[ISS4E] Fwd: [New post] A Network of Intelligent DER

S. Keshav keshav at uwaterloo.ca
Thu Sep 18 13:25:34 EDT 2014

A very interesting article by Steven Low!


Forwarded message:

> From: Rigor + Relevance <comment-reply at wordpress.com>

> Energy and the environment are probably the most critical and massive 
> problems of our times. The transformation of our energy system into a 
> more sustainable form will take decades, determination, and 
> sacrifices. In the case of power networks, several powerful trends are 
> driving major changes. In this post, we will look at two of them.
> The first trend is the accelerating penetration of distributed energy 
> resources (DER) around the world. These DER include photovoltaic (PV) 
> panels, wind turbines, electric vehicles, storage devices, smart 
> appliances, smart buildings, smart inverters, and other power 
> electronics. Their growth is driven by policies and incentive 
> programs. California, for instance, has ambitious policy goals such 
> as:
> * Renewable Portfolio Standard (2002): 33% of retail electricity will 
> be procured from renewable sources by 2020.
> * Global Warming Solutions Act (2006): Reduce greenhouse gas emission 
> to 1990 level by 2020.
> * California Solar Initiative (2007): Offers solar rebates for 
> customers of three CA investor-owned utilities, from 2007 – 2016.
> * ZNE homes (2007): All new residential construction will be zero net 
> energy by 2020.
> * Energy storage target (2010): The three investor-owned utilities 
> will deploy 1.325 GW of non-hydro storage by 2020.
> Leading the world, in terms of percentage share of non-hydro renewable 
> generations (at approximately 20% now), is Germany.  Its relentless 
> push for renewables, in the face of technical and financial 
> challenges, will no doubt help find a way forward and benefit us all. 
>  See a recent New York Times article ( 
> http://www.nytimes.com/2014/09/14/science/earth/sun-and-wind-alter-german-landscape-leaving-utilities-behind.html?hpw&rref=science&action=click&pgtype=Homepage&version=HpHedThumbWell&module=well-region&region=bottom-well&WT.nav=bottom-well&_r=0 
> ) , where a proud German reader commented, “And that's what I love 
> about my country, it is a pain, it causes frustration and malice, but 
> nobody questions the vision.”   The question is not whether we 
> should move to a sustainable future, but how we overcome the many 
> challenges on the way (e.g., see Adam's earlier post about Germany's 
> challenges ( 
> http://rigorandrelevance.wordpress.com/2014/06/23/energiewende-is-giving-renewables-a-bad-name/ 
> ) ); and the earlier we start, the less painful the process will be.
> The second trend is the growth of sensors, computing devices, and 
> actuators that are connected to the Internet. Cisco claims that the 
> number of Internet-connected “things” exceeded the number of 
> people on earth in 2008, and, by 2020, the planet will be enveloped in 
> 50 billion such “Internet-of-things ( 
> http://share.cisco.com/assets/images/Internet_of_Things_Infographic.jpg 
> ) ”.  Just as Internet has grown into a global platform for 
> innovations for cyber systems in the last 20 years, Internet-of-things 
> will become a global platform for innovations in cyber-physical 
> systems.  Much data will be generated at network edges. An important 
> implication on computing is that, instead of bringing data across the 
> network to applications in the cloud, we will need to bring 
> applications to data. Distributed analytics and control will be the 
> dominant paradigm in such an environment. This is nicely explained by 
> Michael Enescu (a Caltech alum!) in a recent keynote ( 
> https://www.youtube.com/watch?v=1WfbnMU7CMc ) .
> The confluence of these two trends points to a future where there are 
> billions of DER, as well as sensing, computing, communication, and 
> storage devices throughout our electricity infrastructure, from 
> generation to transmission and distribution to end use. Unlike most 
> endpoints today which are merely passive loads, these DER are active 
> endpoints that not only consume, but can also generate, sense, 
> compute, communicate, and actuate. They will create both a severe risk 
> and a tremendous opportunity: a large network of DER introducing 
> rapid, large, frequent, and random fluctuations in power supply and 
> demand, voltage and frequency, and our increased capability to 
> coordinate and optimize their operation in real time.
> At Caltech, we are interested in developing an intellectual framework 
> to understand and guide this historic transformation and to address 
> engineering and economic challenges that will arise in the coming 
> decades.   There is no shortage of intellectually interesting and 
> practically important problems – if you are starting out your 
> graduate study, you should definitely consider this area.
> For instance, a radically different control architecture for future 
> grid is endpoint-based control where each DER self-manages through 
> local sensing and computation, and communicates with its neighbors. 
> They make local decisions based on their own states and possibly 
> information from their neighbors. The global behavior that emerges 
> from the interaction of these local algorithms must be stable, robust, 
> efficient, and above all, understandable.
> An example of this approach in the context of load-side participation 
> in frequency regulation is discussed in my previous blog post ( 
> https://rigorandrelevance.wordpress.com/2014/07/15/communication-and-power-networks-reverse-and-forward-engineering-part-ii/ 
> ) .   Though frequency regulation has been mainly implemented on the 
> generator side, there are three important advantages to ubiquitous 
> continuous and distributed load-side participation.
> * Unlike spinning reserve, load-side control does not waste fuel or 
> produce extra emission.
> The ubiquity of load-side control can better localize disturbance and 
> produce more reliable response through the law of large numbers. The 
> paper “Achieving controllability of electric loads ( 
> http://web.eecs.umich.edu/~hiskens/publications/05643088.pdf ) ” by 
> Callaway and Hiskens provides an example where 60,000 air conditioners 
> can be controlled to track the output of a wind farm accurately 
> without deviating from the desired temperature by more than 0.15 
> degree:
> http://rigorandrelevance.files.wordpress.com/2014/09/1.png&h=104
> and an example where 20,000 electric vehicles can be controlled to 
> track demand profile accurately without impacting their charging 
> requirements:
> http://rigorandrelevance.files.wordpress.com/2014/09/2.png&h=245
> Finally, since loads have low or no inertia, they can respond fast. 
> The simulation in our recent CDC2014 paper “Optimal decentralized 
> primary frequency control in power networks ( 
> http://users.cms.caltech.edu/~czhao/ZhaoLow_CDC2014.pdf ) ” 
> demonstrates that load-side participation can significantly improve 
> both the steady-state and transient behavior over generator-only 
> control:
> http://rigorandrelevance.files.wordpress.com/2014/09/olc.jpg&h=221
> Add a comment to this post: 
> http://rigorandrelevance.wordpress.com/2014/09/18/a-network-of-intelligent-der/#respond

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