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Biomass fuels and the future: Interview with Gustavo Best, FAO Senior Energy Coordinator


Fossil fuels - oil, coal and gas - are key contributors to global warming, which threatens agriculture and other human activities in a number of ways. Experts are also saying that fossil fuel reserves will only last another 40 or 50 years. These two facts alone mean that the search for alternative sources of energy has never been more urgent. FAO Senior Energy Coordinator Gustavo Best spoke about biomass fuels and other alternative energy sources.

Gustavo Best, FAO Senior Energy Coordinator

How do energy matters relate to climate change?

Climate change is very intimately linked to patterns of energy use. The first way of reducing climate change is to reduce the amount of fossil fuels we use. The second way is to change the sources of energy that we use and that is where renewable energies, and biomass energy in particular, come in. Biomass energy is the only energy source that is completely CO2 neutral - meaning that it does not increase the carbon dioxide in the atmosphere.

What are biomass fuels?

There are many different kinds of biomass fuels - from the traditional fuelwood used for cooking in a very inefficient way, to very sophisticated modern biofuels which are produced from purposely grown biomass. Farm residues - like animal waste - can also be biomass fuels. In European countries such as Germany, France and Holland animal waste is becoming an environmental problem. But it can be used to produce energy through a fermentation process. In China they've been using this technology for more than 20 years. They've now got 10 million biogas digesters using animal waste.

What sort of plants are used as biomass fuels?

They can be fast-growing trees, grains, vegetable oils, agricultural residues or, as in the case of Brazil, sugar cane.

Can you give some examples of the uses biomass fuels are put to today?

With sugar cane, either the sugar or the bagasse can be used as a source of energy. The bagasse is what's left after you squeeze the cane - and it's very useful as fuel, animal feed, and construction material. Sugar mills use the bagasse as an energy source, to provide heat during the sugar-producing process. With modern technology the bagasse is used a lot more efficiently so there's a lot left over that can then be used to generate electricity through a normal combustion/generation power plant.

Imagine a sugar mill that uses the heat for producing sugar, but also feeds electricity to the grid, to the wires of the city. So, a food-producing industry becomes an energy-producing industry as well. They're doing this in many countries. In Brazil they are also famous for using part of the sugar products to produce alcohol to put in cars. They have six million cars running with a mixture of 25 percent alcohol in their petrol. This has the advantage of reducing pollution and also you don't need to use lead, so you have a lead-free petrol.

So you have different ways to process biomass fuels. You have combustion, distillation, gasification, fermentation and pyrolysis. And there's a tremendous variety of biomass fuels. Obviously, our main interest regarding climate change is trying to promote a massive use of biomass energy because that is one of the main ways of reducing carbon dioxide emissions.

A Cambodian woman cooking with biogas made from human and animal dung

What are their advantages over other forms of energy? (fossil fuels, solar energy, wind ...)

As regards fossil fuels, the major advantage is that they are CO2 neutral, they are renewable. Fossil fuels will only last another 40 or 50 years. The problem with climate change is that we're going to reach the peak of the emissions within the next ten or 20 years but their effect will last a lot longer. But the next generation will see the end of fossil fuels.

Both solar and wind power have certain limitations regarding the kind of energy they produce, that is electricity, mechanical power or heat. With biomass fuels you have a whole variety. You can use biomass fuels to produce a gas that you burn, or to produce a liquid that you put in tanks and carry and sell in pumps, or you can use biomass to produce something like charcoal that you put in bags and export. It's a versatile fuel in its commercialization and final use. Also, biomass fuels are probably the only alternative primary fuel to petrol for transport.

Obviously, from the point of view of climate change the key thing is that growing biomass absorbs the carbon dioxide from the atmosphere and releases it again when it is burnt. One of the important things about biomass energy from FAO's point of view is that it creates a lot of jobs. It's one way of creating rural infrastructure, it opens new opportunities. Also, it has a tremendous potential for rehabilitating degraded land. For any land that has been degraded, you can find some kind of plant to regenerate that area, and that plant, if it's used for energy, has an added value. It makes land reclamation economically possible.

One important thing that should come out of the meeting on climate change now going on in Kyoto is that oil should become relatively more expensive, both economically and politically.

Are there any constraints to the use of biomass fuels?

The constraints are technical, the availability of land and not competing with food, and price. One has to assess the production of energy from biomass very carefully so that it does not compete with food production, which obviously is a priority. But it has been proven that in many cases the combined production of energy and food enhances both, enhances the economics of the situation as well as the infrastructure, so it can benefit food production.

Technologically speaking I think we're pretty ready. The main constraint to the use of biomass fuels is the price. The energy price agenda in the world needs to be revised because there's no way the Climate Change Convention can be implemented under the present prices of oil. As things stand now, fossil fuels are very cheap, so many of these renewable sources cannot compete. Oil now is cheaper than ten years ago in real terms. There has to be some kind of agreement that that price is false. It doesn't take into account the cost of the whole cycle. If one takes into account the cost of exploring, extracting, refining, as well as the environmental damage, and compares it to the cost of biomass fuels, these become much more attractive. The cost of cleaning the atmosphere is going to be a lot more expensive than helping biomass fuels come into the market now. We are talking in terms of an environment friendly price platform.

So are we looking to a future where biomass fuels would be a major source of energy?

They will be one of the main sources. I think one is looking to a future with a variety of fuels, of energy sources - biomass, solar, wind, geothermal, ocean. Ocean energy is used in three ways - tides, waves, and the third way is using the difference of temperature between the top and the bottom of the waters, which can be a difference of 10 degrees Centigrade. With that you can move a turbine.

Many of these systems will be used to generate hydrogen, one of the most important energy fuels of the future but not available pure in nature. You need heat or electricity to produce it. That electricity could be from solar, biomass, or wind energy. You can use it for transport, among other things. There's already a prototype car using hydrogen. It's all a matter of the research advancing, technology advancing, of society wanting these products, and making the conditions for them to enter the market. To make the conditions for them to enter right now the main tool is price. Later on it will be by necessity because fossil fuels will finish. You will hear the term solar more and more because for biomass, wind, or ocean energy, strictly speaking the origin is solar. You will also hear the terms bioenergy, biowatt, green energy and biofuels more and more.

3 December 1997

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