The Maldives president Mohamed Nasheed stands in the sea off Kurumba to show the threat the islands face. Photograph: Chiara Goia. Source: Guardian.

Plans for a new windfarm are set to make the Maldives the country with the highest proportion of renewable power in the world.

The 30-turbine proposed windfarm, close to the capital Malé, will deliver 75 megawatts of electricity at full capacity, enough to provide electricity for the whole of the capital, the international airport and the surrounding resorts. Excess power will be used to run desalination plants that will produce bottled drinking water from the sea.

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If built, the project will mean that per head of population, the Maldives will be getting about six times more electricity from wind than the UK. Mark Lynas, the British climate change expert who helped the Maldives develop its draft programme for carbon neutrality, welcomed the windfarm proposal, saying that it was an important signal to the rest of the world. “If a middle-income country can cut its emissions by a quarter through standard commercial partnerships, the rich world has little excuse for saying that carbon reductions are too expensive.”

The Maldives government is taking the lead on climate change mitigation in an effort to push larger states into taking more determined action. Last month, President Mohamed Nasheed held a cabinet meeting under-water to highlight the plight of the low-lying island nation as the sea-level rises. In March, he announced a 10-year plan to reduce its use of fossil fuels to zero.

One part of this is a partnership announced in September with the British biochar company Carbon Gold to improve the country’s soils by adding charcoal produced from coconut shells and other woody waste materials. The Japanese government is also giving $10m to provide solar panels to power schools and government buildings in Malé. And Nasheed will be hosting a planning meeting for a group of countries most vulnerable to climate change in the run-up to the UN climate change negotiations in Copenhagen in December.

The $200m windfarm project is being financed and built by Falcon Energy and will use turbines from the American company GE, one of the world leaders in wind energy. The project will start with a year-long analysis of wind conditions to assess the best arrangement for the turbines. It will then take up to two years to build. Hassan Zahir, chairman of the local electricity company, STELCO, said that the windfarm represented an important step in the country’s move towards a carbon-neutral society.

A new gas turbine power station will provide back-up power when conditions are too calm for wind generation. The Maldives has moderate but reliable winds that blow for most of the year, making this source of power a good choice for the country.

Once built, the windfarm and the gas generator will replace old and inefficient diesel generators on which the Maldives has been completely reliant. The project is likely to provide about 40% of the country’s electricity and reduce its overall carbon footprint by about a quarter. When completed, the windfarm should provide this small island state with the largest percentage of electricity sourced from renewable source of any country in the world. Another major windfarm announcement is expected within the next few months.



This article was originally published in the Guardian on Monday 2 November 2009.

Key Farmers Cameroon's coordinator, Etchi Daniel-Jones, at a plot in Ediki, in which the difference between char and non-char maize was exceptionally big. In this case, the plants on the control (left lower corner) were barely in their 8th leaf stage, whereas the plants on the char-plots (right, upper corner), were already tasseling. Photo credit: Laurens Rademakers, Etchi Daniel-Jones. Source: biocharfund.org.

Biochar Fund has reported extremely encouraging first results from its field trials in South West Cameroon. Working with small groups of subsistence farmers around the town of Kumba, the Fund set up and managed a large-scale experiment to assess whether maize (corn) yields were improved by the addition of biochar to the soil. The biochar was made from local agricultural wastes and tree thinnings. The data from the trials strongly suggests that biochar adds greatly to food production. Some areas showed yield improvements of more than 250% over the control plots. The areas dosed with biochar also showed substantially increased production of crop biomass, including roots, stalks, and leaves.

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Many field studies in the tropics carried out by academic researchers have shown that biochar improves soil productivity. (For more details on what biochar is and how it is made, see an earlier article on this site, here.) Biochar Fund’s research did more. It showed that poor farmers typically making less than $300 a year from their crops were able to improve their own yields using simple techniques both for making the char and adding it to the soil. Average production of maize from this area of Cameroon is about 1.7 tonnes per hectare compared to about 7 to 9 tonnes in the EU or US. If the initial results are replicated elsewhere, the impact of biochar could see yields increase by 40% above what would otherwise be obtained.

