Before delving into the detail of the debate, it is worth framing the question in the overall context of the Smart Grid.

A customer based AMI is a key component of the Smart Grid, and its deployment should benefit utilities by improving their efficiency, as well as enabling active participation from electricity consumers. It is likely that the functions which an AMI performs will evolve over time. The AMI will initially allow utilities to dispense with manual meter readings, offer flexible electricity tariffs (including pricing based on two-way power flows) and build a pathway towards demand response. In the medium term, it is hoped that an AMI will enable utilities to obtain detailed visibility of consumer energy consumption and help resolve advanced problems such as power quality. These applications only represent a flavour of an AMI’s functionality, and it is entirely possible that a future AMI may enable applications that cannot be conceived today.

In the UK, the Smart Metering Prospectus (released on 27th July 2010) proposed that the communications system for an AMI will initially be specified by electricity suppliers, before being transferred to a DataComsCo (DCC). The prospectus stipulated that each supplier’s communications system must meet a minimum set of requirements defined in a common technical specification. The prospectus does not mandate any particular communications technology; this will be determined by the market, subject to compliance with the relevant specifications.

A bespoke network could be faster, more secure and more reliable. It could also provide more bandwidth for auxiliary services such as real time power and voltage trace recording. Utilities would be able to assume greater control over their network and if a Smart Grid network roll out was mandated, potentially provide connectivity to more homes than conventional telecoms. A bespoke network also limits supplier risk as the utility does not have to rely on a communications company.

The core disadvantage to a bespoke network is cost. As we know from Smart Grid City, communications deployments can cause costs to escalate dramatically (by 3 times the original estimate in Smart Grid City’s example), and introduce significant delays into the deployment process. EPRI’s AMI analysis in 2007 estimated that communications would make up around 65% of the installation cost of a Smart Meter on a per device basis. It is imperative that Smart Grid projects proceed on time and to budget, or customer and governmental support will wither.

There are also several arguments for and against the shared network.

Perhaps the biggest advantage for the shared network is its comparatively low cost. In contrast to a bespoke network, communications cables already exist to transport broadband traffic and therefore no physical work is required to implement the new network. In the UK, 99.7% of households have access to broadband. Using the existing broadband infrastructure should help to reduce costs and deployment times.

Furthermore, any network performance improvements (for example, bandwidth and latency enhancements) will be subsequently available to AMI applications. Thus, on a shared network, the capacity for AMI applications should scale in line with the expected growth in demand for Internet based services. A shared network solution should also integrate well with 3rd party services and products that might be developed for a customer’s local network.

The biggest disadvantage of a shared network solution centres on security. There are concerns that the shared network will be insecure and an easy route in for hackers.

Furthermore, the technical capabilities of a broadband connection could be insufficient for some Smart Grid applications. For example, if the latency is too high, utilities may not be able to receive real time information or quickly control devices.

On face value, the arguments for and against seem balanced. However, if we take a closer look, the case begins to build against the bespoke network.

A bespoke network could initially be designed with speed and latency advantages over mainstream telecommunications. However, it is likely that this performance differential would be reversed over the medium term. A telecommunications company is driven by its customers to continually invest in new infrastructure to enhance the bandwidth and performance of its service. In contrast, a utility’s metering network would be designed to satisfy the requirements of the Smart Grid now. Further performance enhancements would be made on an ad-hoc basis (if at all) and only when investment was available. The significant danger is that a bespoke network will not grow in capacity over time thus limiting the possibility and / or functionality of future Smart Grid applications.

It is also questionable whether a bespoke network will be accessible to more customers than a shared network. There may be locations in the US which have electricity but no broadband, but it is doubtful that there will be enthusiasm from politicians or consumers to connect these consumers to an AMI ahead of enabling broadband access. Broadband is presumably more valuable to a consumer than connection to an AMI. In the UK, 0.3% of homes have no broadband and it would seem pragmatic to suggest that these homes will not initially be connected to an AMI.

Building and running a bespoke will represent a significant operational challenge for utilities. Telecommunications companies have the most experience of running and building communications networks. By running their own network, the utilities will be taking a significant risk that could manifest in deployment delays and cost overruns.

Another potential disadvantage with a bespoke network is that it is likely to be delivered as a fixed format and size. An insight into the disadvantages of this approach can be gained by considering the SCADA network. The SCADA network was designed to transmit kilo bits over the existing power infrastructure. If SCADA data rates had expanded in line with capacity improvements to the broadband infrastructure, the bandwidth available to the SCADA network would be over one thousand times higher today.

We can also look in more detail into the issue of security implications of a shared network.
In a report published in October 2010, a consortium of companies including Detica, BT and Arquiva highlighted security concerns about the UK’s approach to data security ahead of a DataCommsCo (DCC) being established. They recommended that by delaying the transition to a centrally controlled network and allowing suppliers to use a variety of communications suppliers including mobile and broadband will be a security risk.

