Two things that are interesting about the examples discussed are:
1) They mainly reduce the factories impact on the environment by saving water, energy or reducing emissions which are often product, raw material or byproduct. So the fixed production costs are very often reduced at the same time as the environment benefits.
2) They are seldom complicated or technologically groundbreaking and are often common sense.
A few examples are
Campbell Soup reduced energy consumption by 4,85 and water by 13,45% by installing utility meters, introducing recycling, installing energy saving light bulbs and introducing low flow water nozzles.
Craft Foods reduced its energy cost by 60% for a new cold store by installing it underground in a limestone formation.
General Mills produces 90% of the steam it uses in its milling and preparation plant for Breakfast cereal production production, by burning the bran produced in the plant.
Musco Ollives uses 15 tons of olive pressing waste a day to produce enough steam from waste water to produce power for production.
Kroger distributes 30 million meals a year from food that, although safe and wholesome, is destined for landfill for commercial reasons.
These screenshots are from a Time article on a Conference Poster on a study that evaluated the cost of nutrition sourced from fresh, dried, frozen and canned foods. You will find more information in my Google+ posts. Time article on a Conference Poster
There’s quite some controversy around the new low energy light bulbs. Much depends on how long the bulbs actually last. This is quite difficult as it comes down to perception because it’s not possible to measure the running time of a build in normal household operation.
So when 3 of the 4 the CFLs in my houses street lights failed I had the opportunity to do some experimenting. This post will record what I installed and when so that I can get some firm data.
photo by DIGIVU under Creative Commons some rights reserved
So I put in three new bulbs on 25 March 2012, I have gmailed 3 photos of the bulbs after they were installed, to form a record of the start of lfe of each bulb.
I installed a 11w, Eurolux CFL that cost R 26.99, a 9w, Eurolux CFL at R 29.99 and a 40w Radiant incandescent bulb that cost R 8.99.
The theory says that the CFLs are cheaper after a couple of months and half the total cost after 5 months – see the image below.
Graph prepared by DIGIVU on Apple.Numbers under Creative Commons some rights reserved
However, the real outcome depends on the life of the various products. I must admit though that it seems likely that the CFLs will give big savings as their specified life is more than 5 times the period show in the graph.
It is from a project run by University of California, Davis in Tanzania and Nicaragua on the introduction of a Concentrated Solar Power Dryer for the drying of vegetables.
The book carefully explains the steps, starting from a potentially soiled fruit, through preparation, pretreatment, drying and packaging for Tomatoes, Mangoes, Banana, Pineapple, Sapote and Pity (Dragon Fruit).
Simple and clear – its easy to recommend this book.
Here is the design specification for short term food preservation for Pabal farmers as drawn up by an investigation team that included the University of Cambridge and Engineers Without Borders. Interestingly the need was very similar to what many before them had identified.
from: Eng India (click image for full story online)
They have though, identified the advantage of a solution which does not involve running costs and the need for low cost solutions.
Their report is informative and selects a combination of solar chimney and underground cooling pipe as the technology that would meed the specification developed.
from: Eng India (click image for full story online)
This has been described and analysed in the above report. However, the rigorous theoretical engineering approach has not yet provided a suitable solution, mainly because of the limited experimental data collected to date. The temperature drop achievable with the passive solar chimney is only 2 degrees and forces the author to recommend a battery powered fan which increases the cost and runs the risk of introducing an unsustainable running cost.
It will be interesting to follow this project and see the progress and the solution that arises from this kind of rigorous approach.
The author, John Stanford, highlighted the following points from this diagram that put emmissions in context.
• Soil emissions are the biggest single item
• Farm enteric emissions bigger than the emissions of the whole of food manufacturing
• UK Freight emissions are less than domestic cold storage
• The biggest contributors are Agriculture, Food Production and Trade Balance Household
The direct stem injection method of heating has several advantages such as efficiency, easy control, no fouling on heat transfer surfaces and compactness. It does, however, mean that whatever carry over there maybe in your steam system will get into whatever you are heating.
These pamphlets are broad but short (normally 6 to 8 pages) and give a background about the topic, identifies the things to ask, describes processes, gives trouble shooting information and gives contacts from where further information can be sourced.
In this particular case it describes cooling in the double pot evaporative cooler and sun drying.