As the quantity of renewable electricity generation from wind farms increases in a region, the co... more As the quantity of renewable electricity generation from wind farms increases in a region, the costs associated with integrating it into the broader electricity system also grow. This is primarily due to the need for dispatchable generators that vary power output to compensate for wind farm power variations. Such “balancing services” are an economic cost to the system that is typically not passed on to wind farms. We propose including the use of technical merits other than capacity factor and cost of energy for evaluating new wind farm sites and present a new graphical geospatial method, with the intention of identifying sites that minimize the need for additional electricity balancing service and transmission congestion. Specifically, locations with low correlation to existing wind farms, locations with high correlation to load, locations with high characteristic power time‐shift from existing wind farms, and locations that relieve or do not negatively impact electricity transmission congestion are identified. A geospatial Venn diagram‐based method of visualization is presented. These methods will equip regional planners with new tools to encourage wind farm development in areas that benefit the electricity grid beyond the lowest bid price.
One year of high-resolution driving data from a sample of 333 instrumented gasoline passenger veh... more One year of high-resolution driving data from a sample of 333 instrumented gasoline passenger vehicles are used to create a trip inventory of U.S. vehicle travel requirements. A set of electric vehicles (EVs) is modeled, differing in battery size (kWh), recharging power (kW), and locations for charging when parked. Each modeled EV’s remaining energy is tracked while traversing the entire sample’s trip inventory in order to estimate how well each EV meets all U.S. driving requirements. The capital cost of refueling infrastructure is estimated per car, for gasoline and for each analyzed combination of charging station locations. We develop three metrics of the ability of different EV characteristics to meet trip requirements: the percentage of trips successfully met by each modeled EV, the number of days that the driver must “adapt” EV use to meet more demanding trip requirements, and the total driver time required for refueling. We also segment the market of trip patterns per car, fi...
Electric vehicles rely on public fast charging when traveling outside a single charge range. Netw... more Electric vehicles rely on public fast charging when traveling outside a single charge range. Networks of fast charging hubs are a preferred solution, but should be deployed according to a design that avoids both redundant infrastructure representing overinvestment, and “charging deserts” which limit travel by EVs and thus inhibit EV adoption. We present a two-stage design strategy for a network of charging hubs relying on common public data including maps of roadways and electrical systems, and ubiquitous and readily accessible daily traffic volume data. First, the network design is based on the electrical distribution system, roadways, and a target inter-hub driving distance. Second, the number of fast chargers necessary at each hub to support expected vehicle kilometers is determined such that queuing to charge is infrequent. A case study to prepare Nova Scotia, Canada for the 2030 electric fleet of 15% of vehicles results in a network design with an average hub catchment area of ...
Central to the design of a direct current fast charging (DCFC) network is the question of how muc... more Central to the design of a direct current fast charging (DCFC) network is the question of how much energy a DCFC of a given power can supply to vehicles without users being forced to queue to charge. We define ‘utilization factor’ as the ratio of the energy delivered by a DCFC in a multi-day period to the maximum amount of energy it could deliver in period. Three and a half years of data from 12 DCFCs are examined, characterizing each charging event by both the utilization factor and the time lag since the termination of the previous charging event. Short lags between events are inferred to indicate queuing. To keep the fraction of would-be users who have to queue below 10%, the overall utilization of the DCFC must likewise be limited to 10% (or 7–17% in exceptionally heterogeneous or exceptionally homogeneous traffic patterns, respectively). E.g., a 100 kW DCFC should not be expected to deliver more than 240 kWh per day (100 kW × 24 h × 10%).
Sovereignty claims over insular features and maritime jurisdiction in the South China Sea have be... more Sovereignty claims over insular features and maritime jurisdiction in the South China Sea have been disputed for decades, and a governance regime to address ocean-related issues is urgently needed. This article first introduces the notion of a regime, and examines details of cooperation mechanisms in the Polar Regions. Lessons that can be applied to the South China Sea include that both soft and hard law regimes work to bring States concerned together to cooperate on the “commons” issues even when military conflicts or sovereignty disputes still exist. Consensus among bordering States would be necessary to make the South China Sea a “zone of peace.” Mechanisms that accommodate the various sovereignty claims and freeze existing and new claims to, as well as to prohibit military activities in, the South China Sea are recommended. Lastly, if a cooperative mechanism were to be established in the future, the Arctic regime would be more applicable to the South China Sea than the Antarctic regime due to their geographic nature. Thus, only States bordering the South China Sea should have voting and decision-making rights in the cooperative mechanism. As always, the political will of all parties is paramount to the success of such an endeavor.
