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Five different kinds of domestic-size renewable energy system configurations for very cold climate regions were investigated. From detailed numerical modeling and system simulations, it was found that the consumption of fuel oil for the auxiliary boiler in residential-type households can almost be eliminated with a renewable energy system that incorporates photovoltaic panel arrays for electricity generation and two storage tanks: a well-insulated electric water storage tank that services the hot water loads, and a compact boiler/geothermal heat pump tank for room heating during very cold seasons. A reduction of Greenhouse Gas Emissions (GHG) of about 28% was achieved for this system compared to an equivalent conventional system. The near elimination of the use of fuel oil in this system makes it very promising for very cold climate regions in terms of energy savings because the running cost is not so dependent on the unstable nature of global oil prices., application/pdf

We report measurements of the spectral transmittance and calculations of the total transmittance of magnesium chloride-water solution to be used as the working fluid for a solar pond. The spectral transmittance of MgCl2-water solution in the visible, infrared and nearby regions decreases with increasing salt concentration. The total transmittance of MgCl2-water solution can be calculated using an exact integration method and a simple 5-band partition method over a 3 m depth of pond water. The simple method is useful in practice to calculate the total transmittance for a conventional solar pond, because the rate of difference between the results calculated by the two methods is less than 10% at shallow depths and then it decreases rapidly being followed by 0% at a depth of 3 m. Furthermore, the absorption coefficient calculated from the spectral transmittance of the present work is compared with that from Usmanov's data as shown in references (6) and (7).

We describe the measurements of spectral transmittance and the calculations of the total transmittance for sodium chloride and potassium chloride water solutions. The spectral transmittance of NaCl and KCl water solutions over the infrared and nearby regions increases with increasing salinity. In the visible region, the spectral transmittance of NaCl w-s increases slightly, while that of KCl w-s decreases with increasing salinity. The total transmittance of the two salt water solutions can also be calculated by means of an integral method and a simple 5-partition method over 0∼3 m water depth. The simple method is of practical use to calculate the total transmittance for a conventional solar pond, because the rate of error between the two methods is about 10% at shallow depth and 0% at 3 m depth.

The transmission properties of water and sodium chloride water solutions with various salt concentrations were investigated. This paper concerns the measurement of the spectral transmittance and the calculation of the total transmittance for water and NaCl water solutions. The spectral transmittance of the NaCl water solutions over the infrared and nearby regions increased with increasing salt concentration for constant specimen thickness and air mass. The spectral transmittance was found to be useful for precisely calculating the thermal performance of a solar pond, and by using an effective absorption coefficient, a five-partition method dividing the wavelengths into five bands by which the total transmittance up to a water depth of 3 m could be calculated, was found to be important as a practical method of solar pond technology. © 1997 Scripta Technica, Inc. Heat Trans Jpn Res, 26(1): 1–15, 1997

The transmission property of water and sodium chloride-water solutions with various salinity concentrations was clarified using spectra. This paper deals with the measurement of the spectral transmittance and the calculation of the total transmittance for water and NaCl-water solutions. The spectral transmittance of the NaCl-water solution over the infrared and nearby regions increased with increasing salinity concentration for constant specimen thickness and air mass. It was found that the spectral transmittance was useful for precisely calculating of the thermal performance of a solar pond, and by using an effective absorption coefficient, a 5-partition method dividing wavelength into five bands by which the total transmittance up to a water depth of 3m could be calculated, was found to be important practical example of solar pond technology.

Dissolved methane concentrations (DM) at twelve major lakes in Hokkaido, the northernmost island in Japan were observed in the open water season during 2006 ~ 2009 to estimate diffusive flux from lake surfaces to the atmosphere. An inverse relationship between lake size and DM was obtained in lakes in Hokkaido as was found for the European boreal lakes. All lake images larger than 0.001 km2 were obtained by image processing of map data and area and number distributions were analyzed in order to calculate mass fluxes of diffusive methane. Total area of all (1,269) lakes in Hokkaido is 809 km2. Regional diffusive flux of methane from lakes to the atmosphere in Hokkaido was estimated to be 0.581 Gg CH4 yr–1. Average diffusive flux density (per lake area) was about 0.718 g CH4 m–2 yr–1. This is a similar value to that in European boreal lakes on no-permafrost inland areas. Extremely high flux was found in Lake Abashiri-ko, one of highly eutrophic, meromictic lakes.