The Virtual Life Cycle Part I : Meaning of “Embodied Energy” for the web


After posting to a variety of locations with questions about this project, I realized that the notion of “sustainable virtual design” doesn’t make sense to many. They can understand, for example, keeping your computer a few extra years to reduce your carbon footprint. But the web itself? It doesn’t make that much sense. I suspect that this is due to general confusion (not unjustified) about what sustainability means in the design world. So, the following, based on my crowdsourcing results, continues clarifying the meaning of “Sustainable Virtual Design”.

Web pages are just products

A web page and a website, as well as a casual game or virtual world all are products. They are very similar to the physical products produced in Industrial Design, and the living spaces produced by Architecture and Interior Design. As such, they have a life cycle – they are created, are delivered, used, and finally disappear. Therefore, sustainable frameworks like “cradle to cradle” should apply to the virtual world.

A web page is manufactured just like other products, and this takes energy and resources. In the case of a physical product like a Prius, lots of energy and matter are used to create the car. There is also LOTS of energy and matter used to manufacture the car out of those materials. This includes the machines powering an assembly line and the workstations in the office of the designer.

  1. A web page also has many similarities to the product of Architecture and Interior Design. It’s no accident that web pages have a design principle some call “interior design flow”. Despite being tw0-dimensional, the user “visits” the web page, and “walks through” the 2D features, using the third dimension of time. In a 3D virtual world like Second Life, the comparison is literal. Avatars have to move through computer-generated 3D space in time.
  2. Where a web page differs from physical product is in its extremely lightweight material component. The amount of electrons corresponding to a web page in memory is incredibly small. If you check the “factoid” page on this blog, you’ll see that all the electrons on the entire Internet only add up to a few ounces. This means that, unlike regular objects, web pages can be copied with very little energy expended. I think it is this “lightweight” aspect of virtual products that confuses people – they mentally see all of cyberspace as “weightless”.

The completed product – be it web page, or toothbrush – has “embodied energy”. In the case of the toothbrush, a significant part of the embodied energy is in the heat, chemicals, etc used to form the plastic of the physical object. In contrast, this part of the embodied energy of a web page occurs remote from the factory, on the user’s computer (see below).

Embodied energy of Design

However, there is a second component of embodied energy – the energy that was used during production to design the product. In the case of the toothbrush and web page, this includes all the electricity that kept the workstations running while the toothbrush was designed, as well as the room lights, heating and cooling. The nice thing about this component of “embodied energy” is that it is used only once – one design can be replicated without repeating the design process. As the number of products manufactured increases, its contribution to the eco-budget of the item declines.

Information in theory is just symbols – abstract and weightless. But to express symbolic information we have to make it physical, be it sound waves in a speaking voice, or glowing pixels.

Web pages, have very little of the first kind of embodied energy (they do weigh something, but it isn’t much), may have substantial components of the second, design/programming embodied energy. So, we can speak of the “embodied energy” of a web page as all the work that went into its creation. That would include concept, rapid development process through a series of prototypes, programming, design, art direction – all of it.

So, we have “embodied energy of production”. What about delivery of a virtual product?

Embodied energy of Manufacture and Delivery

The advantage of a virtual product is that, once we burn resources to create it, use a vanishingly small amount of matter (the weight of electrons), and a modest amount of energy each time we make a new copy.

In the physical world, I have to use matter and energy to create each copy of a designed product, and expend additional energy transporting the product to its customer. Industrial designers would include cost of manufacture in their “embodied energy” calculations, and some would include transport costs and showroom costs as well.

In the virtual world, the embodied energy of delivery corresponds to an on-demand production of a copy of the product. This is the cost of sending said electrons through the Internet, and the cost in cpu cycles needed to render it onscreen. We can make the following analogy:

  1. Uploading to the web host is like delivery. However, we deliver a set of raw materials (assets, media) and instructions for assembling them, rather than a complete product. If the web used downloaded bitmaps instead of HTML, it would be more like a physical factory process (bits assembled before delivery).
  2. The server with the files is a sort of showroom that the user visits to “purchase” a web page for delivery.
  3. When the user downloads the page it is a transport step. Remember we are delivering the equivalent of car parts to the user.
  4. Since web pages can be computationally expensive (read: battery life) to render, manufacturing takes place at the end of the process, rather than the beginning. It is as if each user had a little factory to make their product, which almost only energy. Instead of one factory, there are millions of little ones.

