Tony Walsh has, as others do, some doubts about whether Second Life is sustainable as a business. But he also poses another question that I hadn’t come across before: “Is Second Life sustainable ecologically?”
He quotes Philip Rosedale, the head of Linden Lab, the company behind the virtual world: “We’re running at full power all the time, so we consume an enormous amount of electrical power in co-location facilities [where they house their 4,000 server computers] … We’re running out of power for the square feet of rack space that we’ve got machines in. We can’t for example use [blade] servers right now because they would simply require more electricity than you could get for the floor space they occupy.”
Walsh notes that on average there are between 10,000 and 15,000 avatars in Second Life at any given time, a number that’s growing rapidly. He wonders: “How much power do 15,000 human beings consume daily compared to 15,000 avatars?” Hmm. That’s an interesting question.
So let’s do the math.
If there are on average between 10,000 and 15,000 avatars “living” in Second Life at any point, that means the world has a population of about 12,500. Supporting those 12,500 avatars requires 4,000 servers as well as the 12,500 PCs the avatars’ physical alter egos are using. Conservatively, a PC consumes 120 watts and a server consumes 200 watts. Throw in another 50 watts per server for data-center air conditioning. So, on a daily basis, overall Second Life power consumption equals:
(4,000 x 250 x 24) + (12,500 x 120 x 24) = 60,000,000 watt-hours or 60,000 kilowatt-hours
Per capita, that’s:
60,000 / 12,500 = 4.8 kWh
Which, annualized, gives us 1,752 kWh. So an avatar consumes 1,752 kWh per year. By comparison, the average human, on a worldwide basis, consumes 2,436 kWh per year. So there you have it: an avatar consumes a bit less energy than a real person, though they’re in the same ballpark.
Now, if we limit the comparison to developed countries, where per-capita energy consumption is 7,702 kWh a year, the avatars appear considerably less energy hungry than the humans. But if we look at developing countries, where per-capita consumption is 1,015 kWh, we find that avatars burn through considerably more electricity than people do.
More narrowly still, the average citizen of Brazil consumes 1,884 kWh, which, given the fact that my avatar estimate was rough and conservative, means that your average Second Life avatar consumes about as much electricity as your average Brazilian.
Which means, in turn, that avatars aren’t quite as intangible as they seem. They don’t have bodies, but they do leave footprints.
UPDATE: In a comment on this post, Sun’s Dave Douglas takes the calculations another step, translating electricity consumption into CO2 emissions. (Carbon dioxide, he notes, “is the most prevalent greenhouse gas from the production of electricity.”) He writes: “looking at CO2 production, 1,752 kWH/year per avatar is about 1.17 tons of CO2. That’s the equivalent of driving an SUV around 2,300 miles (or a Prius around 4,000).”
Thanks for the quick feedback, Nick.
I understand, that this is a rough illustration for illustrative purposes, of course. I still think it is misleading, though. What you basically do, is, you calculate the PEAK power consumption of an avatar (= active SL account) and extrapolate this over a year to get a yearly power consumption — comparable to those of a resident in a developing nation.
If you would take the PEAK power consumption of a resident of Germany (the country I happen to live in), this is probably while he is driving a car. He will consume some 5o kW then. If you extrapolate that over a year you get around 438,000 kWh. This is correct math but — thank god — not the real energy footprint of the average German; as he is not driving around all alone 24 hours a day, 365 days a year.
The roughly 1,000,000 avatars active now in Second Life – thank god – never are using peak power all at the same time. They all SHARE the energy consumption of the whole Linden Lab data center and a part of their PCs power consumption over the year. And on average they use less than 75kWh per year.
The opener of your article was the question (posed by Tony Walsh), if Second Life is sustainable as a business. If an avatar really would consume 1,750 kWh per year, this might be a problem business-wise – and environmentally, too. At 75 kWh a year, I doubt that the energy consumption will matter much. I would love it if this level were even lower, of course.
I wonder how much energy was used to write, store, present, and ultimately for me (and everyone else) to comment on this post?
In 2009, 32 nanometer CPUs are supposed to be available. 45 nm CPUs that are just going into service now are much more efficient than the previous generations.
Second life needs to switch to carbon free web hosting. Some web server companies are stepping forward with solutions to reduce the energy use of the Internet. Solar Energy Host (http://www.solarenergyhost.com) for example, is hosting websites using 100% solar energy.
