Osmotic power is years from commercial scale, but a new report indicates that cleantech vendors believe it can provide thousands of terawatts per year of baseload electricity.
According to Kachan & Co.’s “Osmotic Power: A Primer” report — written by Jennifer Kho and published by Dallas Kachan, the former managing director of the Cleantech Group — osmotic power is potentially worth “three times more” than solar and wind power, according to experts.
In fact, it has so much potential that it could produce half of Europe’s total energy demand by 2030.
Why? Because it can produce electricity 24 hours a day, seven days a week, doing away with the intermittent power (and thus storage necessary) that’s inherent with wind and solar power.
Here’s how it works: Osmotic power (alternatively, “salinity gradient power”) is produced using the difference in salt concentration between salt water and fresh water, by either the process of reverse electrodialysis, or RED, or pressure retarded osmosis, or PRO.
Both processes use ion-specific membranes to encourage osmosis. The byproduct is brackish water. As such, the process can be used at deltas and estuaries around the world.
Osmotic power isn’t new, by the way — it’s been around for four decades.
According to the report, advocates claim osmotic power could produce up to 1,600 to 1,700 terawatt-hours per year by 2030. That’s about half of Europe’s total energy demand. Some vendors even believe commercial plants will materialize within two years.
The problem? There remain technical, permitting and regulatory hurdles, according to Kachan.
Advantages of osmotic power:
- Large market potential.
- Baseload generation capability.
- Reduction in transmission required (because plants can be located close to power demand, unlike solar and wind).
- Ability to co-locate and therefore share costs with desalination and water treatment plants.
Disadvantages of osmotic power:
- Persistent technical challenges with osmotic membranes.
- Cost.
- Inconclusive environmental assessment studies.
- Commercial risks: NIMBY (”not in my back yard”), permitting, government support.
Still, it holds potential as a way to wean a nation off fossil fuels — especially since wind and solar can’t match the baseload capabilities of those energy sources. It also has wider potential than renewable tech such as geothermal.
Can nature’s elixir double as a power source?
Photos and illustration: Statkraft osmotic power plant in Tofte, Norway. Damian Heinisch/Statkraft/Flickr.
