U.S. strategic solar photovoltaic-powered microgrid deployment for enhanced national security

Abstract

The U.S. electrical grid, the largest and most complex man-made system in the world, is highly vulnerable to three types of external threats: 1) natural disasters, 2) intentional physical attacks, and 3) cyber-attacks. The technical community has recommended hardening the grid to make it more resilient to attack by using distributed generation and microgrids. Solar photovoltaic (PV) systems are an ideal distributed generation technology to provide power for such microgrids. However, both the deployment velocity and the policy of how to implement such technical solutions have been given far less attention than would be normally considered adequate for a national security risk. To address this threat, this paper reviews the technical and economic viability of utilizing defense contracting for the beginning of a national transition to distributed generation in the U.S. First, the technical scale of electrical demand and the solar PV system necessary is analyzed in detail to meet the first level of strategic importance: the U.S. military. The results found that about 17 GW of PV would be needed to fortify the U.S. military domestically. The current domestic geographic deployment of microgrid installations in the critical U.S. defense infrastructure were reviewed and compared to historical grid failures and existing and planned PV installations to mitigate that risk. The results showed a minimal number of military bases have introduced solar PV systems, leaving large parts of the Department of Defense electrical infrastructure vulnerable to attack. To rectify this situation, the technical skills of the top 20 U.S. defense contractors is reviewed and analyzed for a potential contracting transition to grid fortification. Overall the results indicate that a fortified U.S. military grid made up of PV-powered microgrids is technically feasible, within current contractors skill sets and economically viable. Policy recommendations are made to accelerate U.S. military grid fortification.

Introduction

The U.S. electrical grid, the largest and most complex man-made system in the world today [1], is an interconnected network for delivering electricity from generally centralized suppliers to distributed consumers. This electrical system architecture is comprised of substations with variable carrying capacities of electrical load, which are susceptible to widespread cascading failures [1], [2], [3]. Every U.S. sector (military, economy, government, health care, education, etc.) depends on the grid to deliver essential electrical services. Due to its highly interconnected and interdependent nature, electric grid failure has the potential to impair economic and social functions in the event of a power outage [4], [5], [6]. The interdependencies of the power grid and other critical infrastructures are illustrated in Fig. 1. The general consensus in the energy community is that the electrical grid is highly vulnerable to three types of external threats: 1) natural disasters [7], [8], [9], 2) intentional physical attacks [5], [10], [11], [12], [13], and 3) cyber-attacks [14], [15], [16], [17], [18], [19], [20].

The first threat of natural disasters caused by severe weather is responsible for $18 to $33 billion every year in power outages and damages to U.S. infrastructure [23]. These major power outage disasters tend to be widespread, with an average of 700,000 consumers impacted per weather-induced power outage annually [5]. The impacts of past major U.S. power outages are summarized in Table 1. The majority of economic costs result from spoiled inventory, delayed production, and damage to grid infrastructure [23].

The second threat of physical attacks includes traditional acts of terrorism such as bombing or sabotage [14] (e.g. an electromagnetic pulse attack [24], [25], [26]). The traditional power grid infrastructure is incapable of withstanding intentional physical attacks [27]. Damage resulting in physical attack could be long lasting, as power plants operate with large transformers that are difficult to move and source. Custom rebuilt transformers require time for replacement ranging from months and even up to years [27]. For example, a 2013 sniper attack on California's Pacific Gas and Electric (PG&E) substation disabled 17 transformers supplying power to Silicon Valley. Repairs and improvements cost PG&E roughly $100 million and lasted 27 days [28], [29], [30].

