Go Green? Yes, but Read this Article first

Mario HonrubiaSustainabilityTrends

Written by Karl Grimsehl In July 2018, ennomotive launched a challenge that looked for solutions to minimize the accumulation and/or remove the sediment in a hydro power plant in a more efficient way. For 6 weeks, 85 engineers from 35 countries accepted the challenge and submitted different solutions. After a thorough evaluation, the solutions that best met the evaluation criteria were submitted by Leonardo Guzmán and Agustín Galetti, from Argentina, and Karl Grimsehl, from South Africa. In this article, Karl gives some insight about what he thinks works or doesn't work when companies and people try to go green.    Dear reader– even though you found this article on internet it should not be taken as Gospel. It remains, to a certain extent, an opinion piece. The author has no wishes to sway anyone from their worldview, nor to impose his current worldview upon anybody – he will be content with a few grins and a people asking a few questions. So here it goes... As with most things in life, we humans tend to look for shortcuts. We love copy and paste and look for cookie-cutter solutions. Even more so with the advent of the internet – the first thing we do when we stumble upon a challenge is to reach our phones in search of an answer, and this is great! It gives us more time to do the things we really want to do (like spend time on the internet! 😊) The problem with this approach however is that we tend to lose some uniqueness, we shorten our ability to think and to ponder about a problem. We also tend to force solutions into areas where they just don’t quite fit. It’s like saying; my hands are cold – I’ve read that socks are good at warming extremities, I will thus wear socks on my hands.  Sometimes however, you need to think for a while in order for you to find the best solution, the solution that will work best for the environment that you’re living in. For the next section of the article we will look at three classic environmentally friendly, green solutions  or actions that an individual may take and try to evaluate them outside the cookie cutter mould.
  • Buying re-usable stainless steel straws.

It is estimated that 1.7 grams of CO2 is generated for every gram of Polypropylene produced (2). On the other hand, the average CO2 intensity for the steel industry is 1.9 tons of CO2 for every Ton of Steel produced (3). Now let’s consider a straw with a 7mm Outside Diameter, 200mm length and 0.2mm wall thickness. If this straw was made from Polypropylene would weigh 0.8g and 1.36g of CO2 would have been released when it was manufactured. If this straw was made from Stainless Steel it will weigh 6.84g. and 13.0g of CO2 would have been generated when it was manufactured. Thus producing a stainless steel straw releases almost ten times more CO2 than producing a Plastic straw. That means you need to use that straw at least ten times for it to start having a positive carbon impact. You may however argue that plastic straws are also a pollutant and that should be the reason for the ban. Indeed they are, it is estimated that between 437 million and 8.3 billion plastic straws are polluting the worlds coastlines (4). Straws however only make up a very small portion (4% by piece and 0.0002% by weight) of the nearly 9 million tons of plastic that waste that enters the oceans every year (4). Thus in the bigger scheme of things, that little stainless straw you’re carrying around in your purse or man-bag does not really make you an eco-warrior. There is however a place for the stainless steel re-usable straw. In an establishment, such as a restaurant they can be very useful. For such an establishment the uses required for it to have a positive impact on the environment would be reached within a day or so, but for the rest of us my suggestion would rather be – go to your nearest McDonalds, grab yourself a free straw from the counter, pop that in your purse and use it until it starts to gross you out. If you were to re-use that plastic straw 10x it would be the equivalent of having to use a Steel straw 100 times, which is, for me at least, probably more than a year’s usage (and there is a very big chance that I would have lost my Stainless steel straw within that year ). Better yet, dump the straw pucker up and give your beverage a kiss! By drinking directly out of the container you reduce your nasty straw related pollution by give or take, approximately 100%.
  • Rushing to install a Solar PV system. 

Don’t get me wrong, I really thinks solar is great, but it needs to be done correctly…  Step no 1 for installing Solar is to estimate and reduce your demand. Have a look at your behaviour, are there any behavioural change you and your family can make – Examples of these are: 
  • When you boil water, do you fill up the entire kettle or do you only boil the amount of water you need? 
  • How often do you use the hot water tap for activities that does not need hot water? 
  • If you have those mixer taps  with the single hot and cold water lever, do you leave the leaver in the middle where it will give you a mixture of hot and cold water, or do you leave the leaver on the cold side and only move it to the hot side when you need hot water? 
  • How diligent are you in switching off lights and appliances when not in use? 
  • Do you ever stand and ponder about your beverage in front of an open fridge door? 
  • Do you tumble dry all your clothes, or only use the tumble drier when needed? 
  • Do you iron everything, or only the items that require ironing (you don’t really need to iron your tighty whities)
A good idea during this step would be to install an energy monitor for your home, that way you can measure the impact of your behavioural changes. Once you’ve investigated and addressed your family’s behavioural changes then you can have a look at making changes to your home and appliances.  Have a look at your hot water system, do you need hot water at all the taps, are there taps where the hot water can be disconnected, do you have aerators on your hot water taps and is your shower head low flow shower head?  How do you heat your water? Do you use electricity,  gas, heat pump, solar thermal etc? Which of these technologies (or other) will work best for your needs and environment?  How do you do your cooking do you use gas, electric or induction etc?  Have a look at your lights, are they energy efficient?  Have a look at your home insulation, Also have a look at your orientation and shading – maybe a veranda before a North facing window (Assuming your home is in the Southern Hemisphere) may reduce your in home summer temperatures hence reducing your air conditioning loading. Maybe you can plant a deciduous tree in front of your window that will provide sunshine inside your home during the winter months and shade for  your home when its summer. By doing all of these steps you will not only reduce the size and costs of the PV system that you want to install, but by reducing its size you will also reduce the impact your PV system will have on the environment, If by auditing and optimizing your home you are able to buy one less battery then there will be one less battery that you would need to dispose of at the end of its term, there will also be one less battery that would need to be manufactured and shipped from its country of manufacture to your home.
  • Should I own an electric vehicle (EV)?

