Solar thermal systems and hydrogen

Duration: 01.07.2009 - 30.06.2012

In brief: In the "CUVEwaters" project, six multi-stage desalination plants were installed in Akutsima in northern Namibia to contribute to the drinking water supply for the approximately 500 inhabitants.

In Namibia, the driest country south of the Sahara, the north is the most densely populated area with 42 per cent of the country's population. The aim of the joint project was to improve the living conditions of the people in Namibia through integrated water management.

Together with the Jülich Engineering Office for Energy and Environmental Technology, the Solar Institute Jülich has developed a multi-stage desalination system (MSD) for solar thermal water desalination, which is particularly suitable for remote areas with weak infrastructure due to its low-maintenance and robust operation and produces between 60 and 80 litres of drinking water per day, depending on the type of collector. Operation does not require any electrical energy, as the heat supply to the enclosures is purely thermosiphonic.

As part of the project, six such MSD systems were installed in Akutsima, in the north of Namibia, at the end of 2010 and successfully contributed to the drinking water supply for around 500 residents.

Further information can be found under the following link: http://www.bmbf.wasserressourcen-management.de/de/106.php

Project partner:

• Jülich Engineering Office for Energy and Environmental Technology (IBEU)

Funded by:

• Federal Ministry of Education and Research

Project start: August 2017

The aim of the project is to improve the transient operation of solar thermal tower power plants with molten salt as the heat transfer medium with the help of model-based control and operational management methods. To this end, the Solar Institute Jülich, together with partners from research and industry, is developing a model predictive control (MPR) for the operation of the filled receiver and an operating assistance system (BAS) for the operation of the transition between the unfilled and filled receiver.

To map the dynamic behaviour of the receiver, the fluid and component models developed in the DynaSalt and HPMS projects are being further developed. Simplified models are also being created for the MPR and the BAS, which make it possible to carry out model-based process prediction during operation. Finally, the SW framework used in the SiBops project will be further developed and the MPR and BAS will be implemented and tested there.

Project partners:

• German Aerospace Centre - Institute for Solar Research
• Institute for Control Engineering at RWTH Aachen University
• LeiKon GmbH
• General Elctric (Switzerland) GmbH

Funded by:

• Federal Ministry for Economic Affairs and Energy

Project duration: 01.10.2024 - 30.09.2025

In the research project "High-Flux Receiver Camera for the Calibration of Heliostat Fields" (HiRecCam) of the Solar Institute Jülich (SIJ) of FH Aachen, a system is being developed with which the calibration of heliostats of a solar tower power plant can be carried out in real time. The heliostat field calibration system consists of a highly specialised camera system that is installed in the area of the receiver, measures the alignment of the heliostats and corrects it if necessary. The calibration system is to be developed to market maturity. More details on the concept of the calibration system and initial results from a previous research project are published here:

Sattler, J. C., Schneider, I. P., Angele, F., Atti, V., Teixeira Boura, C., & Herrmann, U. (2024). Development of Heliostat Field Calibration Methods: Theory and Experimental Test Results. SolarPACES Conference Proceedings, 1. https://doi.org/10.52825/solarpaces.v1i.678

The project is supported by the Project Management Organisation Jülich.

Funding is provided by the state of North Rhine-Westphalia from the ERDF/JTF programme NRW (NRW patent validation)

Duration: 01.10.2010 - 31.12.2016

The idea of using sand as a storage medium for thermal energy is the basis of this project. Sand's resistance to high temperatures, high availability and low material prices make it an excellent storage material, and the aim of the project is to develop a process for transferring heat from air at temperatures of up to 700°C into sand.

In co-operation with the DLR, the properties of various sands and bulk materials were tested in laboratory trials for their suitability as a heat transfer medium and as a heat storage material. Based on this, a test facility for direct heat transfer from air to sand was designed and built. This will be used to investigate the behaviour of the sand during operation.

This heat exchanger is to be used to realise bulk heat storage in solar power plants. Another conceivable application is in industrial processes for exhaust air heat recovery.

Project duration: 01.10.2014 - 31.12.2016

In the HPMS project, a highly efficient receiver technology with molten salt as a heat transfer fluid is being developed in cooperation with partners from research and industry.

