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Conversion And Resource Evaluation Limited


C.A.R.E. Ltd. offers technical services in biomass and wastes combustion, gasification and pyrolysis for fuels, heat, power, CHP, chemicals and derived products. Our range of services include: 1. Design of complete bio-energy conversion systems from feedstock to electricity, heat and derived products [syngas, biochar, char, pyrolysis liquids, chemical products]. 2. Organisation and evaluation of biomass and waste feedstock testing. 3. Techno-economic modelling and evaluation of bio-energy systems 4. Technology surveys, reviews and feasibility studies on new processes and products. 5. Trouble-shooting of operational systems, practical experience on a range of systems. 6. Due diligence on a range of technologies [gasification and pyrolysis predominantly]. 7. Specialist presentations and course contributions 8. Experienced in a range of technologies, from R&D to commercial processes.


Dr Cordner Peacocke
30 Pinehill Road
Co. Antrim
BT 44 9BP

Conversion And Resource Evaluation Ltd. contributes to "Incentive Scheme for Invader (Encroachment) Bush Management - A Cost Benefit Analysis"

Conversion And Resource Evaluation Ltd. [CARE Ltd.] has been working with Dagmar Honsbein (an official from the Ministry of Finance, Namibia and a policy expert) and the Polytechnic of Windhoek, Namibia on a study on the cost-benefit analysis of removing encroachment bush from farmland in Namibia. The work, funded by the Namibian Agronomic Board, started in late 2008 was completed in June 2009.

Scope of the problem

Some 26 million hectares of prime agricultural land in Namibia are encroached by bush. The Bush Encroachment Research, Monitoring and Management Project has shown that bush thickening results in a reduction of the land's carrying capacity by up to 80% in some areas. In addition, water-use efficiency of natural rangelands has become extremely poor in the encroached areas, which increases the frequency of artificial drought events in a drought-prone country such as Namibia. Since the phenomenon of bush encroachment results in an alarming loss in productivity of Namibian savannas, it is commonly regarded as part of the desertification process.

Bush encroachment has increased drastically over the last 30 years. The Bush Encroachment Research, Monitoring and Management Project, in 2004, estimated that some 10 million hectares of commercial farmland were infested with invader bush in 1970, whilst this figure had increased to 16 million hectares by 2004 in commercial areas. Bush infestation mainly occurs in the higher rainfall areas of the country, where cattle and beef production is dominant. The overall objectives of the work were:

  • Identify a variety of appropriate bush encroachment management practices, based both on current practices as well as promising possible new practices, and synergistic combinations thereof
  • Identify socio-economic constraints that currently deter or prevent farmers from implementing known mechanisms of bush management or utilisation
  • Using international best practice, keeping Namibian realities as a guide, define a cost benefit analysis (CBA) assessment framework that explicitly incorporates economic, ecological and social criteria
  • Using the above CBA assessment framework, conduct comprehensive CBAs, and do a comprehensive cash flow forecast for at least 20 years; data assessment and modelling for the various options, yielding a comparative basis of the returns on investment per N$ of private funds (and also on possible public funds) on each bush encroachment management practice or combination of practices.
  • CBA and cash flow for a range of outputs including impacts on agricultural practices. power generation, socio-economic benefits, charcoal production, wood fuel for heat and other miscellaneous products.

  • Conversion And Resource Evaluation Ltd. tasks

    CARE Ltd. carried out the cost-benefit analysis for a wide range of options, specifically include, the cost benefit analysis [CBA] and cash flow for:

  • the livestock (incl. game) farming enterprise as it benefits from increased grazing available over time, and
  • the financial inter-relationship between each option and the above livestock farming enterprise, i.e. consolidated CBAs and cash flows
  • calculation of the net present value [NPV] for a wide range of clearance [manual clearance, aerial and manual arboricides, mechanical clearance, stem burning] and cattle stocking scenarios

  • From this, the subsequent value added options for the cleared invader bush were evaluated:

  • Bush for domestic wood fuel
  • Bush for non fuel uses - fencing, etc.
  • Charcoal production [small bush kilns]
  • Commercial slow pyrolysis for charcoal only
  • Small-scale downdraft gasification [0.25-1 MWe]
  • Fast pyrolysis for liquids for subsequent power generation in a dual fuelled diesel engine(s) [0.25-13 MWe]
  • Bush combustion in a fluidised bed for power generation [1-70 MWe]
  • Co-firing coal/bush for power generation [3.5-93 MWe]

  • Conclusions

    From the calculation of the NPVs under a range of circumstances, the following results were obtained:

  • All bush clearance scenarios for the three predominant (heavily infested areas where over 50% of commercial farming is carried out) cattle farming areas in Namibia without income from encroachment bush sales showed negative NPV values, indicating that bush clearance is not economically feasible.
  • The breakeven selling price of bush varies between N$7.5 to 35 /t [some € 1- 4 /t] for the different areas and treatments. Bush sales at farm gate at N$124/t [€10/t] or higher lead to clearly profitable encroachment bush clearing projects. However, if the full value chain is to be considered care needs to be exercised at setting wood sales at an arbitrary price, i.e. higher than N$372/t [or €30/t].
  • If bush sales cannot be secured above the breakeven selling price as indicated, then the no clearance scenarios prove to be superior with positive NPV.
  • If transport costs are included in the bush price, the transport distance that leads to zero NPV varies between 45 to 58km, 107 to 120 km and 169 to 182 km for bush prices of N$124, 248 and 372 /t [€10, 20 and 30/t] respectively.
  • Based on the use of the cleared bush for the value added options above, there is a ready, but unquantified market for firewood, however this is seasonal and variable.
  • None of the thermal conversion options considered for power generation would be economically viable in Namibia with the current industrial electricity prices.
  • Using bush for value options such as commercial charcoal production is possible, however this ultimately is dependent on the charcoal sale price; however with consumer demand for more environmentally friendly products, price increases for such products will generally be accepted.
  • Using bush, which is sized and dried appropriately, for small-scale decentralised power generation is the nearest to being economically viable. Sale of heat from the unit would make it commercially viable and options such as using the heat to drive a refrigeration cycle should be considered.
  • The electricity selling prices are N$1.33-1.63/kWh for the ~1 MWe gasification system, which are significantly higher than the present tariffs, but these costs may be fully acceptable in remote locations.
  • Each farm needs to have its own detailed cost-benefit analysis taking into account all local factors in the determination of the overall viability of a range of options.

  • The results of the CBA will be used by the Namibian Agronomic Board to direct future policy in the utilisation of bush and the optimal ways of supporting clearance activities for increased livestock production.


    Conversion And Resource Evaluation Ltd.

    Formed in 1996, C.A.R.E. Ltd. has been working on the research, development, demonstration and commercialisation of advanced thermal conversion technologies for the product of heat, power, combined heat and power and green chemicals from biomass and wastes. C.A.R.E. Ltd. specialises in technical and engineering services to the bio-energy and energy from wastes industry. Our extensive practical experience in combustion, gasification and pyrolysis allows CARE to deliver effective technical solutions to the developing bio-energy industry.

    For further information on these and other services offered by C.A.R.E. Ltd., contact:

    Dr. C. Peacocke
    Conversion And Resource Evaluation Ltd.,
    29 Ardenlee Place, Belfast, Northern Ireland, BT6 8QS
    T. +44 28 90450106
    F. +44 870 0542981
    I. www.care.demon.co.uk
    E. cpeacocke@care.demon.co.uk

    For further information please email Conversion And Resource Evaluation Limited

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