Application of Renewable Energies for Water Desalination
Application of Renewable Energies for Water Desalination
Noreddine Ghaffour King Abdullah University of Science and Technology (KAUST) Co-authors:
T. Goosen, Al-Faisal University, KSA H. Mahmoudi, Chlef University, Algeria S. Sablani, Washington University, USA
CCE, ICHT’11 Conference Muscat Feb. 14 2011
Market Evolution Total capacity: 2006: 40M m3/ d 2010: 64M m3/ d 2015: 98M m3/ d
The review indicates it is growing at a compound annual growth rate of 55%.
2
Source: GWI/ WDR, 2007
Relevant Technologies in Use
3
Introduction to Energy & Desalination Desalination Processes ØThermal – needs thermal and electrical energy ØMembranes – needs electrical energy only Both are energy intensive, accounting for 40-75 % of the operating cost
Why reduce energy consumption à cost and CO2 emissions 4
Introduction to Energy & Desalination (Cont’d)
• To optimize costs à Optimize energy consumption and capital cost • Source of Energy • Fossil Fuel à CO2 emission • Renewable Energies à High capital costs • Nuclear energy à restrictions 5
Energy Consumption
Process
Thermal energy kWh/m3
Electrical energy kWh/m3
Total energy kWh/m3
Capital cost $/m3/d
Unit water cost $/m3
Typical single train capacity M3/day
MSF
7.5 - 12
2.5 – 3.5
10 – 15.5
1000 1500
0.8 - 1
5000 - 70000
MED
4-7
1.5 - 2
5.5 - 9
900 1200
0.6 – 0.8
500 - 12000
3-6
3-6
800 1000
0.5 – 0.8
1 - 25000
0.5 – 2.5
0.5 – 2.5
< 800
0.1 – 0.3
1 - 25000
SWRO BWRO -
6
Minimum Energy Required Minimum energy for separation of pure water from saline water at 25 oC Salinity, ppm
Minimum energy, kWh/m3
35,000
0.71
49,000
0.84
68,600
0.97
104,000
1.16
137,200
1.30 7
Renewable Energy & Desalination
Ø Attractive to reduce dependence on fossil fuels but capital costs still high Ø Can be used in remote and rural areas for small scale applications Ø RE can provide thermal, electrical or mechanical energy 8
Renewable Energy Sources
Solar energy Ø Collectors or solar pond à Thermal àElectrical or Heat Ø PV à Direct conversion of sunlight to electricity
Wind energy Ø Wind turbine à Electrical or Shaft work
Geothermal energy Ocean energy (wave, OTEC) Hydropower Biomass energy
9
RE Desalination Combination
Biomass
RE Desalination Combination (Cont’d)
Other factors to be considered when making the combination Ø Product water quality (TDS) Ø Power requirement Ø Economics Ø Operation and maintenance
11
RE Sources Used for Desalination
50% 45% 40% 35% 30% 25% 20% 15% 10% 5% 0% Solar PV
Solar Thermal
Wind
Hybrid
(Source Tezn and Morris)
12
Desalination Processes Used in Conjunction with RE 70%
60%
50%
40%
30%
20%
10%
0% RO
ED
MSF
MED
VC
Other
(Source Tezn and Morris)
13
RE : Power Oriented Technologies (Electricity Production) Power oriented RE technologies are based on three major resources:
Solar or wind based solutions are particularly suitable for desalination purposes, given the resource availability in most of the water stressed areas Wave energy is available where sea water is available, which is needed for desalination. The technology is little developed but has a huge potential.
RE : Heat Oriented Technologies (Heat Production) Heat oriented RE technologies are based on three major resources:
Thermal Processes and RE MED process MED process, is becoming one of the most efficient thermal desalination technology, especially when coupled to heat pumps, solar energy or waste heat sources. MED takes place in a series of evaporation stages (effects). This permits the seawater feed to undergo boiling without the need to supply additional heat after the first effect.
Thermal Processes and RE (Cont’d)
HDH process Conventional HDH process is formed of three main parts: Ø Humidifier, where the intake air humidity is increased to saturation conditions. Ø Condenser, where the humidified air is cooled to condense the product water Ø Feed seawater heater
Thermal Processes and RE (Cont’d)
MD process MD is an evaporative process in which water vapor, driven by a difference in temperature, permeates through a hydrophobic membrane, thus separating from the salt water phase. This process perfectly works at relatively low temperatures (75-85 ºC) allowing a solar energy supply by conventional flat collectors.