The project aims to reduce the costs of solar tower power plants with molten salt as a heat transport and storage medium by developing a highly efficient receiver system for the next generation of salt tower power plants. The receiver and the solar high-temperature cycle (receiver system) are being optimised from a technical and economic point of view. Both high-flux density and high-temperature receiver concepts are currently being considered as the next generation of salt tower power plants.

By selecting the most promising receiver concept and through detailed design optimisation, the efficiency and service life of the receiver are to be improved and the costs reduced. To this end, improved material concepts and innovative coatings are taken into account.

In the receiver system, the losses that occur during operation and start-up and shut-down processes are to be optimised, thereby significantly reducing operating costs. For a subsequent project phase, the basic engineering for a test receiver system will be created based on the results of the project.

Project partner:

• German Aerospace Centre | DLR
• Babcock Borsig Steinmüller GmbH | BBS
• Bilfinger Piping Technology GmbH | BPT
• M + W Germany GmbH | M+W
• STEAG Energy Services GmbH | STEAG
• Salzgitter Mannesmann Forschung | SZMF
• Outokumpu VDM GmbH | as associated partner
• BASF | as associated partner

Project duration: 01.12.2016 - 31.12.2019

In the "Indiref" project, a process of indirect solar-heated reforming for the production of methanol from carbon dioxide and natural gas is being further developed. The conventional production of synthesis gas, which is the starting product for many chemical products such as methanol, causes significant carbon dioxide emissions. Emissions can be greatly reduced by using concentrated solar radiation. Carbon dioxide recycling in the process further reduces emissions. In this way, the utilisation of solar energy can be extended to the chemical industry.

The focus is on the development of the reforming reactor and a modified solar receiver for this application, which can be technically realised and tested under solar conditions. In order to maximise the efficiency and cost-effectiveness of the overall system, a process simulation model will be developed in parallel and validated using the test results. Based on this, a virtual upscaling of the process is carried out in order to assess the technical and economic potential for a market launch.

So far, the solar-heated reforming reactor has been developed for the production of synthesis gas. With the help of CFD simulations, the SIJ achieved a particularly effective heat transfer and synthesis gas generation for the bayonet tube reactor concept developed, on the basis of which a test reactor was constructed. The test setup was constructed as part of the project in the Synlight (DLR's artificial sun) in Jülich, where tests with artificial solar radiation are subsequently carried out. A process simulation of the solar-heated reforming plant was modelled and simulated on an industrial scale using Dymola software.

Project partner:

• German Aerospace Centre e. V.
• Hilger GmbH
• Hille & Müller GmbH

Funded by:

• Ministry of Economic Affairs, Innovation, Digitalisation and Energy of the State of North Rhine-Westphalia using ERDF funds

Link to the PVeCarport homepage: PVeCarport

Project start: October 2019

A significant proportion of today's greenhouse gases and air pollutants are emitted by the transport sector. Electromobility represents a promising opportunity for the sustainable and environmentally friendly transformation of road transport: Electric vehicles produce fewer pollutants and CO2 emissions compared to combustion engines. This effect is significantly enhanced if the required electricity is provided by renewable energies. With the increasing expansion of electromobility, the demand for electricity generated from renewable sources as well as a nationwide charging infrastructure and smart solutions for relieving the load on the electricity grids is also increasing.

In the PVeCarport project, the Solar Institute Jülich is developing a digitalised photovoltaic energy carport system for large-scale parking spaces. The system consists of a PV carport enclosure, several charging stations and stationary and mobile battery storage units. The focus of the development work is on networking the subsystems and developing a digital solution for controlling and managing the enclosure's energy. This means that the enclosure can be used not only as a solar charging station for charging electric vehicles, but also as a virtual power plant for providing balancing energy.

In addition, the individual wishes of the vehicle owner, such as the parking duration or desired charging capacity, are to be incorporated into the system control via a mobile application programme (app). This in turn enables flexible and cost-effective charging of electric vehicles.

Project start: May 2017

The aim is to improve the quality of drinking water in rural regions of Morocco. The project realises an environmentally friendly and ecological water resource management of Morocco through renewable energies.

At the end of the project, a solar demonstration plant for water desalination will be installed and put into operation near Oujda, Morocco, thus providing clean water of high drinking water quality for the local population. The aim is to offer the technology, which has been perfected and thoroughly tested by the Solar Institute Jülich, primarily on the Moroccan market at favourable prices.

