How Sustainable Is a Solar Powered Website? • Hacker News Board

Re: How Sustainable Is a Solar Powered Website?

#111

Post by admax88q » Thu, Jan 30, 2020, 2:29 PM UTC

belorn wrote: post #106

philipkglass wrote: post #86

Earlier quoted context omitted.

That study is also badly outdated. Under section 5, Life Cycle Inventory Data, it says "The authors have assembled this LCI data set to the best of their knowledge and in their opinion it gives a reliable representation of the crystalline silicon module production technology in Western-Europe in the year 2005/2006 and Balance-of-System components of the year 2006." I would love to see a life cycle assessment using wh…

For an apple to apple comparison we would need to define exactly what is being compared. Should we use the exact PV module that they bought and compare that to the exact power plant that supply energy to their area? We could also compare a hypothetical PV module using the latest models and compare that to the latest models of power plants and energy grids. Depending on incentives and purpose one can choose which fact…

If we are discussing the viability and sustainability of any particular thing we should be using the current industry standard numbers and a reasonable estimate of where the industry is going. There's no sense discussing whether option A is sustainable or not if nobody actually produces option A is outdated and the next decade of installations will use option B.

Re: How Sustainable Is a Solar Powered Website?

#112

Post by chameleon_world » Thu, Jan 30, 2020, 5:37 PM UTC

hannob wrote: post #26

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. p…

You wouldn't have posted this if this project wasn't created. You wouldn't have discussed this with other people. It's hard to fix a big problem when most people don't even understand the problem.

Re: How Sustainable Is a Solar Powered Website?

#113

Post by gwbas1c » Thu, Jan 30, 2020, 6:15 PM UTC

zrm wrote: post #98

gwbas1c wrote: post #15

Earlier quoted context omitted.

> 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.

It's possible to use erasure coding to avoid needing that many more copies. With 75% erasure blocks you can lose any 75% of the nodes hosting the data without compromising availability, and that only requires the equivalent of four copies. Moreover, distributing that number of copies has negligible overhead when data is requested much more often than it's modified, as is normally the case. It's also possible to cache…

> powered on regardless

Bad assumption: Most people use laptops, which aren't "powered on regardless", or mobile devices, where the power consumption of being active on a P2P network will kill the battery.

Re: How Sustainable Is a Solar Powered Website?

#114

Post by agentultra » Thu, Jan 30, 2020, 9:12 PM UTC

gwbas1c wrote: post #113

zrm wrote: post #98

Earlier quoted context omitted.

It's possible to use erasure coding to avoid needing that many more copies. With 75% erasure blocks you can lose any 75% of the nodes hosting the data without compromising availability, and that only requires the equivalent of four copies. Moreover, distributing that number of copies has negligible overhead when data is requested much more often than it's modified, as is normally the case. It's also possible to cache…

> powered on regardless Bad assumption: Most people use laptops, which aren't "powered on regardless", or mobile devices, where the power consumption of being active on a P2P network will kill the battery.

Does it need to be always on though? Scuttlebutt-like gossip networks and caches might be more what I was thinking about. In the ideal case you find the content local to you in one request, cache it, and the solar-powered server is none the wiser.

The network might be slower overall but we're talking about optimizing for lower power consumption so I feel like that would be a lesser priority.

Now I'm starting to wonder if there is a away to simulate the power draw of such a network.

Re: How Sustainable Is a Solar Powered Website?

#115

Post by lowtechmagazine » Thu, Jan 30, 2020, 9:21 PM UTC

maelito wrote: post #102

lowtechmagazine wrote: post #85

Earlier quoted context omitted.

The carbon intensity of the national grid is calculated as follows: carbon emissions of burning coal and gas in power plants (say 600 g/kWh) + carbon emissions of wind turbines, solar panels and the like (0 g/kWh). Embodied energy is not taken into account.

Is it particular to spain ?

No, it's not just Spain. I only looked at European power grids, but their carbon intensity is all calculated in the same way.

Re: How Sustainable Is a Solar Powered Website?

#116

Post by maelito » Thu, Jan 30, 2020, 10:57 PM UTC

lowtechmagazine wrote: post #115

maelito wrote: post #102

Earlier quoted context omitted.

Is it particular to spain ?

No, it's not just Spain. I only looked at European power grids, but their carbon intensity is all calculated in the same way.

I'm pretty sure these numbers are LCAs : https://www.electricitymap.org/?page=country&solar=false&rem...

Hydro, nuclear, wind turbines would all be 0g/kWh if it was only about fuel.

Re: How Sustainable Is a Solar Powered Website?

#117

Post by belorn » Fri, Jan 31, 2020, 10:38 AM UTC

admax88q wrote: post #111

belorn wrote: post #106

Earlier quoted context omitted.

