So called “environmentalists” often claim that burning wood is “evil” but mostly forget in their argument, that domestic energy has to be produced somehow for humankind to survive. There is nothing evil about burning wood, quite the opposite in fact, wood can be a renewable energy source, when used properly. Simply put: To keep it sustainable, it's important not to burn more wood than nature is able to reproduce (i.e. grow trees) and to increase the amount of usable energy that can be harvested.

In order to avoid disastrous deforestation, which happened on the Easter-Islands, is currently happening on Haiti and will become more obvious in India and Africa in the near future, it's imperative to help these people now, by putting a stop to burning wood in open fires or simple stoves and not to implicitly deem them evil because, as of now, they simply have no other choice but to burn wood.

To find a more rational answer to this question, the best approach is to look at it from a standpoint of data, trying to assess the past, present and future situation worldwide and make a reasonable distinction between facts and common “environmentalistic” propaganda.

Wood used to be the traditional primary energy source of all people for Millenia until the industry nations started to rely heavily on coal, followed by the electrification of households. On the other hand, many “developing” nations still rely on fuelwood as primary energy source. Therefore, the first step is to find multiple sources to assess, how much wood was, is and is going to be used as primary energy source in households worldwide.

Estimations of world fuelwood consumption made during the 1990s (million m³ p.a.)

Actual & projected fuelwood consumption, main developing regions (million m³ p.a.)

Source: FAO, 2001 http://www.fao.org/

Actual & projected fuelwood consumption, by region (million m³ p.a.)

Source: MEAD, 2005

The consumption volume of fuelwood is commonly expressed in cubic meters which allows comfortable comparison to other scientific publications. Unfortunately, this is an abstract volume for the brain to put into relative perspective, because no one can really imagine how much that is, for example, in trees.

Michael Matuschek, Head of Forest-District 6 in Munich, suggested an average tree, 25m in height and 25cm DWH (Diameter Waist Height) at roughly 1 m³ harvest volume. Using the same data, the DENZIN model, commonly used by forest scientists, estimates the average harvest volume for one tree at 0.63 m³. To keep the estimation as accurate and fair as possible, the factor is averaged evenly (1 tree = 0.815 m³):

Parameters and formula (DENZIN extended)

Assuming 1 average tree occupies an area of 20m²:

This is equivalent to the size of Switzerland.

Actual & projected number of people depending on traditional biomass (millions)

Source: IEA, 2006

Although newer data indicates, that the consumption levels are lower than the 1990 projections, all projections have one thing in common: Unless humankind develops alternative, sustainable & clean energy sources, available to everyone worldwide, fuelwood will continue to be the only available energy source for more than a quarter of the population on the face of the earth. These people rely on it to survive and have no alternative to seize, in order to minimize the impact their actions may have on their environment and their own health for at least another 20 years.

Because of travelling long distances to collect fuelwood, women and children are often left with limited time for other activities resulting in low agricultural productivity and inadequate time to pursue educational opportunities. Living on the brink of survival also doesn't invite the opportunity to educate people and research alternatives. It's nice to see projects like “1 Laptop per Child” but what good is a laptop, when most children have neither the time to play with it nor power to keep it running?

Right now, while you read this, there are over 2.5 billion people cooking their food on open fires or simple stoves using only wood as primary fuel. And while they have no choice but to burn wood, they also have no technology to help them making the process more efficient. It's easy to say “Burning wood is bad”, when you have the luxury to live in a place, that can give you virtually unlimited power and the process of energy creation is shielded from you, in distant power-plants. You just flip a switch and cook your meal. The argument also implies, that a new technology, which uses wood as fuel, “can't be a good idea, since we all agreed not to burn more wood”. But this is just plainly deceptive.

A fuel-efficient TLUD helps to address energy poverty by reducing household fuelwood requirements by up to 50% while providing the same amount of energy compared to an open fire or simple stove. Households that previously purchased wood can save money and have greater resources for spending on other vital areas such as education and food. The reduced exposure to smoke leads to improved health for women and children, while the threat to forests around the world is lessened substantially.

When wood is used to generate energy – particularly for heating – this benefits humans and the environment in a variety of ways: first, wood is a renewable energy source; second, its use is climate neutral as the burning of wood releases the same amount of carbon dioxide as the trees removed from the atmosphere while growing. The combustion of wood in the latest furnace systems helps to keep emissions low.Federal Office for the Environment (FOEN) - Switzerland

Experiments with alternative biomasses like pellets made out of sawdust (byproduct of saw-mills), crop residue, fruit seeds and dung cake to minimize the need to cut down trees even further.

Adding biochar to the soil also increases the water and air holding capacity of the soil, and it promotes the proliferation of mycorrhizal fungi and other beneficial soil microbes. Biochar improves the cation exchange capacity of the soil and prevents nutrients from being washed away. When biochar is incorporated into the soil, we see a 50% to 80% reduction in nitrous oxide emissions, as well as a reduced runoff of phosphorus into surface waters and a reduced leaching of nitrogen into groundwater.

As a soil amendment, biochar significantly increases the efficiency of, and reduces the need for traditional chemical fertilizers, while greatly enhancing crop yields.International Biochar Initiative (IBI)

Use of biomass as primary energy source for households in itself is not a cause for concern. However, when resources are harvested unsustainably and energy conversion technologies are inefficient, there are serious adverse consequences for health, the environment and economic development. Over 1 million people — mostly women and children — die prematurely every year because of exposure to indoor air pollution (Smoke of open fires). Valuable time and effort are devoted to fuel collection instead of education or income generation. Environmental damage can also result, such as land degradation and regional air pollution.

The environmental impacts of inefficient fuelwood use are not really new. Burning wood has contributed to the deforestation of numerous regions of the world. Even at the early stages of industrialization, local pollution of air and water was a well known problem.

One of the biggest risks for the success and good reputation of sustainable biomass energy systems comes from the industry nations: If a considerable amount of primary energy is shifted from oil, coal or gas to biomass, the consequences could be serious. Going “green” is a trendy topic these days and the dependency on “fossil” fuel-price markets makes renewable biomass even more attractive to possible investors. However, an industrial scale shift to biomass will drastically increase the demand for biomass, eventually leading to industrial scale biomass plantations that take away arable land which no longer will be available for food production, which in turn, could lead to even higher food prices. This may or may not be obvious, since most industry nations and companies have shown no scruples to protect their own forests by legislating and enforcing appropriate laws and then cut down the whole forest of another developing nation to satisfy their “needs”.

Burning wood is neither good nor bad. The systematic tendency of “developed” society and industry to blow things out of sustainable proportion is bad. Being controlled by blind greed or irrational belief and fear, not considering the consequences or not reacting to early warnings is worse. But the worst thing is, to simply do nothing.

The goal in biomass fuel and energy conversion research should be to find ways to support households and people in developing nations, who have been traditionally relying on wood as primary energy source and currently have no means to help themselves protecting their health or environment. Simple, cheap and easy to build open-resource hardware like Helios or any other TLUD concept can address these issues.

People in industry nations, who statistically need significantly more power per person than developing nations and choose to burn wood in an environment, where other options are available, should consider small and efficient biomass-gasifiers in local, community operated cogeneration systems like a GEK or this one to generate heat and electricity at the same time.

Burning biomass must not become a simple and cheap way to relieve the political and industrial dependency on oil, coal and gas by firing big industry operated grid-power plants with biomass.

There is also still much potential in wood/biomass waste recycling, to put industrial or agricultural wood or biomass byproducts into an optimized pellet