How much load can be served from 1m² of sunlight

&gt; With an idle load, this particular laptop draws 14W of power with the screen turned off.<p>That&#x27;s an extremely high idle power usage, I also have a laptop with a Ryzen 9 4900HS (the ROG Zephyrus G14, the only laptop with this chip, to my knowledge), and it idles around 9-11W with the screen <i>on</i>. Most of that is actually because of the RTX 2060 that&#x27;s bundled with it, and won&#x27;t turn off in Linux because Nvidia doesn&#x27;t give a shit. I also suspect the author doesn&#x27;t have a lot of power saving tunables enabled.<p>By comparison, another laptop I have with a 4700U (also eight cores) and no discrete GPU idles at 2-3W.<p>EDIT: If this author is reading this, this [0] is a good page to start from, along with powertop. I&#x27;d install and enable TLP, disable boost for efficiency, enable the tunables suggested by powertop, and maybe try nouveau for putting the GPU in the lowest power state.<p>[0] <a href="https:&#x2F;&#x2F;wiki.archlinux.org&#x2F;title&#x2F;Power_management" rel="nofollow">https:&#x2F;&#x2F;wiki.archlinux.org&#x2F;title&#x2F;Power_management</a>

Adding the obligatory &quot;what if M1&quot; comment.<p>Anandtech tested power draw of an M1 Mac Mini and found 4.2W at idle, 26.5W for the average multithreaded workload. 1&#x2F;3rd idle power and the same power draw while running multithreaded benchmarks compared to the laptop serving a single client. Would be interesting to compare.<p><a href="https:&#x2F;&#x2F;www.anandtech.com&#x2F;show&#x2F;16252&#x2F;mac-mini-apple-m1-tested" rel="nofollow">https:&#x2F;&#x2F;www.anandtech.com&#x2F;show&#x2F;16252&#x2F;mac-mini-apple-m1-teste...</a>

Rather than inverting 12V DC to 240V AC and back, you could skip a step and use a laptop car charger, converting 12V DC straight to ~20V DC.

I run my static blog on a Raspberry Pi3B+ Powered by solar [0] and it doesn’t even flinch when it is hit by hacker news.<p>It idles at around 3.1 watts and that power usage includes a step down converter from 12 volt to 5 volt.<p>A bunch of lead acid batteries of various capacities provide backup. Lead acid is a terrible choice because charge times are long, but it is sufficient for now.<p>Just see it as performance art.<p>[0]: <a href="https:&#x2F;&#x2F;louwrentius.com&#x2F;this-blog-is-now-running-on-solar-power.html" rel="nofollow">https:&#x2F;&#x2F;louwrentius.com&#x2F;this-blog-is-now-running-on-solar-po...</a>

I did this 20 years ago and ran the server for about 10 years. I down-scaled the server hardware when I transitioned to solar, but soon discovered that the low-power server just could not keep up with the demand. I upgraded to something in the middle that could handle a decent number of web users while still not using all the solar. I had 1280W of panels (16x80), a 1500W inverter, and three deep-cycle 12V 50AH batteries.<p>The remnants of the system can still be seen here: <a href="http:&#x2F;&#x2F;jsl.com&#x2F;solar" rel="nofollow">http:&#x2F;&#x2F;jsl.com&#x2F;solar</a>

The title is a bit misleading as it&#x27;s specific to the OPs setup (which is quite inefficient).<p>Would have liked to to see numbers of how much power is actually being output by the panel, and a shunt on the battery to see accurate consumption.

You won&#x27;t get 200W from a 200W panel in direct sunlight, but it will still generate some watts at other times, so it should work out.<p>&quot;A 4.6b year old yellow dwarf as a light source&quot; loved that

The armchairs here are all great. If they used a raspberry pi and rewrote their javascript in ARM assembly and reinvented a more power-efficient compression algorithm and solved your favourite problem of serving static pages instead of the problem they actually want to solve, they could maybe get more instructions per watt.<p>But really, I&#x27;m glad that they&#x27;re actually doing it instead of talking about doing it and spending all of their time musing about _what if_ they did this other thing instead. This looks great.

To see another attempt of serving a webpage off of solar power: take a look at <a href="https:&#x2F;&#x2F;solar.lowtechmagazine.com&#x2F;about.html" rel="nofollow">https:&#x2F;&#x2F;solar.lowtechmagazine.com&#x2F;about.html</a> -- it has techniques I find pretty unique for conserving power. All the images are rasterized in order to reduce page size among other things.

Obviously there is infinite room for optimization of this problem, but this was a fun blog post. I’m interested to see where the author goes with the series.

