از نگاه سازمان بین المللی انرژی (IEA)

مهمترین الویتهای پژوهشی توصیه شده توسط آژانس بین المللی انرژی در حوزه های مختلف انرژیهای تجدید پذیر

منبع:
Renewable energy : RD&D priorities, insights from IEA Technology Programmes / International Energy Agency,

 

Description

 

Paris : OECD/IEA, c2006 
221 p. : col. ill. ; 27 cm. 

ISBN

9264109552

 

The research, development and demonstration (RD&D) priorities by technologies

 

RD&D priorities identified by each International Energy Agency (IEA) Renewable Energy Implementing Agreement are briefly outlined in the following tables.

 

 

Bioenergy

Content

 

Title

Current research efforts in bioenergy include technology development and reliability in areas such as:

 

  • Gasification (for biofuels, IGCC).
  • Biological conversion (for ethanol, biogas, etc.).
  •  Anaerobic digestion (for biogas).
  • Municipal solid waste incineration (for electricity and heat).
  •  Co-firing applications (for electricity and heat).
  •  Flash pyrolysis (for bio-oil).
  •  Production of bioethanol and biodiesel from sugar, oil-based crops and lignocellulosics.
  • Production of biohydrogen.
  • Current research efforts in feedstock technology reliability in areas such as:
  • Short Rotation Forestry (SRF).
  • Woody biomass (state-of-art forest management techniques).
  • Grasses (all pre-treatment operations).
  • Straw (seasonable availability, problems of fluidising bed gasifier).
  • Refuse-derived fuel (RDF) (feeding systems for fluff RDF).
  • Sewage and other industrial sludges (for thermochemical energy applications).
  • Efforts to increase the energy density per unit volume of biomass fuels focus primarily on pelletising.

Current RD&D

  1.  

 

 

Bioenergy (continued)

Content

 

Title

Primary objectives of additional RD&D are to:

  • Promote market deployment of technologies and systems for sustainable energy production from biomass.
  • Actively encourage the maintenance and development of networks of participants involved in RD&D and education, and to provide for the effective dissemination of information on bioenergy.

Short-term technology needs include:

  • Increasing the relative availability of cheap feedstocks in large quantities; the development of fuel quality standards.
  • Improving the efficiency of some basic processes while reducing their costs; innovative approaches in materials.

Medium-term needs include:

  • Further development of the biorefinery concept for biomass feedstocks.
  • Production of ethanol from lignocellulosics.
  • Development of dedicated crops tailored to the requirements of biorefineries.

Long-term needs include:

  • Development of pathways for bioenergy to start playing an important role in the evolving hydrogen economy through gaseous and liquid biofuels.

Additional RD&D

Priorities

 

 

Hydropower

Content

 

Title

The main issues facing hydropower are grouped below:

 

Large Hydropower

The technical challenges are already mostly covered by the few manufacturers of major equipment and the numerous suppliers of auxiliary components and technology. While no major breakthroughs have occurred in machinery, the advent of computers has led to vast improvements in monitoring, diagnostics, protection and control technologies, as well as in many other areas.

 

Small Hydropower

The technical challenges are both a by-product of the large hydro industry and the application of appropriate technology by small manufacturers, organisations and agencies. Small hydropower has a huge variability of designs, layouts, equipment types and material types. It can be said that there is no “state of the art” in small hydropower, but rather a huge body of knowledge and experience in designing and building projects to fit the site and the resources of the developer.

 

Additional energy at existing power plants and dams

One of the greatest opportunities for hydropower is to maximise the energy produced from existing projects through modernisation. Gains of 5% to 10% are not an excessive target for most hydropower owners; where there are significant numbers of dams without generation, the numbers could be much higher.

 

Extension of asset life provides an additional opportunity through the identification of aging and improved maintenance practices, risk assessment, asset management and improvements in surveillance systems.

 

Integration of non-firm renewables including wind-hydro and hybrid systems (e.g., hydrogen) is another area that shows potential.

 

 

 

 

Current RD&D

 

 

 

Hydropower(continued)

Content

 

Title

Additional RD&D can be classified under the categories:

technology, implementation and development, as well as public

acceptance and project approval.

 

Technology

  •  Improvements in efficiency.
  • Reductions in equipment costs.
  • Reductions in operating and maintenance costs.
  • Improvements in dependability (reliability and availability).
  • Integration with other renewables.
  • Development of hybrid systems, including hydrogen.
  • Development of innovative technologies.
  • Environmental technologies.
  • Education and training of hydropower professionals.