Biochar Fund research techniques
The experimental methods seem robust. A large number of small groups, comprising 10 to 30 members, were asked to participate. They cultivated 75 test areas across very different soil types, including weathered, degraded land as well as productive volcanic plots. Each area was asked to plant 12 sub-plots, 4 without biochar, 4 with biochar applied at 10 tonnes an acre, and 4 with 20 tonnes an acre. Each type of plot was then divided into areas without any fertiliser, with organic-only fertiliser, with artificial fertiliser, and with both types of fertiliser together. The fertiliser was applied at the rate usually used in the research area. (Because of a shortage of money, many areas would usually not have fertiliser applied.)

The biochar was made in a low-technology kiln using agricultural wastes from the previous harvest and some wood cut back from trees surrounding the cultivated areas.

The farmers sowed seed densely and harvested the corn when it was ready. They weighed the whole plant, including roots, the cobs, and also the grain itself. Some of the groups did not produce usable results because the grain was stolen (‘because it looked so good’ report the affected farmers) or because of pest damage or because of misunderstandings about how to apply the methodology. But 41 of the 75 test plots yielded data on biomass weight and slightly fewer on grain yield.

The results
The principal results from the experiment are as follows:

• a) Adding biochar at the rate of 10 or 20 tonnes a hectare typically added about 85% to the weight of grain produced compared to the adjacent plot with no fertiliser.
• b) This is about the same increase as would be gained by adding both organic and artificial fertiliser to the unfertilised soil. So biochar is as effective at increasing yields as heavy application of fertiliser.
• c) If both biochar and two types of fertiliser are added, the yield rises to an average of about 140% of the level without any additions. Biochar therefore substantially increases the food production of land above what would be achieved either with or without added fertiliser.
• d) It seems as though the most striking results are found on the poorer soils.

Full data analysis is here and in PDF form on the data page.

These results are preliminary but they show the powerful benefits that biochar might bring to food availability in many tropical soils. Getting heavy doses of char into the soil will be demanding but the great advantage of biochar may be that it only needs to be applied once and its effects persist for decades. The results from the second maize sowing of the year (to be harvested in the next few weeks) will show whether the yields improvements continue.

The implications of the research
The beneficial results from the application of biochar on degraded tropical soils are now too frequently reported to be a statistical artefact. Biochar works. The remaining opponents of biochar focus on the dangers of using native forests as the source for the combustible material. If biochar is so good at improving yields, they say, then forests will be cut down to improve soils. The Cameroon results show that this should not be the case. Here are some numbers from the experiment:

• Applied at 10 tonnes a hectare, biochar added about 4.5 tonnes a hectare to the total biomass, excluding the food grains, of unfertilised land.
• One tonne of organic matter will typically produce about one third weight of biochar – say 1.5 tonnes a hectare.
• So the weight of biochar added to the soil (10 tonnes/ha) will be repaid in increased biomass production (not just food) within about 6-7 years.
• Therefore, if one seventh of the land has biochar added for seven years the net biomass availability by the end of this period will be higher, prospectively for ever if biochar permanently increases yields.
• There should therefore be very limited pressure to cut down forests to make biochar – biochar can be made from the incremental biomass produced on the land to which it has been applied.
• This conclusion would be even stronger if we took into account the fact that some areas, such as parts of Cameroon, can produce two crops a year. Payback would be twice as quick.

The most important result from this remarkable experiment in Cameroon may be that it lays to rest the worry that biochar will exacerbate deforestation. In fact, by increasing biomass production biochar should reduce the need to cut down trees for fuel.

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The experiments in Cameroon will continue. Biochar Fund (www.biocharfund.org) is also running several other trials. Here is an excerpt from its recent email:

Given your continued interest in biochar research, we are glad to keep you up to date on our activities in the future. These activities include a large project in the Democratic Republic of Congo, which is aimed at reducing the deforestation rate resulting from slash-and-burn farming; a project that aims to build highly integrated agroforestry farms which protect biodiversity and ecosystem services; and the development of a novel cocoa drying technology which coproduces biochar.

If I may give a personal view, I think these research projects are among the most important in the world today. Please consider giving your support to Biochar Fund and Key Farmers Cameroon in whatever way you can.

Barley field near Wallington, Hertfordshire. Copyright: Paul Dixon. Licensed for reuse under a Creative Commons Licence.

