A Simple Stove Solution?



As we’ve written before, there are many exciting and technically advanced efforts in the field of clean cookstoves. These efforts seek to solve the indoor air pollution problems associated with wood fuels, thereby improving the lives of millions of women and children worldwide. Many of these stove technologies also cite reductions in carbon emissions and reduced deforestation as indirect benefits (often leveraging these offsets as a potential funding source). While we applaud these efforts for their ingenuity, there may be far simpler (albeit less elegant) solutions that can achieve the same ends rapidly at a fraction of the cost.


The answer may lie in  LPG, or liquified petroleum gas. LPG is a combustible refinery byproduct that can be compressed and transported in metal cylinders (pictured above). In Kenya, LPG stoves are the preferred cooking method for the middle and upper class. A simple LPG stove can be purchased for <$30, which is less than the cost of the leading clean biomass cookstoves. Gas bottles of various sizes can be purchased and refilled at virtually any market or fuel station, giving the user a clean source of cooking fuel. These stoves are far superior to any biomass stove in terms of both emissions, temperature control, heat output and startup time. So why are they not more popular?

As with most improved technologies in Kenya, cost is a major barrier. To obtain a 13kg gas cylinder, a user must make a deposit of 8,000 Kenyan Shillings (~$80). This deposit is to prevent users from selling the canister as scrap metal after it is used. Compared to wood fuel or charcoal, LPG has much higher upfront costs. But what if there were a way to remove some of these cost barriers? How does the actual incremental cost of LPG compare to charcoal fuel?

Currently, it costs 2,000 Kenyan Shillings ($20) to fill up a 13kg LPG cylinder in our town of Bungoma. On average, a full cylinder can last 6-8 months with daily use. This translates to a weekly cost of between 62 and 83  shillings, depending on intensity of use. By contrast, an approximately 4kg tin of charcoal costs between 70 and 100 shillings, depending on price fluctuations. Most families in urban and peri-urban areas purchase 2-3 4kg tins of charcoal per week. So, the actual incremental cost of LPG is as little as 60% of that of charcoal.

The barrier for the majority of users in Kenya is the high upfront bottle deposit and filling costs. 10,000 shillings to acquire a gas bottle and fill it represents as much as 1/3 of the average annual income in the region. Even though the deposit is refundable, few BOP customers can afford to have so much of their money tied up at once. But what if these costs could be subsidized, or paid over time?

In the early 90’s the government of the Dominican Republic began a program to modernize cooking fuel usage. The government provided subsidies to users seeking to switch from biomass fuels to LPG. By subsidizing the fixed costs of the stoves and fuel bottles, users quickly adopted the more modern systems. Within five years, there was a 20.5% increase in the use of LPG stoves across income sectors. This growth of demand for LPG has had ripple effects, encouraging the government to build modern natural gas refineries and filling stations. It has even led to the conversion of gasoline-powered automobiles to LPG-based systems, which have lower emissions and improved efficiency.

Could such a program be duplicated in Kenya? Most certainly. Filling stations already exist throughout the country, and the benefits of LPG are widely known to consumers. The main drawback of LPG is the obvious– it’s a fossil fuel and fossil fuels aren’t renewable. However, there is an emerging technology that could solve even this seemingly intractable obstacle: compressed biogas.

Biogas is an LPG substitute made from decomposed human, animal and food waste. Biogas production is cost-effective and rapidly growing in India and Pakistan. With proper compression equipment, biogas can be made locally in urban, peri-urban or rural areas and packaged into the same cylinders used for LPG. Compressed biogas could then integrate seamlessly into the existing LPG supply chain.

We hope that simple, yet potentially impactful technologies like LPG stoves and compressed biogas continue to grow, as they represent some of the most cost-effective and cleanest cooking technologies in existence.


One Response to A Simple Stove Solution?

  1. deborablando December 12, 2011 at 2:30 pm #

    decomposed human, animal and food waste? ugly :S