Search

A self-sustained, zero-CO 2 emission RES-H 2 Hybrid Energy System (HES) was developed at Lavrion Technological & Cultural Park (Attica, Greece) to cover electric power, heating/cooling loads (tri-generation) of an office building located in its premises. The primary energy is harvested from RES and directly applied to cover contingent loads, whereas the excess energy is converted to hydrogen to be used as energy storage system and thus as a green fuel to cover the building heating needs through direct combustion or to produce combined heating and electricity by means of fuel cells. In this study, the performance of the functional RES-H 2 HES is evaluated as well as its impact by applying the methodology of Life Cycle Assessment. HES resulted in the reduction of Global Warming Potential, Acidification Potential and Photochemical Oxidant Formation by 40%, 42% and 35%, respectively, compared to the exclusive use of Greek energy grid mix for electricity. • Life Cycle Assessment of a hybrid RES-H 2 Hybrid Energy System developed in Greece. • Hybrid Energy System reduced GWP by 40%, compared to the use of GR-energy grid mix. • AP is decreased on Hybrid Energy System by 42%, compared to the GR-energy grid mix. • POF of Hybrid Energy System was 35% less compared to the use of GR-energy grid mix. • Environmental impact of PVs was 5 times higher, compared to WTs. [ABSTRACT FROM AUTHOR]

In the present paper, the potential use of lignite fly ash in the control of acid generation from sulphidic tailings disposed of at Lavrion, Greece was studied. Long-term laboratory column kinetic tests were performed on tailings containing 27% S, which were homogeneously mixed with various amounts of fly ash, ranging from 10 to 63% w/w. The drainage quality of the columns was monitored over a test period of 600 days. Chemical and mineralogical characterisation of column solid residues was performed after a 270-day test period. The hydraulic conductivity of the mixtures was also measured to evaluate the potential of fly ash to form a low permeability layer. Based on the results, the addition of fly ash to sulphidic tailings, even at the lower amount, increased the pH of the drainage at values of 8.6-10.0 and decreased the dissolved concentrations of contaminants, mainly Zn and Mn, to values that meet the European regulatory limits for potable water. Higher fly ash addition to tailings, at amounts of 31 and 63% w/w also reduced the water permeability of material from 1.2 x 10(-5) cm/sec to 3 x 10(-7) and 2.5 x 10(-8) m/s, respectively.