[TH] Each Bitcoin transaction uses 4,200 gallons of water, enough to fill a swimming pool, could potentially cause freshwater shortages

[Shihab]

Of course it is. Every gallon which evaporates, eventually precipitates. What goes up must come down. Where do you think that water goes?

If you prefer a more scholarly viewpoint, there are numerous resources to confirm my statement, such as: Investigating the mesoscale impact of artificial reservoirs on frequency of rain during growing season - Degu - 2012 - Water Resources Research. Or The influence of large dams on surrounding climate and precipitation patterns - Degu - 2011 - Geophysical Research Letters. Both of which found small, but statistically significant increases in local precipitation due to artificial reservoirs.

Should I have emphasized "on its own" in my last post?

There is an "effect" on local climate, but what you are proposing isn't some increase in local precipitation, you're saying that, and I quote, "most precipitation" falls near where it [evaporates]. This a volumetric comparison between evaporation and precipitation. Skimping over the papers you've linked, neither address this.

You didn't read the study carefully. The underlying figures are from this reference: "The generation-weighted average WCFs of thermoelectricity and hydropower are 1.25 (range of 0.18–2.0) and 16.8 (range of 0.67–1194) L/kWh, respectively.

The WCF is the water consumption factor. Hydro may be a small portion of the mix, but far more water evaporates from a hydro reservoir than other sources, meaning it contributes an outsized impact.

These figures are for the US. And do read the entire sentence. It continues: "and the generation-weighted average WCF by the U.S. generation mix in 2015 is estimated at 2.18 L/kWh."

The composite intensity is closer to thermo's 1.25 than hydro's 16.8 because apparently the US also has hydro as a minority contributor.

My primary disagreement with Endymio's arguments is on water cycle. I may be misinterpreting, but they seem to be saying that it doesn't matter how much water we use, because it all comes back eventually. The latter is entirely true. However you can use, and in many places we are using, the accessible fresh water faster than it's being replenished.

The fact that the water equilibrium equation has ins and outs and equilibrium is maintained only if ins more or less equal the outs should be obvious to anybody with an average or above intellect.

Mass balance is the basis for how we quantify how water flows in the environment. But reducing it to merely "ins an outs" is a dangerous reductionism. Any realistic system has internal "storage" that introduce lag between said in and out (and often attenuating the former). On the long term, the volumes do equal out. On the shorter term, however, the out can be dramatically less than the in.

 

[Denver]

Yes, and comes with it's own challenges, primarily energy requirements and what to do with the resulting brine. Surmountable challenges, but definitely non-trivial.

Well, I believe it's more practical than living without water. Solar panels have become significantly more affordable in recent years, and there are also numerous vacant, deserted areas that could accommodate enormous desalination plants. With the advantage of economies of scale, implementing such large-scale solar-powered desalination facilities could further enhance the cost-effectiveness of this solution.

 

[Endymio]

Skimping over the papers you've linked, neither address this [comparison] ...

Yes they do. Both found that artificial reservoirs increase local precipitation -- except in very humid subtropical areas (where evaporation from these reservoirs is naturally very low anyway, and water shortages aren't typically an issue).

And do read the entire sentence. It continues: "and the generation-weighted average WCF by the U.S. generation mix in 2015 is estimated at 2.18 L/kWh."

Thank you for proving my point. The intensity from thermoelectric sources is only 1.25 -- but even though hydro constitutes only 6.5% of the mix, it nearly doubles the overall intensity to 2.18. QED.

Any realistic system has internal "storage" that introduce lag between said in and out (and often attenuating the former). On the long term, the volumes do equal out.

Yes, and what is that average "lag time" in the atmosphere. It's roughly 9 days:

JetStream Max: What a Cycle | National Oceanic and Atmospheric Administration (noaa.gov)

If you model such a situation mathematically, you see this: if an artificial reservoir is created, evaporation from it will lower total surface freshwater for a 9 day period, until increased precipitation catches up to the steady-state solution.

It looks like the notion of order eludes you. You said that the dams are created for other purposes first. That is false, the fact that they use huge investments for multiple purposes doesn't change that they are built for hydroelectric power first.