Virtual Products may have greater energy use

Virtual products may require much more energy to produce than a web page. This is because virtual products may have encyption schemes associated with them to create “singletons” (only one electronic copy can ever exist), or validated copies. Networks and protocols using these virtual products could require a specified amount of energy was needed to generate the product.

An example of such a system is found in bitcoin (virtual currency) .  Here, we have “miners” who create bitcoins using their computers or GPUs. The amount of energy needed to create a bitcoin is significant (hundreds of watts?) and it may also increase over time. The bitcoin wiki computes energy needed to create and use bitcoins. The bitcoin example shows that the energy needed to create the actual electrons of virtual products is nonzero – until recently, the energy needed to create bitcoins (processing to building an encrypted stream) was more than the market value of bitcoins. See

The Web is like Santa Claus

This description is very similar to the “Santa Claus machines” described in fiction (e.g. The Diamond Age by Neal Stephenson). In this book, ultra-advanced 3D printers are in the home, replacing visits to the mall.  You buy a product by downloading the software assembly program to your printer, and it uses “feedstocks” to create the product via nanotechnology.

Right now, we can’t do this well with ordinary matter, but we can do it well with electrons, the lightweight component of atoms. If you’re having problems with “embodied energy” or “sustainability” as it applies to a web page, think of it as a super-lightweight product, designed by a company, sent via electrons, and assembled by your personal Santa Claus machine.

The same advantage of manufacture applies to the virtual. That is, if you take a lot of resources to design a page but it is very popular and serves a real need, the importance of the embodied energy of the design/development step declines.


A few principles fall out right away from this analysis:

  1. Elaborately-coded “cult pages” visited by a few are less sustainable than popular pages with the same amount of development behind them.
  2. A dynamic website automatically constructing user-specific pages will be more energy-efficient than a static site. In the 1990s, many “personal” sites required lots of work per individual page. Today, CMS systems use a smaller number of templates. At that level, CMS is good.
  3. Pages that cause a lot of “cpu grind” are less sustainable. This was the problem with mobile flash, and people noticed since mobiles have limited energy available to render web pages.
  4. “Authoring Layers” which attempt to abstract code generation for web pages are only “sustainable” if the page popularity is small. An authoring almost always will create code that is slower and more cpu-intensive than hand-coding. But hand-coding requires lots more work on the part of the developer, and the designer, since they must understand decisions/tradeoffs in design that allow for efficient coding.
  5. For low volumes, the smaller “embodied energy” of production will trump the enbodied energy of delivery. Authoring layers are OK in this environment. Possibilities might include computer-based training, where non-techie educators use authoring tools to create learning materials for a focused student audience. Here, we trade off increased more energy used for delivery versus less used energy in design.
  6. For high numbers of copies (high traffic web pages), the reduced code quality from the authoring layer will cause a greater amount of of energy in rendering the page, which will trump savings at the design end. Also, if the page loads more slowly, it may slow down users – design was made easier by pushing the saved time onto the users. If someone uses a Flash to HTML5 burner that makes clumsy code, and it becomes the next Angry Birds, it is a sustainability problem. At the very least, the code should be refactored.
  7. This makes the “code free world” recently touted by Adobe a challenge to sustainability. Code-free worlds are bad. Design will drift into creating inefficient and sloppy websites, games, and other “interactive experiences”, due to the ignorance of the underlying code.
  8. This did happen for assembly language – hardly anyone codes in assembler anymore, and that means our compiled software is inefficient. But in traditional software, nearly all the energy is consumed operating the system, and is not embodied energy. On the web, many pages are for viewing only, which means that the embodied energy of rendering is more significant. As web pages become more interactive, and they handle more user interaction, they will become more and more like traditional software. So, over the long run, embodied energy of delivery might decline in importance again.

This analysis shows how embodied energy is about more than computer power – it feeds into the design of the web page, and, by extension, how we go about the design process itself. In the next post, I’ll cover energy of operation.

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