The article is focused on the issues of economic evaluation of Miscanthus cultivation on agricultural land in the Czech Republic. The methodology of economic assessment is based on the calculation of minimum production cost - minimum price of heat in EUR/GJ of heat in biomass. The minimum production cost represents the threshold of economic efficiency of production for the investor and its determination utilizes an economic model capturing all processes related to the cultivation of biomass for energy purposes. Miscanthus vegetation is considered for the production of biomass for direct combustion (a so-called spring harvest after the winter). Input data used in the model come from the experimentally collected data from the research plots of Miscanthus and from the market valuation of the individual activities using 2010 prices. The minimum price of Miscanthus varies between 3-12 EUR/GJ (2010 prices) depending on the yields and the date of harvest.

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For the purpose of studying manufacture of CaO catalyst for biodiesel production, a calcined limestone of commercial availability was ground in the presence of biodiesel and the resultant CaO-biodiesel mixture was employed for transesterification of vegetable oil with methanol. Biodiesel, which used as the grinding solvent, allowed surface oxide phase of CaO catalyst to be guarded against atmospheric CO₂ and H₂O, because the wet-grinding was much more effective in activating CaO catalyst than the atmospheric dry-grinding. Then, the wet-grinding was carried out with the industrial machines of media-agitating type for preparation of CaO catalyst consisting of fine particles. The prepared CaO catalyst was so fine that its average particle diameter reached 0.5 μm. The activity measuring tests provided data indicating that the transesterifying activity of CaO catalyst was enhanced by reducing its average particle diameter. Moreover, a small amount of water contained in biodiesel, which was used as the grinding solvent, seemed to enhances the transesterifying activity of CaO catalyst. Finally, we discussed a way to recycle CaO catalyst collected after the transesterification, for verifying that CaO catalyst consisting of fine particles is feasible for biodiesel production process.

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It is important for citizens to get interested in science, energy, and environmental problems in order to be able to make scientifically sound judgments. For the purpose of this activity we have chosen the example of dye-sensitized solar cells. Although dye-sensitized solar cells are known as a handmade experiment, they still require high-technology such as nanotechnology and have a very high cost. We have invented dye-sensitized solar cells with materials that are closely used in everyday life. The efficiency of the dye-sensitized solar cells is lower, but it is possible for citizens to make handmade dye-sensitized solar cells by themselves. We expect this invention will generate increased interest in science, energy, and environmental problems and aid citizens in making more scientifically sound judgments.

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