[HN Gopher] How Sustainable Is a Solar Powered Website?
___________________________________________________________________
How Sustainable Is a Solar Powered Website?
Author : tshannon
Score : 131 points
Date : 2020-01-29 18:26 UTC (4 hours ago)
(HTM) web link (www.lowtechmagazine.com)
(TXT) w3m dump (www.lowtechmagazine.com)
| maelito wrote:
| > However, we're comparing apples to oranges. We have calculated
| our emissions based on the embodied energy of our installation.
| When the carbon intensity of the Spanish power grid is measured,
| the embodied energy of the renewable power infrastructure is
| taken to be zero. If we calculated our carbon intensity in the
| same way, of course it would be zero, too.
|
| I don't get it. The carbon intensity of the national grid should
| result from a life-cycle analysis, so all emissions should be
| included in the figure. As far as I know, apples and apples are
| compared, and the home-made version is worse.
| alex_young wrote:
| Even with the additional upfront expense, lithium batteries would
| make this setup much more efficient due to the larger allowed
| cycles and would also reduce the environmental impact due to the
| low impact nature of lithium extraction.
| ip26 wrote:
| Lead acid batteries are eminently recyclable. Something like
| 99% of the lead in a new car battery is from old recycled car
| batteries.
| alex_young wrote:
| That's interesting, I couldn't find any reference to that
| statistic. I've seen estimates in the range of 60-80%
| recycled content for new lead batteries in the US, but that
| data seems pretty shaky.
|
| I have seen statistics around a recycling rate of 99% or
| higher in the US, but also that much of that is done in
| Mexico or other places with very weak environmental and
| occupational regulations.
|
| In any case, lead poisoning is a very serious problem which
| is exacerbated by lead recycling and production.
| bmgxyz wrote:
| It may be worth repeating what the article already states: this
| project is based in Barcelona, where there is considerable
| sunlight. Other locations may be unsuitable for this sort of
| thing. I do like the idea, though, and its implementation is
| impressive.
| kragen wrote:
| It's an interesting exercise. In some ways it's similar to what
| we were doing at Satellogic: a Satellogic satellite is solar-
| powered, runs on batteries, and contains computers running Linux.
| (All of that is public; I'm not revealing anything unpublished
| here.)
|
| They seem to be running on a Raspberry Pi that uses two watts, so
| they can run Linux. But a website wouldn't have to run Linux.
| Contiki includes a webserver and can run on an STM32F103. (I'm
| not sure if the Contiki webserver fits on an STM32F103, though;
| Contiki is pretty customizable.) They say they have 865,000
| yearly visitors, but unfortunately don't explain how many hits
| that is; if we assume it's 1000 hits per visitor, that's 865
| million hits a year, which is 27 hits a second, in the ballpark
| of what you could do on a 486. So it ought to be within the
| capacity of a 72MHz 32-bit STM32F103, which uses 50 mA going full
| tilt -- 165 mW if you're running on 3.3 volts. That's better than
| an order of magnitude less power.
|
| This is probably an interesting experiment to do for resiliency
| purposes, but I don't think it makes a lot of sense for reducing
| resource usage in this case. If we assume "Kris De Decker" is the
| name of a human body that dedicates most of its time to writing
| this magazine, well, that body dissipates about 100 watts. You
| could run the magazine on 102 watts by using a 2-watt webserver,
| or 100.17 watts by using a 165 milliwatt webserver. But if they
| eat beef once a week, well, beef wastes about 96% of its energy
| input, converting it to cow poop instead of food; that's 4.8
| watts of beef produced from 119 watts of soybeans and corn. By
| replacing one of those beef meals per year with a vegetarian meal
| -- eating beef 51 times a year instead of 52 -- they could reduce
| their energy consumption by more than the entire web server power
| budget.
|
| Or, to look at it another way, eating beef once a year uses as
| much power as the web server: 72 MJ/year, 2.3 W.
|
| (I'm ignoring the embodied-energy calculation because the article
| shows that it's small compared to the ongoing power use.)
