REAPower: Electricity from brine

the search is on all over the world for new ways of generating electricity in an effort to meet our growing demand for safe clean affordable energy one of the latest innovations is salinity gradient power harnessing the chemical energy available from the difference in salinity between two solutions like seawater and freshwater reverse electro dialysis is a revolutionary technology that can be used to convert the controlled mixing of the two solutions into electricity this is how it works the salt in seawater consists of positively and negatively charged ions the ions are present in fresh water too but in smaller concentrations when the ions are allowed to move between the two solutions they tend to move from the high to the low concentration to balance the difference in salinity between the sea and the freshwater special membranes are used to control the process which allow only negatively or only positively charged ions to pass through by placing the membranes in an alternating way between the seawater and the fresh water the ions are forced to move in specific directions generating a current that can then be easily converted by electrodes into an electrical current freshwater has a low concentration of ions which limits the amount of electricity that can be produced but in the repower project we use seawater as the low concentration solution and mix this with brine which is water with very high salinity levels so by introducing much more salt into the process we managed to overcome one of the technologies limiting factors enabling us to produce much more electricity the repower project brought together 11 companies universities and research institutions with financial support from the European Commission the project has turned this novel approach to reverse electrodialysis from an idea into an operating prototype it's taken a huge amount of work the membrane development stack design simulations optimizations and economic analysis but all that hard work is now producing real results on the ground a number of small prototypes have operated for some time in the lab but now the first pilot is operating in a real working environment here in Trapani in sicily we are producing salt here since three thousand years this is a very small salt work we are producing five thousand tonnes of sea salt per year and it is very very interesting that we can use this side also for producing energy in a very new and at the frontier of research and development well the Trapani site is ideal for the reverse electrodialysis technology because there is plenty of availability of different saline solutions so we have basically from river water brackish water sea water and all sorts of different concentrated brines this is the outcome of a four years activities project and eventually we are here with our installation working operating and leaving us hope for a wonderful future this prototype is the first plant in the world to be producing electricity from brackish water and dry it's a prototype of one kilowatt so about the electricity that one small household needs we have scaled it up to this size of prototype and we do see a operation that is reaching our targets this is a very clean energy it's very silent there are no moving parts there are no pollutants there are no emissions so you can have a very good result the clean energy that's available at any time irrespective of when the wind blows or when the sun is shining we started already years ago with the first fundamental studies in the labs and now we gradually gradually getting bigger and more confident that with this technology this kind of research can only be carried out by using public funds the European Commission is practically the only source for such high-risk project and of course we must consider the full potential of this technology in an area like for example the Mediterranean basin the sky's limit I would say but because it's a modular approach depending on how much water and salt is available then you can just scale it up in principle indefinitely you you

Channel: WIP Renewable Energies

Views: 72,305

Keywords: salinity gradient power, reverse electrodialysis, Electricity (Industry), Renewable Energy (Industry), salt, brine, fp7, european commission, SGP, REAPower

Id: VY32O5cy4BQ

Length: 6min 1sec (361 seconds)

Published: Thu Sep 18 2014