Current technologies have become a source of omnipresent electromagnetic pollution from generated electromagnetic fields and resulting electromagnetic radiation. In many cases this pollution is much stronger than any natural sources of electromagnetic fields or radiation. The harm caused by this pollution is still open to question since there is no clear and definitive evidence of its negative influence on humans. This is despite the fact that extremely low frequency electromagnetic fields were classified as potentially carcinogenic. For these reasons, in recent decades a significant growth can be observed in scientific research in order to understand the influence of electromagnetic radiation on living organisms. However, for this type of research the appropriate selection of relevant model organisms is of great importance. It should be noted here that the great majority of scientific research papers published in this field concerned various tests performed on mammals, practically neglecting lower organisms. In that context the objective of this paper is to systematise our knowledge in this area, in which the influence of electromagnetic radiation on lower organisms was investigated, including bacteria, E. coli and B. subtilis, nematode, Caenorhabditis elegans, land snail, Helix pomatia, common fruit fly, Drosophila melanogaster, and clawed frog, Xenopus laevis.

Power-to-gas technology plays a key role in the success of the energy transformation. This paper addresses issues related to the legal and technical regulations specifying the rules for adding hydrogen to the natural gas network. The main issue reviewed is the effects of the addition of hydrogen to natural gas on the durability of diaphragm gas meters. The possibility of adding hydrogen to the gas network requires confirmation of whether, within the expected hydrogen concentrations, long-term operation of gas meters will be ensured without compromising their metrological properties and operational safety. Methods for testing the durability of gas meters applied at test benches and sample results of durability tests of gas meters are presented. Based on these results, a metrological and statistical analysis was carried out to establish whether the addition of hydrogen affects the durability of gas meters over time. The most important conclusion resulting from the conducted study indicates that, for the tested gas meter specimens, there was no significant metrological difference between the obtained changes of errors of indications after testing the durability of gas meters with varying hydrogen content (from 0% to 15%).

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Thermal gas meters represent a promising technology for billing customers for gaseous fuels, however, it is essential to ensure that measurement accuracy is maintained in the long term and in a broad range of operating conditions. The effect of hydrogen addition to natural gas will change the physicochemical properties of the mixture of natural gas and hydrogen. Such a mixture will be supplied through the gas system, to consumers, including households, where the amounts of received gas will be metered. The physicochemical properties of hydrogen, including the specific density or viscosity, differ significantly from those of the natural gas components, such as methane, ethane, propane, nitrogen, etc. Therefore, it is of utmost importance to establish the impact of the changes in the gas composition caused by the addition of hydrogen to natural gas on the metrological properties of household gas meters, including thermal gas meters. Furthermore, since household gas meters can be installed outdoors and, taking into account the fact that household gas meters are good heat exchangers, the influence of ambient and gas temperature on the metrological properties of those meters should be investigated. This article reviews a test bench and a testing method concerning errors of thermal gas meter indicators using air and natural gas, including the type containing hydrogen. The indication errors for thermal gas meters using air, natural gas and natural gas with an addition of 2%, 4%, 5%, 10% and 15% hydrogen were determined and then subjected to metrological analysis. Moreover, the test method and test bench are discussed and the results of tests on the impact of ambient and gas temperatures (‒25 °C and 55 °C, respectively) on the errors of indications of thermal gas meters are presented. Conclusions for distribution system operators in terms of gas meter selection were drawn based on the test results.

STRESZCZENIE: W ostatnim czasie można zaobserwować rosnące zainteresowanie dodawaniem do sieci gazowej wodoru pochodzącego ze źródeł odnawialnych, tzn. technologią power-togas. Umożliwia ona przekształcenie wyprodukowanej energii elektrycznej do postaci wodoru i zmagazynowanie go w systemie gazowniczym. Technologia ta może stać się jednym z istotnych czynników zwiększenia udziału energii odnawialnej w całkowitym bilansie energetycznym. Skutkiem dodawania wodoru do gazu ziemnego będzie obecność w sieciach gazowych mieszaniny gazu ziemnego oraz wodoru, która siecią tą docierać będzie do odbiorców końcowych, w tym odbiorców w gospodarstwach domowych. Właściwości fizykochemiczne wodoru, takie jak np. gęstość właściwa czy lepkość, istotnie różnią się od właściwości fizykochemicznych składników gazu ziemnego, takich jak metan, etan, propan, butan, azot itd. W związku z powyższym właściwości mieszaniny gazowej po dodaniu do niej wodoru będą się znacznie różnić od właściwości obecnie stosowanego gazu ziemnego. Tym samym elementy systemu gazowniczego, a także odbiorniki gazu u odbiorców końcowych będą podlegać oddziaływaniu wodoru. Konieczne staje się zatem zapewnienie, że w granicach przewidywanych stężeń wodoru elementy systemu gazowniczego, a także odbiorniki gazu będą w stanie długotrwale pracować bez pogorszenia swych właściwości funkcjonalnych oraz zmniejszenia bezpieczeństwa technicznego. W niniejszym artykule omówiono wyniki dotychczasowych badań prowadzonych w INiG-PIB dotyczących wpływu mieszaniny gazu ziemnego i wodoru na: urządzenia gazowe użytku domowego oraz komercyjnego, rozliczenia i pomiary paliw gazowych, jakość paliw gazowych, gazomierze miechowe oraz reduktory średniego ciśnienia. Słowa kluczowe: power-togas , PtG, P2G, wodór ze źródeł odnawialnych, gaz ziemny, infrastruktura gazociągowa, urządzenia gazowe. ABSTRACT: Recently, there has been a growing interest in adding hydrogen from renewable sources to the gas network, i.e. Powerto-Gas technology. This technology makes it possible to convert the produced electrical power into hydrogen and to store it in the gas network. It may become one of the significant factors of increasing the share of renewable energy in the overall energy mix. The addition of hydrogen to natural gas will result in the presence of a mixture of natural gas and hydrogen in the gas networks through which it will reach end users, including household customers. The physicochemical properties of hydrogen, such as specific density or viscosity, differ significantly from those of natural gas components, such as methane, ethane, propane, butane, nitrogen, etc. As a result, the properties of a gas mixture, after adding hydrogen, will be significantly different from those of the natural gas currently in use. Thus, both gas network components and gas appliances of end users will be exposed to hydrogen. It is therefore necessary to ensure long-period operation of gas network components and gas appliances, within the limits of anticipated hydrogen concentrations, without deterioration in the...