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Friday, March 22, 2013

Small scale biochar for developing nations: a triple win situation…?

Biochar, as a GHG removal technology, is a potentially crucial component in the fight to limit atmospheric CO2 concentrations and avoid dangerous climate change.  But what else can it do? In this guest blog, Jayne Windeatt argues that integrating small scale biochar systems in the developing world has the potential to be a triple win situation if it’s done properly.

Duda Arraes / Foter.com / CC BY-NC-ND

Biochar is the name given to the charcoal like product of the thermal processing of biomass, and it is hoped that its applications will give value to people and the planet, such as soil restoration or greenhouse gas removal. Yet the properties, characteristics and benefits of biochar can vary greatly under that definition. With such a diversity of feedstocks, biochar production methods and end-uses, which routes have the most potential to benefit people and the planet? One particular area of focus is the use of biochar in developing nations, and if done correctly it could be a win, win, win scenario in many locations.

Improving degraded soils:

As a soil amendment, biochar can (under the right conditions) help to restore degraded soils and increase crop yields.  Since land degradation is often a crucial issue in food insecure nations, this could help to alleviate food shortages, protect biodiversity and build ecosystem resilience; allowing more food to be sustainably produced where it is needed.

However, in order to have a truly sustainable impact, the biomass used to produce biochar must come, naturally, from a sustainable source. Cutting down areas of rich, diverse, healthy forest to turn it into biochar with little consideration for its long term management is probably not a good idea!

Improving nutrient uptake:

Taking biochar systems a step further, one does not have to consider biochar in isolation. Biochar research is increasingly finding that ‘activating biochar’ to ‘implant’ nutrients onto it  (by composting or fermenting) or combining the use of biochar with targeted fertilizer use to aid plant growth, may be a key part of achieving desired yield effects.  Including this stage into the biochar system could increase the soil quality and yield benefits and also offer benefits regarding fertilizer use including reduced demand (thus reduced costs) of mineral fertilizers and reductions in the associated greenhouse gas emissions related to fertilizer use.

Energy co-benefits:

The third win has the potential to offer local renewable energy production!  Systems to produce biochar can also produce energy co-products.  Some of this gaseous and liquid energy can even be used to fuel the process, making it energy self-sufficient, with the remaining energy used for other things, perhaps on the farm or within the community or home.

So is it a win, win, win?

In reality, the feedstocks and methods for producing biochar can vary greatly, and these in turn determine the characteristics of the biochar, its performance in the environments and communities it’s targeted at, and therefore its ultimate value. The more advanced biochar systems that give a greater level of control over charcoal properties and co-benefits such as energy are currently more expensive than their conventional rivals.  Ultimately, to achieve maximum yields, and to harvest the energy products, a more complicated, thus expensive, system is required, as are mechanisms for financing such systems.  Options for financing biochar projects include achieving economic viability as a soil amendment (providing increased crop yields and better performing soils) and incorporation of biochar into carbon credit schemes such as the Clean Development Mechanism (CDM).  Current barriers to these economic mechanisms include uncertainties in the variation in biochar types and effects, and the uncertainties around the timeframes for carbon storage in soil.

Care is required when installing biochar systems, even for these small scale projects.  Each project needs to be assessed for the sustainable supply of biomass (perhaps agricultural wastes), the costs of set-up and maintenance, and the effectiveness that biochar will have on the soil and crop types within the system.  If, after these deliberations, a suitable biochar system is installed, the benefits achieved could help to alleviate hunger and poverty, provide energy sources and sequester carbon.

Jayne Windeatt is a PhD student with the Doctoral Training Centre in Low Carbon Technologies at the University of Leeds.

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