Are there serious research about how much this "green" tech is actually greener or not?
And what are the actually greenest energy we can have right now?
Another interesting example of environmental trade-offs is the plastic bag ban (where the disposable, ultra-light-weight plastic bags at supermarkets are banned in favor of heavier, reusable plastic and paper bags).
The lighter bags:
- break more easily, making them harder to re-use
- tend to blow around and get stuck in trees, rivers, etc, causing visible pollution
However, the heavier bags:
- emit a lot more carbon through their transportation (because of the extra weight)
- put more total plastic into the world at the end of the day unless everyone reuses all of them (which many people don't)
Just like there's no single definition of "healthy food", there's no single definition of "good for the environment".
That said I fully agree with the larger point. We have to be willing to weigh and accept tradeoffs.
https://www.theverge.com/2018/5/12/17337602/plastic-tote-bag...
The issue there, of course, is that we have a whole modern civilization built around consuming and discarding, and it's hard to achieve change once these habits are built and there's little direct incentive for change. It's entirely feasible--sometimes people point to "labor specialization", but it takes a day (if that) to learn to do basic sewing and weaving pretty well--but we would need to drastically shift (back) to a rather un-capitalist society of home industry with very strong incentives for mending rather than replacing.
That is not what the report in that article says[1]. In Table IV, for a conventional cotton bag, it has to be re-used 52 times in order to equal the LDPE plastic bag in the climate change metric.
For a woven PP bag (which is the most common plastic re-usable bag in my experience), the numbers it has to be re-used is only 5.
[1] https://www2.mst.dk/Udgiv/publications/2018/02/978-87-93614-...
> A 2011 study by the U.K. government found a person would have to reuse a cotton tote bag 131 times before it was better for climate change than using a plastic grocery bag once. The Danish government recently did a study that took into account environmental impacts beyond simply greenhouse gas emissions, including water use, damage to ecosystems and air pollution. These factors make cloth bags even worse. They estimate you would have to use an organic cotton bag 20,000 times more than a plastic grocery bag to make using it better for the environment.
It would appear I was misremembering somewhat, but I think my point (and the GP's that I was referring to in my earlier comment) still stands: These decisions are often about tradeoffs. Sometimes things can be green on one axis, and not so green on another.
The Michael Moore produced documentary Planet of the Humans[0] tries to answer that question. Strongly recommended.
https://www.lowtechmagazine.com/2018/05/ditch-the-batteries-...
TL;DR: Lithium ion batteries have a ratio of around 10:1, whereas compressed air or pumped water are 200:1 or better.
This is just storage - I'd be interested in the ratio on solar photovoltaic, wind, or similar power generation tech.
https://newatlas.com/mit-offshore-wind-concrete-sphere-energ...
(Edit: better link)
It blows my mind that it takes 1/10 of the energy it will ever store to manufacture a lithium ion battery.
However, with an electric-to-electric efficiency of only 40-52% compressed air has a net efficiency of ~ 0.5:1 even if construction costs suggest 200:1 that just means it stays 0.5:1.
Think about all the ore-bearing rock and soil that had to be mined, sifted, transported, refined, formed, milled, transported again, and so on, just to produce the machine that puts a label on a box.
Even putting truly complex tech aside, the amount of resources we collectively tear through, day after day, to get to this (not particularly admirable) place is staggering.
There's not a huge difference in going from 91% efficiency (10:1) to 99.5% efficiency (200:1).
What's more concerning are the other negative externalities -- pollution, ecosystem destruction, etc, as described in the original article. This won't be captured by looking at energy stored vs. energy used in production.
3000mAh*3.8v /1000 = 13.3Wh in a phone battery.
13.3Wh * $0.20/kWh * 365 ~= $0.95 a year
This is sometimes expressed in time range (which depends on average generation rate based on where it is installed etc) or just energy vs energy ratio (Eg kWh to produce vs lifetime kWh generated)
As others have said this statistic is not the whole picture, type of pollution generated due to the construction of the solar panel, wind turbine etc should vs other technology should also be take into account so this gets pretty complex pretty quickly.
Some recent studies [0] show a break down of input/output for solar with Switzerland of 9-10:1, this is likely higher if panel was installed in Australia for example and goes into some detail showing a fairly minimal amount of storage in an electricity grid (8%) increases the amount of usable generation for wind and solar which improves that ratio.
Wind I believe has a better EROI but has a lot more complexity when it comes to installation, maintenance so how much this is taken into consideration and will likely vary for onshore vs offshore installations. Numbers I’ve read before were in the 16-20:1 range but can’t find any decent study sources at the moment.
Hope that helps.
[0] https://www.sciencedirect.com/science/article/pii/S030142151...