Emmanouil Kakaras

The Challenge of Energy Storage in Europe: Focus on Power to Fuel

The energy sector in the European market has been changing significantly over the last years. European Union (EU) energy strategy includes the EU low-carbon roadmap milestone, which indicates for 2020, a 20% reduction in carbon emissions, and a 20% EU-wide share for renewables, and by 2030 a 40% reduction in carbon emissions and 30% EU-wide share for renewables. The increased renewable energy sources (RES) penetration and their intermittent energy production have led to the emerging need for energy storage technologies. Especially in the European energy market, large-scale energy balancing with sustainable technologies with product flexibility and cost-effective operation are being investigated. The carbon capture and utilization (CCU) concept, as a means for low-carbon sustainable industries, is integrated in the energy storage technologies. The present paper addresses the integration of power to fuel concept in the energy storage sector with simultaneous emission reduction. Grid management, the scale, and the efficient operation of electrolyzers are the basis for the implementation of Power to Fuel technology. The use of surplus and/or low-cost electricity via water electrolysis to commute captured CO2 from industrial plants to versatile energy carriers such as methane and methanol is being investigated in the present paper. Shadow operation of fossil fuel power plants under minimum load conditions leads to optimized energy dispatch of the power plants and provides product flexibility in terms of electricity, grid services, and chemical production. The produced fuels can be used in highly efficient and well-established power systems and further used in the transportation sector or for covering heat demands. The energy efficiency of the different processes is presented and a comparison is made in terms of cost effective energy storage solutions via the simultaneous grid management optimization, the reduction of carbon dioxide, and the production of valuable chemicals. The cross-sectorial concept of the Power to Fuel is presented for Steel and Power industry for the case of methane and methanol production. A review of the U.S. and European markets is made for the application of Power to Fuel.

Numerical investigation of the aerodynamic breakup of diesel droplets under various gas pressures

Financial support from the MSCA-ITN-ETN of the European Union’s H2020 programme, under REA grant agreement n. 675676 is acknowledged.

The Current Trends in Conventional Power Plant Technology on Two Continents From the Perspective of Engineering, Procurement, and Construction Contractor and Original Equipment Manufacturer

In terms of CO2 emissions, the year 2030 has been addressed as a very crucial deadline for both European Union (EU) and the U.S. Whereas the U.S. Clean Power Plan proposes the reduction of national CO2 emissions from the existing power stations by 30% with respect to 2005, the EU aims at cutback by 40% from their levels in 1990. Due to the restricted emission goals dictated by the European and U.S. energy policies, both energy markets witness currently drastic changes. Whereas the U.S. wants to shift away from coal, the EU shifts away from gas due to high natural gas prices in Europe while drastically increasing the feed-ins from renewable energy sources (RES). In some of the European countries constantly growing installation of renewable energy plants is superseding natural gas-fired power plants and thus causing the electrical grid stabilization to be overtaken by coal fired power stations. On the contrary, the U.S. market due to increasing extraction of shale gas and low natural gas prices puts the gas power plants in favor and poses increasing pressure on closing some coal fired plants. A solution that uses the potential of the existing site and reduces overall emissions is converting from coal into gas-fired power plants, so-called fuel switch. Whereas for the U.S. market the later solution is relevant, in the vast majority of EU Member States the focus is on increasing the flexibility of coal fired power plants. The challenges and technical solutions developed and applied according to the demands of the market in both EU and U.S. are addressed in this paper. Both currently applied technologies and technologies under development are shortly presented.

High-efficiency pulverized coal power generation using low-rank coals

Abstract Low-rank coals such as lignites are without doubt one of the most abundant fossil fuel sources worldwide. Due to their usually high moisture content and low heating value, the combustion of low-rank coals leads to higher specific CO2 emissions compared to the combustion of other fuels like natural gas. Nevertheless, by using state of the art technology to reach the highest possible plant efficiency, specific CO2 emissions can be considerably reduced, even when utilizing low-rank coals of extremely poor quality. Moreover by implementing state of the art Air Quality Control Systems flue gas emissions including CO, NOx, SO2, and dust are reduced, so that the strictest European environmental limitations can be kept. In this sense, using state of the art technologies for the utilization of low-rank coals may contribute to an affordable, cost competitive, and environmentally friendly electricity production for every type of low-rank coal to be utilized.

Role of heat transfer in bubble dynamics neglecting phase change. A numerical study

Financial support from the MSCA-ITN-ETN of the European Union’s H2020 programme, under REA grant agreement n. 675676 is acknowledged.