Water Saving Calculator

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Hi All

Many of us are used to calculating how much CO2 we are saving as a result of the items we repair, using either Fixometer or Farnham’s Carbon Calculator, but has anyone any experience of converting those figures in water saving. We know that both energy and manufacturing are water intensive and that water is one of our most treasured resources available.

I know there are calculation formulas out there, but how relaiable are they?

Many thanks

Pete

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Hi Pete,

Great question! Totally agreed that it would be great to know roughly how much water we could save by not manufacturing each new product.

When we were building the current version of the Fixometer’s CO2e calculator back in 2021, we did consider adding water consumption as an additional metric. At the time we found that there simply wasn’t enough product-specific information out there about water consumption at each of the various stages of a product’s lifcycle (extraction, manufacturing, transport, use, end of life etc.)

Press here for more detail about that

From the 1,600+ reports and papers we sourced, we found that most companies only report the minimum types of impacts they can. While that often (though not always) included CO2e, it very rarely included water consumption. To pick one example, Apple (one of the companies that actually provides more environmental impact data about its products) still doesn’t report on water use for its latest devices (see their recently announced M5 MacBook Air report here). They do have a ‘[u]Water Strategy[/u]’, but again, there are no real figures here.

Most of the water consumption figures we did find came from papers in academic journals. But while useful, due to differing methodologies and the relatively small number of products covered, we couldn’t determine a predictable relationship between CO2e production and water consumption, especially when comparing products across different categories (e.g. textiles vs. electrical devices vs electronics).

As a result, we weren’t able to add a water consumption calculator.

I have to confess that I haven’t really kept up with this closely enough over the last couple of years. But I’d be a little sceptical of formulae that claim to calculate water consumption for a few reasons:

  • CO2e figures themselves are generally estimates at best. Calculating water consumption based only on this is essentially estimating based on an estimate, making it potentially very unreliable.
  • This is especially true if the calculator doesn’t account for the type of product in question. E.g. it takes something like 10 litres of water to produce 1 kg of plastic, but somewhere around 7,000-10,000 litres to produce 1 kg of cotton. But producing plastic is far more cabon-intensive; 1 kg of cotton releases around 8 kg of CO2e, roughly equivilent to a single plastic bag weighing mere grams. And electronics/electricals are much more complex.
  • Like CO2e, water consumption will vary considerably depending on where and how the product was manufactured.

All that said, I do need to update myself in this area. Do you have examples of these calculation formulae?

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