What is a parabolic Solar cooker
Parabolic solar cookers concentrate sunlight to a single point. When this point is focused on the bottom of a pot, it can heat the pot quickly to very high temperatures which can often be comparable with the temperatures achieved in gas and charcoal grills. The highly reflective parabolic shape has the property of bringing parallel rays of light (such as sunlight) to a central focal point. If the axis of symmetry(Center of parabola) is aimed at the sun, any object that is located at the focus receives highly concentrated sunlight, and therefore becomes very hot. This is the basis for the use of this kind of reflector for solar cooking.
Because it uses only concentrated sunlight, it requires no additional fuel source and is a completely renewable cooking solution that produces no greenhouse emissions at all. SunFire Solar Cookers have a lifespan of 5 to 10 years, and can save an enormous amount of emissions and lives in its use. The reflective coating loses its properties after 8-10 years and upon replacement, the cooker will function as normal. Replacement of this costs as little as R200.00 ZAR.
Paired with other technologies such as a heat retaining bag and an efficient wood-burners, the savings in emissions, and health benefits are staggering.
Wood and Paraffin in South Africa
The Department of environmental affairs, South Africa, recently found that roughly 7% of the population(3,8 Million) use primarily paraffin for their cooking needs and a further 11%(5,8 Million) use wood. The average open fire will emit 1,9 kg of CO2 for every kilogram of wood burnt, and an extra 0.07 kg of black Carbon(Soot). This equates to an average of 28,5 kg of CO2 emitted by a single household per day(calculated at 15kg of wood per day at an average of 4 people per household). We are now looking at a staggering 40 Million kg of CO2 and 1.5 Million kg of Black Carbon emitted in South Africa every day from only wood used for cooking. The paraffin use amounts to a further 2.5 Million kg per day of CO2, However it also deposits 700 000 kg of black carbon(soot) into the atmosphere, daily.
Black carbon is the most strongly light-absorbing component of particulate matter, and is formed by the incomplete combustion of fossil fuels, biofuels, and biomass. Black Carbon is emitted directly into the atmosphere in the form of fine particles. emerged as a major contributor to global climate change, possibly second only to CO2 as the main driver of change. The particles strongly absorb sunlight and give soot its black color. It is produced Black Carbon has recently both naturally and by human activities as a result of the incomplete combustion of fossil fuels, biofuels, and biomass. Primary sources include emissions from diesel engines, cook stoves, wood burning and forest fires. Reducing CO2 emissions is essential to avert the worst impacts of future climate change, but CO2 has such a long atmospheric lifetime that it will take several decades for CO2 concentrations to begin to stabilize after emissions reductions begin. In contrast, Black Carbon remains in the atmosphere for only a few weeks, so cutting its emissions would immediately reduce the rate of warming, particularly in the rapidly changing Arctic. Moreover, reduced exposure to Black Carbon provides public health co-benefits, especially in developing countries.
Surveys and hospital records between 1996 and 2001 in South Africa (not including our neighbouring countries), estimated
80,000 children ingest paraffin (kerosene) every year.
40 000 children develop chemical pneumonia each year as a result of ingesting/inhaling paraffin.
More than 200 000 people per year are injured or lose part/all of their property from paraffin (kerosene) related fires.
The following figures were attained from nine medical facilities from the Cape Town and Buffalo City
Municipalities over the course of 2008.
As you will notice, paraffin accounts for a huge number of incidents such as ingestion and burns.
We now(next graph) look at the age groups in which these incidents have occurred and it is important to note that the highest incident rate occurs among children in the age group of 1-4. This is an alarming statistic indeed. Because paraffin is colourless and almost odourless, it is easily ingested by toddlers.
Why Solar Cooking?
Approximately 500 Million Africans use firewood to meet their daily cooking needs. Until recently, few other choices were available; communities often say “the trees are running away from us”. Globally this is one of the largest social and environmental issues of our time, yet it remains virtually invisible. Solar cookers provide many benefits, just a few are listed:
-Free cooking energy for 10 years and beyond
-Less risk of illness from toxic smoke/Paraffin inhalation (“indoor air pollution is the 4th largest killer of Women and Children in Developing Countries, above Malaria”, WHO.)
– Free water boiling capabilities to improve child mortality by providing an easy to boil water for infant formula
– Ensure cooking fuel doesn’t cost more than the food/nutrition in the pot..!!
– Reduce deforestation, habitat loss and “black soot” – a low hanging carbon particle identified as a major driver of climate change, 3 Billion people use firewood to prepare meals each day
– Provide communities with long-term sustainable tools to strengthen their culture, society and eco systems
– Are an ideal tool kit to tackle and root out systemic and interlinked issues such as Climate Change, gender equality, child education, nutrition and access to clean drinking water – in One elegant energy intervention
Calculated from the figures above, we see that the average household(using wood and paraffin for cooking) in South Africa produces 6,5 tons of CO2 per year. Along with 0.7 tons of CO and 0.3 tons of black carbon. The introduction of a solar cooker to a wood or paraffin using household would mean that we could cut these numbers drastically. The use of a Solar cooker can reduce the need of these fuels by up to 60% per day as the only time wood or paraffin would need to be used, is in the evening and on rainy or cloudy days. Considering we get roughly 320 Sunny days in a year on average in South Africa, the Solar cooker is a perfect replacement to traditional fuels whenever the sun is shining.
If we consider these figures, it shows that a Solar cooker integrated within a households cooking schedule will save up to 3,7 tons of Co2 per year. Considering the Solar cooker has a minimum effective lifespan of 5 years, a single cooker can save up to 18,5 tons of CO2 by itself, along with CO and Black Carbon emissions cuts of 1,2 tons and 950 kg respectively.
Integrated clean cooking
The figures above can be further increased by the integration of other emission savers such as the efficient burning stove and the heat retaining bag. SunFire Solutions have bundled these three products into our Clean Cooking Kits.
With the necessary training on the integrated use of these products, the emission reduction becomes apparent. The Solar cooker brings the traditional average of 17,7kg per day per household down to 7.1kg. Our clean burning stove uses up to 50% less wood to cook with than an open fire and has a CO2 emission reduction of up to 70%, this means that the carbon emission can be reduced to 1.1 kg per household per day. This is a saving of up to 16,6kg of CO2 per day.
With a lifespan of 5 years, our Clean Cooking Kits will be able to offset 26,5 tons of CO2 from a single household during its use.