I have read that the total embodied energy cost of consumer electronics (e.g. computers, smart phones, digital cameras, etc.) identifies these devices as products of an unsustainable energy economy.
Regardless of how these devices are disposed of after use, is there a general recommendation for how long such devices should be used by owners in order to 'break even' on the energy used to produce and distribute them?
While these devices take a fair amount of energy to produce, I'd be careful about labelling their construction, and economy which surrounds them, unsustainable based on that - since it then opens up a minefield of questions about how you can use them for a set period of time to become "sustainable." The questions it opens up in this regard don't actually make an awful lot of sense.
When we're talking about permanent, or semi-permanent technological devices designed to manufacture energy, such as solar panels or wind farms, we can make this judgement call. We can calculate that the energy required to make a square metre of monocrystalline solar cell is x, and that the average energy it produces over its lifetime in a UK climate properly positioned on a south facing rooftop is y. It's then a relatively straightforward comparison.
But with devices that don't produce energy, only consume it, this is much less clear cut. What even counts as breaking even? Doing a certain amount of work, making a certain amount of calculations? Being in service for a certain amount of years? The degree to which the containing components can be recycled? Since they don't produce energy, no such device will ever break even in a simple, single unit sense of the word.
I believe this is the reason why there is no commonly accepted "minimum time" that you should own and use a device before disposing of it, and the challenges we face most in this regard are much more along the lines of how to properly recycle and manage this level of waste that we just didn't have 15 years ago, rather than how to work out if we've somehow "broken even" on the energy used to produce the device, and can now morally move on.
One approach is to look at what changes in behavior your electronics enable, and compare the benefits of those changes (typically per unit time) to the cost (overall) of the device. Some examples:
This raises some possible equivalances. How many hardbacks have the same energy footprint as the production and purchase of the Kindle?
It all depends what you use the electronics for. A TV is probably never going to be balanced out. A smartphone that replaces larger and more expensive devices may constitute an immediate savings. A smartphone for someone who already owns and uses larger and more expensive devices, and continues to buy and replace those large devices, will also never balance out. So this gives you a framework for thinking about that.