It is also worth considering the many examples of online services which successfully secure important information on the Internet. RSA encryption is relied upon by governments, banks and retailers to send highly sensitive information on a daily basis. The sensitivity of the information being transferred across an AMI network is (at least initially) likely to be of comparatively low risk, and comprise of billing information, tariff updates, and technical measurements.

In conclusion, it is my opinion that the case for the shared network is compelling, and warrants further investigation. If the challenges regarding security can be overcome, the Smart Grid has a lot to gain from using a developed communications infrastructure.

Acknowledgement:Thanks to the Smart Grid Executive forum on LinkedIn for inspiring this article and some interesting and enlightened perspectives on this topic.

Thinking Grids was in Detroit to present some exciting research and scope out the latest ideas around smart grids.

Thinking Grids’ artificial intelligence experts carried out some data-mining on the keywords of all papers presented at the conference (roughly a thousand in total),and produced the following tag-cloud (with some help from www.wordle.net). We removed some of the more obvious and less useful keywords (power, system, engineering and energy) for clarity.

With 220 mentions, Wind jumps out as the most popular area of research. This is perhaps unsurprising given the current focus on wind (and renewable) energy integration as part of the Smart Grid, and the complexities associated with installing large variable power sources into a power system. Lots of papers mention Smart as a keyword; again this is unsurprising as ‘smart grid’ is popping up all over the place as a catch all term for new technology. However, with many smart grid specific conferences being held worldwide (almost one every two months), it is a positive sign to see it make such a strong appearance at the premier academic conference on power systems engineering where such a breadth of topics are discussed.

Despite the organiser’s focus on electric vehicle research (including keynote speeches during the opening session), it may be telling that academic community only mentioned the keyword vehicle in 37 out of the 1052 papers. The term was beaten by solar and photovoltaics (combined 58) and storage technologies (55). It is hard to see why the academic community is not focussing harder on tackling difficult problems such as large scale EV (electric vehicle) integration and vehicle to grid storage.

A look at the technologies being discussed reveals that wind is completely dominating the recent research interests:

Drawing any meaningful figures about other smart grid drivers, such as consumer participation in smart grids or efficiency savings, is difficult as these topics are largely driven by policy decisions. Questions such as – ‘How would demand response be implemented?’, ‘How would you pass on smart grid savings to a consumer?’ and ‘What level of automatic network control would be permitted in a smart distribution network?’ – do not lend themselves to academic research. Nevertheless, there is a large body of research pushing smart grid research forward, with a significant focus on wind power.

As future conferences are hosted, Thinking Grids will attempt to provide a similar summary on the major topics of research and new trends emerging from the academic community.

DMSs are currently installed and operational in most utility networks. DMSs originally started as an extension of the supervisory control and data acquisition (SCADA) system [2], and have advanced to cover a variety of applications. The Smart Grid DMS will both increase the pervasiveness of existing applications and incorporate newer more advanced techniques.

The applications covered by existing DMSs are focussed on helping utilities operate their networks more efficiently and help reduce and inform future capital expenditure. To cover these objectives, DMSs cover both online and offline analytical functions.

A DMS includes online components to help with fault detection, isolation and service restoration (FDIR) (see for example, SNC-Lavalin’s Fault Detection, Isolation, and Service Restoration). FDIR algorithms automatically restore service to the maximum number of customers using intelligent optimization restoration algorithms. A DMS can provide approximate information on fault location, and pre-empt network issues by highlighting overloaded cables and transformers. FDIR significantly improves the reliability of networks by reducing fault restoration time from several hours to a few minutes [2].

The operational efficiency of the network is enhanced by online DMS functionality such as integrated voltage / VAR control (IVVC). IVVC helps to reduce feeder losses and maintain an optimum voltage profile during peak and normal operating conditions. Optimal network reconfiguration reduces power losses through load balancing of transformers and maintaining an optimal voltage profile. A DMS also typically provides online switch order management functionality which feeds back switching plans to operators for execution (or rejection) and relay coordination which verifies protection settings.

DMSs contain functionality to assist with several offline processes which ultimately help DNOs plan network reinforcements and maintenance in a structured and informed manner. Contingency and short circuit analysis evaluates the performance of the network given certain outage conditions [2]. DMSs can also help plan the optimal placement of voltage re-enforcement devices by performing offline studies and optimizing the network wide voltage profile for maximal loss reduction.