I regularly work outside during summer, powering a MacBook Pro exclusively by sunlight (panel about 1m^2). For a few hours I can get a good 50+ watts, buffering thru a 100Wh battery. Keeping the load typically around 10-15 watts isn&#x27;t hard, so long as paying attention.<p>Of note, I persuaded Atlassian to remove the (rather nice) animated clouds from their &quot;you have been logged out&quot; web page because it pulled 30 watts (even when web page was hidden). Running on solar&#x2F;battery exclusively, that was a problem; kudos to them for acting on it.

The point of the piece is at the bottom:<p>&gt;By increasing our utilization rate, we have increased power efficiency by a factor of 6.<p>&gt;Economies of scale are more important than intuition would suggest for efficiently serving requests

Cool idea, the numbers in this blog post are very much a worst case scenario outside of running the entire process on 1080 GPU or something though

Of course, you can juice this a bit by doing two things: 1) using concentrating photovoltaics with multifunction solar cells to achieve ~30-40% efficiency. (This requires active cooling.) 2) use 2 axis tracking. 3) solar cells on the back of your array. (Bifacial solar arrays do this in an integrated manner but aren’t concentrating.)<p>These three together give you on the order of a factor of 3 greater total energy. (Note: concentrating buys you about 20% greater raw efficiency BUT means capturing diffuse light basically doesn’t happen. Might be better off with a non-concentrating bifacial multijunction panel that is still two axis tracked. Concentrators can still help financially because multijunction solar panels are EXPENSIVE.)<p>Also, if your laptop already has a beefy battery, you don’t need a separate battery. You’ll need a custom MPPT with the right output voltage, but you could hook it straight into your laptop. That saves money (potentially) and a lot of inefficiency.

This is an aburdly bad result, mostly caused by the questionable 14W base power draw, but also due to the questionable choice of gzip compression, which is not exactly on the frontier of compression technology. Even zlib-deflate would decompress twice as fast at the same size ratios, but something like lz4 or snappy would be an order of magnitude less CPU time cost for similar compressed size.<p>The real way to have an energy-efficient service is to amortize away your idle usage and all of these inefficient conversion steps by just hosting your junk on App Engine.

The authors &quot;92%&quot; efficiency calculations will be with the inverter and power supply at high load.<p>When drawing only 20 watts, I expect you&#x27;ll see more like 80% efficiency, and maybe as low as 50%.

I look forward to your next posts in the series!<p>I&#x27;d start by skipping the inverter and using a car USB-C charger instead, then fussing with power settings to drive down the quiescent power of the laptop. Everything after that starts to feel like actual work, like changing the serving software or actively aiming the solar panel.<p>You might be able to find some single board computer with a modern CPU and no graphics silicon whatsoever.

I would encourage anyone interested in this to go plug example size of small pv systems into this calculator for your location:<p><a href="https:&#x2F;&#x2F;pvwatts.nrel.gov&#x2F;" rel="nofollow">https:&#x2F;&#x2F;pvwatts.nrel.gov&#x2F;</a><p>You can use a round number like 1000W, which would be the same as four fairly cheap 250W 60 cell polycrystalline cell pv panels. You will get the cumulative kWh production expected per month.

One question of great relevance is the change in the statistic implied by the article&#x27;s title over the past couple decades, and the projected change in the decades to come. Is this Moore&#x27;s-law-esque? If so, eventually, these concerns will be trivial. Is an asymptote approaching? If so, this metric becomes increasing relevant and crucial.

It would be interesting to set up a server&#x2F;PC that throttled The CPUs&#x2F;GPUs by power use rather than thermal readings. It’s analogous to the burst credit system used on some EC2 instances, but it would be a cool kernel or hardware feature for devices that are completely solar powered.

Is there a name for this effect in an abstract sense? I see it pop up a lot where the gains from scaling are super-linear to the scale itself. Or is it just called &quot;economies of scale&quot;.

What about router&#x2F;modem power draw? Needs to be some sort of connection to the internet to truly function as a website. (Not being connected would mean it&#x27;s a wan site or intranet site)

Are smartphones a good option here in terms of energy use?

The curious brain cell in me would like to know if wget||curl + xargs -P $(nproc) + awk would produce more &quot;efficient&quot; results?

&gt; <i>12v to 240v inverter</i><p>Can someone explain this part of his equation? What’s he doing with 240v? Or maybe he meant 24v for charging the laptop?

Technically, it should be &quot;200 watts&quot;. The losses happen due to all the inversion and conversion (I think... right?)

I think the title is misleading because the load depends on, well, the workload. But it’s a thought provoking idea.

What is the bottleneck is this system?

What if you ditch the OS and code the server on the bare metal?