As part of the project, scientific analyses will be carried out with regard to the price-performance ratio of the technology. Based on this, new innovative designs will be developed and system simulations carried out for further optimisation. A prototype will then be built and extensively tested.

The solar desalination plant offers a cost-effective and_CO2-free drinking water supply. The desalination system developed by the Solar Institute Jülich and Ingenieurbüro für Energie- und Umwelttechnik Jülich (IBEU) has many potential applications in arid, sunny regions of North Africa (e.g. settlements, farms, schools and small hotels) due to its simple design, handling, maintenance options, cleaning options and efficient operating behaviour.

Project partner:

• Mohamed Premier University (MPU)
• Subcontractor: Jülich Engineering Office for Energy and Environmental Technology (IBEU)

Funded by:

• Federal Ministry of Education and Research

Project duration: 01.10.2012 - 31.03.2017

The ReSol project is investigating the retrofitting of existing parabolic trough power plants (PRK) with solar towers in order to utilise the synergies of both technologies and reduce the levelised cost of energy to an attractive level.

The project aims to further increase solar power generation. The retrofit, by integrating a solar tower, promises to improve efficiency and increase the flexibility and availability of the enclosure. The retrofit potential is analysed with regard to the following retrofit features (A and B) (see figures):

A: Retrofit to increase yield while maintaining the size of the power plant. This involves dismantling part of the existing solar field and erecting a solar tower on the freed-up area.

B: Retrofit to increase the nominal output. Here, the overall thermal performance is increased by adding a solar tower in order to find the optimum ratio of trough and tower enclosure.

Project partner:

• MAN Diesel & Turbo | MAN
• German Aerospace Centre | DLR

Project duration: 01.06.2022 - 31.05.2025, extended until 31.12.2025

Four different solar cookers are being developed, built and tested in the SoCoNexGen project. The solar cookers are intended for indoor integration and three of the four models are equipped with large energy storage units to ensure flexible cooking behaviour. The energy storage system consists of a thermal sand storage system in two models and an electric battery storage system in one model. Depending on the model, the energy is provided by solar thermal collectors, PV collectors or a combination of both systems.

In the project, an international consortium from Morocco, Algeria, Tunisia, Portugal and Germany is working together to develop and test the solar cookers. Within this framework, test campaigns are planned at the partners' locations, which will be supplemented by the creation and utilisation of detailed simulation models. In addition, potential studies for the use of the cookers in the North African region will be carried out. The aim is to develop robust and easy-to-use solar cooker systems that achieve a high level of acceptance among the local population.

Partner:

• Solar Institute Jülich (Germany)
• Engineering office for energy and environmental technology (Germany)
• low-tec gemeinnützige Arbeitsmarktförderungsgesellschaft Düren mbH (Germany)
• Universidade de Évora (Portugal)
• Université Mohammed Premier Oujda (Morocco)
• Université de Tunis El Manar (Tunisia)
• Centre de développement des énergies renouvelables (Algeria)

Funded by:

• Federal Ministry of Research, Technology and Space
• LEAP-RE project (The LEAP-RE project receives funding from the Horizon 2020 Research and Innovation programme, grant agreement 963530)

Further information on the LEAP-RE website.

Project start: 01/07/2010 - 31/12/2013

The Jülich solar thermal test power plant (SVJ) is the first power plant of its kind in the world to be built in Germany. This project serves to improve the use of storage technology and the associated reduction in power plant operating costs. The focus of this project is to use new numerical simulation tools to increase the efficiency, degree of utilisation, flexibility and operating time of the storage system. The optimisations should result in an innovative storage system concept that is predestined for use in solar tower power plants.

Project partner:

• KBA-MetalPrint GmbH | KBA
• Kraftanlagen München GmbH | KAM

Link to the EDITOR homepage: EDITOR

Project duration: 01.10.2015 to 30.09.2018

The objective of EDITOR is to demonstrate and verify the base load capability and performance of a solar thermal system designed for continuous operation. During the project period, a system consisting of a medium-sized parabolic trough collector, concrete heat storage tank and boiler will be installed in Cyprus. The system will produce saturated steam and feed it into the steam system of a beverage manufacturer.