Biochar increases crop productivity in many tropical soils. The reasons probably include improved water retention, reduced leaching, and better availability of nutrients to plant roots. In temperate conditions, studies have been fewer in number and haven’t produced results that are as clear. A new study[1] adds usefully to our knowledge.

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Alfred Gathorne-Hardy and colleagues at Imperial College, London applied varying amounts of biochar and of nitrogen fertiliser to barley. Their research showed that biochar improved yields substantially but only in those trials when large amounts of artificial fertiliser were also applied. Adding 20 tonnes a hectare (2 kg a square metre) of biochar to a soil fertilised with 100 kg of nitrogen a hectare increased the crop yield by over 30%. Loosely put, biochar improves the effectiveness of the nitrogen. But for soils with no added fertiliser, increasingly heavy applications of biochar tended slightly to reduce the crop yield.

This is an extremely interesting result for two reasons. Firstly, it shows that it may be financially rational for UK and other temperate zone farmers to add biochar to the soil. Secondly, the improved crop yields may be arising from greater retention of nitrogen in the soil. This is important because it would probably imply reduced run-off of nitrogen into water courses. Run-off may be the most important source of nitrous oxide from agriculture. (Nitrous oxide is a potent global warming gas, three hundred times worse than CO2.)

Let’s examine these two hypotheses in turn. First, the financial incentive to add biochar. Many barley farmers have an unsaleable surplus of straw. Charring the straw will cost money but biochar will usually remain in the soil for many years. In the tropics, many biochars seem to have half-lives of several centuries. So if the result identified in the paper is replicated in the field biochar will add to crop yields for many years. Typical barley yields are about 6 tonnes per hectare and recent prices for good quality grain have averaged about £80 per tonne. A 30% increase in yields is therefore worth about £150 a hectare a year. Over ten years the undiscounted value is perhaps £1,500, a number vastly greater than the cost of charring 20 tonnes of straw. I guess that the cost of the biochar might eventually be as low as £10 per tonne.

So it may make financial sense to apply biochar to UK soils, even before considering the impact on emissions. We should therefore move on to the impact on GHGs. At today’s prices in the European Emissions Trading system, the value of 20 tonnes of pure carbon newly sequestered in the soil is more than £700. (Carbon dioxide has 3.67 the weight of CO2, currently trading at more than £10 a tonne.) Also important is the impact on nitrous oxide emissions. If biochar reduces nitrous oxide emissions by holding nitrogen better in the soil, the value will add to the impact of CO2 reduction. IPCC studies suggest that 1% of the nitrogen in fertiliser ends up as nitrous oxide gas, usually through interaction with water in fields and in drainage ditches at field edges. More recent studies suggest that the actual number may be much higher, particularly in wet climates like the UK. But even the IPCC figure suggests that 1 kg of nitrous oxide emissions per year – equivalent to about 300 kg of CO2 – will be avoided, perhaps for many years, by the use of biochar. But let’s assume the nitrous oxide reduction only persists for ten years. The value of this at £10 per tonne of CO2 equivalent is about £30.

Here’s a highly simplified summary of the benefits of biochar, at today’s crop and carbon permit prices (all numbers are per hectare):

The key conclusions are that yield improvement values dwarf the monetary value of carbon emission improvements but also that it should be worthwhile sequestering biochar even if yield gains are negligible or non-existent.

Appendix: some data on straw
Barley straw weighs approximately the same as the grain from a field. So each hectare produces about 6 tonnes of straw per year. A tonne of straw might produce char of about a third of the weight. So each hectare should produce char of about 2 tonnes per year of crop production. To apply 20 tonnes per hectare thus requires about 10 hectares of straw. But even if biochar lasts as little as 10 years, the straw per hectare will produce enough char to generate the crop productivity improvements. So there is no need for external inputs of biomass to produce the fertility improvements – the biochar can be generated on the farm itself.



Footnote
[1] Alfred Gathorne-Hardy and others, ‘Biochar as a soil amendment positively interacts with nitrogen fertiliser to improve barley yields in the UK’, IOP Conference Series: Earth and Environmental Sciences, 6 (2009), 372052 http://bit.ly/Gathorne-Hardy2009 (doi:10.1088/1755-1307/6/7/372052).