Field trial testing of an electricity-producing portable biomass cooking stove in rural Malawi

Abstract

A novel off-grid electricity-producing device has been designed for integration with biomass-fuelled improved cooking stoves commonly in use in the developing world. The device operates on the thermoelectric principle whereby small amounts of electricity can be produced in response to a temperature difference across a thermoelectric generator, or TEG. The energy produced by the integrated generator can be used for direct charging or stored in a rechargeable lithium-ironphosphate (LiFePo4) battery. The generator is equipped with a standard USB output which allows the user to charge a variety of 5 Volt appliances. Five technology demonstrator electricity generating stoves have been integrated with locally produced clay cooking stoves in the Balaka district of Malawi, Africa. This study details the results from an 80-day field trial of the devices. The data reveals that the stoves are in use for a greater time than was anticipated. The data also indicates that the generators perform adequately in the field and provide the user with the ability to charge LED lights and mobile phones from the generator stoves every day if necessary.

Adaptive design of a prototype electricity-producing biomass cooking stove

“…The circuitry used to charge the lithium-iron-phosphate battery is designed to be as simple as possible. Previous studies using this basic circuit have shown that the system approaches the maximum power point when the temperature difference across the TEG is close to or above 150°C (Kinsella et al, 2014;O'Shaughnessy et al, 2014). Sophisticated maximum-power-point-tracking (MPPT) techniques such as those investigated in Ko Ko et al (2011), Montecucco and Knox (2015), Sungkyu et al (2010), and Xiaodong et al (2010) were not employed.…”

“…Power to the 12 V fan/motor assemblies was supplied with an Aim-TTi EX2020R desktop power supply. For all modified fan tests, power was supplied by the TEG and accompanying circuit almost identical to that described in O'Shaughnessy et al (2014).…”

Energy and Water Needs Analysis: Towards Solar Photovoltaic Water Pumping in Rural Areas of Malawi

“…In terms of risks associated with developing such a water services strategy, those related to evidence of the community's 'willingness to pay' are significant. For example, a wide range of variables can influence empirical evidence of willingness to pay [73], which need to be explored in further work around suitable business models. Such variables as respondents' age, household size and occupation of the household head have been shown to be significant factors in determining willingness to pay for water services.…”

Design and implementation of a portable TEC-based heat-to-electricity converting module

“…This can be accomplished by collecting the energy of solar radiation to heat on hot side of TEC and cool it by heat sink on the other side, then the electricity is generated [3]. Several TEC-based heat-to-electricity converters have been proposed and demonstrated for battery charging and lighting purposes under different infrared sources such as heat generators [4], automotive [5], candles [6], wood burning stoves [7-8], camp fire [9], and cooking stoves [10][11][12][13]. Particularly, there are new designed cooking stoves which can directly receive heat and convert it to electricity by itself [10] and can directly collect heat from biomass [11][12][13].…”

“…Several TEC-based heat-to-electricity converters have been proposed and demonstrated for battery charging and lighting purposes under different infrared sources such as heat generators [4], automotive [5], candles [6], wood burning stoves [7-8], camp fire [9], and cooking stoves [10][11][12][13]. Particularly, there are new designed cooking stoves which can directly receive heat and convert it to electricity by itself [10] and can directly collect heat from biomass [11][12][13]. Because the use of a heat sink and a cooling fan for heat dissipation at the cold side of the TEC is not enough to cool it downs, these modules cannot be operated for a long time as an electronic power supply.…”