Chicken or dop? ...or how to become more energy efficient.
Published on 07-10-2013
World-wide there is a focus on energy conservation and becoming more energy efficient.
If you would like to conserve energy, rather drink alcohol than eat chicken. This article explains why.
- Say a chicken weighs 1 kg. To have achieved this, the chicken would have had to consume 2 kg of maize with a Feed Gain Ratio of 2 ([i])
- Lets now further assume that 80% of the chicken is edible. This means it took 2 kg of maize to produce 0.8 kg of edible chicken meat or in other words 1.25 kg of maize per kg of chicken meat.
- Chicken meat has an energy density of 9.05 MJ per kg ([ii]) and maize has an energy density of 13.4 MJ per kg ([iii]). In other words: It requires 33.5 MJ of energy (from maize) to produce only 9.05 MJ of energy (in chicken)
- Taking these figures we can calculate an Energy conversion ratio of 0.27 (MJ from chicken per MJ from maize)
Now, on the other hand: If we do the same calculation for ethanol we get the following results:
- Ethanol has a energy density of 26.8 MJ/kg ([iv]) and it requires 1 kg of maize ([v]) to produce 0.5L of ethanol. But ethanol has a density of about 0.789 kg/liter.
- This means 2.53kg of maize is required to produce 1kg of enthanol.
- Or, in energy values: 33.96 MJ (from maize) converts to 26.8 MJ (in ethanol) with a resulting Energy conversion ratio of 0.39 which is about 46% better than the maize to chicken energy conversion!
Also: in pure energy terms:
- Consuming 100g of chicken meat will provide you with 90.5 kJ of energy while consuming 100g of alcohol will provide you with 268 kJ of energy!
- Or you only have to consume 33 g of alcohol to get the same energy as eating 100g of chicken!
South Africa consumes about 1.8 million ton of chicken ([vi]) per year - if we can replace this with 0.6 million ton of alcohol, we can save approximately 5 Million MJ energy per year!
[i] Chicken Feed Gain ratio = 2 from http://www.earth-policy.org/books/pb2/pb2ch9_ss4 ; http://en.wikipedia.org/wiki/Feed_conversion_ratio
[ii] Energy in roasted chicken (meat and skin) : 815kJ per 90 gram or 9.05 MJ/kg from http://www.moe.gov.sg/education/programmes/holistic-health-framework/files/nutrition-tables.pdf
[iii] Maize energy density: 13.4 MJ/kg from http://www.dpi.nsw.gov.au/agriculture/livestock/dairy-cattle/feed/research/energy
[iv] Ethanol energy density: 26.8 MJ/kg from http://hypertextbook.com/facts/2003/RoxanneGarcia.shtml
[v] Ethanol yield from Maize: 0.52L ethanol from 1 kg Maize from http://www.mhprofessional.com/downloads/products/0071487492/DrapchoCh4.pdf
[vi] Chicken consumption of 1.8Million ton per year from http://www.indexmundi.com/agriculture/?country=za&commodity=broiler-meat&graph=domestic-consumption