10

There are drainwater heat recovery systems in production. It is mostly made of copper and in principle it's a passive, opposite flow heat exchanger. The freshwater coming to the house circulates through thin pipes wrapped around a bulky waste-water pipe. Any obstructions in the way of waste-water could cause clogging, that's why there is (probably) only one ...


6

Would levying taxes on non-organic meat be an effective means to reduce consumption and thus reduce the environmental harm? Yes. But. It would add complexity compared to just taxing all meat, and thus make the tax less efficient. The increased costs would be the primary cause of reduced consumption. Whether only taxing conventional meat would have a ...


6

Another sustainability aspect of bitcoin (and cryptocurrencies in general) is the electricity consumption of mining: "The electricity used to mine bitcoin this year is bigger than the annual usage of 159 countries" (http://businessinsider.de)


4

they remove the centralised middle man from individuals transactions Indeed. However, this doesn't mean that the resulting system is more sustainable. people will be able to use a more secure version. Security is not the #1 concern with BTC. I would be much more worried about volatility. Providing security is an engineering exercise. Stability, however, ...


4

Yes, PV is viable. That's why somewhere around a billion solar panels have been connected to the grid - about 200 GW of capacity, with another 50 GW or so coming online in 2016. I'm afraid that the costs you have are quite wrong. Remember, PV generates electricity - that's a higher-quality (high exergy) energy than heat from gas. To get electricity from ...


4

I did some digging and found data with a bit more resolution. First, polysilicon prices since 2010: Source: Fu, et al, Economic Measurements of Polysilicon for the Photovoltaic Industry: Market Competition and Manufacturing Competitiveness. Then, crude oil prices since 2010: Source: www.macrotrends.net, Crude Oil Prices - 70 Year Historical Chart. Note ...


4

No. As the graphs provided show, the prices both spike during the GFC, loosely speaking, but the oil price spikes later and declines faster, then continues a general slow rise while the price of silicon falls. Note that in late 2005/early 2006 oil drops abruptly while silicon is rising sharply, but during the 2011 blip in silicon prices you see a similar ...


3

No, decentralised currencies won't help society be more sustainable. Removing the role of a Central Bank makes it much harder to cope with macroeconomic changes in circumstances. There's nothing sustainable about making the whole economy more volatile. am making the assumption that decentralised communities are more sustainable That's a really big ...


3

Here's a quick answer; hopefully we'll see some more in depth answers too. Looking at the given charts closely, the price of polysilicon appears to decline from around $75 in early 2010 to $17 in 2014, but the price of oil appears to gradually rise from $80 to $100 over the same period. This is very different behaviour, and says to me the relationship ...


3

Added at start: To answer this question at the depth requested could require a few reams of paper and its own website :-). The original statement about repowering was somebody's simplificatioin of one small part of a complex ongoing process. The basis for the claim can be seen in various sources but it is arguably not justified as a pithy one line ...


3

tl;dr: A lot of soy ink is used, but mixed with petroleum-based ink. According to Wikipedia: A major problem with soy ink is that it takes more time to dry than petroleum-based inks, due to its lack of evaporative solvents in the form of VOCs. "VOCs" are Volatile Organic Compounds -- organic in the chemistry sense, not the farming-process sense. ...


2

Communities are more than what currency they are using, whether Bitcoin or cash or debit/credit cards (considering a debit/credit card as a proxy for cash). Thinking about what makes a currency useful there are a couple of important characteristics: stability of value, portability, and acceptability for transactions. Bitcoin fails on two of these at the ...


2

I don't know about to what extent it currently exists, but I can imagine it could be implemented successfully with a "reasonable usage" policy. In my experience as a customer, being asked to pay very exact, tiny amounts for one thing or another is often frustrating, especially if I've paid good money for something like a hotel room. However, when my phone ...


1

One of the issues I think would be cost of installing water and electricity meters for each room, including the associated labor cost. It would add to the capital cost of the building. The other issue is with reading the meters. Do you trust a human to correctly read the meters on a daily basis, at check-out times? This adds to the operating costs of the ...


1

Is there a metric to measure average 'environmental impact' per economic dollar? I don't think that this is possible. If you're working in the oil and gas sector, your environmental impact per dollar you earn is going to be very high. If, on the other hand, you work at a telecommunications company like I do, or at a law firm, your environmental impact per ...


1

Mass producers of the grain consumed in feedlots proudly assert that they are feeding the world, as if they want a medal for their efforts. This is an obvious consequence of cognitive dissonance. They have doubts about their own activities, but if you ask them what they fear about the future based on what they know, you will see "environmental impacts" in a ...


1

Both of Tim's points (re: negative population growth and elastic demand) are important points, but I don't think they're doing a good job of answering your question. Unlike people living in the 1980s, a lot of people today expect marginal changes in their carbon footprint to have marginal global effects within their own lifetimes. Therefore, a plan of not ...


1

Someone has to suggest the obvious answer... for the record. Q: "is there an entirely different solution?" A: Don't have children. Earth's problem isn't solely and exclusively with what its Human inhabitants are doing... how many are doing it is the main problem. No matter how carnivorous and voracious a single Human is (or could be), their consumption ...


1

Yes, hotels could implement room-based monitoring systems for electricity and water consumption, but they have no financial motivation to do so and the effects of doing so are marginal verging on insignificant. Assuming the 7% reduction (due to IHDs, determined by the meta study) is accurate and translates to hotels, and given that rooms account for only ~...


1

The best way to find out would probably be to try to obtain a contact in the company who is responsible for running the program, or at least for answering questions about it, and arranging a meeting to give them a friendly but intensive interview grilling about it. If they seemed reluctant, offering to write up an article for sharing with the media may ...


1

Tracking PV means (by it's definition) a more complex construction. It means more complex servicing and installation. But why not add features to reach a much better solar gain and lower price per Watt? The pros can outweigh the cons. I give you one example for all, a concentrating PV ZenithSolar Z20 (just acquired by SunCore). The advantages it features ...


1

Lots of tracking PV has NOT been build. Recently I read a story that current PV installations are running about 1 GW/week. Yes, WEEK. That is about the same amount as all of the 20th century. PV tracking made sense when the price of PV was very high compared to the price of tracking. Tracking doesn't drop very fast. As PV costs come down it becomes ...


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