Ground-source heat pumps and underground thermal energy storage: energy for the future

We need energy for space heating—but in most cases not where or when energy sources are available. Energy storage, which helps match energy supply and demand, has been practised for centuries, also in Norway. Energy storage systems will increase the potential of utilising renewable energy sources such as geothermal energy, solar heat and waste heat. The most frequently-used storage technology for heat and ‘coolth’ is Underground Thermal Energy Storage (UTES). The ground has proved to be an ideal medium for storing heat and cold in large quantities and over several seasons or years. UTES systems in the Nordic countries are mostly used in combination with Ground-Source Heat Pumps (GSHP). Several different UTES systems have been developed and tested. Two types of system, Aquifer (ATES) and borehole (BTES) storage, have had a general commercial breakthrough in the last decades in the Nordic countries. Today, about 15,000 GSHP systems exist in Norway extracting about 1.5 TWh heat from the ground. About 280 of the Norwegian GSHP installations are medium- to large-scale systems (> 50 kW) for commercial/public buildings and for multi-family dwellings. The two largest closed-loop GSHP systems in Europe, using boreholes as ground heat exchangers, are located in Norway

A comparison of laboratory and in situ methods to determine soil thermal conductivity for energy foundations and other ground heat exchanger applications

Soil thermal conductivity is an important factor in the design of energy foundations and other ground heat exchanger systems. It can be determined by a field thermal response test, which is both costly and time consuming, but tests a large volume of soil. Alternatively, cheaper and quicker laboratory test methods may be applied to smaller soil samples. This paper investigates two different laboratory methods: the steady-state thermal cell and the transient needle probe. U100 soil samples were taken during the site investigation for a small diameter test pile, for which a thermal response test was later conducted. The thermal conductivities of the samples were measured using the two laboratory methods. The results from the thermal cell and needle probe were significantly different, with the thermal cell consistently giving higher values for thermal conductivity. The main difficulty with the thermal cell was determining the rate of heat flow, as the apparatus experiences significant heat losses. The needle probe was found to have fewer significant sources of error, but tests a smaller soil sample than the thermal cell. However, both laboratory methods gave much lower values of thermal conductivity compared to the in situ thermal response test. Possible reasons for these discrepancies are discussed, including sample size, orientation and disturbance

A summary of the EEA project geothermal energy – a basis for low-emission heating improving living conditions and sustainable development – preliminary studies for selected areas in Poland

Artykuł przedstawia cele, działania, wyniki, propozycje i rekomendacje predefiniowanego Projektu EOG "Energia geotermalna – podstawa niskoemisyjnego ciepłownictwa, poprawy warunków życia i zrównoważonego rozwoju – wstępne studia dla wybranych obszarów w Polsce". Stanowi podsumowanie głównego opracowania Projektu – Raportu z wizyt studyjnych. Projekt był realizowany przez międzynarodowe grono specjalistów. Z Polski były to zespoły: IGSMiE PAN (lider Projektu), Akademii Górniczo-Hutniczej im. S. Staszica w Krakowie oraz Politechniki Wrocławskiej, natomiast z zagranicy przedstawiciele światowych liderów w zakresie geotermii płytkiej – Christian Michelsen Research AS z Norwegii i głębokiej – z Krajowej Agencji Energii z Islandii (krajów Darczyńców Mechanizmu Finansowego EOG), a ponadto z Europejskiej Rady Energii Geotermalnej, eksperci i przedstawiciele miast do których adresowany był Projekt – Lądka-Zdroju, Konstantynowa Łódzkiego, Poddębic, Sochaczewa. Projekt zrealizowano w okresie od lipca do listopada 2017. Był on istotnym elementem wspierania szerszego rozwoju ciepłownictwa geotermalnego w Polsce, jednym z pierwszych projektów geotermalnych, jakie były wykonane w Polsce w ramach grantów Europejskiego Obszaru Gospodarczego. Otworzył drogę do kolejnych projektów z zakresu geotermii w ramach wymienionego mechanizmu finansowego w nadchodzących latach.The article presents the objectives, main activities, results, proposals and recommendations of the pre-defined EEA Project "Geothermal energy – a basis for low-emission heating, improving living conditions and sustainable development − preliminary studies for selected areas in Poland". It summarizes the main Project outcome – Study visits Report. The Project was carried out by the Polish experts; from MEERI PAS (Project leader), the AGH University of Science and Technology in Kraków, the Wrocław University of Science & Technology as well as world leaders in shallow geothermal: Christian Michelsen Research AS from Norway and deeper geothermal: National Energy Authority, Iceland (donor countries of the EEA Financial Mechanism), in addition to the European Geothermal Energy Council, experts and representatives of towns to which the Project was addressed – Lądek-Zdrój, Konstantynów Łódzki, Poddębice, Sochaczew. The Project was conducted from July to November 2017. It was one of the important ways to support the broader geothermal heating development in Poland, and one of the first geothermal project to be implemented in Poland within the EEA grants. It opened the way for further geothermal projects within the framework of the mentioned financial mechanism in the coming years

NORPERM, the Norwegian Permafrost Database – a TSP NORWAY IPY legacy

NORPERM, the Norwegian Permafrost Database, was developed at the Geological Survey of Norway during the International Polar Year (IPY) 2007-2009 as the main data legacy of the IPY research project <i>Permafrost Observatory Project: A Contribution to the Thermal State of Permafrost in Norway and Svalbard</i> (TSP NORWAY). Its structural and technical design is described in this paper along with the ground temperature data infrastructure in Norway and Svalbard, focussing on the TSP NORWAY permafrost observatory installations in the <i>North Scandinavian Permafrost Observatory</i> and <i>Nordenskiöld Land Permafrost Observatory</i>, being the primary data providers of NORPERM. Further developments of the database, possibly towards a regional database for the Nordic area, are also discussed. <br><br> The purpose of NORPERM is to store ground temperature data safely and in a standard format for use in future research. The IPY data policy of open, free, full and timely release of IPY data is followed, and the borehole metadata description follows the Global Terrestrial Network for Permafrost (GTN-P) standard. NORPERM is purely a temperature database, and the data is stored in a relation database management system and made publically available online through a map-based graphical user interface. The datasets include temperature time series from various depths in boreholes and from the air, snow cover, ground-surface or upper ground layer recorded by miniature temperature data-loggers, and temperature profiles with depth in boreholes obtained by occasional manual logging. All the temperature data from the TSP NORWAY research project is included in the database, totalling 32 temperature time series from boreholes, 98 time series of micrometeorological temperature conditions, and 6 temperature depth profiles obtained by manual logging in boreholes. The database content will gradually increase as data from previous and future projects are added. Links to near real-time permafrost temperatures, obtained by GSM data transfer, is also provided through the user interface