The analysis of a solar installation operation was conducted on the example of a detached house in the Lesser Poland province in Poland. A gas boiler and three flat-plate collectors are located inside the house, which are used for heating water in the hot water tank with a volume of 220 dm3. The installation was established in 2012. The heat measured system (for solar gains) was added in 2014. In 2015–2019 solar heat gains measured per area of absorber were higher than 340 kWh/m2. During a two-week period in June 2015, the insolation on the horizontal plane and the temperature were measured in 4 different points of the hot water tank. On this basis, heat losses from the storage tank were determined, i.e. a decrease in temperature during periods with and without the consumption of hot water by the residents. During this period, a temperature higher than 80°C was observed several times in the hot water tank. In two parts of the hot water tank, rhe determined temperature decreases were used to obtain the heat loss amount. In the analyzed period (2 weeks), 9 days were observed with solar heat gains higher than 9 kWh/day. For these days, the value of heat loss from the solar hot water tank was estimated at over 6 kWh/day. This data corresponds to the actual heat demand for hot water preparation in the building at 7.3 kWh/day. The correlation between daily solar heat gains and solar hot water tank heat losses were also determined. In addition, based on the amount of heat losses, the value of the tank loss coefficient was estimated. The obtained value was compared with the manufacturer’s data and reference data.
In Poland an increase in the of number solar thermal collectors is observed in household applications. For economic and ecological profitability the creation of a solar thermal installation design in a proper manner is essential.
In order to determine solar installations size, software calculating future solar heat gains is used. SHW software is an examples of such software. The aim of this work was to compare the simulation results with the real results of the solar installation operation. The comparison was performed by an example of a single-family house with flat plate collector installations located in south-east Poland. This installation supports domestic hot water preparation in a house occupied by four people (in two-year period of analyses). The additional heat source in this building is a gas boiler. Solar fraction parameter values were chosen for this comparison. Solar fraction is calculated as a ratio of solar heat gains used in the domestic hot water preparation process to the heat desired for domestic hot water preparation. The real results of Solar Fraction turned out to be higher than the simulation results from May to August (there were many days with Solar Fraction = 1). A difference of 20–50 percentage points was observed (Solar Fraction). Apart from this period no special differences were observed.
Additionally analyses of differences between solar heat gains calculated by Get Solar simulation software with real values (for analyzed building) was performed. This simulation analysis was done before process of building installations.
The operation of thermal devices and installations, in particular heat exchangers, is associated
with the formation of various deposits of sediments, forming the boiler scale. The
amount of precipitate depends on the quality of the flowing liquids treatment, as well as
the intensity of the use of devices. There are both mechanical and chemical treatment methods
to remove these deposits. The chemical methods of boiler scale treatment include the
cleaning method consisting in dissolving boiler scale inside heat devices. Worked out descaling
concentrate contains phosphoric acid (V) and the components that inhibit corrosion,
anti-foam substances, as well as anti-microbial substances as formalin, ammonium chloride,
copper sulphate and zinc sulfate. Dissolution of the boiler scale results in the formation of
wastewater which can be totally utilized as raw materials in phosphoric fertilizer produc
A domestic hot water (DHW) system has been modernized in a multi-family house, located in the southeastern part of Poland, inhabited by 105 people. The existing heating system (2 gas boilers) was extended by a solar system consisting of 32 evacuated tube collectors with a heat pipe (the absorber area: 38.72 m2). On the basis of the system performance data, the ecological effect of the modernization, expressed in avoided CO2 emission, was estimated. The use of the solar thermal system allows CO2 emissions to be reduced up to 4.4 Mg annually. When analyzing the environmental effects of the application of the solar system, the production cycle of the most material-consuming components, namely: DHW storage tank and solar collectors, was taken into account. To further reduce CO2 emission, a photovoltaic installation (PV), supplying electric power to the pump-control system of the solar thermal system has been proposed. In the Matlab computing environment, based on the solar installation measurement data and the data of the total radiation intensity measurement, the area of photovoltaic panels and battery capacity has been optimized. It has been shown that the photovoltaic panel of approx. 1.8 m2 and 12 V battery capacity of approx. 21 Ah gives the greatest ecological effects in the form of the lowest CO2 emission. If a photovoltaic system was added it could reduce emissions by up to an additional 160 kg per year. The above calculations take also emissions resulting from the production of PV panels and batteries into account.
There are many financial ways to intensify the construction of new renewable energy sources installations, among others: feed in tariff, grants. An example of photovoltaic grant support in Poland is the “Mój Prąd” [My Electricity] program created in 2019. This program, with a budget of PLN 1 billion, is intended for households in which installations with a capacity range of 2–10 kWp have been installed. During its first edition 27,187 application were submitted. Over 98% of installations cost less than PLN 6,000/kWp. The total installed capacity is 151.3 MWp, which gives the average amount of co-funding per unit of power at the level of PLN 884.7/kWp. The average power of the installation on the national scale is 5.57 kWp, the indicator per 1000 inhabitants is 3.94 kWp, and per unit of area is 0.484 kWp/km2. These installations will produce around 143.5 GWh of electricity annually, contributing to the reduction of CO2 emissions by approximately 109,800 Mg per year. Most applications came from the Silesian Province (3855), which translated into the largest installed capacity of 21.82 MWp, as well as 4.81 kWp/1000 inhabitants and 1.77 kWp/km2 (over 3 times higher than the average in Poland). The installed capacity in the individual province was closely correlated with the population of the province (correlation coefficient – 0.95), while the installed capacity indicator per 1,000 inhabitants with insolation (0.80). The highest power ratio per 1000 inhabitants was achieved in the Podkarpackie Province and amounted to 5.05, and the lowest in the West Pomeranian Province (2.41).
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