The parabolic trough collector uses an innovative vacuum receiver to heat a new, environmentally friendly thermal oil to over 400 degrees Celsius. An innovative new concrete heat storage system stores the heat obtained so that it can be used for the production of saturated steam at times when there is no (sufficient) direct solar radiation.

The project includes the technical activities of installation, commissioning and operation of the enclosure, as well as commercial aspects such as feasibility in terms of upscaling, identification of future customers and the accompanying communication process with the potential market.

Project partner:

• protarget AG
• Cyprus University of technology
• CADE Soluciones de Ingeniería, S. L.
• German Aerospace Centre e. V.

Project start: November 2017

The aim of the HELIBO project is to reduce the cost of solar-thermally generated electricity through technical developments to improve the efficiency of heliostat fields in operation. Measures, in particular improved measurement, control and regulation technology for the heliostats, have significant potential to increase the utilisation of the mirror surface and future enclosures by 10 - 15 % are expected.

The Solar Institute Jülich has the research goal of improving the tracking accuracy of two-axis tracking heliostats with a new, precise and fast online control method based on laser technology. With this patented online control method, laser beams are emitted from a central position onto a mirror to be measured. Due to scattering processes in the atmosphere, the beams reflected by the mirror become visible to cameras and are photographed. To determine the orientation of the heliostat, the photos are automatically analysed using an evaluation algorithm and the correction of the orientation for the heliostat in the azimuth and zenith angle is calculated.

In the project, a prototype of a laser system with tracking will be produced by a project partner in accordance with the requirements developed by the SIJ in order to carry out the tests in the heliostat field. The prototype should make it possible to measure a small group of heliostats automatically.

Project partner:

• German Aerospace Centre - Institute for Solar Research
• CSP Services GmbH
• LeiKon GmbH
• Radiant Dyes Laser & Accessories GmbH

Funded by:

• State of North Rhine-Westphalia

Project duration: 01.09.2013 - 31.08.2016

The aim of the project is the investigation, development and assessment of a closed helium turbine cycle in conjunction with a pressurised solar receiver. To this end, various power plant concepts are modelled using the EBSILON®Professional simulation software. Furthermore, a helium receiver is being developed, constructed and tested on a laboratory scale. The concentrated solar energy is imitated by a near-infrared radiation module.

Benefits for the general public: Solar-powered gas turbine processes have great potential to reduce the costs of solar thermal power generation. Helium has very good thermal properties. This means that heat exchangers can be smaller in size. In addition, no corrosion processes need to be taken into account when using helium. Another advantage is that helium has a low pressure loss in the circuit. This has a positive effect on the overall efficiency.

Project funding: Federal Ministry of Education and Research

Project partner:

• Heaeus
• Enertech
• German Aerospace Centre e. V.

Project start: March 2018

The MHF project pursues the overarching goal of reducing the investment costs for a heliostat field by developing, manufacturing and qualifying a mass-production-capable and material-saving microheliostat. This corresponds to a drastic reduction in investment costs in the heliostat field and thus a significant overall reduction in investment costs for solar thermal tower power plants. The competitive LCOE achieved in this way should accelerate the expansion of CSP technologies and bring about a further reduction in environmentally harmful greenhouse gases.

To this end, the Solar Institute Jülich, in cooperation with Hilger GmbH, has developed a new heliostat technology, the microheliostat (MH). The first MH prototypes have already been built and tested under laboratory conditions. The results showed that this heliostat technology is suitable in principle for use in solar thermal power plants. In the MHF project, the microheliostats are to be investigated on an industrial scale, i.e. in a larger test field and under real conditions. In order to fully exploit the advantages of the MH concept, the microheliostats are also to be optimised for mass production.

So far, the source code of a proprietary ray tracer software "SolCal" has been extensively revised for the design of the MH fields. The results of the simulations carried out have been analysed and the optimum MH field set-up has been determined. The SIJ has created CFD and FEM models to simulate the temperature and mechanical loads on the microheliostat. In addition, an initial series of tests with a small MH prototype has already been carried out and the functionality of the acquired laboratory equipment for measuring mirror surfaces has been partially proven.