For an apple to apple comparison we would need to define exactly what is being compared. Should we use the exact PV module that they bought and compare that to the exact power plant that supply energy to their area? We could also compare a hypothetical PV module using the latest models and compare that to the latest models of power plants and energy grids. Depending on incentives and purpose one can choose which fact…

If we are discussing the viability and sustainability of any particular thing we should be using the current industry standard numbers and a reasonable estimate of where the industry is going. There's no sense discussing whether option A is sustainable or not if nobody actually produces option A is outdated and the next decade of installations will use option B.

I can see value in both approaches. One is a test of what happens if you go right now and buy a PV module from a nearby store. This has the implication that the module has been in the store for a while and the raw material was mined and collected many years ago. Then you compare it to getting the power from the wall socket, which similar implications that the power plant that generates the power was built many years ago using old technology.

The other approach compare the state of the art PV module vs the state of the art power plant, both being built using the latest mining and construction methods.

The answer of what is more sustainable is going to depend a lot on context. Are we comparing what a person can do right now, or what we should be doing in the future? For powering websites the general answer from the industry is currently to build data centers in depopulated areas in countries with cold climates, near a hydro power plant and with plenty access to cooling water. This is however not a solution that you can apply if the requirement is that the server must be located in Spain.

Re: How Sustainable Is a Solar Powered Website?

#118

Post by falcolas » Fri, Jan 31, 2020, 3:59 PM UTC

lowtechmagazine wrote: post #108

falcolas wrote: post #57

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.

A cost analysis remains to be done. But it's not as bad as it seems: we save $600 per year on hosting services.

Comparing a static site on a Raspberry Pi to a commercially hosted CMS is like comparing an apple to a walnut grove.

Re: How Sustainable Is a Solar Powered Website?

#119

Post by zrm » Fri, Jan 31, 2020, 5:11 PM UTC

gwbas1c wrote: post #113

zrm wrote: post #98

Earlier quoted context omitted.

It's possible to use erasure coding to avoid needing that many more copies. With 75% erasure blocks you can lose any 75% of the nodes hosting the data without compromising availability, and that only requires the equivalent of four copies. Moreover, distributing that number of copies has negligible overhead when data is requested much more often than it's modified, as is normally the case. It's also possible to cache…

> powered on regardless Bad assumption: Most people use laptops, which aren't "powered on regardless", or mobile devices, where the power consumption of being active on a P2P network will kill the battery.

The people using laptops wouldn't leave them on longer than they would be otherwise, you'd just get the data from the one that happens to be on at the time, so they'd be "powered on regardless" for the same period of time they would be otherwise.

Moreover, the average mobile device spends something like eight hours a day (while the owner is asleep) connected to the charger where battery life is irrelevant. So give the network two modes, one where the device participates fully in the network and is a preferred source for data and one where it only registers what it has with another node and is then a provider of last resort for data not otherwise available elsewhere, and operate in one mode or the other depending on whether the device is running on battery.

Notice also that the amortized number of hits over the whole network is one per object per device, i.e. the average number of times a node has to upload each thing it downloads is only once. That doesn't take an insurmountable amount of battery even if you couldn't shift most of the load to the devices that are plugged in.

Re: How Sustainable Is a Solar Powered Website?

#120

Post by kragen » Fri, Jan 31, 2020, 7:51 PM UTC

lowtechmagazine wrote: post #90

philipkglass wrote: post #86

Earlier quoted context omitted.

That study is also badly outdated. Under section 5, Life Cycle Inventory Data, it says "The authors have assembled this LCI data set to the best of their knowledge and in their opinion it gives a reliable representation of the crystalline silicon module production technology in Western-Europe in the year 2005/2006 and Balance-of-System components of the year 2006." I would love to see a life cycle assessment using wh…

The obsolescence of life cycle analyses is a topic in itself, and the lack of accessible data is a problem for anyone who tries to investigate high-tech products. For the solar powered website article, it's the order of magnitude that matters. You say I overestimate the energy use of solar panel production, but in our configuration it corresponds to just 1 liter of oil per year.

You can get a reasonable estimate by taking the wholesale price of the thing you're analyzing, dividing by an average price of electricity for industrial use (like, around US$60/MWh, in the quaint non-SI units traditionally used in the trade), and multiplying that by some fudge factor like 20% to account for the fact that much of the cost of things is due to non-energy inputs like raw materials, skilled labor, and interest. This gives a result correct to within a factor of 3 for the vast majority of goods and services, while using LCA numbers from a quarter century ago did not. In this case the result is 2.3 MJ per watt (peak) of low-cost solar panels using €0.17/Wp from PVXchange and SolarServer. That's almost an order of magnitude lower than the 22 MJ/W you used in the article (assuming 16% efficiency; with 21% efficiency it's 16.7 MJ/W. I'm not sure which one your original number was for.) So I think you may have gotten within an order of magnitude, but only just.

If the numbers you were using were correct, then just the energy input for the solar panels would have cost more than the wholesale price for the modules.