|
| Average marketed energy consumption in the rich world is about 10
| kilowatts per person, although typically that figure doesn't
| include things like corn and beef. Interestingly, in another
| article https://www.lowtechmagazine.com/2016/05/how-to-go-off-
| grid-i... the author explains that their laptop uses 20 watts of
| power, and their external monitor uses 16.5 watts, together 18
| times the power used by the web server. If they could manage to
| do their writing with a USB keyboard plugged into an Android
| cellphone with an OTG cable, they could probably reduce that to 3
| watts, a reduction of 11 times the web server's entire power
| (although maybe they only write 8 hours a day, so maybe it's only
| 4 times.) If they could use an incrementally updated e-ink
| screen, an option I explored in some detail in Dercuano, they
| could use another order of magnitude less still.
|
| I feel like _sustainability_ is a bigger question than resource
| use, though. I can 't sustain the laptop I'm writing this on
| because it contains parts I don't know how to fix, even if I
| could supply it all the energy it needs with like a bicycle
| generator or something. In fact, nobody in my country knows how
| to build a laptop like this; a lot of the knowhow only exists in
| China, and other parts only exist in Korea. Exploiting its CPU
| backdoors requires knowledge that is presumably only available in
| certain companies in the US. These seem like much bigger
| sustainability concerns to me than the really quite minimal power
| usage of the machine, which is a tiny fraction of the power usage
| of, for example, a candle ([?]80 watts).
| saltcured wrote:
| Also, sustainability of a web server doesn't mean that much if
| you don't consider the net impact in the world. It seems to me
| that you could have a web server require substantially more
| power and still be a net benefit if it actually influences many
| users to consume less in their daily lives.
|
| What is the marginal cost of the web traffic it creates and
| replaces? Would tuning the software and data payloads be more
| impactful than worrying about the server wattage?
|
| What is the marginal cost of other user activities which it
| influences? Not just the website operator, but the user
| behaviors happening as a result of their relationship with the
| service? Do they stop using other less efficient services or
| just increase their overall footprint? Could it reduce their
| consumption of energy and material goods? Change their diet or
| travel habits...?
| Polylactic_acid wrote:
| The posts on low tech magazine are interesting but I feel that
| the solar power idea doesn't make much sense. Why are we
| running an entire OS and device for a single static site? This
| could easily sit on a data center and use virtually no power
| and actually no power while its not being requested unlike a
| rpi that has to sit online constantly waiting for requests.
| cjnicholls wrote:
| Previous Thread: https://news.ycombinator.com/item?id=20038619
| dang wrote:
| Also https://news.ycombinator.com/item?id=19407847,
|
| and from 2018: https://news.ycombinator.com/item?id=18075143
| kome wrote:
| Better link to the same article:
| https://solar.lowtechmagazine.com/2020/01/how-sustainable-is...
|
| (it's on the solar powered website itself)
| SeanFerree wrote:
| Enjoyed this article!
| markovbot wrote:
| >The owner of this website (www.lowtechmagazine.com) has banned
| your IP address ([redacted])
|
| Anyone else seeing this? Looks like they allow me to access it
| via https://solar.lowtechmagazine.com/2020/01/how-sustainable-
| is..., but if they actually banned my IP specifically I don't
| really want to violate their wishes, I just wonder why I'm banned
| :/
| frabert wrote:
| Seeing as how their website is run from a low-power device,
| maybe your IP (range?) was submitting too many requests and
| they decided to ban it.
| m_coder wrote:
| >>More likely is that we eventually switch to a more poetic
| small-scale compressed air energy storage system (CAES).
|
| Please do this!! I want to see that article on CAES actually
| worked out in real life not just theory with no howto steps .
| alacombe wrote:
| City-wide application are discussed regularly here...
|
| https://news.ycombinator.com/item?id=19442938
| https://news.ycombinator.com/item?id=19782760
|
| Also online.. https://www.lowtechmagazine.com/2018/05/history-
| and-future-o...
|
| Down the line, problems are efficiency and all the downside of
| working with gases.
