Seabed Sediment as an Annually Renewable Heat Source

Thermal energy collected from the sediment layer under a water body has been suggested for use as a renewable heat source for a low energy network. A prototype system for using this sediment energy was installed in Suvilahti, Vaasa, in 2008 and is still in use. It provides a carbon-free heating and cooling solution as well as savings in energy costs for 42 houses. To be a real, renewable heat source, the thermal energy of the sediment layer needs to replenish annually. The goal of this paper is to verify the possible cooling or annual heat regeneration. The sediment temperatures were measured and analyzed in the years 2013–2015. The data were compared to the same period in 2008–2009. All measurements were taken in the same place. This paper also confirms the potential of the sediment heat, especially in the seabed sediment, using the temperature differences between the lowest and the highest values for the year. The results demonstrate that the collection of the heat energy does not cause permanent cooling of the sediment. This result was obtained by calculating the temperature difference between measurements in the warmest month and the month with the coldest temperatures. This indicates the extracted energy. The difference was found to be around 9.5 °C in 2008–2009, rising to around 11 °C for the years 2013–2014 and 2014–2015. This indicates the loaded energy. The energy utilization is sustainable: the sediment temperature has not permanently decreased despite the full use of the network for the heating and cooling of houses between 2008 and 2015.fi=vertaisarvioitu|en=peerReviewed

Seabed sediment : a natural seasonal heat storage feasibility study

The new discovery among renewable energy resources, seabed sediment, has been utilised as a heat source for 42 houses in Vaasa since 2008. Sediment heat is annually loaded by the Sun. In this study the amount of annually charged energy is estimated. The difference of sediment temperatures between the coldest and the warmest month during the year is a key value in the approximation of the loaded energy. Sediment temperatures are measured once per month via optical cable by distributed temperature sensing (DTS) method. The monitoring period is three years, 2014–2016. The estimation of incoming energy (575 MWh) versus known exploited energy (560 MWh) is reasonable. Despite of the extraction this seasonal heat storage in the seabed of the Baltic Sea seems to reload well annually.fi=vertaisarvioitu|en=peerReviewed

Reliable Renewable Hybrid Energy Solutions

Worldwide studies, including the Paris agreement, show that it is necessary to reduce dependency on the non-renewable energy sources and fossil fuels such as oil and coal. Transition to renewable energy is evident, and different reliable renewable energy systems are needed. The energy production with renewable energy sources is typically non-continuous when using only a single technique. This can be avoided by using a hybrid system and/or seasonal storage. This study introduces several hybrid systems and examples of storages operating mainly in Finland most of them in co-operation with University of Vaasa. Hybrid renewable energy systems (HRES) can be implemented in multiple different ways, scope varies from larger energy villages and other residential areas to single buildings. The amount of renewable energy generated by any HRES depends on both the technology and the meteorology. Some energy sources like different forms of geoenergy (geothermal energy) are available around the year. Instead, some renewable energy sources like solar and wind are often season dependent energy. To ensure constant production in HRES for the electric grid or the heating network, the energy storage or backup energy systems are in almost all cases needed. Advantages of the hybrid techniques are reliable, constant energy production and scalable energy production. When designing a hybrid system it also needs to be solved, what to do with the excess energy; whether to deliver it to the grid, use the dump loads or the storage systems.© SDEWES Centre, Conference on sustainable development of energy, water and environment systems.fi=vertaisarvioitu|en=peerReviewed

Statistical investigation of climate change effects on the utilization of the sediment heat energy

Suvilahti, a suburb of the city of Vaasa in western Finland, was the first area to use seabed sediment heat as the main source of heating for a high number of houses. Moreover, in the same area, a unique land uplift effect is ongoing. The aim of this paper is to solve the challenges and find opportunities caused by global warming by utilizing seabed sediment energy as a renewable heat source. Measurement data of water and air temperature were analyzed, and correlations were established for the sediment temperature data using Statistical Analysis System (SAS) Enterprise Guide 7.1. software. The analysis and provisional forecast based on the autoregression integrated moving average (ARIMA) model revealed that air and water temperatures show incremental increases through time, and that sediment temperature has positive correlations with water temperature with a 2-month lag. Therefore, sediment heat energy is also expected to increase in the future. Factor analysis validations show that the data have a normal cluster and no particular outliers. This study concludes that sediment heat energy can be considered in prominent renewable production, transforming climate change into a useful solution, at least in summertime