You are (intentionally?) misquoting both me and your own source. I stated that most dams would exist regardless of hydroelectric power generation, and the mere fact you found the word "hydroelectric" in your link doesn't mean the primary purpose of this project was electricity generation, nor -- even if it were -- that the dam itself wouldn't exist sans the power plant.

My primary disagreement with Endymio's arguments is on water cycle. I may be misinterpreting, but they seem to be saying that it doesn't matter how much water we use, because it all comes back eventually. The latter is entirely true. However you can use, and in many places we are using, the accessible fresh water faster than it's being replenished.

Of everyone here, you alone have analyzed the situation correctly. However, my point is slightly more nuanced. When you flush a gallon of water down your toilet, it eventually comes back ... but it doesn't increase your overall freshwater budget whatsoever: total precipitation doesn't change. But when you evaporate a gallon of water in a cooling tower, most of that returns in the form of additional precipitation. Your total freshwater budget has thus increases.

 

[Shihab]

Yes they do. Both found that artificial reservoirs increase local precipitation -- except in very humid subtropical areas (where evaporation from these reservoirs is naturally very low anyway, and water shortages aren't typically an issue).

Increase in local precipitation =/= most reservoir evaporation precipitates locally.
"Volumetric comparison"

Thank you for proving my point. The intensity from thermoelectric sources is only 1.25 -- but even though hydro constitutes only 6.5% of the mix, it nearly doubles the overall intensity to 2.18. QED.

This comment is meaningless.
A weighted average would not omit a term just because you don't like it. It computes its contribution based on its relevance, quantified in the titular "weight." If you want hydro's contribution to be zero or have no effect on the overall intensity, you'd have to physically shutdown all hydroelectric plants.
The math is sound. Your statement that the study's methodology is flawed is baseless.

Yes, and what is that average "lag time" in the atmosphere. It's roughly 9 days:

JetStream Max: What a Cycle | National Oceanic and Atmospheric Administration (noaa.gov)

Ironically, this is where your objection to averages does apply. Global precipitation averages are skewed by oceans, which have both high magnitude (lower lag) and weight (area, precipitation volume).

If you model such a situation mathematically, you see this: if an artificial reservoir is created, evaporation from it will lower total surface freshwater for a 9 day period, until increased precipitation catches up to the steady-state solution.

Skipping over the limitations of climatologic models, the second part of the statement makes assumes a closed or semi-closed, local hydrological cycle, which is obviously impossible, because for this to happen, you must have -at the very least- precipitation occuring upstream within the same watershed, the runoff coefficient needs to be a perfect one, and stream network must exhibit no routing.
The former may happen (notwithstanding my objections about volumes), but the latter two do not exist in the real world.

 

[Endymio]

A weighted average would not omit a term just because you don't like it. It computes its contribution based on its relevance, quantified in the titular "weight."...

I'm not sure why you're having so much trouble understanding the math here. Let's try a different way. You claimed the contribution from hydropower was "insignificant". But the non-hydro (thermoelectric) intensity factor is only 1.25. With hydro, it nearly doubles, to 2.18. The flawed hydroelectric figures very significantly affect the final result.

Increase in local precipitation =/= most reservoir evaporation precipitates locally.

Still missing the point. When you're speaking of a global issue, it doesn't matter where it precipitates. All of it precipitates **somewhere**.

Furthermore, you're attempting to move the goalposts with that response. Your original claim was that artificial reservoirs "don't increase precipitation". Multiple studies confirm they do.

Global precipitation averages are skewed by oceans, which have both high magnitude (lower lag) and weight (area, precipitation volume).

True, but irrelevant. The global average is nine days. For the lag time to be significant in exacerbating a global problem, the latency (lag time) would have to increase to many years, if not decades. It's a quite simple differential equation: once the latency period has passed, the steady-state solution dominates.

 

[Shihab]

I'm not sure why you're having so much trouble understanding the math here. Let's try a different way. You claimed the contribution from hydropower was "insignificant". But the non-hydro (thermoelectric) intensity factor is only 1.25. With hydro, it nearly doubles, to 2.18. The flawed hydroelectric figures very significantly affect the final result.

Glossing over the fact that I never called it "insignificant." You're the one having trouble with math here, my friend. Spinning numbers post aggregation serves little. One could use your same logic, put hydro in the denominator and say 2.18 is only 13% of 16.8, which is equally meaningless. To avoid this mess, we rely on the aforementioned weighted averages to give each term a fair representation, as the [second] study author's did.

