Desalination by reverse osmosis: the economics?

35bn tons of desalinated water are produced each year, absorbing 250 TWH of energy, or 0.4% of total global energy consumption.

These numbers have already doubled since 2005 and could rise sharply in the future: water use per capita remains 50-90% lower in the emerging world than in the United States, populations are growing and aquifers depleting.

Hence, this model quantifies the energy economics of desalination via reverse osmosis, which requires 3.6kWh of energy per m3 of desalinated sea-water. A cost of $1.0/m3 is necessary for a passable IRR.

Impacts can be stress-tested from varying energy prices, CO2 prices, capex costs, opex costs and energy efficiency. Our own base case estimates are derived from past projects and technical papers.