Buonjiorno, Ennio.

Please, find some info inclosure.

Best regards, Vasily

dear ennio,

here a "link" to a document probably useful for you:

http://www.water.gov.il/hebrew/planning-and-development/desalination/documents/desalination-in-israel.pdf

the data are not really "latest news", but, at pag 10, you read

>

costante

Electricity consumption depends on raw water quality (individual ions concentration) Reverse osmosis system design (system recovery rate, number of stages, type of membranes, etc.) and operating conditions (water temperature). 

You can use Reverse osmosis design simulator to estimate electricity consumption. It is not an accurate result but will give you a very good idea, and making some tries in different conditions will precise the results. No electricity consumption result from another system will be exactly the same as yours. The reasons are that:  they don't have same water quality, same pumping equipments and same type of system (in term of design) as yours.

I use ROSA, a Dow-Filmtec membrane systems simulator. It is a free software that you can download on their website and install on your computer. It will give you a bunch of information including electricity consumption.

Try it. If you need help, let me know.

Best regards.

Philippe K.

I read recently a lot of publications on the topic but I did not find a univocal answer.

The values cited in literature range from 2.2 kWh per cubic meter in desalination plants of Canary Islands (see attached publication) to 6.3 kWh per cubic meter, which is the value reported in the document about Malta desalination plant, suggested by Vasily Kovalev.

Middle values are reported in many other publications (3.5-5 kWh/m3 in a IRENA report, 3.6 kWh/m3 in the report suggested by prof. Invernizzi)

All the publications refer to seawater desalination with similar properties of raw water (the seawater salinity should be in range of 35+-10% g/kg for most areas in the world) and the difference is probably related to the energy recovery systems used.

Can anyone confirm?

Thanks,

Simone

https://www.irena.org/DocumentDownloads/Publications/IRENA-ETSAP%20Tech%20Brief%20I12%20Water-Desalination.pdf

Article Energy efficiency and desalination in the Canary Islands

Hi colleagues.

Only theoretical calculation of thermodynamic required labor on separation (seawater desalination) in isothermic case could be named a constant. And this value is tiny.

First of all Energy consumption of RO plant depends on of perfection of pumps, valves and tubing. Incoming water temperature affects great either.

There is some info enclosure concerning technical attempts to decrease power consumption in RO plant.

Best regards.

Dear all,

While the above answers are great, I just thought I'd chime in by saying that the total electricity consumption of a plant is not just from the RO process.  For example, the electricity consumption of a large plant in Australia (Gold Coast) is broken down in this paper by Bartels & Andes from Hydranautics: dx.doi.org/10.1080/19443994.2012.700038

The total consumption is 3.6 kWh/m^3, while the RO process consumes 2.9 kWh/m^3. This is higher than the state-of-the-art (~2 kWh/m^3), largely because it utilizes a two-pass process.

Energy consumption is also briefly discussed (with similar values as the above example) in this informative presentation at IDA by Casanas of Dow Filmtec: http://www.emwis.org/documents/meetings/events/international-conference-desalination-sustainability-casablanca-morocco-01-03/future-membranes-seawater-desalination

Regards,

Jay

Based on experience with Pacific water in California the energy use for the RO system will be 2.5 kWh/m3 while for the entire plant will be around 3.5 kWh/m3.

 Thank you all for the informative answers and links .. may i ask for for a small clarification please  ..

A study (http://www.sciencedirect.com/science/article/pii/S0011916412005723) puts the range for MSF as following {  Thermal energy (7.5–12) + electrical energy ( 2.5–4) =  10–16 kWh/m^3 }

Excluding the RO as i am asking about the thermal desalination, does this mean the mentioned answers didnt include the thermal energy ?

IRENA report as well mentioned thermal energy 290 kJ/kg but in the tables in the appendix kept the total number at 5kWh/m^3.

Thanks alot 

More question than answer; Is water and brine transport calculated in the equation for energy efficiency? In California environmental protection advocates are adamant about NOT depositing BRINE in a single area especially within the 20 miles of coastline. That transportation, distribution, and dilution costs a significant amount of energy doesn't it?

Dear Mostafa. Thank you for the information.

Energy consuption in sewawater desalination by RO ranges from 2 Kwh/m3 to 4.5Kwh/m3. This includes intake, pre-treatment and post-treatment but not distribution. The record rported by Saline water corporation SWCC (KSA) is 2.27KWh/m3 (I am not sure if it for RO alone or not). But the minimum specific energy for salt and water separation can be calculated and it depends on salt concentration and recovery rate. it is roughly around 1KWh/m3, but in practice we need more than double of this value.

Dear Mokhtar Guizani, thank you for the information.