessmann.com/) Nathalie Bachmann Task 37 Availability and viability of small on-farm biogas plants 7

8 How to choose? Reactor type Reactor temperature Number of phases Agitation system Key parameter Dry matter content of feedstock Risk for pathogens Composition of substrates, acidification risk Dry matter content of feedstock Options - CSTR for liquid substrates - Plug-flow or batch digester for solid substrates - Mesophilic temperature when no risk for pathogens - Thermophilic temperatures when risk for pathogens (organic house waste) - One phase systems when no acidification risk - Two-phase system for substrates with a high content of sugar, starch or proteins - Mechanical agitators for high solids concentration in the digester - Mechanical, hydraulic or pneumatic agitation systems for low solids concentration in the digester Nathalie Bachmann Task 37 Availability and viability of small on-farm biogas plants 8

9 Viability of small-scale plants Framework conditions Plant management Legislative framework: Administrative procedure, state support Institutional framework: Local framework: Farm and surroundings Plant constructors, engineering offices, banks Economic viability of small-scale plants Feedstock management Operation control Digestate and energy management Nathalie Bachmann Task 37 Availability and viability of small on-farm biogas plants 9

10 Local framework and energy management Nathalie Bachmann Task 37 Availability and viability of small on-farm biogas plants 10

11 Feed-in tariffs As an effective state support instrument reserved for small-scale plants (<100 kw) Nathalie Bachmann Task 37 Availability and viability of small on-farm biogas plants 11

12 Example of economics Investment costs [ ] CHP 45 kwel Total: > / kwinstalled! Incidential costs Electric installation Heat connection Outdoor facilities Gas holder Digester & holding tank Pumps, pipelines, valves Flare Cogeneration unit (40 KW motor + local) Pretreatment (cutter) Nathalie Bachmann Task 37 Availability and viability of small on-farm biogas plants 12

13 Economics Plant operation Example - CHP 45 kwel Benefit: /a Example from Switzerland Conditions: - 80% borrowed capital % interest rate - 60 CHF/t gate fee - Feed-in tariff: 40 ct/kwh Nathalie Bachmann Task 37 Availability and viability of small on-farm biogas plants 13

14 Conclusions Availability - Vast technological options - Many new plant suppliers references must be checked carefully - Don t choose the cheapest option, but the most adequate for your situation Viability - Good framework conditions are necessary - Careful evaluation - Full energy recovery - creative solutions are often beneficial! Nathalie Bachmann Task 37 Availability and viability of small on-farm biogas plants 14

15 Thank you for your attention! Nathalie Bachmann Task 37 Availability and viability of small on-farm biogas plants 15