LPG cooking system

Introduction

Liquefied Petroleum Gas (LPG) is a gaseous fuel obtained during petroleum refining and consists mainly of butane or propane. LPG can also be obtained from fossil coal. LPG is non-toxic, easy to handle, energy efficient and burns very cleanly. See also article on Cooking with LPG.

LPG stoves are very convenient for users as they heat up quickly and temperature can be precisely controlled. However, LPG stoves are mainly used by middle and high income groups in urban areas due to higher capital investment into devices and higher running costs for fuel. In rural areas, LPG supply can be unreliable, if accessible at all. Less wealthier households tend to use LPG as a minor part of their energy mix especially in situations when smaller food amounts need to be heated fast, e.g. at breakfast.

The important feature of LPG is that its stove efficiency of about 55-60% is much higher than that of many other stoves.

LPG Stoves

Technology

A typical LPG cooking system is made up of a steel cylinder filled with LPG, a pressure controller, a tube connecting the cylinder to the pressure controller and the burner, and finally the burner itself. The burner can consist of one or more cooking tops.

The size of the system depends on the size of the cylinder. Cylinders exist in various sizes e.g.: 2.7 kg, 6 kg, 12 kg or 16 kg. A survey in 20 countries showed that low-income countries households mainly use cylinders smaller than 6 kg. Nevertheless, the majority of currently available LPG cylinders are larger (up to 47.5 kg). This proves problematic for low-income households both in the acquisition as well as the recharge of LPG.

Costs

Households require capital to buy hardware such as the LPG stove and the cylinder. LPG stoves cost around 30-100 US$. This is a barrier for many households. In Nigeria for example, a competitive kerosene-based cooking systems is 83 % cheaper. Furthermore, households need to be able to pay the running costs for LPG. The price of LPG is affected by taxes, subsidies and market distribution costs.

The illustration below shows how LPG stoves compare to other stove types in terms of upfront and lifetime costs.

Efficiency and Emissions

Traditional LPG stove models have a fuel efficiency of about 55%. Newer designs can even reach about 90% fuel efficiency. However, many of these models are quite expensive.

LPG stoves can lead to household air pollution reductions of 90% compared to open fires or traditional stoves, if used exclusively. However, the Global Alliance for Clean Cookstoves resumes that few impact evaluations have focused on consumers’ use of LPG stoves. Field research also suggests that, while theoretical benefits can be significant (i.e., elimination of most negative health effects of solid fuel cooking), actual impacts are likely to fall far below this potential because many users along LPG stoves still continue to use traditional stoves. Besides the frequency of use also the correct use of LPG stoves is of relevance. Although LPG stoves typically emit much lower levels of CO than most alternatives when operating under optimal conditions, CO can be emitted at unsafe, high levels when the stove, particularly the burners are not maintained properly.