Water and Energy

For a variety of reasons, I’ve been starting to pay attention of late to the water-energy nexus. Which is why this drew my eye:

According to news reports, Tampa is reviewing a request from Port Sutton EnviroFuels LCC for up to 500,000 gallons of freshwater per day to run Florida’s first Ethanol production plant. The facility today would be the city’s fifth-largest water customer, bigger than Tampa General Hospital, the University of South Florida or Busch Gardens. It is planned for the plant to transition to reclaimed water as the primary water source in the future.

Consumptive water use by ethanol plants largely comes from evaporation during cooling and wastewater discharge.


  1. In a similar vein – in case you didn’t know – there’s the water-carbon nexus as well. Plant plantations to sequester C, and streamflow drops. (In the general case where forests replace a background matrix of grassland, which has a lower ET loss.)

  2. Looks like a perfect application for grey water. Increasingly we are going to have to separate toilet wastes and such from the waste supply in order to efficiently use the grey water streams without the expense of full waste treatment.

  3. Unfortunately, here where I live in the West, there’s generally no such thing as “grey” water that is simply wasted. The largest tributary in the middle reach of the Rio Grande, where I live, is the Albuquerque sewage treatment plant. To the extent that we find uses for the grey water here in town, we remove it from the river.

    There are substantial efforts underway throughout the West to use treated effluent (golf courses are watered with it in Tucson, for example). But every time you do that you’re taking whatever away from wherever the treated effluent was already being disposed of. In arid climates, there is no free water lunch.

  4. Especially when you’re recharging your aquifer with your treated sewage as Missoula does. They pump upgradient east of town and inject the sewage downgradient on the west end. Far as the infrastructure, ask Portland OR how much they’d like to spend on something like that. They are in the completion process of a $1B infrastructure upgrade to pipe all of their sewage, including storm water runoff, into a new huge sewage treatment plant.

  5. Eli –

    Good point. But I guess my point is that wherever you are, there’s either plenty of water, in which case the water required for energy isn’t a big deal. Or water is scarce, in which case utilizing grey water isn’t much of an answer, because it’s not really free.

  6. True John, but what I think I was arguing, is that if Tampa is long on grey water (and grey beards), it makes sense to do things there that can use the resource, save on waste treatment and ship the EtOH to NM (what you do with it can vary….)

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