| m_coder wrote:
| Yes, I did read those articles and it has me very interested.
| What I would be more interested in is some sort of applied
| DIY situation. Something I could cobble together myself and
| it would have the potential to get the efficiency that is
| discussed in lowtech mag. It seems to me that with the sorts
| of articles they write, I would be able to follow along on a
| small scale if I wanted. In particular, how do you make a
| compressor going one way and a generator going the other?
| agentultra wrote:
| I wonder how much more efficient this would be if the content was
| distributed on a p2p network?
|
| I would love to get into distributed web tech. I'm not sure how
| much of a market there is for it though.
|
| The benefit of being able to have these scuttlebutt networks of
| low-power, efficient devices is a lower-overall carbon footprint
| for the common case of serving low-fidelity content like web
| pages and small applications. As well as the network and content
| being resilient to local changes in climate events (flash floods,
| fires, etc). And possibly bringing access to more areas where
| network connectivity is slow, expensive and unreliable.
| bmgxyz wrote:
| There was a project I stumbled upon over a year ago that
| implemented a P2P Web, but I can't seem to dig it up now. There
| was a client that mediated the connection between your machine
| and the network, and you'd just browse the web normally by
| pointing your browser at localhost:someport. It was kind of
| neat, since everyone who visited a resource could act as the
| server for somebody else, but it looked to me like it was
| pretty much only used by Chinese dissidents. Good for them, I
| say, but not so useful for someone casually looking for a
| better version of the existing Web. I think until technologies
| like this are better than the Web for ordinary use, not just
| hiding from authorities for whatever reason, they'll only find
| use in those areas.
|
| Of course, there's always IPFS, but that project comes with its
| own issues (e.g. modifying content).
| fwip wrote:
| Check out Beaker Browser!
| gibspaulding wrote:
| Were you thinking of i2p? I believe it's a similar project
| that I've always intended to look into, but never actually
| have.
| gwbas1c wrote:
| > I wonder how much more efficient this would be if the content
| was distributed on a p2p network?
|
| This is pure speculation on my part, but probably much less
| efficient. In order to make the p2p network reliable, you'd
| need many more copies floating around. I also suspect that
| "finding" your data is more energy intense compared to basic
| DNS lookups.
| philipkglass wrote:
| The author is drastically overestimating the lifecycle emissions
| and embodied energy of modern solar photovoltaic modules.
|
| The article claims that it takes "3,514 MJ of energy to produce
| one m2 of solar panel."
|
| The source for that assertion is this article from 2017:
|
| "Energy Payback Time of a Solar Photovoltaic PoweredWaste Plastic
| Recyclebot System"
|
| https://www.e-helvetica.nb.admin.ch/api/download/urn%3Anbn%3...
|
| _That_ article cites this article from 2006 as its source for
| energy intensity of solar manufacturing:
|
| "Embodied energy analysis of photovoltaic (PV) system based on
| macro- and micro-level"
|
| https://sci-hub.tw/10.1016/j.enpol.2005.06.018
|
| _That_ publication finds that silicon purification and
| processing accounts for the lion 's share of embodied energy in
| solar PV.
|
| But if you read section 6 of the paper, "Embodied energy of
| silicon purification and processing", you see that _those_
| authors are using material production energy intensity numbers
| from _2004 and 1998._ They are also assuming the use of
| electronic grade silicon for solar manufacturing, and a silicon
| requirement of 12 grams per watt-peak of solar module. Cheaper
| and less energy intensive solar grade silicon has entirely
| replaced electronic grade silicon in PV since the early 2000s.
| Modern solar module silicon use is about 3 grams per watt-peak,
| not 12; see Table 1 in
| https://pubs.rsc.org/en/content/articlehtml/2020/ee/c9ee0245....
|
| What first appears to be a reasonably recent citation for PV
| embodied energy is actually a chain of painfully outdated
| assumptions going all the way back to the 1990s.
| jedberg wrote:
| I feel like they could get almost 100% uptime with a lot less
| effort if they just put a second server on the other side of the
| world.