What are The Limitations in Using RE? q Intermittent, difficult to predict and fluctuant. q Occupy large areas (cases of solar collectors, solar PV fields or wind farms) q Adverse impact on the environment: • Visual impacts, • Affection to marine and aerial life • Noise (Wind for example )
Limitations of Solar Desalination Indirect collection systems – Characteristics
20
MEB Using Hot Seawater, Baja Peninsula in Mexico
Carlsbad SWRO Project
• Solar thermal Plant at PSA Almeria, Spain • MED has 14 effects treating seawater • 3 m3/ h • Parabolic trough collectors • Aperture area 2672 m2
22
Seawater Greenhouse
Seawater Greenhouse
Dry and hot air
Humid air
Cold and dry air
Hot Water Reservoir Cold water reservoir
Fresh water reservoir 24
Seawater Greenhouse (Oman) Inside the greenhouse
25
Perth SWRO – Largest Plant using RE • Capacity (XL): 140,000 m3/ d • Energy demand: (3.5 kWh/ m3) • Plant’s total energy consumption is offset by energy production from a 82 MW wind farm situated at 260 km from the plant (48 turbines)
Sureste SWRO Plant • Capacity (small): 25,000 m3/d • Photovoltaic cells (rooftop): minor share of RO energy demand • Rest from grid: energy mix includes wind energy
Almeria, Spain Solar MD
Solar distillation
MSF plant with CSP
The Desert of Tomorrow! Heaven on Earth
Idea developed by Dr. Paton, SWGH, England
29
Conclusions RE systems have proven to be reliable. They are the technologies of the future and will play a role in future scenarios § It has great potential in the Middle east and Africa § Presently it cannot be used for large scale applications due to technological and economic constraints § There is limited scope to decrease the energy consumption in commercial desalination processes to make them powered by solar energy § Presently CO2 contribution from desalination plants is about 0.3% of total CO2 load to atmosphere 30
Conclusions (Cont’d) § Current trends in fossil fuel cost increase and developments in solar collectors may make the solar desalination a feasible option in another ten years § Presently solar desalination can be used for small/medium scale applications in remote locations where grid electric power is not available § More R&D is needed to improve desalination systems coupled with RE technologies and to reduce the cost of desalinated water § Improving the HD process and modification of commercial desalination processes is required to make them suitable for remote location applications 31
32
Noreddine Ghaffour King Abdullah University of Science and Technology (KAUST) Co-authors:
T. Goosen, Al-Faisal University, KSA H. Mahmoudi, Chlef University, Algeria S. Sablani, Washington University, USA
CCE, ICHT’11 Conference Muscat Feb. 14 2011
Market Evolution Total capacity: 2006: 40M m3/ d 2010: 64M m3/ d 2015: 98M m3/ d
The review indicates it is growing at a compound annual growth rate of 55%.
2
Source: GWI/ WDR, 2007
Relevant Technologies in Use
3
Introduction to Energy & Desalination Desalination Processes ØThermal – needs thermal and electrical energy ØMembranes – needs electrical energy only Both are energy intensive, accounting for 40-75 % of the operating cost
Why reduce energy consumption à cost and CO2 emissions 4
Introduction to Energy & Desalination (Cont’d)
• To optimize costs à Optimize energy consumption and capital cost • Source of Energy • Fossil Fuel à CO2 emission • Renewable Energies à High capital costs • Nuclear energy à restrictions 5
Energy Consumption
Process
Thermal energy kWh/m3
Electrical energy kWh/m3
Total energy kWh/m3
Capital cost $/m3/d
Unit water cost $/m3
Typical single train capacity M3/day
MSF
7.5 - 12
2.5 – 3.5
10 – 15.5
1000 1500
0.8 - 1
5000 - 70000
MED
4-7
1.5 - 2
5.5 - 9
900 1200
0.6 – 0.8
500 - 12000
3-6
3-6
800 1000
0.5 – 0.8
1 - 25000
0.5 – 2.5
0.5 – 2.5
< 800
0.1 – 0.3
1 - 25000
SWRO BWRO -
6
Minimum Energy Required Minimum energy for separation of pure water from saline water at 25 oC Salinity, ppm
Minimum energy, kWh/m3
35,000
0.71
49,000
0.84
68,600
0.97
104,000
1.16
137,200
1.30 7
Renewable Energy & Desalination
Ø Attractive to reduce dependence on fossil fuels but capital costs still high Ø Can be used in remote and rural areas for small scale applications Ø RE can provide thermal, electrical or mechanical energy 8
Renewable Energy Sources
Solar energy Ø Collectors or solar pond à Thermal àElectrical or Heat Ø PV à Direct conversion of sunlight to electricity
Wind energy Ø Wind turbine à Electrical or Shaft work
Geothermal energy Ocean energy (wave, OTEC) Hydropower Biomass energy
9
RE Desalination Combination
Biomass
RE Desalination Combination (Cont’d)
Other factors to be considered when making the combination Ø Product water quality (TDS) Ø Power requirement Ø Economics Ø Operation and maintenance
11
RE Sources Used for Desalination
50% 45% 40% 35% 30% 25% 20% 15% 10% 5% 0% Solar PV
Solar Thermal
Wind
Hybrid
(Source Tezn and Morris)
12
Desalination Processes Used in Conjunction with RE 70%
60%
50%
40%
30%
20%
10%
0% RO
ED
MSF
MED
VC
Other
(Source Tezn and Morris)
13
RE : Power Oriented Technologies (Electricity Production) Power oriented RE technologies are based on three major resources:
Solar or wind based solutions are particularly suitable for desalination purposes, given the resource availability in most of the water stressed areas Wave energy is available where sea water is available, which is needed for desalination. The technology is little developed but has a huge potential.
