Fossil fuel power station is also beneficial to the environment. In some instances, torrefaction of biomass may be needed if biomass is the material the converted fossil fuel power plant will be using. Improving energy efficiency of a coal-fired power plant also reduces emissions. For example, emissions can be reduced by upgrading existing plants or building new high-efficiency, low-emissions plants. Such plants emit almost 20% less CO than a subcritical unit operating at a similar load. Over the longer term, HELE plants can further facilitate emission reductions because coal-fired plants operating at the highest efficiencies are also the most appropriate option for carbon capture
Evolutionary history of plants appeared suddenly by delaying the occurrence of meiosis until a fully developed multicellular sporophyte had formed. Since the same genetic material would be employed by both the haploid and diploid phases they would look the same. This explains the behaviour of some algae, such as "Ulva lactuca", which produce alternating phases of identical sporophytes and gametophytes. Subsequent adaption to the desiccating land environment, which makes sexual reproduction difficult, might have resulted in the simplification of the sexually active gametophyte, and elaboration of the sporophyte phase to better disperse the waterproof spores. The tissue of sporophytes and gametophytes of vascular plants