I also notice that now you're saying the hydroelectric figures themselves are flawed.

Still missing the point. When you're speaking of a global issue, it doesn't matter where it precipitates. All of it precipitates **somewhere**.

Furthermore, you're attempting to move the goalposts with that response. Your original claim was that artificial reservoirs "don't increase precipitation". Multiple studies confirm they do.

No, that specific point was on a local issue. I used the term locally, you claimed the precipitation happens nearby to the reservoir, and the studies you cited were local in scope, or as you yourselves pointed out, "the mesoscale".
I used "don't cause [by themselves]" not "don't increase." But ok. I'm not going to dwell too much on the difference and yield that I used the wrong phrasing here.

That said, the actual goal post here was you stating that "most precipitation falls near where it occurs." Which I did point out to be a volumetric comparison. i.e. volume x evaporated, volume y precipitated, ratio between the two is z.
The multiple study you cited did not confirm this.

True, but irrelevant. The global average is nine days. For the lag time to be significant in exacerbating a global problem, the latency (lag time) would have to increase to many years, if not decades. It's a quite simple differential equation: once the latency period has passed, the steady-state solution dominates.

Again with the jumping between local and global views.

But no. The local system will never reach a steady state, even with your underestimated atmospheric lag, because:

the statement makes assumes a closed or semi-closed, local hydrological cycle, which is obviously impossible, because for this to happen, you must have -at the very least- precipitation occuring upstream within the same watershed, the runoff coefficient needs to be a perfect one, and stream network must exhibit no routing.

Disregarding the plethora of climatologic and anthropogenic factors that would also affect a real world system.

 

[Endymio]

Glossing over the fact that I never called it "insignificant."

Your exact quote was "Hydro ... doesn't have much effect on the overall consumption figure." The reality is hydro nearly doubles the overall water consumption figure.

I also notice that now you're saying the hydroelectric figures themselves are flawed.

Err, I've been saying that since the beginning. That's the entire point. Generation of hydroelectric power consumes *zero* water. Even if one ignores the fact that evaporation generates additional rainfall, the fact remains that those large artificial reservoirs aren't created to generate power: they're used to capture excess water in periods of high precipitation. Without the reservoir, that water would simply flow directly back into ocean. Instead -- the reservoir contains it, where it can be disbursed in more arid periods. A small portion evaporates, yes -- but without the dam, ALL the water would simply be wasted.

This explains why there are literally hundreds of thousands of dams and reservoirs that do not generate power. They mitigate flooding, aid in river navigation, and increase the overall supply of water for the region. And even the dams which generate hydropower don't consume water during generation -- they could, in fact, generate that power directly without the reservoir at all (and a few do just this.)

Disregarding the plethora of climatologic and anthropogenic factors that would also affect a real world system.

Name one.

 

[Shrek]

"Each Bitcoin transaction uses 4,200 gallons of water"


A car engine uses how many gallons of water per minute for cooling... so in the lifetime of a car, how many gallons have been used?

One must be careful with such calculations.

 

[Shihab]

Your exact quote was "Hydro ... doesn't have much effect on the overall consumption figure." The reality is hydro nearly doubles the overall water consumption figure.

The overall intensity did not exist prior to inclusion of hydro and can't be defined without it. But if we're doing this weird analysis on the aggregate, I'd stick to using the delta from each extreme, avoiding cherry-picking of denominators to suite our agenda (which I've already demonstrated can be used either way). Or, graphically:

For comparison, the arithmetic mean would be 9.02. But since whoever wrote that paper knows what they are doing, they used weighted each term to get a much less 2.18 figure due to hydro having less contribution to generation, ergo less say on what the average is. But it still has some say that, again, we cannot disregard just because we don't like it.

Generation of hydroelectric power consumes *zero* water. Even if one ignores the fact that evaporation generates additional rainfall, the fact remains that those large artificial reservoirs aren't created to generate power: they're used to capture excess water in periods of high precipitation. Without the reservoir, that water would simply flow directly back into ocean. Instead -- the reservoir contains it, where it can be disbursed in more arid periods. A small portion evaporates, yes -- but without the dam, ALL the water would simply be wasted.