|
| The antipode of Barcelona (where this is based) is pretty close
| to New Zealand.
|
| If they put a second server there and then used a anycast IP,
| chances are one of the servers would be up at all times with no
| battery at all.
|
| Edit: Changed multicast to anycast because for some reason my
| computer wants to auto-correct it. :(
| kragen wrote:
| That is an excellent idea. With three or four servers they
| could entirely avoid batteries.
|
| I think you mean anycast, not multicast, but a less exotic
| option would be to use DNS failover, or even just round-robin
| DNS with no explicit failover:
| https://webmasters.stackexchange.com/questions/10927/using-m...
| https://www.nber.org/sys-admin/dns-failover.html
| driverdan wrote:
| You wouldn't want to power directly from the panels without a
| battery. It would cause high instability on cloudy days,
| possibly leading to file system corruption.
| kragen wrote:
| The panel voltage is pretty stable until the illuminance
| gets really low (unless you're drawing a lot of current).
| Diodes such as solar cells are roughly constant-voltage
| devices. You can get a pretty long way avoiding filesystem
| corruption by mounting things read-only, but (I've heard)
| some SSDs aren't really read-only even when they're read-
| only, because of read disturb and the attempt to compensate
| for it in the FTL. 10 seconds of 2 W at 3-6 V is about two
| farads, so you might be able to get acceptable stability
| with a supercapacitor in the 1-10 farad range instead of a
| battery.
| lightedman wrote:
| "The panel voltage is pretty stable until the illuminance
| gets really low"
|
| I'd like to see what panels those are, because the ones
| I've built while working as a PV manufacturing tech, both
| mono and poly (roughly 21% efficiency,) will have greatly
| varying voltages with even the tiniest hint of cloud
| cover over one cell, even with the junction box working
| to help separate out sections of the panel to maintain
| better voltages. Typical 60 cell 30-32V panel will drop
| to ~18-20 with just two cells on one 20-cell section of
| the panel covered. Sure this is still enough for the
| paltry voltage this specific server needs, but if they
| used smaller and more affordable panels like those used
| for cell phone chargers or similar size (within about
| 18"x18" form factor,) I can guarantee you those do not
| take to shading or even bad orientation well at all. 45
| degrees off direct-exposure and you could be looking at
| that smaller panel producing a mere 2V or less.
| kragen wrote:
| Is that the MPPT voltage or the open-circuit voltage? I
| was thinking of a near-open-circuit voltage (which is
| what you have if you're powering a 2-watt webserver from
| a 50-watt solar panel), but MPPT will vary a lot more.
| Also, covering 6% of your cells will drop your voltage a
| lot more than covering all your cells 6%.
| lightedman wrote:
| Open circuit. This is one specific behavior we looked out
| for when testing panels before shipping, after the EL
| test, lamination, and junction box installation.
| driverdan wrote:
| That's a reasonable point. So long as the panel's output
| voltage is higher than the controller's minimum required
| input it would be stable.
|
| I still wouldn't want to run a Pi directly off solar. I'd
| want enough warning to shut it down rather than killing
| the power.
| yjftsjthsd-h wrote:
| Could you use a (big) capacitor then? Enough to smooth
| power out, but AFAIK doesn't degrade like batteries.
| jedberg wrote:
| Yeah I meant anycast (fixed above). And it's true, the other
| options would work too, but there would be added latency.
| kragen wrote:
| With DNS failover there is only added latency during the
| time interval between when a server goes down, causing the
| DNS to get updated, and when the dead IP times out
| everywhere, which can easily be a few minutes. If the
| server can anticipate that it is going to go down it can
| remove itself, and then only people using shitty ISPs that
| don't respect the TTL will ever see extra latency.
| jedberg wrote:
| > and then only people using shitty ISPs that don't
| respect the TTL will ever see extra latency.
|
| In my experience running large websites, that's about 10%
| of the internet, if not more.