Estimating the impact an EV will have on the environment is tricky (9) and multiple factors need to be taken into consideration before you can state with confidence that your decision to drive an EV is the best environmentally friendly option for you. Here are a few aspects that you need to consider.
  1. Have a look at  your habits.

Before buying an EV reconsider your needs. For example, Is it really necessary for you to travel to the office every day, the fourth industrial revolution is upon us – can’t you rather communicate with the office via  skype or e-mailed? And if you have to travel, can’t you get away with walking, using a bicycle, motorcycle, lift club or public transport?  A single occupant driving in a vehicle designed to carry four occupants is a waste irrespective if it runs on petrol, diesel electricity or puppy hugs and kisses.
  1. How will you charge the vehicle?

If you will be charging your vehicle from a plug supplied by a Utility provider, then you need to find out how your utility provider produces their electricity. In South  Africa the vast majority of our electricity is generated from coal fired power stations. The thermal efficiency of such a plant is approximately 37% (5) and the CO2 generated by burning coal is 0.34kgCO2/kWh (6). In addition to this there is approximately 5% transmission losses (8) This means that for every kWh of electricity produced by coal fired power station 0.97kgCo2 will be released into the environment.  The thermal efficiency of a petrol Internal combustion engine varies greatly but fore this analysis we will be using 35% (7). Burning petrol releases 0.25 kgCO2/kWh (6) This means that for every kWh of energy generated by your car 0.71kgCo2 will be released into the environment. Thus, in this example, an electric vehicle powered by electricity generated by a coal fired power station Creates more CO2 than using a normal internal combustion engine, the only difference would be that the pollution is moved from your direct environment to the power station. This is however a completely different story of you’ve got access to Solar charging stations or if you’re power utility makes extensive use of renewables.
  1. EV manufacturing emissions.

Depending on the model, range, energy used for manufacturing etc. there is an environmental impact associated with the manufacturing of an EV (or any vehicle for that matter). Before you buy a new EV, have a look at your current vehicle and ask yourself: is it in a good condition, why do you want to replace it, and how many km’s do I need to travel to before you break even with the CO2 emissions generated by the manufacturing of the EV you’re thinking of replacing it with. You may just find you that for your specific scenario, doing nothing might be better for the environment that doing something.. A Cookie cutter everyone can use
    1. Taken some time to measure your current impact on the environment, install energy monitors, log  your traveling and have a look at the impact of your lifestyle.
    2. Next REDUCE – cut the fat and remove what you don’t need 
    3. Measure the effects of your changes
    4. Only then should you start implementing green technologies, but before implementing remember to consider the total lifecycle implications of the technology, not only the short term impact.
    5. And lastly, Measure the impact of these technologies. 
Also remember that you are part of a system and your actions should not only have on positive impact for you but on the whole system. Let us know tricks and tips to go green and explore what ennomotive has to offer. Join our community of engineers


  1. https://stanfordmag.org/contents/the-link-between-plastic-use-and-climate-change-nitty-gritty
  2. Eco-profiles of the European Plastics Industry POLYPROPYLENE (PP) by I Boustead for PlasticsEurope, March 2005
  3. CO2 Emissions in the steel Industry, M. Kundak et al (2009) 
  4. https://m.phys.org/news/2018-04-science-amount-straws-plastic-pollution.html
  5. https://en.wikipedia.org/wiki/Fossil_fuel_power_station
  6. https://www.volker-quaschning.de/datserv/CO2-spez/index_e.php
  7. http://large.stanford.edu/courses/2011/ph240/goldenstein2/
  8. https://www.eia.gov/tools/faqs/faq.php?id=105&t=3
  9. https://www.carbonbrief.org/factcheck-how-electric-vehicles-help-to-tackle-climate-change