Recent research in the process of aluminum alloy die castings production, which is nowadays deeply implemented into the rapidly growing

automobile, shipping and aircraft industries, is aimed at increasing the useful qualitative properties of the die casting in order to obtain its

high mechanical properties at acceptable economic cost. Problem of technological factors of high pressure die casting has been a subject of

worldwide research (EU, US, Japan, etc.). The final performance properties of die castings are subjected to a large number of

technological factors. The main technological factors of high pressure die casting are as follows: plunger pressing speed, specific

(increase) pressure, mold temperature as well as alloy temperature. The contribution discusses the impact of the plunger pressing speed

and specific (increase) pressure on the mechanical properties of the casting aluminum alloy.

Hybrid Power Sources/Systems (HPS) are generally treated as local prosumer supplies. The paper presents a new approach to the strategy of electricity contracting from HPS, considering hybrid systems as a new type of quasi-centrally dispatched power units operating in Polish market conditions. The possibilities of contracting electricity from HPS, consisting of three electricity generation technologies: biogas plant, wind power plant and solar power plant, are presented. The opportunity to obtain additional income from the electricity trading on the balancing market was used. Proposals for a new mathematical description of HPS topology were also presented, including a feasibility function, which can be used for technical and economic analyses. The obtained results can be used as a direction of development in the field of optimization of hybrid source operation in cooperation with the power grid. Based on the conducted analyses, it can be observed that electricity sales contracts concluded for each hour of the day may bring additional profit for the investor. However, the strong dependence of the proposed strategy on the situation on the balancing market or other local electricity markets similar in their operations should be emphasized.