Surface water abstraction does not require reservoirs.
And honestly, your whole argument is just absurd. Damming the river is an action where you trade evaporation (amongst other things) for something. Power, irrigation, flood control, a combination thereof, whatever. And since inflow and yields are limited, we are limited in the number of we uses we can pay for. Build a dam for power, you lose evaporation that could be lost in a reservoir for irrigation instead.
We can optimize our operation to reduce loss, but it will never be zero. Water uses have been and will always be in competition.

It has been pointed out that the study (including the second one for the US) are only concerned with evaporation due to power generation. Distinction is clearly made between multi-purpose dams and those strictly used for power generation. And no, this isn't just a disclaimer. From the full text of the Lee et al study:
The 16.8 figure is actually a composite that is lower than intensity for strictly hydro-electric reservoirs (which was estimated 21.4).

Name one.

Seasonal, daily and hourly changes in temperature, humidity, wind, etc.
[Short-term] temporal/spatial variability in precipitation upstream.
[Short term] Land cover/land use changes.
Variability in abstraction from the reservoir/watershed.
Operational rules of the reservoir in-question and of upstream reservoirs if applicable.
That one variable you forgot to change from float to double.
Et cetera, et cetera...

 

[Endymio]

Hydro increased the overall intensity by zero. Because the overall intensity did not exist prior to inclusion of hydro and can't be defined without it.

Err, what? The thermoelectric intensity is 1.25. If there were no hydroelectric contribution, the overall intensity would be the thermoelectric term (actually, slightly lower, due to wind/solar/etc). Claiming that a non-hydroelectric intensity "can't be defined" is, quite frankly, absurd. You spend money on food each month, but your non-food budget certainly has a clear definition.

For comparison, the arithmetic mean would be 9.02. But since however wrote that paper knows what they are doing, they used weighted each term to get a much less 2.18 figure

Of course. Each term is weighted according to its power generation contribution. And because of that weighting, hydro - despite being a small contributor to total generation -- now becomes a very large contributor to calculated water consumption. This isn't rocket science.

Surface water abstraction does not require reservoirs.

It does when there's no water to abstract. Why do you think dams were built in the days before hydroelectric power? With no dam, sometimes there's far too much water in the river, and sometimes far too little. The reservoir allows you to "bank" the water in times of plenty, and use it when there's not enough.

Distinction is clearly made between multi-purpose dams and those strictly used for power generation. And no, this isn't just a disclaimer. From the full text of the Lee et al study:

Multiple errors. From Water consumption from hydroelectricity in the United States - ScienceDirect

"While it is clear that water is being “used” for hydroelectricity, that use is qualitatively different from water use in other major energy systems...There is currently no accepted methodology for allocating impacts to multiple reservoir purposes; Part of the issue with reservoir-based allocation is that a multipurpose dam's products are not typically discrete, well-defined outputs: “coproducts” to which environmental impacts are assigned are often highly subjective .... Net evaporation reflects the fact that landcover evapotranspires water before inundation by a reservoir, and the evaporation associated with the open water surface of the reservoir might be higher or lower than the original evapotranspiration. Depending on transpiration rates of the original vegetation, then, net evaporation can be positive or negative. While gross evaporation from the reservoir surface is important for analyses like regional water balances, the net evaporation—that is, the change induced by inundation—more accurately describes human appropriation of water for dam-related uses."

The errors in Lee's study:
(1) net evaporation is *always* less than the gross evaporation calculated; the creation of a reservoir can in some cases actually decrease net evaporation.
(2) there is no objective methodology to apportion the multiple purposes of a dam, and whether the dam would still exist without one of those purposes.
(3) the assumption that evaporated water just mystically "vanishes" off the planet, rather than adding (some or all) of it back to the precipitation budget.
(4) Artificial reservoirs exist to capture excess water and prevent it from going to waste. They add to the water budget, not subtract.

And, most of all:
(5) Hydroelectric generation consumes no water because it doesn't require a reservoir. If one truly wished to build a "power-generation" only hydro project, it can easily be done-- and in fact, IS done. (see the so-called ROR hydro projects). Even when the dam has hydroelectric as one of its purposes, the reservoir behind the dam does not.

