14

TLDR; cadmium telluride panels have the highest EROI of the mentioned PV panels (around 34.2) EROI estimates vary widely. This is because of differences in the method of calculation, scope of the study, installation location, assumed lifespan of a panel, etc. This also makes it relatively easy to manipulate EROI calculations. Pessimistic The most ...


13

It's correct that the production of 1 ceramic mug requires much more material and energy than the production of 1 plastic cup, but this isn't a fair comparison. Plastic cups are generally used once or perhaps twice and then disposed of. A ceramic mug is likely to be used several hundreds of times before it breaks and is thrown away. Let's assume you use a ...


10

I think this is a great example of how sustainability really is multi-faceted. LED lighting may be great from an energy consumption standpoint, and not as good with respect to finite material usage. Energy Use vs Material Supply I think it's important, however, to apply some weighting to the different factors. I don't believe we're yet at a critical ...


10

You've pictured a disposable plastic cup. If you assume that you can use it a few times, then you might consider that you get through one a day. A ceramic cup lasts until you drop it. The cup in your photo is only for cold drinks anyway. Paper or expanded polystyrene are usually used for hot drinks. This link runs the numbers: In summary, ceramic is best. ...


9

Your most sustainable choice is an old straight razor, but there's a reason the replacement is called a "safety razor"... you're much less likely to kill yourself with a safety razor. But these last a long time and you can shave using a small amount of water and a soap stick. You can buy one second hand, that's how long they last. Much safer is an old style ...


9

"To compare purely the electricity usage ... Desktops are clearly worse for the environment in this respect." — That certainly used to be the case, and still often is, but only because people buy/build systems that are overpowered. In 2019 it is possible to build a 'serious' desktop system that consumes very little power — provided you don't play the sort ...


7

I would be surprised if any pen would be more sustainable than a sustainably sourced pencil. In terms of sustainability, I still think that "green" pens should come after refillable pens, pencils and fountain pens. There are also refillable cartridges for standard fountain pens, which usually come with plastic cartridges. For example, this middle one looks ...


7

While I have no clue which one does biodegrade better I'd like to focus on some other life-cycle aspects of liquid soap vs solid bars. But of course it's certain that liquid soaps (need to) contain substances that are simply not required for a bar of soap - such as emulsifying agents. Liquid soap contains added water and is therefore heavier. Transportation ...


7

It is hard to say because there is such a wide variation in ink formulations. Also, no company is going to tell you what is in their ink, as they will consider that a trade secret. That being said, the only consumable part of a mechanical pencil is made entirely of graphite which is 100% Carbon and Clay. Go with the pencil! Here is a "How it is made" video ...


7

Unless you're into printing color photos, the laser printer is the way to go. The retail prices of toner cartridges may seem a bit steep, but there are ways to refill them. The toner lasts a long long time (a few thousand printed pages if you know what you're doing) and does not dry up, ever. Laser printers are efficient, very fast, and hardly ever break ...


6

This will depend on where you live. It is a question of energy; First of all take into account the carbon footprint of the electric shaver relative to it's expected lifespan - this is likely to be higher than the safety razor proposed by Nui (Which I agree with by the way). Secondly - as I alluded too; it will depend on where you live, more precisely - ...


5

Executive summary It's too early to tell what the resale value is, as contemporary turbine designs are not as old as the lifetime of a wind-turbine, so we have very little experience of the economic value that results from decommissioning 1.5MW turbines; however, a rough first-order calculation puts the scrap value of the metals, based on Feb 2016 UK prices, ...


5

Life cycle assessment (LCA) is about assessing the environmental impacts of a product, process or service over it's full life cycle, so from production, usage and disposal. This assessment includes the impact of all subcomponents/subprocesses down to the (extraction of) the natural resources. There isn't really a single 'best use' for a LCA. LCAs are ...


5

I was able to find several different news articles discussing this topic: "Paper towels least green way of drying hands, study finds" - The Guardian "Electric Hand Dryers vs. Paper Towels" - Slate "The Use and Abuse of Paper Towels" - The New York Times The most thorough treatment I found comes from an MIT study*, referenced by The Guardian: "Life Cycle ...


4

Software The most basic, free tool to create an LCA would simply be a spreadsheet like OpenOffice Calc. However, dedicated LCA software does make things easier for you, but most software is not free. The few good and free LCA software packages I know are: OpenLCA: open-source software, supports databases in EcoSpold or ILCD format, also has free and paid ...


