Strategic distribution network planning with smart grid technologies

This paper presents a multiyear distribution network planning optimization model for managing the operation and capacity of distribution systems with significant penetration of distributed generation (DG). The model considers investment in both traditional network and smart grid technologies, including dynamic line rating, quadrature-booster, and active network management, while optimizing the settings of network control devices and, if necessary, the curtailment of DG output taking into account its network access arrangement (firm or non-firm). A set of studies on a 33 kV real distribution network in the U.K. has been carried out to test the model. The main objective of the studies is to evaluate and compare the performance of different investment approaches, i.e., incremental and strategic investment. The studies also demonstrate the ability of the model to determine the optimal DG connection points to reduce the overall system cost. The results of the studies are discussed in this paper

Benefits of demand-side response in providing frequency response service in the future GB power system

The demand for ancillary service is expected to increase significantly in the future Great Britain (GB) electricity system due to high penetration of wind. In particular, the need for frequency response, required to deal with sudden frequency drops following a loss of generator, will increase because of the limited inertia capability of wind plants. This paper quantifies the requirements for primary frequency response and analyses the benefits of frequency response provision from demand-side response (DSR). The results show dramatic changes in frequency response requirements driven by high penetration of wind. Case studies carried out by using an advanced stochastic generation scheduling model suggest that the provision of frequency response from DSR could greatly reduce the system operation cost, wind curtailment, and carbon emissions in the future GB system characterized by high penetration of wind. Furthermore, the results demonstrate that the benefit of DSR shows significant diurnal and seasonal variation, whereas an even more rapid (instant) delivery of frequency response from DSR could provide significant additional value. Our studies also indicate that the competing technologies to DSR, namely battery storage, and more flexible generation could potentially reduce its value by up to 35%, still leaving significant room to deploy DSR as frequency response provider

Pengaruh Keberadaan Habitat Alami terhadap Keanekaragaman dan Kelimpahan Serangga Pengunjung Bunga Mentimun

Keberadaan serangga pada suatu habitat pertanian dipengaruhi oleh beberapa faktor salah satunya adalah habitat alami. Tujuan penelitian ini adalah untuk mempelajari pengaruh jarak habitat alami terhadap keanekaragaman dan kelimpahan serangga pengunjung bunga pada pertanaman mentimun. Penelitian dilakukan di lahan mentimun pada 12 lokasi yang terletak di Kabupaten Bogor, Cianjur, dan Sukabumi, Jawa Barat. Jarak habitat alami dengan lahan pertanian dikategorikan dalam dua kelompok, yaitu dekat dengan habitat alami (kurang dari 200 m) dan jauh dari habitat alami (lebih dari 1000 m). Pengamatan serangga pengunjung bunga mentimun dilakukan dengan cara menghitung jumlah serangga pengunjung bunga mentimun yang hinggap pada 100 unit bunga yang dilakukan pada empat transek berbeda. Penghitungan jumlah serangga pengunjung bunga dilakukan pada empat waktu yang berbeda dan pada hari yang berbeda. Hasil analisis menunjukkan bahwa perbedaan jarak habitat alami dengan lahan pertanian berpengaruh terhadap keanekaragaman spesies serangga pengunjung bunga, tetapi tidak berpengaruh terhadap kelimpahannya. Spesies serangga pengunjung bunga dominan yang ditemukan di pertanaman mentimun adalah Aphis sp., Tapinoma sp., dan Thrips parvispinus Karny, sedangkan serangga penyerbuk dominan yang ditemukan adalah Apis cerana Fabricius. Jarak habitat alami dari lahan pertanian berpengaruh terhadap keberadaan serangga pengunjung bunga khususnya serangga penyerbuk yang memiliki peran penting dalam meningkatkan hasil pertanian

Does Landscape Complexity and Semi-Natural Habitat Structure Affect Diversity of Flower-Visiting Insects in Cucumber Fields?

Presence of insects in agricultural habitat is affected by the surrounding circumstances such as the complexity and structure of landscape. Landscape structure is often formed as a consequence of the fragmentation of semi-natural habitat, which can negatively affect species richness and abundance of insects. This study was aimed to study the effect of complexity and structure of landscape on the diversity, abundance and traits of flower-visiting insects in cucumber fields. This study was conducted in cucumber fields surrounded by other agricultural crops, shrubs, semi-natural habitat and housing area, in Bogor, Cianjur and Sukabumi regencies, West Java, Indonesia. In a total of 16 agricultural areas, complexity and parameter of landscape especially class area (CA), number of patches (NumP), mean patch size (MPS), total edge (TE), and mean shape index (MSI) of seminatural habitats were measured. Sampling of flower-visiting insects was conducted using scan sampling methods. The result showed that landscape complexity affected species richness (but not abundance and trait) of flower-visiting insects both for mobile and less-mobile insects. Flower-visiting insects also responded differently to landscape structure. Species richness, abundance and variation of body size of mobile insects were affected by structure of semi-natural habitat

Komunitas Lepidoptera Dan Parasitoidnya Pada Pertanaman Mentimun Di Bogor, Sukabumi Dan Cianjur, Jawa Barat