Energy storage technologies can provide services to the electricity grid that are necessary for i... more Energy storage technologies can provide services to the electricity grid that are necessary for its usability, stability, and reliability. The services, such as power factor correction and renewable energy arbitrage, are defined by duration, cycling occurrence, power, and market price. Storage technologies suitable to these applications, such as pumped hydro and batteries, are defined by their usable energy, power, efficiency, operating range, availability, lifetime, and cost.
AbstractA simple yet extensible electrical system model, suitable for studying the effects of ren... more AbstractA simple yet extensible electrical system model, suitable for studying the effects of renewable energy integration, is presented. The model uses publically available historical data to create a representative sample time-series of system loads. Historical conditions are scaled to future target years in accordance with projected system-wide electrical load growth. Renewable energy generation is evaluated regionally and subregionally from coincident climatic conditions, combined with regionally appropriate generator transform functions. Renewable energy generation is scaled to target years based on legislated requirements or projected growth. Future dispatchable generation requirements and conditions are developed as the difference between the projected load and projected renewable energy deployment. A case study conducted in the eastern Canadian province of Nova Scotia is presented. Legislated renewable energy targets will significantly increase the ramp rates required of dispatchable generation.
An accurate, single-user beach-elevation profile device that relies on lightweight, inexpensive m... more An accurate, single-user beach-elevation profile device that relies on lightweight, inexpensive materials is described. The device is used to rapidly survey beach topographic profiles and is appropriate for scientific data collection. The profiler consists of two vertical legs and two ...
Plug-in Electric Drive Vehicles (EDVs) are becoming in-creasingly popular and a number of auto ma... more Plug-in Electric Drive Vehicles (EDVs) are becoming in-creasingly popular and a number of auto manufacturers are planning on introducing pure Battery Electric Vehicles (BEVs) or plug-in hybrids within the next two years. When parked and plugged into the electricity grid, these EDVs can be used as a large distributed battery that can be used to regulate electric power on the grid — a concept known as Vehicle-To-Grid power or V2G power. To effectively use these EDVs as storage resources, the grid operators require a certain minimum power capacity, which cannot be provided by an individual vehicle. Hence, a group of EDVs need to come together and form a coalition that can provide the required capacity to the grid. In this paper, we formally model the coalition formation problem for EDVs and discuss some interesting open research ques-tions that this problem poses — for example, how much capacity can a coalition of EDVs report to the grid opera-tors, which vehicles within the coalition ...
As the quantity of renewable electricity generation from wind farms increases in a region, the co... more As the quantity of renewable electricity generation from wind farms increases in a region, the costs associated with integrating it into the broader electricity system also grow. This is primarily due to the need for dispatchable generators that vary power output to compensate for wind farm power variations. Such “balancing services” are an economic cost to the system that is typically not passed on to wind farms. We propose including the use of technical merits other than capacity factor and cost of energy for evaluating new wind farm sites and present a new graphical geospatial method, with the intention of identifying sites that minimize the need for additional electricity balancing service and transmission congestion. Specifically, locations with low correlation to existing wind farms, locations with high correlation to load, locations with high characteristic power time‐shift from existing wind farms, and locations that relieve or do not negatively impact electricity transmission congestion are identified. A geospatial Venn diagram‐based method of visualization is presented. These methods will equip regional planners with new tools to encourage wind farm development in areas that benefit the electricity grid beyond the lowest bid price.
One year of high-resolution driving data from a sample of 333 instrumented gasoline passenger veh... more One year of high-resolution driving data from a sample of 333 instrumented gasoline passenger vehicles are used to create a trip inventory of U.S. vehicle travel requirements. A set of electric vehicles (EVs) is modeled, differing in battery size (kWh), recharging power (kW), and locations for charging when parked. Each modeled EV’s remaining energy is tracked while traversing the entire sample’s trip inventory in order to estimate how well each EV meets all U.S. driving requirements. The capital cost of refueling infrastructure is estimated per car, for gasoline and for each analyzed combination of charging station locations. We develop three metrics of the ability of different EV characteristics to meet trip requirements: the percentage of trips successfully met by each modeled EV, the number of days that the driver must “adapt” EV use to meet more demanding trip requirements, and the total driver time required for refueling. We also segment the market of trip patterns per car, fi...
Electric vehicles rely on public fast charging when traveling outside a single charge range. Netw... more Electric vehicles rely on public fast charging when traveling outside a single charge range. Networks of fast charging hubs are a preferred solution, but should be deployed according to a design that avoids both redundant infrastructure representing overinvestment, and “charging deserts” which limit travel by EVs and thus inhibit EV adoption. We present a two-stage design strategy for a network of charging hubs relying on common public data including maps of roadways and electrical systems, and ubiquitous and readily accessible daily traffic volume data. First, the network design is based on the electrical distribution system, roadways, and a target inter-hub driving distance. Second, the number of fast chargers necessary at each hub to support expected vehicle kilometers is determined such that queuing to charge is infrequent. A case study to prepare Nova Scotia, Canada for the 2030 electric fleet of 15% of vehicles results in a network design with an average hub catchment area of ...
