Archive for the 'water filtering' Category

Retrieved from Centerpeace.org

Desal or Not?- Big Meets Small in the Nexus with the Future Up for Grabs

by Miles Ten Brinke

Desalinisation is a fascinating expression of the water-energy nexus, and its inherent contention. Though there are many technical approaches to actually achieving the desired results, the idea is simply to produce fresh water from salt water. Depending upon your perspective, this technology and it likely approach to water management can generally be one of two things- a brilliant technical fix or a socio-environmental nightmare.

Regardless of one’s positionality, there is a strong backing (powerful stakeholders some of whom have access to lots of capital) for desalinisation and the problem it purports to solve will only spread out and increase in intensity over time. Should it prove technically feasible at some signifiant scale, we may see more than just demonstration plants in the next ten years and increasing commercialisation by 2050. An interesting question for folks considered about more than just security of supply is the sustainability of desal technologies. One interesting prospect for instance is the potential for solar powered desalination.

This past month has been incredibly busy for me, in no small way due to progress on my pursuit of a PhD. As I’ve moved through the application process the project has been refined and my ideas polished. My focus will be on arid case studies, places with scarcity of both energy and water (a major hypothesis being that there’s cross causality there). The conditions that make desal look viable, its potential impacts and the socio-technical system itself all exemplify this. As a part of a centralised resource management plan, desal would include both energy for water (the desalinisation process itself is extremely energy intensive, and so is moving around all that water from points of production to its diffused consumption)  and water for energy (centralised power which is usually produced using large thermal electricity plants which consume fuels such as coal, gas and uranium often use water as their primary coolant). Desalinisation in many ways represents a central dualism in socio-environmental policymaking, one I hope to explore at length in my research.

That is, between two broad scales of technology and governance structures- technocratic centralisation vs. democratised dispersion (for those of you familiar with energy policy, its essentially Amory Lovin’s Road Not Taken- Hard Path vs. Soft Path, with more socio-political considerations added in). Briefly now let me tool this apart before going back to Desal and a specific case. On one hand you have the technology on a continuum of degree of centralisation (really just big vs. small). Think nuclear power plant versus solar panel. On the other you have decision making, and how it’s concentrated. In a strong technocratic system, its an unelected elite of experts making all the calls with little or no transparency and access by other stakeholders. The opposite of that would be a system with very diffuse decision-making with non-experts and regular folks having a lot of input in a very open system. Its your classic top-down versus bottom-up divide. Even with water and the Nexus itself I often relate things back to this thinking. To keep it simple lets just think of it as big vs. small (both in tech and governance).

Near the end of February, the New York Times published a piece on the development of a $1 billion desalinisation plant in Carlasbad, California which began construction in late 2012. The San Diego County Water Authority (SDCWA) has agreed to purchase 48,000 acre-feet of water (one of the main units of measure in water policy, one acre-foot being equivalent to about 326,000 American gallons) per year at $2,000 an acre-foot. This will supply 7% of total water supplies for 30 years.

Beyond of the socio-environmental considerations of this reverse-osmosis plant the central debate in the area is on cost. Both the firm building the plant, Poseidon Resources and the SDCWA are betting on a continuation and acceleration of the trend in rising water demand.  In its scenario calculations the SDCWA estimates that this may be cheaper than status quo cost projections by 2024. They currently get their water from the Metropolitan Water District of Southern California for about $1000 per acre-foot. Its a gamble, but both the agency, the firm and their backers argue that in a time of dwindling fresh water supplies and growth demand will inevitably rise. Critics, both from environmental NGOs and independent research institute argue strongly that not only will this raise consumer water bills but also electricity as more energy is needed to power the plant, and that there’s no guarantee on the development of the region’s shifting thirst. Their proposed alternative is greater investment in demand side management (DSM), that there isn’t a need for a supply-driven drive to forge a new market for desal plants to solve our water crisis.

This is a classic case of big vs. small. Right now there’s only one other commercial scale desal plant in the US- in Tampa Bay, Florida. It’s not been a dramatic success for the burgeoning industry, lots of costly mistakes. That goes with the territory, risks are always higher at the opening of a market. Over time the costs may go down and with the right governmental support there very well may be a boom. The problem is that even should one accept it as a viable and acceptable approach, desalinisation will in all likelihood dis-incentivise water conservation & reuse and investment in efficiency. Think about it, you invest all this money and sign a contract for guaranteed supply. If you can reach a point where this becomes the new cheap option, why go back to sorting out your demand?

It really does matter where you start. From a supply orientation (big) you have a shortage that needs to be plugged by any means necessary and using economies of scale. Demand orientation (little) means focusing on using what’s already available more effectively and working to change the conditions that caused the shortage to begin with. The former generally does little to curb demand growth and is resource inefficient, but the latter risks supply insecurity if DSM isn’t effective enough.

I’m going to leave you all with a rather unfair quandary now, a dichotomy (of sorts) to revisit soon. No matter what we decide, we set ourselves down a trajectory which may not be easy to change further down the line. This is infrastructure we’re talking about, decisions made at one moment will shape decades to come.

Question is, which do we bet our money on?

~ Miles on Water