|
| When I made a DNS change, only about 70% of the traffic
| dropped off in the TTL. The rest took anywhere between a
| few hours and a few weeks (and some never dropped off, we
| had to just let them fail after a while).
| kragen wrote:
| Thanks, I didn't realize it was that large. :'(
|
| Do you think the advent of DoH will improve that
| situation?
| jedberg wrote:
| I don't think so. DoH deals more with streamlining the
| transmission of requests and responses, but I don't
| recall any part of the RFC dealing with TTLs.
|
| You'll still be talking to your local DNS server with its
| own caching rules.
| yjftsjthsd-h wrote:
| I thought part of the big deal with DoH was precisely
| that you _don 't_ use your local DNS server (or more
| importantly, your ISP's DNS server). If DoH _effectively_
| means that more people pull DNS straight from Cloudflare,
| then I would expect the TTL situation to improve.
| dragontamer wrote:
| For more local purposes, solar + wind is a nice complement.
| Wind is strongest at night, while solar is best in the day.
|
| Nuclear usually needs to keep running, and fewer people use
| electricity at night (unless you live in Philippines where it
| is common to only run AC at night to save on electricity).
| tr352 wrote:
| > Wind is strongest at night
|
| This depends on where you are. In many places wind is
| actually strongest during daytime.
| EGreg wrote:
| Also, you can use a refrigerator at night... the cold IS the
| battery.
| falcolas wrote:
| That makes me wonder the viability of using a peltier as
| the pump/sink for a temperature differential battery.
| ozim wrote:
| Peltier eficiency sucks, so not really an option.
| wtracy wrote:
| That assumes that each location receives enough sunlight to
| keep the server operational for at least twelve hours a day,
| which doesn't sound realistic for a setup with no batteries.
| Three servers spaced equidistant around the world might work.
|
| If you're going down that route anyway, you could add redundant
| servers at different latitudes to hedge against cloudy weather.
| jedberg wrote:
| > That assumes that each location receives enough sunlight to
| keep the server operational for at least twelve hours a day
|
| Only one of them needs to be up at a time. By choosing the
| antipode, by definition one of them will be in sun when the
| other is not (weather notwithstanding). The equinox would be
| the hardest day to deal with because they would both be at
| low energy at sunrise/sunset.
|
| So yes, you're right, a third server would probably make it
| work almost 100% of the time.
| bacon_waffle wrote:
| I don't think the equinox is special in this regard - as
| the days at one point get longer, they shorten at the
| antipode.
|
| As a practical matter insolation at dawn/dusk won't be able
| to power much, without a PV array that would be quite
| oversize during the day.
|
| Lots of interesting optimisation problems in this area. But
| at this scale batteries and solar panels come in discrete
| sizes, so it's a bit academic.
| jedberg wrote:
| Ah, I see what you mean. If they are antipodes, then dusk
| and dawn will happen together every day. This is a good
| point. I was thinking there would be more overlap on the
| other days, but you're right, there wouldn't be.
| jandrese wrote:
| Multicast doesn't work on the big-I Internet.
|
| A battery system is almost certainly easier than physical
| servers spread across the globe, even when you account for the
| cost of the battery.
| jedberg wrote:
| I meant anycast (fixed now). But based on this writeup, they
| don't seem to care about how much of their own time it takes,
| only to prove it is possible. It was in that vain that I
| suggest two servers would be better.
| falcolas wrote:
| About $100 in gear ($30 144wh battery, $20 controller, $50 50w
| solar panel) to offset around $2 worth of electricity (9.53kwh *
| 0.17 euro/kwh) per year.
|
| The battery should be replaced about every 5 years, the solar
| panels 25 years, the controller every 10 years.
| ReactiveJelly wrote:
| I see they're still using dithered PNGs instead of JPEGs for
| images.
|
| The first time I saw it (I don't have the numbers handy now) I
| ran some experiments and it seemed clear to me that a JPEG would
| work much better, and if dithered PNGs were really a good option,
| more people would be doing them. This was on photographs, where
| JPEGs are kind of a home-run and PNGs aren't good no matter what
| you do to them.
