Many international policies encourage a switch from fossil fuels to bioenergy based on the premise that its use would not result in carbon accumulation in the atmosphere. Frequently cited bioenergy goals would at least double the present global human use of plant material, the production of which already requires the dedication of roughly 75% of vegetated lands and more than 70% of water withdrawals. However, burning biomass for energy provision increases the amount of carbon in the air just like burning coal, oil or gas if harvesting the biomass decreases the amount of carbon stored in plants and soils, or reduces carbon sequestration. Neglecting this fact results in an accounting error that could be corrected by considering that only the use of ‘additional biomass’ – biomass from additional plant growth or biomass that would decompose rapidly if not used for bioenergy – can reduce carbon emissions. Failure to correct this accounting flaw will likely have substantial adverse consequences. The article presents recommendations for correcting greenhouse gas accounts related to bioenergy.

No abstract

No abstract

No abstract

The efficiency of an electrochemical power source, to a great degree, depends on the internal resistance of the system. This internal resistance includes interface resistance between current collector and active electrode mass, solid electrolyte and electrode, and other systems. The developed method and device enable non-destructive, non-contact evaluation of the interface resistance. Results enable the prediction and optimization of electrochemical power sources properties, especially their power.

Exergy is a measure of energy quality. The amount of exergy in energy carriers is very different. Normally the price includes only the value of quantity and not the quality of energy. Exergy is the only part of energy available to do work. For different purposes we need energy with different amounts of exergy: for heating and cooling the energy mixture between small amount of the exergy and large part anergy is needed. Transition to sustainable energy system, without GHG emissions, based on RE, open the questions how to evaluate exergy from solar energy. Solar energy in all form (irradiation, water flows, wind, and biomass) consists of nearly 100% of exergy. Solar energy is free, conversion systems are not. To exploit at maximum the solar exergy we need a sustainable energy system using in great amount the present infrastructure and existing or new developed energy conversion technologies. There is common agreement that we need four main presently used energy carriers: electricity, gaseous, liquid and solid fuels.Our vision is the new Sustainable Energy System (SES) based on the use of solar and planetary energy for production of renewable electricity as a base for production of hydrogen. Hydrogen is a raw material for carbon recycling from biomass, making synthetic methane and methanol. The proposed SES is based on the existing infrastructure and known chemical processes. With regard to availability of renewable energy resources (RES) it is unrestricted and harmless in comparison to present fossil fuels use. The proposed SES consists of the three main exergy carriers: solar electricity, synthetic methane (CH4) and synthetic methanol (CH3OH).

No abstract

No abstract