The current body of research around DMSs suggests that future commercial DMSs will include further functionality to reduce the operational expenditure of network operators and advanced techniques to defer long term infrastructure investment and operate the network closer to stability boundaries. It is likely that increased monitoring of customers (through the deployment of an Advanced Metering Infrastructure (AMI)) and DNO assets (through increased monitoring of in-accessible units such as pole top transformers) will enable significant advances in the accuracy of a distribution system state estimator. Load estimation and load modelling algorithms are likely to significantly enhance in accuracy, utilising accurate recordings from meters installed at customer premises and the wider network [2].

Future DMSs are likely to facilitate the anticipated increases in renewable generation with functionality able to automatically control fault levels through busbar splitting and network reconfiguration. Future DMSs will also improve network efficiency through advanced voltage control and voltage reduction strategies (see for example, voltage optimisation), made possible by increased network monitoring and improved accuracy of a DMS’s state estimator.The overall reliability of the network may be enhanced through a DMS’s advanced FDIR techniques which cover optimization for complicated network topologies [2], potentially utilising advanced algorithmic techniques (for example, advanced statistics or artificial intelligence (AI) techniques such as Neural Networks and Support Vector Machines (SVM)). Fault location using short circuit analysis may be available through the DMS using impedance based fault location algorithms. The information architecture of a DMS is likely to incorporate greater use of visualisation incorporating DNO geographical information systems (GIS). It is also likely to integrate securely and more fully into other DNO systems such as outage management systems (OMS) (such as eMeter’s Outage Event Management) and meter data management (MDM) systems (for example, Oracle’s Utilities Meter Data Management or Siemens’ Meter Data Management (MDMS)).

Lastly, future DMSs may be able to perform advanced offline studies. The increase in network monitoring will allow DNOs to assess system wide power quality issues such as voltage sags , unbalance , harmonics and flicker, and estimate their resulting impacts on consumers. The DMS will supply accurate historical data which will allow DNOs to analyse the effects of new loads and generation such as PHEVs and distributed generation.

Acknowledgement:The image of the futuristic control centre is the Moesk Control Center by Arch-group and ABTB in Moscow, Russia.

References

1. H. Farhangi, "The path of the smart grid", IEEE Power and Energy Magazine, vol. 8, 2010, pp. 18-28. DOI.
2. . Jiyuan Fan, and S. Borlase, "The evolution of distribution", IEEE Power and Energy Magazine, vol. 7, 2009, pp. 63-68. DOI.
3. . Ke Li, "State estimation for power distribution system and measurement impacts", IEEE Transactions on Power Systems, vol. 11, pp. 911-916. DOI.
4. E. Handschin, and C. Dornemann, "Bus load modelling and forecasting", IEEE Transactions on Power Systems, vol. 3, pp. 627-633. DOI.

The government clearly loves wind along with all green technologies, but unfortunately it seems that the public – at least those with the loudest voices – do not. A constant stream of news articles proclaiming protests to the erection of on-shore turbines litters the internet. Even those attempting installation on their own land to counteract rising electricity costs run into trouble when too close to heritage sites (6 miles away). Protestors to a small fleet of potential eye-sores in Lincolnshire are questioning why on-shore turbines are even required – won’t off-shore farms produce all wind power we need?

Well it could – at a greater cost. And it’s a cost that’s going to be passed to the energy consumers. With gas and electricity prices already soaring and fuel poverty in the UK making the headlines – what kind of person would want to add to these costs further by pushing all our wind generation out to sea?

Added to this we have the ever present protests to the erection of new pylons. Plans by National Grid to cut swathes through mid Wales with a stream of pylons were not met completely favourably by various forces (including TV weathergirl Sian Lloyd who feared plans to “turn Wales into one gigantic power plant”). Even if the people are happy with where the power is coming from – they’re not happy with how you get it to where it needs to be. National Grid are even installing expensive submarine HVDC cables, partly in order to avoid many of the potential headaches that come with trying to put up pylons these days. There are some hopes that developments in design will lead to pylon designs more pleasing on the eye – but these are unlikely to come around quick enough to help with the first waves of infrastructure development required.

Striking new pylon design by Dietmar Koering of Arphenotype

So what does it mean for Smart Grids in the UK?

Smart Grids need renewable power generation, they need distributed power generation, and they need a power transmission network that is capable of handling these rapidly varying sources of power injection. Unfortunately public objection is standing in the way of the developments in all of these areas.

Reasons for public disapproval of renewable energy technologies can be complex, including political prejudice, and concerns over the fairness of the decision making process (concisely discussed in this report) but popular support must be garnered if future developments are to come to fruition. It may require stronger government backing to support distributed generation applications (with the DECC’s Feed-in Tariffs being an example of support being targeted in the right places) or it may require greater public education as to the true implications of ‘going green’ (not only in terms of cost). In any case, it seems unlikely that simplest solution – reducing electrical demand – will be widely adopted.