RE : Heat Oriented Technologies (Heat Production) Heat oriented RE technologies are based on three major resources:
Thermal Processes and RE MED process MED process, is becoming one of the most efficient thermal desalination technology, especially when coupled to heat pumps, solar energy or waste heat sources. MED takes place in a series of evaporation stages (effects). This permits the seawater feed to undergo boiling without the need to supply additional heat after the first effect.
Thermal Processes and RE (Cont’d)
HDH process Conventional HDH process is formed of three main parts: Ø Humidifier, where the intake air humidity is increased to saturation conditions. Ø Condenser, where the humidified air is cooled to condense the product water Ø Feed seawater heater
Thermal Processes and RE (Cont’d)
MD process MD is an evaporative process in which water vapor, driven by a difference in temperature, permeates through a hydrophobic membrane, thus separating from the salt water phase. This process perfectly works at relatively low temperatures (75-85 ºC) allowing a solar energy supply by conventional flat collectors.
What are The Limitations in Using RE? q Intermittent, difficult to predict and fluctuant. q Occupy large areas (cases of solar collectors, solar PV fields or wind farms) q Adverse impact on the environment: • Visual impacts, • Affection to marine and aerial life • Noise (Wind for example )
Limitations of Solar Desalination Indirect collection systems – Characteristics
20
MEB Using Hot Seawater, Baja Peninsula in Mexico
Carlsbad SWRO Project
• Solar thermal Plant at PSA Almeria, Spain • MED has 14 effects treating seawater • 3 m3/ h • Parabolic trough collectors • Aperture area 2672 m2
22
Seawater Greenhouse
Seawater Greenhouse
Dry and hot air
Humid air
Cold and dry air
Hot Water Reservoir Cold water reservoir
Fresh water reservoir 24
Seawater Greenhouse (Oman) Inside the greenhouse
25
Perth SWRO – Largest Plant using RE • Capacity (XL): 140,000 m3/ d • Energy demand: (3.5 kWh/ m3) • Plant’s total energy consumption is offset by energy production from a 82 MW wind farm situated at 260 km from the plant (48 turbines)
Sureste SWRO Plant • Capacity (small): 25,000 m3/d • Photovoltaic cells (rooftop): minor share of RO energy demand • Rest from grid: energy mix includes wind energy
Almeria, Spain Solar MD
Solar distillation
MSF plant with CSP
The Desert of Tomorrow! Heaven on Earth
Idea developed by Dr. Paton, SWGH, England
29
Conclusions RE systems have proven to be reliable. They are the technologies of the future and will play a role in future scenarios § It has great potential in the Middle east and Africa § Presently it cannot be used for large scale applications due to technological and economic constraints § There is limited scope to decrease the energy consumption in commercial desalination processes to make them powered by solar energy § Presently CO2 contribution from desalination plants is about 0.3% of total CO2 load to atmosphere 30
Conclusions (Cont’d) § Current trends in fossil fuel cost increase and developments in solar collectors may make the solar desalination a feasible option in another ten years § Presently solar desalination can be used for small/medium scale applications in remote locations where grid electric power is not available § More R&D is needed to improve desalination systems coupled with RE technologies and to reduce the cost of desalinated water § Improving the HD process and modification of commercial desalination processes is required to make them suitable for remote location applications 31
32
