What Smart Grid utilities really need
In May 2016, there was an inconspicuous news item in the press about the beginning of consumption trading on the energy market. In other words: consumers will receive payment for allocated consumption. Unfortunately, this is one of the first, tangible outputs of the European Commission’s ’20-20-20 strategy’.
The Challenge of Energy Investment
The key question is, how will the necessary investment into the power sector, such as new distribution lines, backup, protection against negative influences of RES, etc., be funded?
Let’s have a look to the effects of the strategy long term… they say that ‘the road to hell is paved with good intentions.’ The main intention of Strategy 20-20-20 was to decrease the carbon footprint – and this will be achieved – however, its impacts are definitely not positive all round.
Grid Instability and Imbalance Regulation
The main negative effects include energy overflow from lower to higher voltage networks and the significant impact of imbalance regulation on the grid. Both effects go hand in hand, and the way to remedy them is very similar.
Instead of R&D, grid modernisation, and system control continuing in a verified evolutionary way, the method chosen that was based on idea that technology is powerful and will solve any and all challenges.
The Reality of Smart Meter Rollouts
Immediately, a telecommunication solution (i.e. standardisation and interoperability) was requested, but the development of such a process has been a long time coming. The ‘perfect’ systems proposed via theory and the world of academia, showed nice studies that had a lot of praise for these proposed solutions, but few real-life applications.
Based on the 20-20-20 strategy, big rollouts of smart meters should be well underway in most countries in Europe. These meters were supposed to solve all sorts of problems. But have they really? Rollouts that began with ovations were quickly finished and it does not look like they will continue.
The Myth of Interoperability
Interoperable systems do not fulfil the needs of today’s power industry. They are not able to offer a quick response at mass rollouts. Other ‘interoperable’ system which claim to be open, quick and robust, are suitable only on condition that you will not need anything new in future. In many cases, the interoperability mentioned exists only on the paper, not in real life.
Several utilities were also enthusiastic about a system that promised higher communication rates, namly, broadbanded BPL. However, this system is not standardised, interoperable, and due to a high sensitivity to disturbance, small resistance to overvoltage, and its short communication reach, its rollouts is impossible.
A Path Forward: Proven Standards
What then, is the way forward? Those who deal with R&D, know the progress is accompanied by blind alleys and false starts and they are not surprised from today’s situation. The only standard, that has proven its worth across its lifetime, is the OBIS code.
Thanks to these codes, every participant is able to talk to each other, which is a positive thing. Furthermore, it has been proved on the universal communication platform – PLC – operating in a defined frequency range of 9-130kHz with robust modulation, and matured error correction.
The Role of Data Concentrators
This is the only platform that is able to serve all consumer points of delivery on the high voltage level. The basic requirement is not the rate of communication, but the robustness and stability of communication channel.
Realised pilot projects have proved the necessity of carefully selecting transferred data. It aims to utilise proprietary protocols, that (if they are proven), could be used as a standard, which is the common way in the telco sector as well.
Addressing Network Complexities
Characteristics and behaviours of consumers’ meters lead to the necessity of multilevel communication chain creation. This will prevent the transfer of negative issues (overflows/ imbalances) into the upper layers.
On an old power network with significant topology changes, it is necessary to account for e-meter migration and new power networks with cable lines suffer from overheating. It is thus clear that there has to be a device over the PLC network, ie: a data concentrator, which will solve requests from the PLC network autonomously, and moreover, will have satisfactory computing capacity for the application of distributed control.
The Need for Decentralized Control
Due to power energy overflow dynamics, primarily coming from photovoltaic panels situated at the distribution level, it is not possible to realize executive control at a central level – this has to be realized at the level of PLC layer control.
Pilot projects have proven that the data collection realized from the center via a simple gateway is not operating properly, even with a small number of consumers points of delivery. Experiences from these projects have thus helped with request definition for data concentrators and their successful validation.
How to solve overflows and imbalances?
The only possibility is dynamic load control on the consumer side. The only significant controll consumption is hot water production for households (postponed consumption in the form of accumulation).
We can extend consumers load control via managing appliances through a higher variety of tariffs. Heating is also an interesting possibility; however, it is not a year-round issue, and, moreover, low-energy houses do not help with this at all.
Conclusion
Arising from pilot projects, there are a couple of requests necessary for solving the basic requirements of utilities at the beginning of the third millennium. They are:
- Definition of rational and guaranteed latency for command execution
- Necessity of distributed control at lower layers due to the high dynamics of negative effects in power system
- Offer of appliance control to the end users so that it would be beneficial for both parties
- Openness of end-user device (e-meter) because of future development dynamics and new characteristics requested in future
Every day, we are affected by negative effects in power industry that are enhanced by political decisions. Furthermore, their number will increase in future. Let’s analyze realized pilot projects without lobbyist pressure and choose solutions that prove their worth as a solution to the above mentioned utility requests.