Supply and Demand Management, a key piece in the energy puzzle
Climate change, growing populations and electrification of energy use, cost efficiency plus many other factors cause decision makers, engineers and researchers to rethink the power system. It has to support generators with random output, distributed energy resources and new loads such as electric vehicle chargers, electric heat pumps, etc.
In this new era, keeping the balance between demand and supply, as well as using transmission and distribution capacity as economically as possible, without overloading, are major challenges. One potential piece in this puzzle is intelligent management of (distributed) supply and demand – or in other words: the integration of these new users of the power system into power markets and schemes for balancing and protection. International standardization of aspects such as interfaces, performance and safety in this field can provide many benefits. However, this endeavour is not without challenges. Understanding and recognizing these is a step towards success.
Embrace a multidisciplinary approach
The fundamental challenges to be solved with SDM (supply and demand management) are electrotechnical in nature. However, managing loads and generation at locations which are several orders of magnitude greater than today, requires massive online distributed optimization systems and communication infrastructures. Moreover, the flexibility used in SDM deployments originates from commercial buildings, homes, industries and other ‘grid users’ that do not have power system operations as their main task. This requires careful design of control and compensation strategies.
While there is no fundamental incompatibility between electrotechnical, ICT, and socio-economic design principles, those who practice them, clearly have different backgrounds and ‘languages’. When developing standards in this field, all these different viewpoints need to be covered – from the business processes and services which need to be supported by the system under consideration, to the information exchanged, the electrotechnical behaviour, etc. More importantly, their interrelationships should be clearly defined.
Cater for variations
While from an electrotechnical perspective, the energy conversion chain shows large similarities throughout the world, the way the power utilities sector is structured varies greatly between countries. It ranges from vertically-integrated government-owned power utilities, to very liberalized markets with possibilities for competition on a range of services.
SDM and Smart Grid
Moreover, SDM is a Smart Grid application area which causes shifts in which organizations take on which roles, the introduction of new roles and the entrance of new players. As such, it has the potential to fundamentally change the structure of the power utility market/sector. As SDM can be deployed in various use cases, from local grid oriented optimizations, to commercial portfolio optimization, its standardization touches many elements in the power utility vertically. A major challenge in the standardization of SDM is its robustness to changes in the market structure.
Modelling the most fundamental roles (stereotypes of parties) in the context of SDM is a key tool in ensuring this. As an example: introducing a simple single interface between the power system and buildings is a major barrier for adoption that is waiting to happen. In practice there will be market structures where many different parties aim to use SDM but ‘sharing an interface’ is not straightforward, if possible at all.
Large solution space, design for change
Standardization, setting a norm, requires consensus on subject matter. In the case of SDM it is not necessarily clear what this subject matter is. Even if the requirements (from the various viewpoints mentioned before) are clear, there still is a tremendously large solution space.
Introducing a time-dependent tariffing system or direct load control are straightforward options. However, many new techniques are being developed and experimented with, some more mature than others. Examples include introducing trade mechanisms (transactive control) to smaller consumers and producers, (simplified) power services being provided by new players, etc. Bear in mind that these are just categories in the solutions space
SDM and design for change
All in all, the SDM application area shouldn’t be considered mature. At the same time, the need for SDM solutions is there and waiting for the best solutions to emerge simply does not suffice. Two things need to be balanced from this perspective: 1) standardization of those types of solutions which are promising on the short term; 2) without hampering the uptake of future innovations.
On this point an important anti-pattern is tight-coupling. For example tight-coupling between the SDM approach (from a conceptual point of view) to lower layer communication protocols. Another example is the tight-coupling of the interactions between ‘actors’ in the SDM approach (e.g. expressing a bid in transactive control) and the actual operations of the energy resources (loads, generators, storage).
In other words, simply put, design for change.
About the author
Frens Jan Rumph is a researcher and consultant in the field of IT and Smart Grids at TNO with a background in computer science. His main expertise is in architecture, algorithm and protocol development for ICT intensive service delivery architectures and data infrastructures. Supply and demand management systems, new energy services and their operation and management is the application area he focusses on. He participates in national and international standardization of communication and information specifications for Smart Grids and Electric Mobility. He is a member of the Dutch national mirror committees of IEC TC57 and TC69, CENELEC TC205 and also of the ‘methodology’ working group of CEN, CENELEC and ETSI’s Smart Grids Coordination Group. Rumph was elected as an IEC 2012 Young Professional (YP) Leader at the IEC YP – 2012 workshop in Oslo.