Public acceptance and project approval

  • Identification and implementation of appropriate mitigation measures for environmental and social impacts.
  • Reinforcement of acceptance of hydropower as renewable and sustainable.
  • Establishment of renewable premiums and credits for all hydropower.
  • Streamlining legal and financial procedures for hydropower development and the approval process.
  • Conducting impact assessments, including both western and indigenous peoples’ approaches.
  • Implementation of certification of sustainable energy sources.
  • Identification of new hydro sites which meet sustainability criteria.
  • Improvements in public relations.

 

Additional RD&D

Priorities

 

 

Hydropower(continued)

Content

 

Title

Implementation and development

  • Exploration of innovative financing, including sharing of costs for multiple uses.
  • Understanding of the true cost of hydropower compared with

Other energy sources.

  • Establishment of development mechanisms (CDM etc.).
  • Address integration issues with wind and thermal.
  • Address integration into distribution systems.
  • Increase understanding of the risks of decision-making in plant modernisation
  • Develop approaches to add hydro plants to existing dams.
  • Pursue a systematic approach to development that fulfils sustainability requirements.

 

 

Additional RD&D

Priorities

 

 

Geothermal

Content

 

Title

Some of the current priorities being addressed are:

 

  •  Environmental impacts of geothermal energy.
  •  Enhanced geothermal systems such as hot dry rock.
  • Advanced geothermal drilling techniques.
  • Direct use of geothermal energy, including geothermal heat pumps, space heating, etc
  • Encourage use of rural electrification and mini-grid power systems

Current RD&D

 

Some of the specific priorities for additional RD&D could include funding to expedite the completion of current priorities, as well as new topics, and increased production and dissemination of information to support:

 

  • Development of better exploration, resource confirmation and management tools.
  • Commercial development of enhanced geothermal systems
  •  
  • Development of deep (>3,000 m) geothermal resources.
  • Increased geothermal co-generation (power and heat).
  • Reduction of costs of geothermal well drilling, logging and
  •  
  • Increased direct use of geothermal resources for space/district
  • heating and multi-purpose “cascading”.
  • Improved understanding and mitigation of environmental effects
  • Dissemination of appropriate information to stakeholders.

 

Additional RD&D

Priorities

 

 

Geothermal (continued)

Content

 

Title

More general priorities being proposed include:

 

  • Life-cycle analysis of geothermal power generation and direct use systems.
  • Sustainable production from geothermal resources.
  • Power generation by improved conversion efficiency cycles.
  • Shallow geothermal resources for small-scale individual users.
  • Induced seismicity related to geothermal power generation (conventional and enhanced geothermal systems (EGS)).

 

Additional RD&D

Priorities

 

 

Wind energy

Content

 

Title

During the last five years, industry RD&D has put emphasis on developing larger and more effective wind turbine systems, using knowledge gained from national and international generic RD&D programmes.

 

Continued RD&D is essential to ensure the necessary reductions in cost and uncertainty, to realise the anticipated and desired level of deployment, and to improve understanding of how extreme wind situations, aerodynamics, and electrical generation affect wind turbine design.

 

The challenge is to try to find the evolutionary steps which will further improve wind turbine technology, including,

 

  • Large-scale integration of wind turbines into electric grids.
  • Elimination of uncertainties by incorporating wind forecasting results and information on grid interaction with other energy sources.

Current RD&D

 

 

 

Wind energy (continued)

Content

 

Title

RD&D priorities in the mid- and long-term time frame in wind  energy include:

Increase value and reduce uncertainties in areas such as:

  • Forecasting power performance (target of uncertainty of power output (5% to 10%)
  • Reduce uncertainties related to engineering integrity, improvement and validation of standards in terms of providing better understanding of extreme environmental conditions, safety, power performance and noise.
  • Storage techniques                                                                                                                                                                                           Continue cost reductions through:
  • Improved models for aerodynamics/aeroelasticity.
  • Improved site assessment including off-shore.
  • New intelligent structures/materials and recycling.
  • More efficient generators and converters.
  • New concepts including devices such as highly flexible down-wind

machines and diffuser-augmented turbines

  •  Improved stand-alone and hybrid systems that integrate PV or diesel generating systems for remote locations where grid connection is not feasible.

Enable large-scale use through:

  • Electric load flow control and adaptive loads.
  •  Improved power quality (especially in weak grids).