|
| This time they're doing diagrams, which would probably be best as
| regular PNGs - The dithering requires you compress a pattern
| that's almost noise, and a JPEG would add artifacts without being
| any smaller.
|
| Here's some other thoughts:
|
| - WebP does exist, but of course you have to do some negotiation
| to avoid blank images on browsers that won't decode it.
|
| - The site is behind CloudFlare anyway, so if it's a static site
| with no auth you can probably just put the whole thing on CF /
| AWS / whatever and it won't use more energy in the cloud than
| proxying for your own server already does.
|
| - CloudFlare probably has a button that re-compresses everything
| as WebP for you.
|
| - Economies of scale always apply.
|
| On scale: The transmission losses for the whole US grid is well
| under 10%. If solar is such a great idea, build a solar farm and
| run 1,000,000 websites. Or 1,000 houses. It'll be more efficient
| than putting panels on individual houses or servers. There is no
| power source that gets more efficient when you have a bunch of
| individuals running it instead of a power company. Whether the
| power company is trustworthy is a question of politics, not
| technology.
|
| This always gets to me when I see EV chargers with VAWTs at a
| grocery store. If VAWTS are so great, why isn't the grid building
| them? The grid already has the big wind turbines which are
| presumably more efficient than a VAWT. So why not buy power from
| the grid? Because it's a PR stunt.
|
| In short, I wish they'd be more clear about it being a cool thing
| and not a practical thing. Solar is practical. Wind is practical.
| At scale.
| ctdonath wrote:
| "At scale" has to include several standard deviations of
| insufficient light/wind availability. When batteries deplete,
| you have no power. This gets very expensive when you're backing
| up for cases that won't happen more than one day per year (or
| decade).
| hannob wrote:
| This may sound snarky, but...
|
| I really wonder how helpful such projects are. Making the
| Internet greener is undoubtedly an important goal, but I feel
| this is perpetuating a myth that we're gonna fix the climate
| crisis with small-scale projects from below.
|
| Practically this is doing nothing to provide any relevant fix for
| the problem. What we should be doing is thinking about how we can
| fix the problem at scale, e.g. pressuring large IT companies to
| get real about the green image they like to peddle. (i.e. care
| more about news like this
| https://news.ycombinator.com/item?id=22167858 )
| mpfundstein wrote:
| before you'll be able to run you need to learn to walk u
| know....
|
| at least this shit is inspiring
| rebuilder wrote:
| I think it's a good way of finding and demonstrating the real-
| life gotchas of sustainable energy. For example, I don't think
| most people have a good understanding of the cost-benefit
| calculations that go into how much renewable energy production
| capacity we can build while keeping to co2 emission targets,
| given that new capacity needs to be built with the current
| energy setup. The "embodied energy" aspect of this article
| illustrates that.
| nothal wrote:
| I think that seeing things like this should serve more as a
| point of inspiration, not a full faceted solution.
| LinuxBender wrote:
| One use case I imagine would be for folks that live off-grid,
| but still want to have some home automation. Realistically
| these folks are using large banks of batteries, large solar
| panels and big inverters, but there is no harm in optimizing
| the load for long run time when there are periods of low
| sunlight and wind.
| mc3 wrote:
| For real efficiency we'd need renewable feeding the grid, then
| massive and efficient server racks, with your tiddly website
| running in a docker container on there somewhere, hopefully
| this is on an edge node close to the person viewing the site.
| In other words economies of scale.
|
| The nice thing about that is that you don't have to change the
| tech much, you can still use digital ocean or whatever, but
| they need to get their power from renewable, which in turn
| means their grid needs to.
|
| The not so nice thing is we are not changing fast enough. I
| hope pure price pressure from tech advantages will get us from
| fossils to renewable.
| bacon_waffle wrote:
| One benefit of small projects is that they give people a sense
| of scale, and a better mental framework for thinking about
| energy use. Electrical power is something we don't (usually)
| see or physically interact with, this project gives an idea of
| what a PV panel or battery that can run a tiny computer looks
| and feels like.
