Optimizing plug-in electric vehicle charging in interaction with a small office building

This paper considers the integration of plug-in electric vehicles (PEVs) in micro-grids. Extending a theoretical framework for mobile storage connection, the economic analysis here turns to the interactions of commuters and their driving behavior with office buildings. An illustrative example for a real office building is reported. The chosen system includes solar thermal, photovoltaic, combined heat and power generation as well as an array of plug-in electric vehicles with a combined aggregated capaci-ty of 864 kWh. With the benefit-sharing mechanism proposed here and idea-lized circumstances, estimated cost savings of 5% are possible. Different pricing schemes were applied which include flat rates, demand charges, as well as hourly variable final customer tariffs and their effects on the operation of intermittent storage were revealed and examined in detail. Because the plug-in electric vehicle connection coincides with peak heat and electricity loads as well as solar radiation, it is possible to shift energy demand as desired in order to realize cost savings. --Battery storage,building management systems,dispersed storage and generation,electric vehicles,load management,microgrid,optimization methods,power system economics,road vehicle electric propulsion

Assessment of the Economic Potential of Microgrids for Reactive Power Supply

As power generation from variable distributed energy resources (DER) grows, energy flows in the network are changing, increasing the requirements for ancillary services, including voltage support. With the appropriate power converter, DER can provide ancillary services such as frequency control and voltage support. This paper outlines the economic potential of DERs coordinated in a microgrid to provide reactive power and voltage support at its point of common coupling. The DER Customer Adoption Model assesses the costs of providing reactive power, given local utility rules. Depending on the installed DER, the cost minimizing solution for supplying reactive power locally is chosen. Costs include the variable cost of the additional losses and the investment cost of appropriately over-sizing converters or purchasing capacitors. A case study of a large health care building in San Francisco is used to evaluate different revenue possibilities of creating an incentive for microgrids to provide reactive power

Plug-in Electric Vehicle Interactions with a Small Office Building: An Economic Analysis using DER-CAM

It is generally believed that plug-in electric vehicles (PEVs) offer environmental and energy security advantages compared to conventional vehicles. Policies are stimulating electric transportation deployment, and PEV adoption may grow significantly. New technology and business models are being developed to organize the PEV interface and their interaction with the wider grid. This paper analyzes the PEVs' integration into a building's Energy Management System (EMS), differentiating between vehicle to macrogrid (V2M) and vehicle to microgrid (V2m) applications. This relationship is modeled by the Distributed Energy Resources Customer Adoption Model (DER-CAM), which finds optimal equipment combinations to meet microgrid requirements at minimum cost, carbon footprint, or other criteria. Results derive battery value to the building and the possibility of a contractual affiliation sharing the benefit. Under simple annual fixed payments and energy exchange agreements, vehicles are primarily used to avoid peak demand charges supplying cheaper off-peak electricity to the building during workdays

Future-proof tariff design: Recovering sunk grid costs in a world where consumers are pushing back

Traditional analysis of distribution grid user’s reaction to tariffs assumes a low price sensitivity and a lack of alternative technologies to grid connection. This is radically changing with two technology breakthroughs: (1) Photovoltaics (PV) enable domestic and commercial consumers to self-produce energy; (2) Batteries allow self-producers to set both their grid energy and capacity parameters. Contributing to the state of the art, the grid cost recovery problem is modelled as a non-cooperative game between consumers. In this game, the availability and costs of new technologies (such as PV and batteries) strategically interact with tariff structures. Four states of the world for user’s access to new technologies are distinguished and three tariff structures are evaluated. The assessed distribution network tariff structures are: energy volumetric charges with net-metering, energy volumetric charges for both injection and withdrawal, and capacity-based charges. Results show that the new distribution world -open by new technology choices for grid users- is highly interactive and threatens grid regulation not understanding it

Future-proof tariff design: Recovering sunk grid costs in a world where consumers are pushing back

Traditional analysis of distribution network tariff design assumes a lack of alternatives to grid connection for the fulfilment of consumers' electricity needs. This is radically changing with breakthroughs in two technologies: (1) Photovoltaics (PV) enable domestic and commercial consumers to self-produce energy; (2) Batteries allow consumers and self-producers to gain control over their grid energy and capacity parameters. Contributing to the state of the art, the grid cost recovery problem for the Distribution System Operator (DSO) is modelled as a non-cooperative game between consumers. In this game, the availability and costs of the two named technologies strategically interact with tariff structures. Four states of the world for user's access to technologies are distinguished and three tariff structures are evaluated. The assessed distribution network tariff structures are: energy volumetric charges with net-metering, energy volumetric charges for both injection and withdrawal, and capacity-based charges. Results show that in a state of the world with new technology choices for grid users both efficiency and equity issues can arise when distribution network charges are ill-designed