Enter the HVDC Super Grid. The vision is of an interconnected HVDC grid connecting the various wind farms in the North Sea and transferring their power to the various interconnected countries that require it with minimal losses. Furthermore, such a system with controlled power flow at every node would facilitate electricity trading between multiple European countries on a scale not witnessed before. Not only would this drive down prices but it would allow more efficient power transmission, allowing central European countries to make use of the vast hydropower storage reserves in Scandinavia and avoid the need for spinning fossil fuel generation capacity. Yet more benefits include the ability of the power electronics in the HVDC converters to support wind farm reactive power requirements and to electrically isolate them from the AC grids they’re connecting to, making them more resilient to external faults.

It seems like a technical solution with socio-economic benefits too good to be true – and maybe it is.

Wind farm development is already underway and will need to be connected up soon. The amounts of generation being talked about by 2020 (likely to be even higher now that many European countries are shying away from nuclear power [also]) will demand connection capacities in the gigawatts very soon.

So why has no work started on the super grid?

As well as all the clear incentives to get underway, there are many (unfortunately large) hurdles to overcome – not least technologically. HVDC manufacturers are claiming they will have large (over 1 GW) VSC-HVDC converters in the future – but how soon? And at what voltage level? It may be that 800kV is achievable in the future – but it’s not now, and work needs to start now. A constant HVDC system voltage is needed but set it too low and you limit future capacity, set it too high and work can’t start until the manufacturers deliver the developments they’re promising. Then there are DC circuit breakers – currently a nonexistent item but crucial for the success of an interconnected super-grid. No one is going to be happy if the whole grid has to be shut down and isolated on the AC side every time a fisherman trawls through a line. But current technology in this area is lacking – solid state devices have large losses and mechanical ones are too slow (reliant on resonance to force a zero crossing in the current).

Then you have to decide who pays for what? Norwegian customers are not going to be happy if they’re funding a project that benefits Britain far more than themselves. Measuring the socio-economic impact of the grid in order to proportion fair contributions from participating nations is a complex task.

Once it’s built – who will operate it? British regulatory restrictions mean that National Grid can’t directly own or operate the HVDC links – but such archaic restrictions are not in place in other countries. Is it feasible for one single entity to manage the entire network as an HVDC network operator?

The problems could have solutions (provided a lot of R&D work is done on the technological challenges now) but the main show-stopper is that there’s no one here to force the issue through. When the EU was so proactive in signing up to renewable energy promises they overlooked the transmission infrastructure development that would be required and seem somewhat oblivious to it now. The hurdles aren’t insurmountable, but there may not be the drive and motivation to get over them all quickly enough.

The report compares the viability of a whole host of renewable and low carbon technologies including, wind power, photo-voltaics, tidal energy, wave, nuclear power and carbon capture and storage. The report also touches on the ongoing debate between greens and the nuclear lobby over how much wind and nuclear energy should contribute to the UK’s future energy mix.

According to the report, consumers are likely to be paying between 5p and 10p per kWh for nuclear energy and between 7p and 13.5p for wind (at a 10% discount rate). On costs alone, it would seem that nuclear is edging out wind as the most economical option.

However, one aspect that the report does not quantify in detail is the economic benefit which the UK will gain from strategically nurturing either the nuclear or wind industries. The UK’s growth in both of these industries will derive from firstly deploying and maintaining the new generation output and secondly, by exporting ancillary services and manufactured products.

At first glance, there would seem to be a huge potential to export manufacturing expertise and services on the back of successful local deployments. For wind power especially, it is easy to see how the UK could become a market leader. As one of the windiest countries in the world, the UK has the potential to generate over 400TWh per year from offshore wind energy, which represents double the energy currently generated by the UK’s nuclear reactors.

To add some figures to the debate, the following table compares the economic benefits in terms of jobs and GDP for both the wind and nuclear industries between now and 2050. Nuclear energy is forecasted in the report to still be a large contributor to the UK’s energy mix in 2050, but it is not expected to grow significantly. In contrast, the Carbon Trust expects that the UK could employ up to 230,000 people in the wind energy sector by 2050, with 80% of those employed in the export sector. This could mean a contribution of £10 billion to year on year GDP by 2050.

Economic Benefits of Nuclear & Wind Energy in the UK

Just how much benefit the UK gains from its development as a UK wind energy hub will depend on many factors, not least the competitiveness and quality of the manufacturing and services offered within the UK. However, the potential for extra economic benefits adds an additional argument for the development of the UK’s offshore wind capacity that is sadly lacking form the climate change report.

References

• The Carbon Trust’ Analysis on the Impact of Wind on the UK Economy
• Renewable Energy Review: Committee on Climate Change Report, May 2011