| ctdonath wrote:
| To compare, I'm a solar powered user. All summer I work outside
| on a notebook writing apps, powered by several combinations of
| solar panels and matching batteries.
|
| On the whole it works. Excess PV panel capacity charges battery,
| ensuring enough backup to run during unfavorable angle, cloud
| cover, weather, shadows, and night.
|
| Most common issue is re-positioning panels every few hours to
| favorable angles & avoiding shadows.
|
| Greatest concern is prolonged cloud cover, depleting batteries
| after a couple days of insufficient light. The cost of preparing
| backup against "multiple standard deviations" is substantial,
| buying rarely used batteries (and extra panels to charge them in
| reasonable time) - hundreds of $ of gear (2-4x base cost) used
| maybe one day a month. Winter makes this outlier the norm,
| magnified by its own outliers.
|
| Also, one becomes very aware of app power consumption. Found one
| web page (AgileCraft logout page) pulls 30 ways for no good
| reason.
|
| I'm sure solar powered web server would face comparable issues.
| Depleted batteries are a brick wall, waiting for not just light &
| time to recharge, but to run the system ASAP.
| MuffinFlavored wrote:
| Can you link to what panel/battery/supporting hardware/etc. you
| purchased + used?
| ctdonath wrote:
| GoalZero.com : Boulder 100 Briefcase, Nomad 20, Nomad 13, &
| Nomad 7 panels; Yeti 400, Yeti 100, Yeti 100AC, Yeti 50, &
| Guide 10+ batteries. Running a MacBook Pro, MacBook Air,
| iPhones, & iPad Pro.
| Polylactic_acid wrote:
| The extra batteries can be justified because they reduce the
| load over the entire setup so maybe you could get by with half
| the batteries but you would be using the batteries twice as
| much and they would wear out twice as fast.
| clarry wrote:
| > Solar PV power has high embodied energy compared to
| alternatives such as wind, water, or _human power_.
|
| Did they calculate the energy required to construct a human that
| is capable of powering this server?
| agumonkey wrote:
| side note: with potential sub 7nm semiconductor processes, a wide
| amount of sophisticated chips could run on small ~solar (say 1W)
| jandrese wrote:
| You can run a fair bit of web traffic off of something like a
| Raspberry Pi, and you don't need a ton of battery to keep that
| running overnight. Heavy database driven websites probably
| won't be an option, but the bottleneck for static sites would
| likely be the Ethernet interface.
|
| In fact that's pretty much exactly what they did. 168Wh battery
| pack is a small Deep Cycle SLA. A 50w Solar Panel and
| associated charge controllers and the like is like $80 at
| Harbor Freight. The whole thing is quite achievable on a
| budget.
| Polylactic_acid wrote:
| I tried running an rpi on a lead acid battery and a 40w
| panel. It seemed to be running fine for the first 2 weeks but
| then I think it had a few days where it drained the battery
| to 0 which ruined it and then it was turning off every night.
| I'm not sure what to do with the setup now since it seems
| like lead acid is not the way to go but all of the DIY solar
| charge controllers use lead acid.
| jandrese wrote:
| Did you use a deep cycle battery? Letting a standard lead
| acid battery go to 0 is a surefire way to kill it.
| ip26 wrote:
| As is often the case, the most obvious target for optimization
| (the computer, 1-2W) has already hit diminishing returns. Their
| biggest energy hog is the router (10W), which they aren't
| running on solar.
| agumonkey wrote:
| but what's the manufacturing process of router chips ? surely
| a router inner logic is way less than a rpi SoC so it could
| be trimmed down over time through simple smaller features ..
| ?
| Polylactic_acid wrote:
| Home routers are just a general purpose CPU (ARM or MIPS)
| running a trimmed down OS. Thats why you can install
| openWRT on a lot of them and run arbitrary code.
| ip26 wrote:
| IMO the problem is like with cable boxes- forget about the
| manufacturing node, there's just little incentive for the
| router companies to optimize power because few people pay
| attention to it.
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