 

[Shihab]

Of course. Each term is weighted according to its power generation contribution. And because of that weighting, hydro - despite being a small contributor to total generation -- now becomes a very large contributor to calculated water consumption. This isn't rocket science.

I agree, it isn't rocket science. We've been doing analyses like this for decades and it has been working well for us.
I'm frankly tired of going over the same point over and over. You can either trust that this is the correct way, or don't.

It does when there's no water to abstract. Why do you think dams were built in the days before hydroelectric power? With no dam, sometimes there's far too much water in the river, and sometimes far too little. The reservoir allows you to "bank" the water in times of plenty, and use it when there's not enough.

I could go on about the differences between perennial and ephemeral streams, intake design, river restoration, and whatnot. But as I said, this discussion has gotten tiresome.

 

[Bones]

I agree, it isn't rocket science. We've been doing analyses like this for decades and it has been working well for us.
I'm frankly tired of going over the same point over and over. You can either trust that this is the correct way, or don't.


I could go on about the differences between perennial and ephemeral streams, intake design, river restoration, and whatnot. But as I said, this discussion has gotten tiresome.

I agree - Water will keep flowing downhill no matter what you do or use it for and that's something we'll never be able to change.
BItcoin mining useage (Or not) won't change that either.

 

[the54thvoid]

If you prefer a more scholarly viewpoint, there are numerous resources to confirm my statement, such as: Investigating the mesoscale impact of artificial reservoirs on frequency of rain during growing season - Degu - 2012 - Water Resources Research. Or The influence of large dams on surrounding climate and precipitation patterns - Degu - 2011 - Geophysical Research Letters. Both of which found small, but statistically significant increases in local precipitation due to artificial reservoirs.

I read the research:

In summary, our study reveals that it is easier to establish a physically intuitive connection between large dams and downwind frequency of rain, but it is much more difficult to demonstrate this connection consistently for all the downwind stations in the mesoscale without the use of additional geophysical data

Physically intuitive connection implies a reasoned hunch (which is where theories begin until they gain proof). Without more data, they literally say, they cannot consistently demonstrate their theory consistently. It doesn't mean they're wrong, but it isn't as you claim, confirmed.

Edit - corrected by Shihab.

 

[Shihab]

the topic isn't about damns.

I beg to differ.

 

[the54thvoid]

I beg to differ.

I removed my comment, however, the topic has been derailed from the OG OP. Deep dive discussions about precipitations and usage of stored water has moved on in this thread to have little to do with the premise in post #1.

It's a tangent to this discussion as well, but AI is the new beast on the horizon for power usage and cooling requirements. Using BTC as a target helps reduce focus on other problems. Perhaps we should be more concerned with improving efficiencies in the calculations required. Then again, all that would manage is moar calculations using the same energy envelope.

 

[Shihab]

I removed my comment, however, the topic has been derailed from the OG OP. Deep dive discussions about precipitations and usage of stored water has moved on in this thread to have little to do with the premise in post #1.

It's a tangent to this discussion as well, but AI is the new beast on the horizon for power usage and cooling requirements. Using BTC as a target helps reduce focus on other problems. Perhaps we should be more concerned with improving efficiencies in the calculations required. Then again, all that would manage is moar calculations using the same energy envelope.

I don't disagree.
That was a joke.

 

[the54thvoid]

I don't disagree.
That was a joke.

I see... humour circuits were fried this morning. Oops.

 

[Endymio]

.We've been doing analyses like this for decades and it has been working well ... You can either trust that this is the correct way, or don't.

Congratulations on the very apotheosis of an appeal-to-authority logical fallacy.

Unfortunately, it hasn't been "working well". Misguided beliefs about energy policy took Germany from the cheapest electricity in Europe to one of the most expensive -- on top of the €500B or so in subsidies -- and raised the spectre of nationwide blackouts as well. It's no longer academic when poor people are struggling to heat their homes in the depths of winter.

 

[80-watt Hamster]

Congratulations on the very apotheosis of an appeal-to-authority logical fallacy.

Unfortunately, it hasn't been "working well". Misguided beliefs about energy policy took Germany from the cheapest electricity in Europe to one of the most expensive -- on top of the €500B or so in subsidies -- and raised the spectre of nationwide blackouts as well. It's no longer academic when poor people are struggling to heat their homes in the depths of winter.