Project partner:

• Hilger GmbH
• HELIOKON GmbH

Funded by:

• Ministry of Economic Affairs, Innovation, Digitalisation and Energy of the State of North Rhine-Westphalia using ERDF funds

Project start: April 2017

In this definition project, contacts are being established with processing companies and the state university in southern Kazakhstan. The overarching goal is to develop a supply unit for the rural population in Kazakhstan. This supply unit will use solar applications to obtain drinking water from the air and provide heat and electricity. Due to high temperature differences between summer and winter, the supply of water and heat is a major challenge in rural areas.

In the first part of the planned project, the needs and possibilities in Kazakhstan will be analysed. In the second part, a prototype of the supply unit will be designed and produced. Field tests of the enclosure are then planned in Kazakhstan to test the security of supply.

You can find more details here.

An article by Deutsche Welle can be found here.

Funded by:

• Federal Ministry of Education and Research

Brief information: Application of generic algorithms to optimise the economic efficiency of small heliostat systems (micro heliostats)

The heliostat field accounts for around 50 % of the total investment costs of a solar tower power plant. The SIJ has set itself the task of developing new heliostat concepts in order to reduce these investment costs. The micro heliostat is a two-axis mirror system that tracks the sun. In contrast to conventional heliostats, a large number of individual small mirror facets are coupled together and track the sun synchronously. The tracking takes place within a permanently installed module box. The aim of the project was to develop a numerical optimisation tool to optimise the economic efficiency of innovative concentrator systems as early as the conceptual design phase. To assess the microheliostats, they were analysed in the context of a power plant. For this purpose, simulation tools were developed that determine a resulting radiation flux distribution on the absorber, taking into account the optical effects (ray tracing).

Project duration: 01.09.2012 - 30.06.2015

Project partner:

• Hilger GmbH, Wipperfürth
• Jokey Plastic Wipperfürth GmbH

Funded by:

• Federal Ministry for Economic Affairs and Energy of the State of North Rhine-Westphalia

One of the best renewable technologies for the supply of industrial process heat is concentrated solar thermal energy (CST), especially as it can supply heat on demand with the help of thermal energy storage (TES). The main objective of the S3 industrial research project is to realise a next-generation smart solar system for steam generation based on CST technology. For this purpose, an existing parabolic trough collector (PTC) and a TES, installed at KEAN Soft Drinks Ltd. in Limassol, Cyprus, as part of the previous EDITOR project, will be further developed. The proposed intelligent control system will have predictive and automatic features. One goal is to improve the overall performance of this system and make a transition to Industry 4.0. The project partners are listed below along with selected details of their work content.

• Protarget AG
• University of Patras
• German Aerospace Centre e.V.
• Solar Institute Jülich

Associated partner:

• Cyprus University of Technology

Protarget AG (coordinator): The centrepiece of the smart solar system is a main control unit (MCU) developed by Protarget. The MCU receives various inputs such as CST and TES sensor data, factory boiler sensor data, factory production schedule, DNI and pollution forecasts and real-time data. The MCU selects a suitable control strategy based on these inputs. With the development of next-generation control strategies and new hybrid modes, the operation of the enclosure will become even more efficient.

University of Patras: A newly developed soiling prediction tool will be used to predict the reduction in reflectivity of parabolic trough mirrors due to dust deposits. Based on the soiling forecast, the MCU can decide and suggest dates for cleaning the mirrors. This avoids wasting water and reduces costs, as mirror cleaning is carried out as required and not according to a fixed schedule. The costs for maintenance personnel can also be reduced.

German Aerospace Centre (DLR): DLR will test the HELISOL® XLP heat transfer medium with the aim of achieving higher system efficiency. In particular, the formation kinetics of gases in the 300 - 400 °C range will be analysed. This information will be linked to the solubility of the gases in order to define suitable venting strategies to control the gas concentrations in the system. Optimal maintenance of the HTF system will be determined to control the hydrogen concentration.

Cyprus University of Technology (CUT): The associated partner CUT supports the project and carries out e.g. the inspection of the CST system, the maintenance of a weather station and mirror reflection measurements.

Solar Institute Jülich (SIJ): SIJ focuses on the development of a DNI forecasting tool with the aim of increasing the amount of process steam production and system performance. The DNI forecast data is used by the main control unit (MCU) to decide on the operating strategy for the next day, including when to load or unload the TES. The DNI forecasting tool will use freely available cloud forecast data with a resolution of 1 hour as input. The forecasting tool will be tested on and optimised for the KEAN CST enclosure. The SIJ is also carrying out simulation work to assess the fossil fuel cost savings for the KEAN plant with an enlarged CST enclosure.