Minimise environmental impacts by addressing issues related to:

  • Compatible use of land and aesthetic integration (e.g., visual impact)
  •  Noise studies.
  • Flora and fauna.

Additional RD&D

Priorities

 

 

 

Photovoltaics

Content

 

Title

New technologies for PV can be divided into two categories:

  • Primarily aimed at very low cost (while optimising efficiency):
  • Sensitised oxide cells.
  • Organic solar cells.
  • Other nano-structured materials.
  • Primarily aimed at very high efficiency (while optimising cost):
  • Multi-junction cells for use in concentrators.
  • e. Novel conversion concepts                                                                                                    

These technologies are still in the early stages of development, except for a and d. Organic (“plastic”) PV is often considered a high-risk, high-potential option. Working devices have been demonstrated, but efficiencies are still low and sufficient stability has yet to be proven.

Primary efforts for further cost reduction focus on areas such as:                      increasing the efficiency of PV components and the PV system as a whole, advanced manufacturing techniques of all PV components, raising the performance and reliability of PV power systems, decreasing energy payback time and reducing environmental impacts.

RD&D in PV is particularly broad in its disciplinary approach, spanning materials science, device physics and chemistry, electronics, robotics, building technologies, electrical transmission systems, and storage of electricity as well as modelling within these different areas.

As market opportunities emerge, two particular aspects arise:

  • The need for a more comprehensive approach on the system
  • The potential for further interaction with existing technologies and industries.

About half of the future cost reduction for PV may result from RD&D in improving materials, processes, conversion efficiency and design. Substantial cost reductions can also be gained through increased manufacturing volume and economies of scale. Increasing the size of components and plants will also reduce costs.

 

Current RD&D

 

 

 

Photovoltaics (continued)

Content

 

Title

Additional RD&D priorities can be categorised as follows:

  • New feedstock production to meet the demand of world
  • market c-Si.
  • Early assessment for immature solar cell technologies, including thin-film manufacturing processes.
  • Better balance-of-system (BOS) components in terms of the efficiency, lifetime and operation of some components, especially inverters and batteries.
  • Performance improvement and further cost reduction of thin-film technologies.
  • Exploration into scientific fields, including nanotechnology,
  • organic thin films and molecular chemistry for novel concepts
  • regarding PV
  • Develop devices with high conversion efficiencies and long-term stability in order to match the expected lifetime of 25 years and more.
  • Building integration, manufacturing issues, quality assurance and standardisation.

 

 

Additional RD&D

     Priorities

 

 

 

 

 

 

 

 

 

 

 

 

Solar heating and cooling

Content

Title

The priority areas for solar heating and cooling RD&D include:

  • Performance of solar façade components.
  • Sustainable solar housing.
  • Solar crop drying.
  • Daylighting in buildings.
  • Advanced storage concepts.
  • Solar for industrial process.

In addition, more effort should be directed towards RD&D projects that are not yet pre-competitive.

Current RD&D

 

A comprehensive and ambitious applied RD&D programme is needed to develop competitive advanced solar heating and cooling systems that can cost-effectively provide 5% to 10% of the overall low temperature heat demand of the IEA member countries. The proposed research priorities are outlined below.

Advanced materials and components including:

  • High performance and cost-efficient materials (e.g., improvement of optical coating technologies, development of low-cost anti-reflective, self-cleaning glazing, and materials with over 20-year durability, including plastic).
  • Advanced solar thermal components (e.g., flat-plate collectors for roof and façade integration, new collectors for medium temperature applications (<250°C), photovoltaic-thermal (PVT) collectors).
  • Advanced thermal energy storage (e.g., development of new materials for storing thermal energy of >0°C to 200°C, including PCMs to allow a reduction of storage volume by at least a factor of three compared to water).

 

Additional RD&D

Priorities

 

 

Solar heating and cooling (continued)

Content

Title

Advanced systems including:

  • Large-scale solar combi-systems for water and space heating (e.g., development and demonstration of solar combi-systems with several hundred kW for multi-family houses, as well as large-scale applications for housing estates and solar-assisted district heating systems with several MW).
  • Solar thermal systems for industrial applications (e.g., more efficient integration of solar energy into industrial processes).
  • Solar cooling applications (e.g., cooling machines for low capacities and machines able to adjust to the solar thermal heat supply, system design, integration and control).
  • Combined solar heating and cooling systems.
  • Building design and integration (e.g., better design integration of solar thermal systems on the building physics – i.e., façade collectors – and HVAC-systems, careful analysis of occupant behaviour, improvement of control shading, glare and window systems).
  • Standards, regulations and test procedures should also be developed.