Lepidopteran community and its parasitoid on cucumber field in Bogor, Sukabumi and Cianjur District, West Java. Cucumber is one of horticultural commodities that are widely cultivated in Indonesia, but information related to Lepidoptera pests and their parasitoids are limited. The aim of this study was to obtain information about Lepidopteran community on cucumber and their parasitoid diversity. Lepidopteran larvae were collected from 16 cucumber sites in the District of Bogor, Sukabumi and Cianjur in November 2014 until May 2015. Larvae were collected from each cucumber plant follow along 60 m transects. Larvae were collected from the field then brought to the laboratory. All larvae were then reared on cucumber leaves until pupation and parasitoids emerged. The data obtained were tested by analysis of the mean and analysis of variance (One way ANOVA) using the program R Stat. The results showed that cucumber plants were attacked by six species (morphospecies) belonging to four families of Lepidoptera. Diaphania indica (Saunders) (Lepidoptera: Crambidae) is the most abundant species found. All species (morphospecies) of Lepidoptera are more common when the cucumber plants are in the generative growth stage. Our result further showed that D. indica was attacked by 9 parasitoid larvae and 3 parasitoid pupae, C. chalcites (Lepidoptera: Noctuidae) by 5 parasitoids dan S. litura (Lepidoptera: Noctuidae) by 2 parasitoids. A braconid, Apanteles taragamae, is the most common parasitoid of D. indica found in the field. Its parasitism rate can reach 27% in the field. Overall, this research revealed that a number of parasitoids, that were found attacking Lepidopteran on cucumber indicates their potential use as biological control agents in this agroecosystems

Assessing the value and impact of demand side response using whole-system approach

This paper describes the whole-system based model called Whole-electricity System Investment Model to quantify the benefits of demand flexibility. Whole-electricity System Investment Model is a holistic and comprehensive electricity system analysis model, which simultaneously optimises the long-term investment decisions against real-time operation decisions taking into account the flexibility provided by demand. The optimisation considers the impact of demand side response across all power subsystems, i.e. generation, transmission and distribution systems, in a coordinated fashion. This allows the model to capture the potential conflicts and synergies between different applications of demand side response in supporting particularly intermittency management at the national level, improving capacity margin, and minimising the cost of electrification. The impact and value of demand side response driven by whole-system approach are compared against the impact and value of distribution system operator or transmission system operator centric (silo approaches) demand side response applications and the importance of control coordination between distribution system operator and transmission system operator for optimal demand side response is discussed and highlighted

Synergies and trade-offs between governance and costs in electricity system transition

Affordability and costs of an energy transition are often viewed as the most influential drivers. Conversely, multi-level transitions theory argues that governance and the choices of key actors, such as energy companies, government and civil society, drive the transition, not only on the basis of costs. This paper combines the two approaches and presents a cost appraisal of the UK transition to a low-carbon electricity system under alternate governance logics. A novel approach is used that links qualitative governance narratives with quantitative transition pathways (electricity system scenarios) and their appraisal. The results contrast the dominant market-led transition pathway (Market Rules) with alternate pathways that have either stronger governmental control elements (Central Co-ordination), or bottom-up proactive engagement of civil society (Thousand Flowers). Market Rules has the lowest investment costs by 2050. Central Co-ordination is more likely to deliver the energy policy goals and possibly even a synergistic reduction in the total system costs, if policies can be enacted and maintained. Thousand Flowers, which envisions wider participation of the society, comes at the expense of higher investment and total system costs. The paper closes with a discussion of the policy implications from cost drivers and the roles of market, government and society

Benefits of smart control of hybrid heat pumps: an analysis of field trial data

Smart hybrid heat pumps have the capability to perform smart switching between electricity and gas by employing a fully-optimized control technology with predictive demand-side management to automatically use the most cost-effective heating mode across time. This enables a mechanism for delivering flexible demand-side response in a domestic setting. This paper conducts a comprehensive analysis of the fine-grained data collected during the world’s first sizable field trial of smart hybrid heat pumps to present the benefits of the smart control technology. More specifically, a novel flexibility quantification framework is proposed to estimate the capability of heat pump demand shifting based on preheating. Within the proposed framework, accurate estimation of baseline heat demand during the days with interventions is fundamentally critical for understanding the effectiveness of smart control. Furthermore, diversity of heat pump demand is quantified across different numbers of households as an important input into electricity distribution network planning. Finally, the observed values of the Coefficient of Performance (COP) have been analyzed to demonstrate that the smart control can optimize the heat pump operation while taking into account a variety of parameters including the heat pump output water temperature, therefore delivering higher average COP values by maximizing the operating efficiency of the heat pump. Finally, the results of the whole-system assessment of smart hybrid heat pumps demonstrate that the system value of smart control is between 2.1 and 5.3 £ bn/year

Whole-system assessment of the benefits of integrated electricity and heat system

The interaction between electricity and heat systems will play an important role in facilitating the cost effective transition to a low carbon energy system with high penetration of renewable generation. This paper presents a novel integrated electricity and heat system model in which, for the first time, operation and investment timescales are considered while covering both the local district and national level infrastructures. This model is applied to optimize decarbonization strategies of the UK integrated electricity and heat system, while quantifying the benefits of the interactions across the whole multi-energy system, and revealing the trade-offs between portfolios of (a) low carbon generation technologies (renewable energy, nuclear, CCS) and (b) district heating systems based on heat networks (HN) and distributed heating based on end-use heating technologies. Overall, the proposed modeling demonstrates that the integration of the heat and electricity system (when compared with the decoupled approach) can bring significant benefits by increasing the investment in the heating infrastructure in order to enhance the system flexibility that in turn can deliver larger cost savings in the electricity system, thus meeting the carbon target at a lower whole-system cost

DER reactive services and distribution network losses

Managing synergies and conflicts between voltage support services and network losses is essential for the cost-effective integration of distributed energy resources (DERs). This study presents the results of studies investigating the impact of using DER reactive power services on distribution network losses. By using year-round optimal power flow analysis, a spectrum of studies on a number of distribution network areas in the southeast of Great Britain was performed to calculate distribution losses under different control scenarios. The studies demonstrate that the use of DERs to provide reactive services to the transmission system may increase distribution network losses. On the other hand, DER reactive services can also be optimised to minimise distribution losses. The studies also analysed the impact of optimising tap changing transformer settings on the distribution network losses reduction