In addition to physical attacks, the electrical grid is also exposed to cyber-attacks. The Pentagon reports spending roughly $100 million to repair cyber-related damages to the electric grid in 2009 [31]. The U.S. electric grid, along with other critical infrastructure systems, is growing increasingly dependent upon the Internet and other network connections for data communication and monitoring systems [16], [32], [33], [34], [35]. While this allows electrical suppliers convenient operation and management of systems, it increases the grid's susceptibility to cyber-attack, which exploit critical infrastructure systems, causing denial of webpage services to consumers, disruption to supervisory control and data acquisition (SCADA) operating systems, or sustained widespread power outages [16], [18], [36], [37]. Unlike a physical attack, cyber attackers are capable of penetrating critical electric infrastructure from remote regions of the world, requiring only an Internet connection to gain pathways and install malware into the electric power grid's control systems. Many efforts are underway to harden the grid from such attacks [17], [21], [35]. However, the integrated nature of the grid, which is based on centralized generation, but diffuse transmission, makes the entire system vulnerable to a concentrated attack, in contrast to a natural disaster that may have local or regional impacts. The U.S. Department of Homeland Security reports responding to approximately 200 cyber incidents in 2012 across critical infrastructure sectors, of which 41% involved the electrical grid [38]. Economic impacts of a successful breach are estimated to cost $243 billion mounting to roughly $1 trillion in an extreme case [39]. According to senior intelligence officials, various nation states (e.g. China, Russia, North Korea) have made attempts to map current critical infrastructure for future navigation and control of the U.S. electrical system [31]. Due to such offensive efforts, several other countries, including the U.S., have added cyber-attacks into their current military defense preparations [33].

As cyber-attacks are becoming increasingly prevalent, it is necessary to recognize the unpreparedness of critical infrastructure operators. In 2008, the Federal Energy Regulatory Commission (FERC) alongside the North American Electric Reliability Corporation (NERC) implemented a mandatory Critical Infrastructure Protection (CIP) Reliability Standards program [40]. Then an Executive Order (EO 13636) was implemented in 2013, in effort to address additional protection measures not listed in the CIP Standards program [41]. Other proposed policy solutions to electric grid cyber vulnerability include better assessment of vulnerabilities and increased cyber security control through strong firewalls and monitoring systems [1], [35], [40].

The technical community has recommended a more direct solution to all of these threats for some time: distributed generation and microgrids [42], [43], [44]. Microgrids allow the generation system to separate from distribution during disturbance events. The system maintains a high level of service and performance while decreasing the chances of cascading failures and enables distributed generation without grid redesign [45], [46], thereby making the entire grid more resilient. Solar photovoltaic (PV) systems, which generate electricity directly from sunlight [47], are an ideal distributed generation technology to provide power for such microgrids [48]. PV costs have dropped significantly [49], [50], due to technical evolution, large-scale manufacturing [51] and a substantial learning curve [52], [53], [54], [55]. Coupled with current decreasing battery costs [56], [57], the transition to solar PV distributed generation microgrid systems can be highly economical [58], [59], [60].

The policy dimensions of how to implement such technical solutions has been given far less attention than would be normally considered adequate for a national security risk as demonstrated by the dearth in the literature as compared to more conventional national security threats. To address this threat, this paper reviews the technical and economic viability of utilizing defense contracting for a start of a national transition to distributed generation in the U.S. The objective of this review is to provide a foundation for thinking of the electrical grid in terms of a security issue and how to use renewable energy sources to increase national security. First, the technical scale of electrical demand and the necessary solar PV system is analyzed in detail to meet the first level of strategic importance: the U.S. military. The current domestic geographic deployment of microgrid installations in the critical U.S. defense infrastructure is reviewed and compared to historical grid failures and existing and planned PV installations to mitigate that risk. Then the technical skills of the top 20 U.S. defense contractors is reviewed and analyzed for a potential contracting transition to grid fortification. Three case studies are presented (Lockheed Martin, Bechtel, and GE) to demonstrate how this transition could take place. A cost sensitivity is performed and the potential revenue increase for the current defense contracts of the top 20 U.S. contractors for 2014 is presented. Then, each of the remaining levels the current grid vulnerabilities is summarized and policy recommendations are made to demonstrate a path to a secure and hardened U.S. electric system made up of PV-powered microgrids.