Central to the design of a direct current fast charging (DCFC) network is the question of how muc... more Central to the design of a direct current fast charging (DCFC) network is the question of how much energy a DCFC of a given power can supply to vehicles without users being forced to queue to charge. We define ‘utilization factor’ as the ratio of the energy delivered by a DCFC in a multi-day period to the maximum amount of energy it could deliver in period. Three and a half years of data from 12 DCFCs are examined, characterizing each charging event by both the utilization factor and the time lag since the termination of the previous charging event. Short lags between events are inferred to indicate queuing. To keep the fraction of would-be users who have to queue below 10%, the overall utilization of the DCFC must likewise be limited to 10% (or 7–17% in exceptionally heterogeneous or exceptionally homogeneous traffic patterns, respectively). E.g., a 100 kW DCFC should not be expected to deliver more than 240 kWh per day (100 kW × 24 h × 10%).
Sovereignty claims over insular features and maritime jurisdiction in the South China Sea have be... more Sovereignty claims over insular features and maritime jurisdiction in the South China Sea have been disputed for decades, and a governance regime to address ocean-related issues is urgently needed. This article first introduces the notion of a regime, and examines details of cooperation mechanisms in the Polar Regions. Lessons that can be applied to the South China Sea include that both soft and hard law regimes work to bring States concerned together to cooperate on the “commons” issues even when military conflicts or sovereignty disputes still exist. Consensus among bordering States would be necessary to make the South China Sea a “zone of peace.” Mechanisms that accommodate the various sovereignty claims and freeze existing and new claims to, as well as to prohibit military activities in, the South China Sea are recommended. Lastly, if a cooperative mechanism were to be established in the future, the Arctic regime would be more applicable to the South China Sea than the Antarctic regime due to their geographic nature. Thus, only States bordering the South China Sea should have voting and decision-making rights in the cooperative mechanism. As always, the political will of all parties is paramount to the success of such an endeavor.
Energy storage technologies can provide services to the electricity grid that are necessary for i... more Energy storage technologies can provide services to the electricity grid that are necessary for its usability, stability, and reliability. The services, such as power factor correction and renewable energy arbitrage, are defined by duration, cycling occurrence, power, and market price. Storage technologies suitable to these applications, such as pumped hydro and batteries, are defined by their usable energy, power, efficiency, operating range, availability, lifetime, and cost.
AbstractA simple yet extensible electrical system model, suitable for studying the effects of ren... more AbstractA simple yet extensible electrical system model, suitable for studying the effects of renewable energy integration, is presented. The model uses publically available historical data to create a representative sample time-series of system loads. Historical conditions are scaled to future target years in accordance with projected system-wide electrical load growth. Renewable energy generation is evaluated regionally and subregionally from coincident climatic conditions, combined with regionally appropriate generator transform functions. Renewable energy generation is scaled to target years based on legislated requirements or projected growth. Future dispatchable generation requirements and conditions are developed as the difference between the projected load and projected renewable energy deployment. A case study conducted in the eastern Canadian province of Nova Scotia is presented. Legislated renewable energy targets will significantly increase the ramp rates required of dispatchable generation.
An accurate, single-user beach-elevation profile device that relies on lightweight, inexpensive m... more An accurate, single-user beach-elevation profile device that relies on lightweight, inexpensive materials is described. The device is used to rapidly survey beach topographic profiles and is appropriate for scientific data collection. The profiler consists of two vertical legs and two ...
Plug-in Electric Drive Vehicles (EDVs) are becoming in-creasingly popular and a number of auto ma... more Plug-in Electric Drive Vehicles (EDVs) are becoming in-creasingly popular and a number of auto manufacturers are planning on introducing pure Battery Electric Vehicles (BEVs) or plug-in hybrids within the next two years. When parked and plugged into the electricity grid, these EDVs can be used as a large distributed battery that can be used to regulate electric power on the grid — a concept known as Vehicle-To-Grid power or V2G power. To effectively use these EDVs as storage resources, the grid operators require a certain minimum power capacity, which cannot be provided by an individual vehicle. Hence, a group of EDVs need to come together and form a coalition that can provide the required capacity to the grid. In this paper, we formally model the coalition formation problem for EDVs and discuss some interesting open research ques-tions that this problem poses — for example, how much capacity can a coalition of EDVs report to the grid opera-tors, which vehicles within the coalition ...
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Papers by Nathaniel Pearre