Kythnos micro grid

Laatst geactualiseerd op 30 november 2009

Eilanden en recreatieparken krijgen van de EU nog de ruimte om zich niet te laten overmeesteren door EdF en EON. Zo mag het Griekse Kythnos ook wat experimenteren met decentrale energieonafhankelijkheid.

Kythnos. Supply of 12 buildings.

Eén van de 12 aangesloten huizen op Kythnos

• The test site is a small settlement of 12 houses.
  Generation: 5 PV units connected via standard grid-tied inverters. A 9 kVA diesel genset (for back-up).

• Storage: Battery (60 Volt, 52 kWh) through 3 bi-directional inverters operating in parallel.

• Monitoring: Data logging equipment.

Technische uitdagingen

• Test decentralized control in a real environment with the aim to increase energy efficiency.

• Technical challenges of the Multi Agent System – test negotiation process.

• Test novel features in MAS implementation including communication capabilities.

• Test of new inverters.

Load control

Zon genoeg op Kythnos. Maar je moet de energie zo veel mogelijk gebruiken als die beschikbaar is. Belangrijke verbruikers zijn de waterpompen. Door de werking van deze pompen af te stemmen op de beschikbaarheid van zonnestroom kan diesel worden bespaard. Daartoe worden de 12 huizen uitgerust met een systeem voor load control.

Wat hebben ze geleerd op Kythnos?

• Fully satisfactory performance of the Load Controllers with embedded processors to host the agents.
• Novel techniques successfully tested, such as: negotiation algorithms, wireless communication, CIM based ontology etc...
• Key issue the communication among the Load controllers. Problems in Wi-Fi (due to humidity) and in the PLC (system frequency near 52Hz) affected the system although this did not affect the citizens.
• The Java applications require a lot of memory
• Architecture too complex for such small systems, but offering great scalability.

Dus eigenlijk: de schaal van 12 woningen is te klein. Toch maar beter werken op meso niveau?

En verder?

• The majority of users would prefer a connection to the public grid; they have not developed a special attachment to their PV powered microgrid system.
• Users do not consider taking responsibility for the system or becoming the owners of it, because they are there only during summer vacations and they lack technical knowledge. Need for local support (technician)
• The system operator (CRES) has tried to offer a similar energy service to the users as the public grid and this was not possible, because the conditions and expectations are very different.
• Ecological aspects have not been sufficiently appreciated; users do not see the advantages and the special value of receiving a green energy supply.

Dus dit soort experimenten moet je niet op vakantie-eilanden doen. Maar gewoon op grote schaal, in een real life omgeving en op professionele wijze. Jammer dat de EU het alleen laat gebeuren in recreatieparken en op eilanden :-(

Geschikt voor toepassing op grotere schaal

• Microgrids operation – the way to unlock the full benefits of DER in
  isolated systems. The coordinated operation of several DGs and Loads
  (Consumers) increases the efficiency and provide opportunities for better network management.
• Decentralized MAS based control well suited to manage multitude of DERs and flexible loads with conflicting objectives and different ownerships
• Decentralized control provides cheap solutions, with low communication requirements, without need for central operator
• The solution provides ‘plug and play’ capabilities
• The approach is suitable for large scale systems

KEMA over Kythnos

An interesting example of a micro-grid scheme that has been successfully deployed is in a small valley on the Greek Island of Kythnos. The system in Gaidouromantra, is a single phase micro-grid composed of the overhead power lines and a communication cable running in parallel electrifying 12 houses. This network is used to test centralised and decentralised
control strategies in islanded mode as well as communication protocols that are a major challenge for such micro-grids.

The innovation was initiated by a combination of a manufacturer and research institutions. The manufacturer was developing products for the operation of power electronics for autonomous electricity supply systems and needed a field application to test and develop the hardware and control strategies. The research institutions contributed to the development of the micro grid concept, the control strategies, the monitoring and the analysis of the data. The commercial driver comes from the social and environmental need for the electrification of small settlements in remote areas based on local renewable resources, mainly Renewable Energy Sources, where conventional power supply systems are too expensive to install, operate and maintain.

The benefits obtained from the project were technical, scientific and commercial for the involved institutions and local residents report they are satisfied from the electricity service provided. The power electronics manufacturer (DC to AC inverter6) gained experience for the developed products and owing to the publicity and good operation of the system has opened new markets. We understand that several hundred new installations of similar inverter systems have followed, which is an example of paving the way for roll-out. With the experience and knowledge gained, research institutions have gone on to participate in new R&D projects broadening their expertise.

It is reported that one of the challenges that occurred during the implementation was the fact that consumers were not adequately involved in the management of the micro-grid and as such they had the tendency to overload the system. This led to some shut downs in the summer period, when all the residents are present and increase the energy demand. It was found that the consumers do not have the necessary technical competence to take over the responsibility for managing the electrical micro-grid system even at a basic level. Currently there isn’t a viable scheme for the operation of the system by the users, which may be a key issue to address for remotely located systems. The energy supply follows the model of the regular energy service provided by the local electricity utility, although the network conditions
and the basis of the energy supply are very different.

The initial installation was financially supported by a European Union program (JOULE) followed by further financial support within the EU Framework Program VI. The investment cost in terms of hardware and installation of the infrastructure including a 3-phase low voltage grid with a total length of about 700 m for the electrification of 12 holiday houses was €280,000. This excludes the cost of monitoring equipment and the work of the engineers of the project consortium institutions that designed and implemented the project.