Just wanted you to know this article is still going around. I just found it today. And there are some good links in the comments, like info on green hosting and green webdesign. A follow up, more refined article might be a good idea.
More important than numbers… If an avatar’s comsumption of energy is almost the same as the one of a brazilian citizen, such as me, why are people all over the world spending so much electricity on the virtual world of Second Life while there are real people out there, in the poor areas of Brazil and other developing countries [or in the ones that are in a worse condition] that are still lighting up their houses with candles?
This sort of analysis is entertaining but ultimately pretty silly due to the large number of variables involved. Let me add a few, as if there aren’t enough already. :)
First a minor point: an avatar is the physical representation of a player. The player himself I believe Linden refers to as an “agent.” The two aren’t the same thing. One can change his or her avatar with a single click, but the player or agent remains the same.
Next, a large number of players have more than one account / agent (called alts) and some percentage of the players have more than one of them active in world at a time. Thus one player is controlling two or more (sometimes upward of a dozen) characters from a single computer, complicating the calculation for the energy used by the player’s computer running the client software.
Why would someone run a large number of alts? Well, it varies but it’s not hard at all to find a remote, closed skybox full of sequentially numbered characters just standing around adding to the “traffic” of a parcel for the purpose of getting a higher score on the search engine. This is like “camping” except the parcel owner controls all the agents and thus doesn’t have to pay out Lindens to keep them there.
Speaking of camping, avis (if I may misuse the word) who are sitting for hours in a camping chair don’t use as much power on the client computer as active avis and there are zillions of people camping at any given time. What an insane waste of power and PC cost! Some of these chairs pay less than 10 Lindens an hour (about 4 cents).
But the general point is that a player uses a varying amount of server/client power (and hence electrical power) depending on whether he is moving around actively doing things or just sitting somewhere “away” or “busy.” Another complication for the calculation.
Finally, there is one consideration that dwarfs everything said on the topic so far. One positive thing you can say about SL energy usage is that, so far as I know, not one single SL user is concurrently DRIVING A CAR – at least I hope not!
That’s a fantastic tradeoff wherever it occurs, as vehicles not only consume fuel and emit carbon, but the roads themselves are (mostly) made of oil and require fantastic energy expenditures to maintain.
Just my thoughts on this humorous topic, coming from a transportation scientist and avid SL player. :)
In 2009, 32 nanometer CPUs are supposed to be available. 45 nm CPUs that are just going into service now are much more efficient than the previous generations.
Cory is right that what ultimately matters is the whole energy picture.
I think Tony is just venting his spleen at SL by seizing on this strange idea that “avatars use up more energy than Brazilians”. He could just as equally say “White people in the United States sitting at their computers all day, at work and at home, use up more energy than brown Brazilians.”
And? So what? It’s like those peas that my mom said I was supposed to eat when I was 8, because people were starving in Bangladesh. Could I mail them my peas, mom? I mean, Brazilians are on Second Life, too! Lots of them! They are one of the largest groups! How much does a Brazilian using Second Life use up by contrast to a poorer Brazilian without a DSL line and a computer with a high-end graphics card? Should we start at home, in Brazil then, if we’re going to be assigning liberal guilt liberally lol? Why don’t those evil Brazilians with SL running on their computers and little businesses and dance floors in SL shut off those damn computers *right now* and make sure that electricity is diverted to a poor village in the mountains! I said march!
Not only “why Second Life” or “why North Americans” or “why avatars” but “why Internet”? Nobody would EVER dream — among that geeky Web 1.0 making set — of saying “The Internet in your dorm room or university officer is using enough energy to power a small third-world village for a month. For shame! Evil imperialist!”
No, the job is to reduce the consumption as much as you can with various “green grid” concepts of cooling and whatnot as IBM has, but not to stop development and use of technology just because not all the have-nots can have it. Eventually you figure out how to make it available. Withholding your own use of SL doesn’t put any peas in anybody’s pot.
I think the operative point about SL as has been said here is that you reduce time and travel and carbon usage attending meetings and organizing international contacts especially, and that saves on energy, of course.
If Tony Walsh had been told that his blogging and use of blogging servers was using up the electricity needed to keep a tiny baby alive in a hospital in Sudan or something, would he stop blogging? I mean, why do you guys come up with silly things like this?!