Review: Desalination Technologies and Renewable Energies. Study Case: PV-RO

Transcription

1 Review: Desalination Technologies and Renewable Energies. Study Case: PV-RO Gonzalo Piernavieja Baltasar Peñate Canary Islands Institute of Technology Instituto Tecnológico de Canarias (ITC) ISES Webinar Solar Desalination Technologies - Current Situation and Trends 28th January 2015

2 The CANARY ISLANDS INSTITUTE OF TECHNOLOGY (ITC) ITC FACILITIES Pozo Izquierdo, Gran Canaria Island Technology center specialized in: Energy Saving/Efficiency, Renewable Energies Water Technologies Other emerging technological sectors International Cooperation (energy and water supply to islands and remote regions

3 CANARY ISLANDS INSTITUTE OF TECHNOLOGY (ITC) We have accumulated 18 years of experience in the development of (stand-alone) solutions for the ENERGY and WATER supply to periurban/rural/remote areas We have carried out consulting and electrification/water desalination projects using RENEWABLE ENERGIES, as well as training and awareness activities in: Mauritania Morocco Tunisia Cape Verde Senegal ECOWAS

4 EL HIERRO: 100% RES ISLAND Commissioned in km inhabitants 7 MW peak 40 GWh/y demand (Diesel) Wind-Pumped Hydro Power Station (incl. desalination)

5 LA GRACIOSA 100% RES Projected La Graciosa: 650 inhabitants 0.7 MW peak 2 GWh/y demand Smart Microgrid with high RES penetration, energy storage (incl. desalination) and electric vehicles fleet

6 TRAINING IN RENEWABLE ENERGY DESALINATION (ITC) E-learning course on RE driven desalination. Introduction to desalination by renewable energies DESRES learning PLATFORM 13 editions with more than 500 students. Students from 37 different countries of the five continents have participated in the course.

7 Review: Desalination Technologies and Renewable Energies. Study Case: PV-RO CONTENTS WATER DESALINATION RENEWABLE ENERGY DESALINATION COMBINATIONS PV-RO EXPERIENCE EUROPEAN RENEWABLE ENERGY DESALINATION ACTION GROUP EIP ON WATER

8 Role of Water Desalination (1/5) Water desalination has been increasing its participation in the worldwide water supply scenario, especially in the last 20 years. Total desalination installed capacity, according to the last IDA inventory (2012), is more than 60 millions of daily cubic meters. New contracted and commissioned capacity of desalination plants increase every year. Annual worldwide desalination contracted capacity by technologies. IDA, 2009 Middle East - 48% of the total capacity America - 18% Europe 14% Very different industrial desalination plant scales - from m 3 /day to m 3 /day normally. The desalination market capacity is expected to reach 94 million m 3 /day in the next years.

9 Role of Water Desalination (2/5) Several technologies are currently used in industrial scale desalination. These technologies could be basically divided in two general categories: thermal processes and membrane processes. Depending on the desalination process (see picture below), energy might be required either as heat, power or even a combination of both energy forms. Desalination Processes Mechanical Energy Thermal Energy Electrical Energy MVC Reverse Osmosis Electro Dialysis Heat removal Heat addition Freezing Solar Energy Steam Solar stills Solar collectors MED MSF HDH MD TVC

10 Role of Water Desalination (3/5) In the case of membrane processes (RO, ED), instead of extracting freshwater from a salty water by evaporation, the water and dissolved salts can be separated by means of selective membranes using energy through pressure or electricity. Theoretically, membrane technology is the most attractive one: 1) it operates at ambient temperature 2) it does not involve any change in phase. The decision on what desalination technology should be used will depend on several factors: local available energy source, saline water quality, freshwater demand and quality and final cost of water production. IDA, 2009 The SeaWater RO technology has superseded distillation processes and is expected to be one of the fastest growing niches in the global desalination market. In general, the SW desalination market volume approximates 13 billion $ per year (USD 0.76/m 3 average cost of desalinated water GWI,2014). Installed desalination cumulative capacities [GWI desaldata/ida, 2009]

11 Role of Water Desalination (4/5) Among all desalination technologies, Reverse Osmosis (RO), Multi-effect distillation (MED) and Multi-Stage Flash distillation (MSF) are the most internationally widespread technologies. Feature MSF MED SWRO Global energy consumption Adaptability to high sea water turbidity Adaptability to high sea water salinity Need of a co-generating power plant high medium low excellent medium low high medium low high medium -- MED plant Product water quality very high very high drinking (2-5 ppm) (2-5 ppm) ( ppm) SWRO membrane rack Maintenance costs low low medium Investment costs medium/high medium low

