Following our previous post on cooking, this post will investigate space and water heating/space cooling needs.
Space and water heating/space cooling
Heating can be an important source of energy consumption in a number of developing countries located far from the Tropics. This function is often associated with cooking, where a central heating point is used both to cook meals and heat the house. Bio-digesters in countries like China, India or Nepal have been able to provide heat on top of cooking.
Another energy service which is more widely used – even if often not considered as a priority – is domestic hot water which can be provided with a solar water heater. South Africa has some very large programmes of dissemination of solar water heaters, notably in townships. Half of the population of Barbados has a solar water heater. Solar water heaters are a mature technology, which can be easily manufactured locally and relatively cheaply, most of the time sold on a cash basis or with a consumer credit.
Solar water heater used in the Cirque de Mafate, Réunion. “Solar heater dsc00632”. Licensed under CC BY-SA 3.0 via Wikimedia Commons – http://commons.wikimedia.org/wiki/File:Solar_heater_dsc00632.jpg#/media/File:Solar_heater_dsc00632.jpg
Cooling renewable energy technologies are less available. For instance solar thermal cooling systems seem to exist mainly as large-scale technology; they tend to be complex to design and generally are quite costly. They are not considered in the STEPs project, which deals with the large-scale dissemination of medium scale collective or individual small-scale mature technologies.
Heat pumps imply dwellings of good quality with good insulation which is not a common occurrence in the case in poor communities. Nevertheless ground-source heat pump could potentially be used at a larger scale (http://unu.edu/publications/articles/geothermal-energy-in-developing-countries-and-the-mdgs.html).
Energy-efficient insulation and passive housing have traditionally been the preserve of developed nations (for example, the developed German passive housing technology sector). However, the potential for efficient insulation and space temperature management with locally-sourced, low-cost renewable materials has been realised in a number of countries, particularly in Sub-Saharan Africa. This includes both traditional methods for adapting households in temperate developing countries, such as cladding and thatch roofing, as well as the more modern concept of passive housing, where thermal energy inputs (for example, from the sun) are used as part of the building’s thermal energy regime, enabling a reduction in the use of air conditioning methods.
Traditional housing for example in Lesotho is adapted to the variable temperatures of the mountain climate the country resides in, with rondavels (traditional huts) having conical thatched roofs and daubed exterior walls for insulation against the often cold climate, and warm air retention.
By K. Kendall (originally posted to Flickr as Rondavel, Gisela) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)%5D, via Wikimedia Commons
Business model examples and projects for efficient insulation in developing countries are few and far between. For instance, the iShack project in Enkanini, an informal settlement in Stellenbosch, South Africa in partnership with the University of Stellenbosch, is predominantly a fee-for-service solar home system project, where users pay a small monthly fee on top of a fixed installation cost for small (50-80W) solar home systems. However, the organisation is also expanding into sustainable insulation and other household services, particularly sustainable wastewater treatment and household-scale biogas installations for cooking.
Enkanini, Stellenbosch from the steps of the iShack hub. Image: Daniel Kerr
– Xavier Lemaire & Daniel Kerr – UCL