Solar cooking, as a technology and group of products, has existed for many decades, with examples being used in the 1970s. The technology in its simplest form has remained relatively unchanged since then, with the basic premise being either a flat or parabolic reflecting surface, placed in the sun, reflecting sunlight onto a cooking chamber. This can be either below the flat-plate reflector, or at the focal point of the parabolic collector. These types of devices are easy to manufacture and can be extremely cost-effective, with little more than a reflecting surface (for example, foil-backed card) and a cooking vessel needed for a minimum setup. These features give this technology particular applicability for targeting bottom-of-pyramid consumers with sustainability interventions: typical prices for simple designs (such as the flat-plate reflector shown below) range from US$3-5.
A number of companies currently distribute simple kits for creating solar cookers from scratch, usually in the form of a reflective card template for the reflecting surface. However, these pre-packed kits are often more expensive than locally-sourcing materials for manufacture, ranging up to US$30-40, without offering meaningful benefits to the consumer aside from convenience. There are also a number of companies in developing countries that distribute full solar cookers to consumers using a direct-purchase business model, such as SunFire in South Africa and L’Obel Solar Power in India. Prices for these designs, commonly higher-quality parabolic mirror cookers, range up to US$200.
As such, it appears there is an opportunity for low-cost solar cooking business to develop markets for cheap, reliable solar cookers for bottom-of-pyramid consumers. In addition, through using alternative payment models for business, higher-cost designs can become more accessible to a greater number of consumers. Offering micro-credit products for deferred purchasing of solar cookers, or engaging with consumers on a fee-for-service basis with consumers paying a monthly fee for their product, would allow mid-range technologies to become accessible to consumers with lower incomes.
Other opportunities exist in the solar cooking market space for complimentary technologies, in particular heat-retention bags such as the Wonderbag from South Africa. This is designed to fit around the cooking vessel to retain heat and slow-cook the contents, after it has already been heated, reducing the overall energy requirement for cooking. Whilst this technology is perhaps most applicable to wood or charcoal-fired stoves, it can also help improve convenience when using solar cooking products. For example, rather than leaving a cooking vessel in the solar cooker for up to six hours, it can be left there for 1.5-2 hours, then transferred to the Wonderbag for further cooking.
For more information on the Wonderbag and use-case studies, please refer to https://samsetproject.wordpress.com/2017/04/10/energy-poverty-in-peri-urban-communities-in-polokwane-south-africa-part-1-identifying-the-issues/
— Daniel Kerr, UCL Energy Institute
Teach A Man To Fish (2009) Solar Cooker Business Guide. Available at: http://www.teachamantofish.org.uk/resources/incomegeneration/Solar-Cooker-Business-Guide.pdf
Gautam (2011) Microfinance Intervention for Financing Solar Cooking Technologies – Financing With Savings. Available at: http://www.microfinancegateway.org/sites/default/files/mfg-en-paper-microfinance-intervention-for-financing-solar-cooking-technologies-financing-with-savings-mar-2011.pdf
Solar Cookers International: CooKit. https://shop.solarcookers.org/?pn=CooKit&cn=Solar+Cookers&p=621&c=27
L’Obel Solar Power Systems: Solar Thermal Products: http://www.lobelpower.com/solar_thermal_product.htm
SunFire Solutions: http://www.sunfire.co.za/wp/
Wonderbag World: http://www.wonderbagworld.com/