Liberalisation of energy markets has led to tremendous growth in message exchange between existing and new market players – system and network operators, data collectors and so on. The increase in the number of consumer groups that have free choice of supplier has meant an increase in the number of market players, in the different types of message, and in the number of messages exchanged. This trend imposes heavy requirements on functionality, performance and security of the communication networks used.
Standardisation of the message exchange is a necessary condition for a market to be really open. Most energy markets started on a national or regional basis. In the Scandinavian countries the regional NORDEL market opened several years ago, with different price regions and power exchanges. This market and its solutions for standardisation of message exchange was an example for many other countries such as the Netherlands, Germany and Spain. Today new methods, techniques and standards for message exchange have been introduced.
Private networks are used to transport messages for security and performance reasons, but there is a trend to use more and more open networks like the Internet. Message exchange with external parties using public networks calls for strict security measures. Security is often regarded as ensuring the confidentiality of data during transport, but aspects such as integrity and non-repudiation are just as important.
When there is a dispute about the contents of a message, there must be a way to prove that the document has not been tampered with, and that it originated in the sending party’s domain. In the current market the number of transactions is often too high to be checked manually, and thus an automated and reliable way to do this is needed. Digital signatures can help, since they include proof of integrity as well as the identity of the sender.
With traditional techniques like EDI, there is no document level security. If a sender and a receiver have two different copies of a document, there is no way to establish which is the original and which the fraud. Traditional EDI strongly relies on transport level security, either on private networks or on encryption during transport. But this doesn’t guarantee anything about the content of a message, and there is no real proof that will help in court in the event of a dispute.
STANDARDISATION OF MESSAGE FORMATS
EDIFACT is one of the early formatting techniques defined by UN/CEFACT to create open trade markets. In the energy industry this formatting standard was embraced by the European gas transmission companies to create the EDIG@S standard, now being used for communication with transmission system operators.
In the early stages of the NORDEL market, EDIFACT was the basis of its EDIEL communication infrastructures. In the Netherlands it was the basis for the EDINE standard and in Germany for the VDEW message definitions. Most countries still create their own standards. Although the basis is the same (EDIFACT) the resulting messages are different. This approach hinders the opening of global markets, which is why initiatives are underway to work towards international standardisation.
With the increasing use of the Internet, XML message formatting was introduced. UN/CEFACT has also begun working on a successor for its EDIFACT standard: ebXML.
We see a trend towards replacing EDIFACT messaging with XML messaging. New standards for exchanging schedules are already formatted in XML, and XML is being considered for enveloping EDIFACT messages during transport through ebXML message handling systems. The issue of migration is important, because the industry has already invested substantial amounts in conventional standards such as EDIFACT. The power industry will be reluctant to accept new standards when the advantages are not clear, even if smooth migration is offered.
The European Transmission System Operators (ETSO) released a market model and XML-based message structure in 2002 for the exchange of schedules (the ESS standard). This standard will be used in Germany and Austria, starting in 2003. Last year the European Federation of Energy Trading companies (EFET) defined an XML-based messaging system for exchange of deals and confirmations.
The task of technical committee 57 of the IEC is to define communication protocols for the power industry. Working Group 16 of TC57 completed a communication infrastructure definition with an example implementation based on ebXML early in 2003. This infrastructure comes with migration paths for existing EDIFACT-based networks.
EBXML, UN/CEFACT AND OASIS
EbXML (Electronic Business using eXtensible Markup Language) sponsored by UN/CEFACT and OASIS, is a modular suite of specifications that enables enterprises of any size and in any geographical location to conduct business over the Internet. Using ebXML, companies will have a standard method to exchange business messages, conduct trading relationships and communicate data in common terms.
UN/CEFACT is the United Nations body whose mandate covers policy and technical development in the area of trade facilitation and electronic business.
OASIS is the international, not-for-profit consortium that advances electronic business by promoting open, collaborative development of interoperability specifications. OASIS operates XML.ORG, the non-commercial portal that delivers information on the use of XML in industry. The XML.ORG registry is an open community clearinghouse for distributing and locating XML application schemas, vocabularies and related documents.
EBXML AND SECURITY
Relatively new standards like XML Signature are created to ensure the persistent integrity and sender identification of a document. For the energy industry, committees like the IEC look at these new standards for use with further standardised market communications. Standardisation is important, since the cost of building and maintaining communication infrastructures is high.
Building a generic communication infrastructure that would serve all different kinds of messaging applications is challenging, since security and reliability requirements differ considerably. Trading deals with a big financial risk, that have to be acknowledged almost in real-time, are very different from messages that contain measurement data, where confidentiality and speed is less important. Fortunately messaging solutions like ebXML are flexible. Users can indicate when sending each message whether it should be transported as confidential (using only secure transport); how time critical it is (specifying how fast an acknowledgement should come back) and so on. So one solution can fit all!
It is interesting to compare the evolution of message handling systems with e-mail. Fifteen years ago there were many flavours – remember UUCP, X.400, CCmail and Compuserve mail – all with different address conventions and giving problems when mail had to be exchanged to another mail system. Today if someone gives an e-mail address you don’t have to ask what kind of address it is: it is Internet (SMTP) mail.
We see the same evolutionary process with secure and reliable messaging solutions. Message-oriented middleware like the IBM MQ-series has existed for years, but is too proprietary and expensive to become a generic standard. EbXML message handling fulfils the requirements of a generic message handling system, and is backed by standardisation bodies like UN/CEFACT and OASIS.
The question remains whether the market will adopt the standard. Because ebXML is often associated with more complex concepts like business process orchestration and repositories, it tends to be overlooked. A potential competitor might be Webservices. Though reliability and security for Webservices have not yet been finalised in (open) standards, industry groups are working on this. We expect that ebXML message services and Webservices will influence each other strongly and will even to some degree join forces.
The first applications in the energy industry have already taken place: ERCOT (the Electric Reliability Council of Texas) replaced their FTP solution with ebXML message handling. VENCorp (the Victorian Energy Networks Corporation) has recently gone live with an industry-wide B2B implementation using the ebXML messaging infrastructure, carrying an aseXML document as the payload. The aseXML is the Australian energy industry’s data description language.
TESTING AND CERTIFICATION
The advantages of using standardised communication protocols are numerous:
- Enable hybrid IT infrastructures (different IT suppliers).
- Create open markets.
- Availability of migration paths.
- Availability of expertise.
Another important advantage is that test facilities will be commercially available to analyse communication networks and prove that vendor implementations are working according to the standard. With respect to testing, different approaches can be recognised – interoperability testing, conformance testing and performance testing.
Interoperability testing evaluates the possibility of data exchange between systems of different vendors. If communication is possible the test result is positive. This does not imply that the data exchange is working according to standard specifications, however.
Conformance testing will reveal if a vendor’s implementation complies with the standard specifications. To be able to prove compliance, the vendor’s system is connected to a reference test system that is maintained by a test organisation. When implementation differences occur, the organisation that maintains the standard specifications will take a decision and the party that interpreted them incorrectly will change its implementation. TSOs will perform the market participant certification in most power markets. Vendors can have their IT systems certified to build trust in the product and advertise compliance with the standard.
Performance testing evaluates the IT system’s behaviour in stress situations, particularly when a backlog of messages must be processed after a communication breakdown.
Testing is particularly valuable when new standards or versions thereof are introduced. In the early lifecycle phase of a new standard, the testing activity will discover interpretation differences, ambiguities and ‘holes’ in the standard. Feedback to the organisation that maintains the standard will improve the specifications.