Apply of energy storages in electricity distribution networks and reserve capacity applications

The Thesis is dedicated to development of an operative tool to support decision making of battery energy storages implementation in distribution networks. The basics of various battery technologies, their perspectives and challenges are represented in the Thesis. Mathematical equations that describe economic effect from battery energy storage installation are offered. The main factors that influence profitability of battery settings have been explored and mathematically defined. Mathematical model and principal trends of battery storage profitability under an impact of the major factors are determined. The meaning of annual net value was introduced to show the difference between savings and required costs. The model gives a clear vision for dependencies between annual net value and main factors. Proposals for optimal network and battery characteristics are suggested.

Assessment of techno-economic use cases for small-scale island grids

The main objective of the study was to define the methodology for assessing the limits for application island grids instead of interconnecting with existing grid infrastructure. The model for simulation of grid extension distance and levelised cost of electricity has been developed and validated by the case study in Finland. Thereafter, sensitivities of the application limits were examined with the respect to operational environment, load conditions, supply security and geographical location. Finally, recommendations for the small-scale rural electrification projects in the market economy environment have been proposed.

Cross-border transmission capacity development – Experiences from the Nordic electricity markets

The liberalisation of the wholesale electricity markets has been considered an efficient way to organise the markets. In Europe, the target is to liberalise and integrate the common European electricity markets. However, insufficient transmission capacity between the market areas hampers the integration, and therefore, new investments are required. Again, massive transmission capacity investments are not usually easy to carry through. This doctoral dissertation aims at elaborating on critical determinants required to deliver the necessary transmission capacity investments. The Nordic electricity market is used as an illustrative example. This study suggests that changes in the governance structure have affected the delivery of Nordic cross-border investments. In addition, the impacts of not fully delivered investments are studied in this doctoral dissertation. An insufficient transmission network can degrade the market uniformity and may also cause a need to split the market into smaller submarkets. This may have financial impacts on market actors when the targeted efficient sharing of resources is not met and even encourage gaming. The research methods applied in this doctoral dissertation are mainly empirical ranging from a Delphi study to case studies and numerical calculations.

Vahdon keskustan sähkönjakeluverkon saneeraussuunnitelma

Vuoden 2013 sähkömarkkinalain uudistuksen myötä verkonhaltijoiden tulee varautua suurhäiriötilanteisiin aiempaa tehokkaammin. Lain toimitusvarmuusvaatimusten täyttäminen vaatii sähköverkkoyhtiöiltä entistä suurempia investointimääriä nopeassa aikataulussa. Caruna Oy investoi vuosittain noin 100 miljoonaa euroa säävarman verkon kehittämiseen ja rakentamiseen. Eltel Networks Oy toimii Carunan pääurakoitsijana useissa saneerausprojekteissa muun muassa Satakunnan ja Lounais-Suomen alueilla. Diplomityö tehtiin Eltel Networks Oy:lle ja tavoitteena oli laatia saneeraussuunnitelma Carunan Vahdon keskustan sähkönjakeluverkkoon sekä kehittää Eltelin suunnitteluprosessia Vahdon case-projektin avulla. Nykyverkon ongelmakohdiksi osoittautuivat käyttöikänsä päähän tulleet tai lähivuosina tulevat verkkokomponentit, verkon alhainen nykykäyttöarvo sekä korkeat keskeytyskustannukset. Suunnitellun verkon nykykäyttöarvo yli kaksinkertaistui nykyverkon arvosta, verkon keski-ikä pieneni seitsemällä vuodella ja keskeytyskustannukset pienenivät yli puolella. Case-projektin aikana suunnitteluprosessissa ilmeni useita kehityskohteita. Esimerkiksi kartta-aineistoja ja ilmakuvia kannattaisi hyödyntää monipuolisemmin suunnittelussa ja ohjemuutosten täytäntöönpanoajankohta tulisi määrittää ohjeen tärkeyden mukaan. Vierekkäisille suunnitteluprojekteille kannattaa hakea jatkossa esimerkiksi yhteiset ELY- ja AVI-luvat erillisten lupahakemusten sijaan, koska se vähentää suunnittelijoiden työmäärää ja nopeuttaa hakuprosessia. Suunnittelijoiden yhteistyötä kannattaa laajentaa niin lupahakemusten, sopimusten laadinnan kuin koko prosessin kattavaksi, koska yhteistyö vähentää virheiden määrää ja nopeuttaa suunnitteluprosessia. Yhteistyöllä suunnittelu voidaan toteuttaa nopeammin laadusta tinkimättä.

Impacts of capacity remunerative mechanisms on cross-border trade

The European ambitious targets to increase the share of renewable generation pose a challenge to the generation adequacy. Many European member states are concerned that energy-only markets alone might not be able to deliver sufficient capacity required to meet the future electricity demand and back up shortfalls of energy from renewable energy sources (RES) during periods of low wind and sun. Many EU members consider to re-design their energy-only markets and establish different forms of capacity remunerative mechanisms (CRMs) to maintain the security of supply. There is a certain concern that market design changes at the level of EU member countries might conflict with the European goal of a single market. As soon as many European markets are highly interconnected, uncoordinated CRMs might create negative crossborder effects and hinder the achievement of the Internal Electricity Market in Europe. The pros and cons of capacity markets are well examined at the national level. However, the cross-border effects of capacity markets within the European market aiming at higher integration have received less attention. This doctoral dissertation examines the cross-border effects of unilateral implementation of CRMs applying both theoretical and case study analyses. The results show that capacity remunerative mechanisms (CRMs) may cause negative cross-border effects, especially if they are implemented unilaterally.

Households’ willingness to engage in demand response in the Finnish retail electricity market: an empirical study

If electricity users adjusted their consumption patterns according to time-variable electricity prices or other signals about the state of the power system, generation and network assets could be used more efficiently, and matching intermittent renewable power generation with electricity demand would be facilitated. This kind of adjustment of electricity consumption, or demand response, may be based on consumers’ decisions to shift or reduce electricity use in response to time-variable electricity prices or on the remote control of consumers’ electric appliances. However, while demand response is suggested as a solution to many issues in power systems, actual experiences from demand response programs with residential customers are mainly limited to short pilots with a small number of voluntary participants, and information about what kinds of changes consumers are willing and able to make and what motivates these changes is scarce. This doctoral dissertation contributes to the knowledge about what kinds of factors impact on residential consumers’ willingness and ability to take part in demand response. Saving opportunities calculated with actual price data from the Finnish retail electricity market are compared with the occurred supplier switching to generate a first estimate about how large savings could trigger action also in the case of demand response. Residential consumers’ motives to participate in demand response are also studied by a web-based survey with 2103 responses. Further, experiences of households with electricity consumption monitoring systems are discussed to increase knowledge about consumers’ interest in getting more information on their electricity use and adjusting their behavior based on it. Impacts of information on willingness to participate in demand response programs are also approached by a survey for experts of their willingness to engage in demand response activities. Residential customers seem ready to allow remote control of electric appliances that does not require changes in their everyday routines. Based on residents’ own activity, the electricity consuming activities that are considered shiftable are very limited. In both cases, the savings in electricity costs required to allow remote control or to engage in demand response activities are relatively high. Nonmonetary incentives appeal to fewer households.