12 Role of Water Desalination (5/5) Desalination technologies are energy intensive, what means negative impact on the environment and economy due to the reliance on oil as primary energy source for desalination plants. Energy consumption is the most important cost in the operation (40-60% of the total water cost). It has a direct impact on the costs reduction of the water produced. Improvements or applied research on installations will always be an advantage for lower water cost. The decrease of desalted water costs in the last decades is remarkable. In the case of SWRO (<3.0 kwh/m 3 ), from more than 1.00 $/m 3 in 1995 to less than 0.60 $/m 3 nowadays. Additionally, the BOOT contracts have resulted in minimal desalination costs in present times. Seawater RO plant water cost distribution example [García- Molina et al., 2009]

13 Renewable Energy driven Desalination (1/6) In general, the application of renewable energies for water desalination is a trending topic. These combinations enable an energy contribution in quality and quantity for replacing the energy supply based on fossil fuel. Different renewable energies (solar, wind, wave.) could be combined with traditional or modified desalination processes (under on-grid or off-grid conditions).

14 Renewable Energy driven Desalination (2/6) Main RES-DESALINATION technologies tested/assessed: Energy used Type of Process Heat Electrical Energy Desalination process Potential RE source Desalination process Potential RE source Distillation Membrane MSF MED Solar stills TVC MEH/H-D MD Solar thermal Thermal ocean Geothermal Bioenergy MVC ED RO Nanofiltration Solar PV Wind energy Wave energy Tidal Concentrated solar power Geothermal Bioenergy

15 Renewable Energy driven Desalination (3/6) Most widespread tested combinations have been PV-RO, PV ED and Wind RO, but the highest desalination capacity tested has been solar MED. (The tested systems have been / area generally small scale pilot plants or demonstrative projects). Technology combinations of 131 RE desalination plants reviewed in Source: ProDes project Roadmap. Currently, the Middle East is the hot spot of initiatives assessed or under construction (PV-RO and CSP-MED).

16 Renewable Energy driven Desalination (4/6) Main technology combinations characteristics. Source: ProDes project Roadmap (2012).

17 Renewable Energy driven Desalination (5/6) Main Barriers Lack of integrated approach: System development (need of integration of energy supply and desalination). Development stage and capacity range of the main technology combinations Source: ProDes project Roadmap (2012). R&D financing: RE-Desalination marginal both in the fields of energy and water. Policies: Water and energy policies are dealt by different administrations. Lack of training and knowledge. New technologies by SMEs in need to open markets. Small-scale technologies struggle in the big picture of water supply.

18 Renewable Energy driven Desalination (6/6) One of the most relevant difficulty to introduce this kind of technology in the market is the high initial investment (CAPEX) of these systems. The relative high cost of the cubic meter produced (from 2 $/m 3 to 10 $/m 3 ) is still quite far away from the costs of conventional desalination plants (less than 1$/m 3 ). The lack of a clear market makes difficult to determine the real economic feasibility and the risk associated with the investment in a particular project. Thus, investors are generally reluctant to invest in this kind of projects. But, the growth of RE technologies has lead to low costs of solar and wind electricity, the (variable) cost of fossil fuel based technologies will continue to increase, the hybrid designs or the exploitation of residual/waste heat could help promote the feasibility of the several combinations in the near future.

19 ITC experience: PV RO (1/6) PV-RO is one of the most promising combinations for small and medium desalination capacities. Two configurations are possible: Stand alone/autonomous PV-RO plants. Grid connected PV-RO plants. When the system is grid-connected the plant can operate 24/365 as a conventional plant and the renewable energy source merely acts as a fuel substitute. Stand alone plants need technological development to stabilize the intermittent energy source. Example of stand alone PV system connected to a RO plant. System installed in a village of the rural community of Tangarfa (Province of Tiznit, Morocco) [ITC] The main problem in off-grid plants is the effect of the variable energy conditions on the membrane (operability and durability) energy accumulation is a solution.