4

The issue with answering this question is that there are inherent assumptions in how one creates a boundary for answering. For example, Voreno's answer suggests comparing two similar products in terms of the eco-footprint of their lifecycle. This is sound, but assumes that use of any product is warranted, and that levels of use and maintenance are fixed. ...


4

Measuring impact I've yet to see a meaningful metric that relates directly to materials, other than the EROEI (Energy Returned On Energy Invested); and there's discussion about whether or not EROEI is at all a useful measure: its probably not that useful, since once it's over 1.0, it's completely subsumed into the economics. The same would be true of a more ...


4

Please consider using an economic input-output model. Alternative (other-than-process-based) methods of calculating net product impact can provide quick, cost effective, and yet comprehensive life-cycle assessments. A free economic input-output LCA is available via the Green Design Institute at Carnegie Mellon. Some background: LCA can currently be ...


4

The question seems to be asking only about the environmental impact of the cartridges, so I probably shouldn't talk about how a laser printers use 100 times more power while they are printing, but allow me just to say that for the whole life cycle the most significant stage for both types is paper usage, followed by the manufacturing of the product and ...


4

Diversify In a paper unearthed recently by our friend LShaver question, a key point is that the worst identified menace today is Biodiversity loss, beyond Nitrogen cycle disruption, and way beyond Climate change... So my answer will encourage you to diversify!, locally. For example, think about the extremes: if there is only milk - too many cows, farmland ...


4

From least damage to most: Wooden pencils. Provided the manufacturer is eco-friendly and uses wood from properly managed forests and non-toxic paints. Faber-Castell (just chosen because I happen to know) is actually carbon-NEGATIVE: They own forests and plantations (with the intention of using the trees that grow there to produce pencils) that absorb about ...


3

One-piece safety razor with replaceable blades might be an option. They are vegan (unlike your Mach3) and you only throw out the blades (although I'm not sure that you can recycle them).


3

Inkjets are the Hummer of printers If you care about the environment, give that inkjet printer to the next person you can find for whom your gift/sale will prevent them from buying a new inkjet. Inkjet printers are planet-hateful products. They are built to be cheap, frequently replaced, throwaway items. Further, a huge amount of engineering goes into ...


3

What's best is if you pipe the water into your house, making for huge savings in transport costs. Now, while this doesn't really apply to fancy things like pop and beer, it's really, really better to not drink bottled water at all. Systemically speaking, the rate that bottles and cans are actually recycled is dismal at around 15%. So in the end the ...


3

Liquid soap can and should be diluted. As with toothpaste, manufacturers profit from consumers inadvertently using too much – often far too much. Dish soap in particular is usually sold explicitly as "concentrated", but the sustainability gain from less bulk is lost unless consumers take great care to use tiny quantities. Dilution is much easier. Packaging ...


3

Update. In my original answer I inadvertently divided at one point when I should have multiplied -- I found the mistake thanks to comments from Frank and THelper. So here's a new tl;dr: By mile 4,000 at the latest, total emissions from a hybrid Prius beat emissions from a standard Corolla. Hybrid electric vehicle (HEV) specific components The HEV ...


3

There's a little bit of information on their FAQ: Energy ranges from less than .4KWH/Liter to over kWh depending upon climatic conditions. And that's just as they've written it. The upper limit is indeed missing. From their products page, the smallest model consumes 0.8-1.8 kW, and generates 30 (presumably US) gallons per day at most. The largest model ...


3

To add some numbers to the discussion, I found a white paper from Fujitsu about a desktop (2018) production energy usage: 6.8 GJ or 450 kg CO2 equivalent use phase energy usage: 9.2 GJ or 30 - 500 kg CO2 equivalent (Norwegian vs. German electricity mix) usage scenario: 5 years TODO: find out h per day or similar. LCA of an Ecolabeled Notebook (2011) ...


2

From what I've read, the energy losses during electric power transmission are usually less than 10% of the original power. This loss decreases as voltage increases, up until a certain point when corona discharges make up for the increased transmission efficiency. When compared to the efficiency of the other parts of energy generation, transmission loss is ...


Only top voted, non community-wiki answers of a minimum length are eligible