All partners: A very important aspect of the project is the dissemination of the project results at the end of the project through publications and a dissemination workshop. The planned dissemination workshop, to which stakeholders from industry and politics as well as the media will be invited, will take place in Cyprus or online towards the end of the project.

Funded by: Ministry of Innovation, Science and Research of the State of North Rhine-Westphalia

Project duration: 01.02.2012 - 31.05.2015

The aim of the project is to increase the efficiency of solar tower power plants through software-based measures. The work focuses on innovative methods for heliostat field control and efficiency-optimised operational management. Building on the partners' preliminary work, software-based methods are being developed and tested at the Jülich solar tower. The methods, which can also be applied to other tower power plant concepts, together with the proof of function at the Jülich solar tower, offer the CSP industry the opportunity to implement them in the near future. At the same time, the research infrastructure at the Jülich solar tower power plant will be upgraded by installing the developed methods and a partially improved heliostat field.

Project partners:

• German Aerospace Centre | DLR
• RWTH Aachen - Institute for Control Engineering | IRT
• RWTH Aachen - Institute for Steam and Gas Turbines | IDG
• Kraftanlagen München GmbH | KAM
• CSP Services GmbH | CSPC
• Stadtwerke Jülich | SWJ
• University of Leuven, Belgium | OPTEC_Group
• LeiKon GmbH

Project start for the SIJ: June 2022

For CSP technology to be cost-effective, highly efficient, flexible CSP technologies equipped with thermal energy storage (TES) must be used. To further reduce costs, it is possible to utilise combined cooling, heating and power (CCHP) systems that can generate additional revenue by meeting the heating and cooling needs of utilities, commercial enterprises or households.

TES4Trig aims to combine the above strategies into a single innovative CCHP system powered by solar parabolic trough collectors (PTCs) and based on the integration of the Organic Rankine Cycle (ORC) and the Ejector Cooling Cycle (ECC) with a low-cost TES system. In modern large CSP enclosures, TES systems with molten salts are usually used. In TES4Trig, a concrete-based solid-state TES is proposed, which has the potential to be more economical, simple and environmentally friendly, but requires investigations to overcome operational obstacles, accompanied by new PTC component designs and cost reductions.

The solar energy stored during periods of excess solar availability is used to generate electricity when needed and to meet space heating needs in winter, while space cooling is generated in summer. To increase the overall utilisation of solar energy, electricity is generated at times when there is no need for heating or cooling. The system will have a control system to increase its flexibility and efficiently adapt the electricity, cooling and heating output to the needs of the consumers. As part of the project, the individual subsystems (PTCs, TES, ORC-ECC module) will be designed and integrated into a TES4Trig prototype, which will be demonstrated on site at a consumer in Greece to prove its feasibility and assess its actual performance in a real operating environment.

Within the TES4Trig project, the SIJ will be responsible for the following main tasks:

• Procurement of a solar measurement station and installation at the TES4Trig site in Greece.
• Development and validation of a simulation model for the TES4Trig system.
• Feasibility study for a scale-up TES4Trig system.

Project partner:

• National Technical University of Athens (NTUA)
• "DEMOKRITOS" National Centre for Scientific Research
• CADE Soluciones de Ingeniería, S.L.
• Protarget AG
• MES ENERGY S.A.
• Solar Institute Jülich of the FH Aachen

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Supported by the:

• Ministry of Economic Affairs, Innovation, Digitalisation and Energy of the State of North Rhine-Westphalia

Project start: September 2016

The open volumetric receiver (HiTRec) technology offers a tried-and-tested, effective and scalable concept for demand-driven solar power generation. HiTRec technology has clear advantages in terms of simplicity and robustness of operation compared to enclosures with molten salt receivers. The higher process temperature also opens up the potential to utilise modern, highly efficient 620°C steam processes.

In this project, new approaches are being developed to improve air receiver technology. Concepts for both short-term and long-term implementation are being developed and tested. The main approach is to modify the geometry of the receiver, including improved recirculation of the hot air. In addition, the efficiency and annual yield are to be increased through optimised operational management.

Project partner:

• German Aerospace Centre | DLR
• Kraftanlagen München GmbH | KAM