20 ITC experience: PV RO (2/6) 1999: First autonomous PV-SWRO pilot system with batteries. Designed and tested at Pozo Izquierdo facilities to satisfy a small water demand (50-75 inhabitants). 2003: Battery-less autonomous PV-SWRO pilot system using commercial devices. Designed and tested at Pozo Izquierdo facilities to adapt to the solar radiation instantaneously. 2004: DESSOL international patent (19 countries). - Autonomous RO desalination driven by solar photovoltaic energy with batteries (up to 200 m3/day). 2006: Autonomous brackish water PV-RO unit in Ksar Ghilène village - Tunisia (2.1 m 3 /h 10,5 kwp 300 inhab.) Spanish-Tunisian cooperation project. 2007: First autonomous seawater pre-commercial DESSOL system with batteries (<3.0 kwh/m 3 ). Integration of solar PV trackers (R&D purposes). Designed and tested at Pozo Izquierdo facilities. 2008: 4 autonomous brackish water PV-RO units in Morroco (1 m 3 /h; inhab.) ADIRA project (MEDAWATER programme - European Commission).

21 ITC experience: PV RO (3/6) DESSOL includes a control system that optimizes the production of desalinated water depending on the amount of solar radiation at the target site, the characteristics of the water to be treated, and paying attention to the service life of its components, especially the RO membranes. A noteworthy aspect of the system is the use of batteries. The DC voltage produced by the PV field goes to the batteries through a charge controller. Energy from the batteries is converted into AC in the inverter to supply electricity to the different loads. This guarantees the production of freshwater even in days when there is less solar radiation and maximises the production of desalinated water. Different designs with respect to capacities and raw water source < 3 kwh/m 3 (SW desalination) 8-10 hours average daily operation Costs (CAPEX): /m 3 installed capacity (brackish water - seawater)

22 ITC experience: PV RO (4/6) Autonomous PV-RO system in Ksar Ghilène (Tunisia) - Uninterrupted 8-years operation Generation system PV field : 10.5 kwp (70 PV modules) Batteries: 660 Ah C10, at 120VDC Charger- Inverter: 10 kw Water system Feed water salinity: 4,5 g / L BWRO plant: 50 m 3 /day (2.1 m3/h) Recovery: 70% Water storage tank (50 m 3 ; 3 days)

23 ITC experience: PV RO (5/6) 4 Autonomous PV-RO units in Morocco (since 2008) Raw water is brackish water from inland wells (salinity g/l). BWRO unit (1 m 3 /h) - PV field (4 kwp). Co-funded by EU, MEDA-water programme.

24 ITC experience: PV EDR (6/6) Brackish water PV-EDR pre-commercial desalination unit (since 2010) A stand-alone (off-grid) 4 m 3 /h commercial EDR plant driven by solar PV energy has been designed and tested at ITC-Pozo Izquierdo premises. EDR plant (<2 kwh/m 3 ) DC/DC PV field Direct current from PV field powers the desalination process in the ED stack. Different internal PV field modulations according to the daily solar irradiation. Each modulation is able to work at different I DC -V values depending on the serial-parallel PV arrangement. For a wide range of solar irradiation (G=250 1,100 W/m 2 ), the ED stack produces the best possible product quality depending of the modulation used in each instant.

25 EUROPEAN RENEWABLE ENERGY DESALINATION ACTION GROUP

26 Main Objectives Renewable Energy Desalination Improve RE-desalination technology and reduce its costs. Establish an economic and institutional support system for RE-desalination. Increase awareness on RE-desalination. Bring new technologies to the market.

27 Members Renewable Energy Desalination Lead: CIEMAT (Research Centre for Energy, Environment and Technology) (ES) Research: ITC (Canary Islands Institute of Technology) (ES); Universities of: Palermo (IT); Aston (UK); Evora (PT); and Agricultural of Athens (EL); Fraunhofer Institute (DE); CRES (Centre for Renewable Energy Sources & Saving) (EL) Industry: Solar Spring (DE); Abengoa Water (ES); Aquaver (NL); Elemental Water Makers (NL); Trunz Water Systems (CH); WIP-Renewable Energy (DE); European Desalination Society (EDS) Contact: Guillermo Zaragoza

28 Main Activities Renewable Energy Desalination Coordinate and promote R&D&I on RE-desalination Support development and commercialization of RE-Desalination products Raise awareness about the technology and demonstrate its market potential Establish a long-term network to act on specific areas that face water problems Support development and promotion of legal structures and policies Disseminate the activities and increase networking

29 Thank you for your attention! ITC: RENEWABLE ENERGIES and WATER TECHNOLOGIES for the sustainable development of Islands and Remote Regions Tel: