Roles of Solar Power from Space for Europe: Space Exploration and Combinations with Terrestral Solar Plants Concepts

The paper presents the prospective roles of SPS concepts for Europe, shows the outcome of the studies undertaken by ESA during the first phase of the European SPS Programme Plan and gives insight into the planned activities. These studies, performed by European industry and research centres in close cooperation with the ESA Advanced Concepts Team, were all directed towards the main goal of the first phase, the assessment of the principal validity and viability of solar power from space concepts in the light of advances in alternative sustainable, clean and potentially abundant solar based terrestrial concepts, taking into account expected changes in the European energy system (e.g. gradual introduction of hydrogen as energy vector). Special emphasis is given to the possibilities of integrating space and terrestrial solar plants. Depending on the timescale and geographic location considered, solar thermal options or solar photovoltaic options are more advantageous, the benefits of the later getting more attractive the further in the future the comparison and the greater the distance to the geographic equator. Laser and microwave power transmission is considered. While laser power transmission offer fundamental advantages for the integration into terrestrial solar power plants, the availability of existing ground receptions, power management and power distribution systems are also beneficial to the economics of the more efficient microwave systems. The relative proximity of good locations in the Sahara desert to the large European energy consumer market puts Europe in a special position regarding the integration of space and terrestrial solar power concepts. The papers presents a method to optimise such an integration, taking into account different possible orbital constellations, terrestrial locations, plant number and sizes as well as consumer profiles and extends the scope from the European-only to a multi continental approach including the fast growing Chinese electricity market. This work intends to contribute to the discussion on long-term options for the European commitment to durable CO2 emission reduction, which probably requires substantial changes in our energy system. Cleaner electricity generation and environmentally neutral transport fuels (e.g. solar generated hydrogen) are two major tools to reach this goal.