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This website has 81% battery power remaining

solar.lowtechmagazine.com

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Re: This website has 81% battery power remaining

#251

Post by divbzero »

gibspaulding wrote: post #239
varenc wrote: post #235

Earlier quoted context omitted.

Digression: Is it true that every single watt my CPU/server/electronics consume is ultimately turned into heat? To put it another way, does a server under a constant 500W produce the exact same amount of heat as a dumb 500W electric space heater? Excluding things like the tiny amount of energy that gets sent out on CAT5 cables, which I believe still gets turned into heat just elsewhere. I think this is true, but it’s…

In short, yes. Exactly (well minus a few used to spin fans and hard drives). Here's one source from a quick search: https://www.pugetsystems.com/labs/articles/Gaming-PC-vs-Spac... I remember seeing a paper referenced here once explaining why that energy loss is actually necessary, but I don't seem to have it saved anymore.

> I remember seeing a paper referenced here once explaining why that energy loss is actually necessary, but I don't seem to have it saved anymore.

Taking a stab at explaining the energy loss…

When computing you are reducing local entropy (e.g. achieving a certain pattern of electric charges in chips and a certain pattern of pixels on the screen) while still increasing global entropy (the second law of thermodynamic). Heat dissipation from the local system to its surroundings accounts for the difference.

This is analogous to Schrodinger’s description of life where life forms increase the entropy of their surroundings to maintain their own low entropy.

Re: This website has 81% battery power remaining

#252

Post by danans »

culi wrote: post #152
onethought wrote: post #141

Earlier quoted context omitted.

How is PV unfit for recycling? It’s pure silicon, with something like Boron on it. Losslessly recycling might be challenge, but you could definitely reuse all the Silicon and remake another panel. Which toxic elements do you mean? What’s the fire hazard?

While solar cells might be almost pure silicon, the panels themselves use a lot more materials to work. For example, 2% of all global copper production was just for panels 2018. The frames and the cells both use aluminum (the actual most abundant material overall). Silver, the most expensive component, has been pushed from about 400mg per panel in 2007 to about 100mg per panel today.[0] Each solar panel contains abou…

> In 2017, a study found that as much as 62% of the cadmium from cadmium telluride models were leached out at room temperature depending mostly on acidity of the solutions.[3]

From the related article:

"The pieces are cut out from modules of the four major commercial photovoltaic technologies: crystalline and amorphous silicon, cadmium telluride as well as from copper indium gallium diselenide."

So they cut pieces from a sealed module? Seems unsurprising that leaching would occur when you cut pieces of a PV panel and expose it to acidic solution for an extended period. Functional installed solar panels are sealed behind a protective glass panel.

Re: This website has 81% battery power remaining

#253

Post by [deleted] »

varenc wrote: post #235
Smithalicious wrote: post #215

Earlier quoted context omitted.

I believe ICs are limited by how fast you can cool them. All that energy goes into heat eventually, so temperature is going to depend only on total energy / area

Digression: Is it true that every single watt my CPU/server/electronics consume is ultimately turned into heat? To put it another way, does a server under a constant 500W produce the exact same amount of heat as a dumb 500W electric space heater? Excluding things like the tiny amount of energy that gets sent out on CAT5 cables, which I believe still gets turned into heat just elsewhere. I think this is true, but it’s…

[deleted]

Re: This website has 81% battery power remaining

#254

Post by dvt »

elbasti wrote: post #242
dvt wrote: post #39

Small technical nit: I love the dithered images and the retro feel, but their CSS should specify `image-rendering: pixelated` to make sure browsers don't interpolate the pixels.

Wouldn't the correct css for the dithered image be `crisp-edges`? From the specification: > The image must be scaled with an algorithm that preserves contrast and edges in the image, and which does not smooth colors or introduce blur to the image in the process. [...] This value is intended for pixel-art images, such as in browser games.

No, `crisp-edges` allows for algorithms[1] like HQ2X and 2xSaI, which would not work with the dithered images, whereas `pixelated` enforces nearest-neighbor scaling.

[1] https://en.wikipedia.org/wiki/Pixel-art_scaling_algorithms

Re: This website has 81% battery power remaining

#255

Post by nijave »

malwarebytess wrote: post #10

> This was caused by a software upgrade of the Linux kernel, which increased the average power use of the server from 1.19 to 1.49 watts I wonder what change in the linux kernel caused the increased load. Someone out there is responsible for this crime!

Could be a scheduler change. I think the default scheduler doesn't try too hard to be power efficient on the assumption servers/desktops generally aren't optimizing for a single watt or less

On Android, the scheduler can have a decent impact battery life

Re: This website has 81% battery power remaining

#257

Post by LeifCarrotson »

gibspaulding wrote: post #239
varenc wrote: post #235

Earlier quoted context omitted.

Digression: Is it true that every single watt my CPU/server/electronics consume is ultimately turned into heat? To put it another way, does a server under a constant 500W produce the exact same amount of heat as a dumb 500W electric space heater? Excluding things like the tiny amount of energy that gets sent out on CAT5 cables, which I believe still gets turned into heat just elsewhere. I think this is true, but it’s…

In short, yes. Exactly (well minus a few used to spin fans and hard drives). Here's one source from a quick search: https://www.pugetsystems.com/labs/articles/Gaming-PC-vs-Spac... I remember seeing a paper referenced here once explaining why that energy loss is actually necessary, but I don't seem to have it saved anymore.

The spinning fans use energy to move air, a (slightly) viscous fluid, which eventually encounters turbulence and friction and turns its kinetic energy into heat. Similar to discs that use energy to overcome friction in bearings and generate noise, which is a kinetic energy in the form of vibrations that also eventually dissipates into heat.

Re: This website has 81% battery power remaining

#258

Post by rrss »

jcoder wrote: post #211
obblekk wrote: post #168

*Technically*, this is very cool, impressive, and generally an elegant work of art. *Pragmatically*, I see 2 flaws in their thesis (as explained on the about page): >> "The entire network already consumes 10% of global electricity production with traffic doubling roughly every 2 years" I think the implication is electricity consumption will also double roughly every 2 years, but Moore's law actually operates on appro…

I thought Moore’s Law is about the density of components on an IC—what about it suggests a constant energy usage of IC as it gets denser?

This property is called Dennard scaling. It mostly does not apply to the latest few generations due to increasing static power (leakage current).

https://en.m.wikipedia.org/wiki/Dennard_scaling

Re: This website has 81% battery power remaining

#259

Post by soheil »

carlio wrote: post #220
obblekk wrote: post #168

*Technically*, this is very cool, impressive, and generally an elegant work of art. *Pragmatically*, I see 2 flaws in their thesis (as explained on the about page): >> "The entire network already consumes 10% of global electricity production with traffic doubling roughly every 2 years" I think the implication is electricity consumption will also double roughly every 2 years, but Moore's law actually operates on appro…

Significantly, shifting the image calculations from the server to the client means the work is duplicated for every client. While it saves energy for the server, it increases the overall energy consumption required to deliver the content.

Can one client do the work and post back the final version to the server so the server sends that version to all the other clients?

Re: This website has 81% battery power remaining

#260

Post by an_ko »

soheil wrote: post #259
carlio wrote: post #220

Earlier quoted context omitted.

Significantly, shifting the image calculations from the server to the client means the work is duplicated for every client. While it saves energy for the server, it increases the overall energy consumption required to deliver the content.

Can one client do the work and post back the final version to the server so the server sends that version to all the other clients?

Don't trust the client with that, or everybody is getting goatse'd.
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