Wasn't the discussion models, not policy?

 

[Noci]

With the original post of this thread in mind, refering to an article of Tom's Hardware and all the comments, commotion, including deviations made here up to now, isn't it clear that despite it is crypto currency or whatever, the (ever expanding) world population is using way too much natural resources per individual (me included) with the obvious countries/regions of a high luxery standard lifestyle as leading example!
For the majority of the world population at this moment it most likely will not apply, but it is human nature to see why the grass of the neighbours is greener and to want to have the same. Ticking timebomb if they can adapt the western lifestyle (consumption wise), mother nature will not be happy.

I personally think I'm too simple to come up with a solution as these matters are waaay too complex, but am convinced it is about time people start realising that there needs to be a future for the generations to come, without making up excuses for the present behaviour and depleting global resources as if there is no tomorrow.

that's enough politics today on a tech-site for me .

Like I like to say: Common sence is not so common.
Let's go back to roasting Bitcoins and miners again

 

[Endymio]

Wasn't the discussion models, not policy?

Models don't exist in a vacuum; policy is being based upon them. And when bad models claim that a clean, cheap, abundant source of energy like hydropower is "bad for the environment", people suffer in result.

The (ever expanding) world population is using way too much natural resources per individual... Ticking timebomb i

In the heyday of the 1960s ZPG (zero population growth) mania, when most pundits were predicting we'd all be starving to death long before the year 2000, a research study showed that simply extending modern farming methods to the Third World would allow enough food production to feed a world population of some 15 billion. That was a half-century ago: we can do much better today.

Regarding metals, minerals, and other natural resources: we're current using less than one ten millionth of what's available in just the earth's upper crust -- and none of the vastly larger supply available to us in the near solar system. And as for the simple matter of physical space, if we built every family on earth a two-story 3500 sq. ft house (that's 325 m sq to you Europeans), we could fit the entire population of Earth into the state of Texas, and leave the rest of the globe depopulated. Switch to 50-story high-rises and we could fit the world population into just one county.

All the way back in 1798, Dr. Malthus convinced a huge number of people that a world population of 1 billion was utterly unobtainable. But the truth is, we haven't even begun to tap the resources available to us.

 

[Shrek]

You covered food, mineral resources, living space... but left out energy.

 

[Endymio]

You covered food, mineral resources, living space... but left out energy.

There is more than enough uranium and thorium on earth to power society for the next 100,000 years -- even if one ignores the 173,000,000,000 megawatts of solar energy continually striking the earth's surface.

I won't even delve into space-based energy schemes, which are far larger in both scope and ultimate capacity.

 

[80-watt Hamster]

Models don't exist in a vacuum; policy is being based upon them. And when bad models claim that a clean, cheap, abundant source of energy like hydropower is "bad for the environment", people suffer in result.


In the heyday of the 1960s ZPG (zero population growth) mania, when most pundits were predicting we'd all be starving to death long before the year 2000, a research study showed that simply extending modern farming methods to the Third World would allow enough food production to feed a world population of some 15 billion. That was a half-century ago: we can do much better today.

Regarding metals, minerals, and other natural resources: we're current using less than one ten millionth of what's available in just the earth's upper crust -- and none of the vastly larger supply available to us in the near solar system. And as for the simple matter of physical space, if we built every family on earth a two-story 3500 sq. ft house (that's 325 m sq to you Europeans), we could fit the entire population of Earth into the state of Texas, and leave the rest of the globe depopulated. Switch to 50-story high-rises and we could fit the world population into just one county.

All the way back in 1798, Dr. Malthus convinced a huge number of people that a world population of 1 billion was utterly unobtainable. But the truth is, we haven't even begun to tap the resources available to us.

Thing is, we can't harvest every resource available, arguably much more than we already are, and expect to have a livable ecosystem left to us. First world living standards and farming methods are both energy- and water- intensive. We're already stressing our water supply, and energy production is a continual challenge. Now you're pulling in space mining? You've made some good points in this discussion and caused me to re-examine some of my assumptions, but you're starting to lose me again.

 

[R-T-B]

The topic. You guys have completely lost it.