Backup Generation Capacity Research Articles

Resilience-Oriented Proactive Management of Microgrids Against Windstorms

This paper presents a microgrid (MG) proactive management framework to cope with adverse impacts of extreme windstorms. Upon receiving alerts for the forecasted windstorm, the framework finds a conservative schedule of MG with the minimum number of vulnerable branches in service while total load is served. The schedule ensures the MG normal operation prior to the windstorm while reducing the MG vulnerability at the event onset. The proposed method makes benefit of network reconfiguration, generation reschedule, conservation voltage regulation, optimal parameter settings of droop-controlled units, demand-side resources, and backup generation capacity. A vulnerability index is defined to assess the effectiveness of the proposed proactive management in reducing the MG vulnerability at the event onset. The proposed model is linearized that guarantees simplicity, robustness, and computational efficiency of the solution. The effectiveness of the proposed method is tested on a real-scale MG against a windstorm.

Cost-minimised design of a highly renewable heating network for fossil-free future

This research presents technical and cost-minimised design to decarbonise the heating network by using large-scale heat pump and thermal heat storage. In this paper, real hourly heat-consumption and heat-production cost data for the city of Aarhus, Denmark are used for calculating techno-economic feasibility of coupling the heating network with electrical grid. An optimum solution is suggested for the entire network with least amount of backup generation capacity, thermal heat storage capacity, natural gas boiler capacity and levelised cost of energy. Aarhus constitutes 5% of the Denmark's total heat demand and 4% of electrical load demand. This can be fulfilled with 160 MW of rated wind generation capacity, 35 MW of solar PV generation capacity, 45 MW of backup generation capacity, 221 MW of natural gas boiler capacity and 3.4 GWh of thermal heat storage capacity. The levelised cost of energy shows that, the coupling between the electrical grid and heating sector reduces the cost by more than 50% to 45 € /MWh. However, the cost-minimised design is possible with wind/solar mix of 85% and renewable energy penetration of 100%. Sensitivity analysis concedes that, the 100% decarbonisation of heating sector relies heavily upon the cost assumed for wind generation and solar PV generation, instead of the operation and maintenance cost for heat pump. Furthermore, the reduction in cost for wind generation and solar PV generation leads to the decrease in levelised cost of energy. Whereas, the reduction in cost for heat pump, thermal heat storage capacity and natural gas boiler capacity leads to an increase in renewable energy penetration. Sensitivity analysis further reveals that, increasing thermal heat storage capacity and the cost of selling excess renewable energy does not have major impact upon the levelised cost of energy and can be instrumental for the economic viability of fossil-free future.

Techno-economic, environmental, and safety assessment of hydrogen powered community microgrids; case study in Canada

This paper proposes a comprehensive design of a renewable hydrogen powered microgrid that can provide backup power to a community in Cornwall, Ontario when disconnected from the power grid. The work employs the implementation of the energy hub concept to optimally design and operate energy generation systems to meet energy loads of a community. Solar PVs, wind turbines, electrolysers, hydrogen tanks, fuel cells and fuel cell vehicles are considered as the components that make up the entire system providing energy within the community. Failure mode and effect analysis (FMEA) is done to assess the safety of hydrogen based microgrid.The major load centers include a fresh food distribution center and a residential complex, where the peak demand is ∼5410 kW. The results of a mixed integer linear programming optimization problem show that a renewable energy generation system size of 2000 kW (400 kW-solar Photovoltaic and 1600 kW-wind turbine) is required. In addition to this, a backup fuel cell generation system of 3000 kW is also needed for the two-day blackout period. One of the positive attributes of implementing vehicle to grid services during islanded operation mode is that it enables the community to offset investment in fuel cell backup generation capacity by 1000 kW. Thirty-eight Toyota Mirai have been used to provide the vehicle to grid service. Due to the scale of the system, it is observed that even after proposing the use of existing market pricing mechanisms for the services offered by the microgrid, the energy system does not have a positive net present value at the end of its project life. Therefore, further economic incentives in the form of bundling costs need to be sanctioned for cleaner microgrid energy systems to be developed. This submission was the Grand Prize Winner of the Hydrogen Education Foundation's 2016 Hydrogen Student Design Contest.