Seasonal temperature variation in heat collection liquid used in renewable, carbon-free heat production from urban and rural water areas

A renewable energy source called sediment energy is based on heat collection with tubes similar to those used in ground energy and is installed inside a sediment layer under water body. In this paper, an investigation of temperature behaviour of heat carrier liquid is made during several years to evaluate utilization of sediment energy. This is done by evaluating temperature variations of heat carrier liquid and its correlation to air temperature. This increases advancement of knowledge how the temperature of the sediment recovers from the heat collection. The temperature variation of the liquid seems to correlate with the mean monthly air temperature. The selected methods clearly indicate that sediment energy seems to be yearly renewable because there is a clear correlation between air temperature and heat carrier liquid temperature.© Authors. This is an open access journal distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)fi=vertaisarvioitu|en=peerReviewed

Distributed Temperature Sensing Method - Usability in Asphalt and Sediment Heat Energy Measurements

Geoenergia koostuu maan sisältä tulevasta geotermisestä energiasta ja auringon säteilyenergiasta. Geoenergiaa on saatavilla maasta, kallioperästä, vesistöistä, sedimentistä ja asfaltista. Asfaltti- ja sedimenttilämpö sekä niiden hyödyntäminen kuuluvat Vaasan yliopiston Teknillisen tiedekunnan Geoenergia-projektin tutkimusaiheisiin. Lämpöenergian käyttäytymisestä asfaltin alla ja sedimentissä tarvittiin lisätietoa, joten näiden kerrosten lämpötiloja oli pystyttävä mittaamaan säännöllisesti. Tässä diplomityössä selvitettiin mahdollisuutta hyödyntää hajautettua lämpötilanmittausmenetelmää (Distributed Temperature Sensing, DTS) asfaltin alaisten maakerrosten lämpötilan mittauksessa ja merenpohjan sedimenttilämmön mittauksessa. Hajautetun lämpötilanmittausmenetelmän hyödyntämistä asfalttilämmön mittauksissa tutkittiin laboratorio-olosuhteissa. Samalla uusi optinen DTS-menetelmään perustuva mittauslaite otettiin käyttöön ja sen ominaisuuksiin tutustuttiin. Laboratoriomittauksilla selvitettiin laitteen ja kaapelin ominaisuuksia sekä määritettiin mittausepävarmuus. Sedimentin lämpötila mitattiin maastossa Vaasan Suvilahdessa. Maastomittaukset antoivat tietoa Suvilahden matalaenergiaverkon sedimenttilämpötilan tasosta. Sedimentistä saatuja lämpötilakäyriä verrattiin muutaman vuoden takaisiin mittauksiin samasta paikasta. Sedimentin lämpötiloja aiotaan mitata jatkossa säännöllisesti. Tämän diplomityön tuloksista voidaan päätellä, että hajautettu lämpötilanmittausmenetelmä (DTS) on tarkka ja monipuolinen menetelmä käytettäväksi asfaltti- ja sedimenttilämmön mittaamisessa. Menetelmä soveltuu hyvin sekä asfaltin alaisten kerrosten lämpötilan tutkimuksiin että sedimentin lämpötilojen seurantaan.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Seaside Renewable Energy Resources Literature Review

This review paper describes seaside renewable energy resources. The motivation and need behind this work are to give background literature on the use of climate change effects as a resource support for shallow geothermal-energy (seaside energy solutions) production. This leads to combating and mitigating climate change by using its effect to our advantage. As a part of my literature review as a report series, this report gives some background about seaside energy solutions relating to water quality and climate change. This review paper addresses all aspects of renewable energy. The methodology implemented in this review paper and other series was a systematic literature review process. After searching and collecting articles from three databases, they were evaluated by title, abstract and whole article then synthesized into the literature review. The key conclusion is that seaside renewable energy is mainly shallow geothermal-energy and most of the methods use climate change effects to their advantage such as sediment heat energy production. The main recommendation is to use the effects of climate change to combat and mitigate its causes and further consequences. The overall conclusions are built on the relationships between different aspects of the topics. The paper contributes a precise current review of renewable energy. It is the last part of a series of four review papers on climate change, land uplift, water resources, and these seaside energy solutions.© 2022 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed

Spatial analysis of fish distribution in relation to offshore wind farm developments

In an effort to support the Kyoto Protocol, the government of the United Kingdom has targeted a goal of obtaining 15% of its electricity supply from renewable sources by 2015. To reach such standards, primary concentration has been placed on renewable sources from the marine environment. However, with increases in the numbers of offshore renewable energy developments (OREDs), proper monitoring and analysis techniques must be established to evaluate the potential impacts these structures and their overall environmental footprint will pose on the marine ecosystem, particularly species distribution. Monitoring techniques have been established by offshore energy developers; however, such methods currently only evaluate animal distribution trends in the short term both pre and post construction. In this study, spatio-temporal analysis of catch per unit effort (CPUE) data was undertaken, utilising geostatistics to enable long term trends to be evaluated for four elasmobranch species common to the North Sea over the 1990-2011 survey period. Overall, the mean CPUE was found to remain stable for all species. However, distribution trends were found to vary throughout the periods examined. Such trends were often correlated to migrating seasons, as well as the habitat preferences for each species. The presence of offshore wind farms and electromagnetic fields associated with subsea cable networks may affect elasmobranch migratory patterns and small-scale orientation. As these species are already vulnerable to overfishing, habitat disruption, and anthropogenic disturbance due to their long life history and low fecundity, consistent monitoring periods and survey locations are essential to their conservation and protection. It is, therefore, unlikely short monitoring periods will provide accurate information on the potential impacts offshore energy developments may have on elasmobranch populations. The approach used is generic enough to provide a basis on which to analyse spatial distribution of organisms in relation to other sources of anthropogenic influence, and environmental parameters

Feasibility study on manganese nodules recovery in the Clarion-Clipperton Zone

The sea occupies three quarters of the area on the earth and provides various kinds of resources to mankind in the form of minerals, food, medicines and even energy. “Seabed exploitation” specifically deals with recovery of the resources that are found on the seabed, in the form of solids, liquids and gasses (methane hydrates, oil and natural gas). The resources are abundant; nevertheless the recovery process from the seabed, poses various challenges to mankind. This study starts with a review on three types of resources: polymetallic manganese nodules, polymetallic manganese crusts and massive sulphides deposits. Each of them are rich in minerals, such as manganese, cobalt, nickel, copper and some rare earth elements. They are found at many locations in the deep seas and are potentially a big source of minerals. No commercial seabed mining activity has been accomplished to date due to the great complexities in recovery. This book describes the various challenges associated with a potential underwater mineral recovery operation, reviews and analyses the existing recovery techniques, and provides an innovative engineering system. It further identifies the associated risks and a suitable business model.Chapter 1 presents a brief background about the past and present industrial trends of seabed mining. A description of the sea, seabed and the three types of seabed mineral resources are also included. A section on motivations for deep sea mining follows which also compares the latter with terrestrial mining.Chapter 2 deals with the decision making process, including a market analysis, for selecting manganese nodules as the resource of interest. This is followed by a case study specific to the location of interest: West COMRA in the Clarion-Clipperton Zone. Specific site location is determined in order to estimate commercial risk, environmental impact assessment and logistic challenge.Chapter 3 lists the existing techniques for nodule recovery operation. The study identifies the main components of a nodules recovery system, and organizes them into: collector, propulsion and vertical transport systems.Chapter 4 discusses various challenges posed by manganese nodules recovery, in terms of the engineering and environment. The geo-political and legal-social issues have also been considered. This chapter plays an important role in defining the proposed engineering system, as addressing the identified challenges will better shape the proposed solution.Chapter 5 proposes an engineering system, by considering the key components in greater details. An innovative component, the black box is introduced, which is intended to be an environmentally-friendly solution for manganese nodules recovery. Other auxiliary components, such as the mother ship and metallurgical processing, are briefly included. A brief power supply analysis is also provided.Chapter 6 assesses the associated risks, which are divided into sections namely commercial viability, logistic challenges, environmental impact assessment and safety assessment. The feasibility of the proposed solution is also dealt with.Chapter 7 provides a business model for the proposed engineering system. Potential customers are identified, value proposition is determined, costumer relation is also suggested. Public awareness is then discussed and finally a SWOT analysis is presented. This business model serves as an important bridge to reach both industry and research institutes.Finally, Chapter 8 provides some conclusions and recommendation for future work