Erinevate energia salvestustehnoloogiate uudsed rakenduspõhimõtted liginullenergiahoonetes

A Thesis for applying for the degree of Doctor of Philosophy in Technical Sciences.In this thesis the renewable energy storage options in residential buildings are under investigation. This is to store cheap electricity due to the temporary overproduction of large wind farms and also on-site solar and wind farms. In an electric system, there should be a balance at all times between energy production and consumption: as much as is produced should also be consumed. Deviating significantly from this balance can damage electrical equipment or cause serious network failures and even blackouts. Unfortunately, both solar and wind energy generation possibilities are associated with (rapid) changes in production. The simplest examples are wind gusts for wind turbines and intermittent cloud cover for solar panels where the electric output power changes in seconds. In order to smooth out the rapid changes in electricity production, the work proposes the possibility to add ultracapacitors to the battery bank for temporary energy storage, which would act as a buffer and are able to temporarily store the produced electricity. So far, the sale of green energy to the electricity grid has been supported at the state level. However, this paper examines the next step in how to support the storage capacity of the produced energy in order to increase self-consumption. To this, a state subsidy measure for battery banks is proposed. Due to short-term overproduction of electricity, there are more and more situations where electricity is sold at zero or even negative prices on the power exchange. The reason is simple - it is more practical for producers to temporarily pay to consumers for electricity consumption than to stop production for a while. This work also proposes a method for storing energy in heat carriers under favorable conditions for the consumer in order to ensure a balance between the production and consumption of the electricity network.Antud doktoritöö käsitleb taastuvenergia salvestusvõimaluste kasutamist elumajades. Seda nii kohapealsete päikeseparkide ja tuulegeneraatorite kui ka suurte tuuleparkide aeg-ajalisest energia ületootmisest tingitud odava elektrienergia salvestamiseks. Energia tootmise ja tarbimise puhul peaks valitsema igas hetkes tasakaal: sama palju kui toodetakse tuleb ka tarbida. Kui sellest tasakaalust väga kõrvale kalduda, võib see elektrilisi seadmed kahjustada või esineb tõsiseid võrgurikkeid ja isegi katkestusi. Paraku on aga nii päikese- kui ka tuuleenergia tootmine seotud (kiirete) muutustega toodangus. Lihtsaimad näited selleks on tuulepuhangud tuulegeneraatorite puhul ning vahelduv pilvisus päikesepaneelide puhul mil elektriline väljundvõimsus muutub sekunditega. Tasandamaks kiireid muutusi elektritootmisel, pakutakse töös välja võimalus lisada akupangale energia ajutiseks salvestamiseks ülikondensaatorid, mis käituks puhvrina ning on võimelised toodetud elektrienergiat ajutiselt salvestama. Senini on riiklikul tasandil toetatud roheenergia müüki elektrivõrku. Antud töös uuritakse aga järgmist etappi, kuidas toetada toodetud energia salvestusvõimalusi eesmärgiga suurendada omatarbimist. Selleks pakutakse välja riiklik akupankade subsideerimise meede. Elektrienergia lühiajalisest ületootmisest tulenevalt esineb üha rohkem olukordi, mil elektribörsil müüakse elektrit null või isegi negatiivse hinnaga. Põhjus on lihtne – tootjatel on otstarbekam ajutiselt elektritarbimisele peale maksta, kui tootmine korraks seisma panna. Antud töös pakutakse samuti välja meetod, kuidas tarbijale soodsatel tingimustel energiat soojuskandjatesse salvestada, tagamaks elektrivõrgu tootmise ja tarbimise tasakaalu.Publication of this theisis is supported by the Estonian University of Life Sciences; and the Doctoral School of Energy and Geotechnology III, (Estonian University of Life Sciences ASTRA project “Valuechain based bio-economy”); and the Estonian Centre of Excellence in Zero Energy and Resource Efficient Smart Buildings and Districts, ZEBE, grant 2014-2020.4.01.15-0016 funded by the European Regional Development Fund