Additional RD&D

Priorities

 

 

Concentrating solar power

Content

Title

Current development needs and perspectives for significant further cost reductions were identified for:

  • Parabolic trough technology using high temperature fluid (HTF)
  • or direct steam generation (DSG).
  • Central Receiver Systems (CRS) using:
  • molten salt
  • saturated steam
  • atmospheric air
  • pressurised air receiver and dish Stirling systems.

Current RD&D

 

The key priority for RD&D should be to focus on improvements of modular components such as concentrators, heliostats or modular receivers, which are essential cost drivers.

New reflector materials should be low cost and have the following traits:

  • Good outdoor durability.
  • High solar reflectivity (>92%) for wave lengths within the range:
  • 300 nm to 2 500 nm.
  • Good mechanical resistance to withstand periodical washing.
  • Low soiling co-efficiency (<0.15%, similar to that of the back-silvered glass mirrors).
  • New supporting structures should fulfill requirements such as lower weight, higher stiffness, more accurate tracking and simplified assembly.

Storage systems are the second key factor for cost reduction. Development needs are very much linked to the specific system requirements in terms of the heat-transfer medium utilised and the necessary temperature. A particular challenge lies in the development of storage systems for high pressure steam and pressurised, high temperature air, which would lead to a significant drop in electricity costs.

Requirements for storage systems are:

  • Efficiency in terms of energy and exergy losses.
  • Low cost.
  • Long service life.
  • Low parasitic power requirements.
  • Significant improvements in the performance of high temperature receivers are possible, whereas potential for performance improvements in the temperature range below 400°C is relatively small (cost improvements are however possible).

Scaling to larger power cycles (except for parabolic trough systems using thermal oil) is also an important factor reducing unit investment cost, unit operation and maintenance costs, and realising increased performance.


 

 

 

 

 

Additional RD&D

Priorities

 

 

Ocean energy systems

Content

 

Title

Ocean energy systems confront the marine environment in its most energetic location, implying a need for devices that can withstand strong wave climate and/or strong currents, while also fulfilling basic economic and environmental requirements such as low cost, safety, reliability, simplicity and low environmental impact.

Current RD&D includes:

  • More efficient design, the use of low-cost and readily available materials and components, and economies of scale.
  • Better management in the process of deployment and construction to ensure safety.
  • Development of devices that are maintenance free or require low site access for repairs and inspections.
  • Development of low environmental impact devices, including positive environment-impact devices such as an ocean energy farm consisting of multiple devices to help create a wildlife sanctuary. (Marine life is known to thrive on man-made structures, and wave energy systems could be integrated into coastal protection strategies).


 

 

 

 

Current RD&D

 

Additional RD&D to support individual technologies includes:

  • Wave energy systems (e.g., further research in wave behaviour and the hydrodynamics of wave absorption, to allow engineers to design the best devices for specific concepts, incorporating reliability and survivability into design; development of reliable mooring techniques for devices installed in deep water (50m to 400m); and improvement of power take-off systems).
  • Tidal stream current systems based on underwater turbines (e.g., further research into the basic knowledge of current speed along the water column in deep water; development of water tight structures; improvement of turbines and rotors that are more cost efficient and reliable; further research of foundation and installation methods to make them safe, easily replicable and cost-effective; encouragement of further knowledge transfer from the wind energy and shipbuilding industries to improve the efficiency of tidal stream current devices).
  • Salinity gradient (e.g., development of functioning and efficient membranes).

Additional RD&D Priorities

 

 

Ocean energy systems (continued)

Content

 

Title

  • Ocean thermal energy conversion (OTEC) (e.g., development of power technologies, integrated systems and control strategies adapted to the marine environment and to ocean thermal applications; further research on the influence of the environment; development of reliable floating systems including mooring techniques, deep water piping and positioning).

Non-technical issues to research include:

 

  • Resource potential assessment.
  • Energy production forecasting and design tools.
  • Test and measurement standards.
  • Environmental impacts.
  • Feasibility study of ocean energy system farms in order to achieve economies of scale.

Dual-purpose plants that combine energy and other structures (e.g., incorporating a wave concept into a breakwater).

Additional RD&D

Priorities