Increasing the Installation Capacity of PV with PEMFC Backup within a Residential Community

Photovoltaic (PV) installation capacity is limited by the availability of backup generation from the centralized electrical grid. One method of increasing PV installation capacity is to install proton exchange membrane fuel cell (PEMFC) systems at the PV generation site. PEMFC systems generate electricity and heat simultaneously, thereby utilizing fuel more efficiently. To study this concept, simulation was performed for a community-scale system consisting of 12 Canadian households - as opposed to single housing units- in order to decrease the fluctuation of the load and increase the modulation capacity of the PEMFC system. A power management strategy was developed to control the PEMFC power output in order to integrate with the PV system to supply the required electrical load. The power management strategy was implemented with a look-forward strategy using forecasted load, which took into account the modulation rate and the range of power output of the fuel cell system. The combined PV and PEMFC system simulation results demonstrated a reduction in the community's reliance on the electrical grid, as compared to a PV only system. The integration of technologies reduced the electrical imports from the central electrical grid into the community by 82.5%. Additionally, the use of both technologies in the community decreased the necessary backup generation capacity from the electrical grid by 24%. These results imply that the PEMFC technologies are able to replace some of the centralized power generation in backing up solar power intermittencies, thus, avoiding the installation of additional centralized power generation. The utilization of residential PEMFC systems can be used to back up solar intermittencies, allowing for increases in PV installation capacity.

Benefits of flexibility from smart electrified transportation and heating in the future UK electricity system

This paper presents an advanced stochastic analytical framework to quantify the benefits of smart electric vehicles (EVs) and heat pumps (HPs) on the carbon emission and the integration cost of renewable energy sources (RES) in the future UK electricity system. The typical operating patterns of EVs/HPs as well as the potential flexibility to perform demand shifting and frequency response are sourced from recent UK trials. A comprehensive range of case studies across several future UK scenarios suggest that smart EVs/HPs could deliver measurable carbon reductions by enabling a more efficient operation of the electricity system, while at the same time making the integration of electrified transport and heating demand significantly less carbon intensive. The second set of case studies establish that smart EVs/HPs have significant potential to support cost-efficient RES integration by reducing: (a) RES balancing cost, (b) cost of required back-up generation capacity, and (c) cost of additional low-carbon capacity required to offset lower fuel efficiency and curtailed RES output while achieving the same emission target. Frequency response provision from EVs/HPs could significantly enhance both the carbon benefit and the RES integration benefit of smart EVs/HPs.

Compressed air energy storage as backup generation capacity combined with wind energy sector in Poland - implementation possibilities

Compressed air energy storage as backup generation capacity combined with wind energy sector in Poland - implementation possibilities

Potential climatic impacts and reliability of very large-scale wind farms

Abstract. Meeting future world energy needs while addressing climate change requires large-scale deployment of low or zero greenhouse gas (GHG) emission technologies such as wind energy. The widespread availability of wind power has fueled substantial interest in this renewable energy source as one of the needed technologies. For very large-scale utilization of this resource, there are however potential environmental impacts, and also problems arising from its inherent intermittency, in addition to the present need to lower unit costs. To explore some of these issues, we use a three-dimensional climate model to simulate the potential climate effects associated with installation of wind-powered generators over vast areas of land or coastal ocean. Using wind turbines to meet 10% or more of global energy demand in 2100, could cause surface warming exceeding 1 °C over land installations. In contrast, surface cooling exceeding 1 °C is computed over ocean installations, but the validity of simulating the impacts of wind turbines by simply increasing the ocean surface drag needs further study. Significant warming or cooling remote from both the land and ocean installations, and alterations of the global distributions of rainfall and clouds also occur. These results are influenced by the competing effects of increases in roughness and decreases in wind speed on near-surface turbulent heat fluxes, the differing nature of land and ocean surface friction, and the dimensions of the installations parallel and perpendicular to the prevailing winds. These results are also dependent on the accuracy of the model used, and the realism of the methods applied to simulate wind turbines. Additional theory and new field observations will be required for their ultimate validation. Intermittency of wind power on daily, monthly and longer time scales as computed in these simulations and inferred from meteorological observations, poses a demand for one or more options to ensure reliability, including backup generation capacity, very long distance power transmission lines, and onsite energy storage, each with specific economic and/or technological challenges.

Onsite Backup Generation and Interruption Insurance for Electricity Distribution

This paper extends recent work on interruption insurance for electric power by introducing onsite backup generation capacity as a supplementary form of interruption insurance. The basic model of interruption insurance as a mechanism for differential pricing is reviewed, the incentive for providing onsite backup generation capacity is demonstrated and the interaction between onsite backup generation and interruption insurance is analyzed. Two types of onsite backup, customer and utility owned, are discussed. It is shown that individuals’ economic incentives to install onsite backup generation dominate the utility’s incentive. Hence customer owned onsite backup decisions will pre-empt the utility’s plan to mitigate compensation payments by providing onsite backup generation.