Though the national government targets related to electrification are hugely important for Lao PDR, actually for 69% of the rural population firewood and charcoal are their primary sources of energy. Furthermore even when electrification does come to an area, cooking with firewood and charcoal continues as before. Though fuel use is a big issue, and it would be useful to find more efficient stoves which use less wood, actually open fires are already amazingly efficient (85% combustion efficiency) and the focus is therefore usually on transferring that heat to the cook pot more efficiently rather that expecting much better combustion performance.

But actually a far bigger problem is not how much or little wood that the stove burns, as important as that obviously is, because though thermal performance is useful a thermally poorly performing stove will just mean more firewood needs to be gathered.

A far bigger problem is so obvious that it is easy to miss when thinking about stoves: which is burning anything at all creates smoke. In a confined area, if the smoke has got lots of particles in it (soot) then people breathe than it. And those black particles are especially unhealthy, especially to children and the vulnerable groups in society. The WHO in Lao PDR has the crude estimate of the cooking smoke causing 6 000 premature deaths per year in Lao PDR. This is because as the smoke gets into the lungs, it clogs up part of the lungs creating ideal environments to allow for chest infections to take hold.

But though this problem is clear and obvious, the solution is not. There are some real variations in the technical performance of stoves and so LIRE and others look very hard at more efficient stoves, and some real improvement can be gained by better designs and better quality control in making the stoves. LIRE recently hosted an international cook stove testing workshop, with trainers from Approvecho in USA, to learn how to better test cook stoves and their thermal performance.

But a complicating factor is actually no two people cook exactly the same, which hugely affects the results of how much of an improvement a stove makes. The Approvecho training covered “Kitchen Performance Tests” (KPT) to see how in real conditions the stoves performed.

And so LIRE is now fully trained and experienced in performing Cook stove tests and analysing how what the results mean.

In May the LIRE team went up to a village in Xieng Xhouang Province and tested some large fixed installation stoves there for an NGO, doing high quality testing and doing a detailed stove design review and design efficiency improvements to help make their 2nd generation of stove installations even more efficient and better than their first generation.

Please download the report here.

And in doing our own research and development and in working with others in this field, we keep seeing 3 really common and simple issues with stoves, even improved ones, which makes them less efficient than they really should be:

1) More weight does not make it more efficient.
Yes insulation is important in a stove, but insulation using heavy concrete, though cheap is problematic. Simply because the heat generated at the start of the day has to heat up the concrete as well as heating up the cook pot: the high weight stoves absorb too much heat to be optimal. Go instead for low-weight high-volume insulating materials; actually which is exactly what we look for in insulating our own houses in Europe and elsewhere.

2) Keep it dry
There is almost nothing in the world which absorbs (has a high latent heat capacity) than water, so starting up a wet stove in the morning will take a lot of heat just to dry out the stove. Problems such as this are not always obvious and often when the stove is made initially the concrete, or whatever other material used, is in great condition. However a cook stove is subject to repetitive heating and cooling and the materials often get more porous as they age. A dry durable stove is key.

3) A smaller fuel inlet
This is perhaps the strangest key area of improvement. If we take any standard stove, and reduce the fuel feed-in slot in size the efficiency increases of the stove as the fuel is constantly and more evenly fed it. The fuel in the stove is burning better and the energy transfer is more efficient. The constant feed in is so important, and furthermore a smaller feed in usually means that the wood has to be cut in thinner sections, further increasing its combustion efficiency.

LIRE furthermore is still researching stoves and how to make them less smoky and more efficient, our focus is to find the next generation of stoves for rural AND urban areas which can burn wood and charcoal in a cleaner, more efficient, more effective way and meet the needs that Lao people have for clean stoves and clean air in a better way.

The question that we are asked often is: why don’t Lao people cook with gas more? Our answer is usually the same: they have that choice and chose not to cook with gas more. We believe in respecting Lao people and their decisions, just as our own mothers cook in a similar way to their mothers, but helping them do it in a clean and healthy way. And for so many in rural areas cooking on gas could not practically ever be an option. But it does not mean that they have to have smoky old-generation stoves, and the health issues which come with them.

But LIRE with its in-house testing and design team has the real and proven capacity to test, review, and if necessary redesign, stoves in Laos to make them more efficient and cleaner.