Utilitarian
05U12


Planned

Year of Execution: 2005/6
Duration: 12 months


Solar Power from Space Programme Plan – phase II
 
Objective:
  
The activity constitutes the second phase of the European SPS Programme Plan as elaborated within the European Network on Solar Power from Space in 2002.

From the overall goals of the SPS Programme Plan, to

  1. Perform a comparison of space based and comparable ground based power generation solutions,
  2. Identify possible synergies between ground and space based power generation solutions
  3. Assess the potential of SPS for space exploration
  4. Establish one to three innovative, realistic and promising SPS concepts
  5. Identify major technical SPS areas, demanding research and development
  6. Perform two to three feasibility studies for near-term demonstrator missions that provide enough information to support a decision on further activities
  7. Assess the most promising ways to integrate SPS into a hydrogen-based economy
  8. Provide focus, stimulus and coordination to European research on SPS
  9. Identify promising opportunities for international cooperation
points 1, 2, 3 were entirely and points 8 and 9 partly dealt with during the 1st programme phase, which was successfully concluded with the 5th International SPS conference in June 2004 in Granada, Spain.

It is the purpose of the study to address the remaining aspects (points 4 - 7) of the programme plan, as laid out above.
 
 
 Relevance to GSP and ESA future programmes:
  
The study explores the potential of solar power together with wireless power transmission technology for extending the range of space activities to missions that are currently only feasible with nuclear power sources. It furthermore takes advantage of knowledge of a research community that has no traditional links with ESA and space in general. In addition to space exploration, the results of this study are potentially relevant for specific science missions as Darwin as demonstrated during the first phase of the SPS Programme Plan.
  
 
 Background:
  
Alternatives to nuclear power sources:

The study on the possibility of solar power satellites and wireless power transmission as alternatives to nuclear power sources for space applications and exploration has shown that based on rather conservative technology assumptions, solar power satellites and wireless power transmission:

  • could be an option for powering Mars surface exploration spacecraft and certain lunar surface missions
  • look promising for very specific small scale science missions
  • cannot power interplanetary spacecraft in a reasonable way and show little potential for powering Earth orbiting spacecraft
Space-Earth Options comparison:

Two studies led by independent energy consultant organisations assessing the validity of space based solar power plant concepts with terrestrial concepts of the same technology maturity level have shown that:

  • Terrestrial solar power plants will very likely precede space-based plants essentially due to:
    • their lower upfront investment costs connected to their low(er)minimal installation size
    • their already higher maturity level and ongoing small plant constructions
    • their comparably lower technical complexity
  • Space solar power plants start to be competitive with terrestrial power plants under realistic assumptions on launch cost evolutions at high total power levels above 10 - 30 GWe;
  • Space solar power plants present much better up-scaling properties towards higher power levels;
  • Space and terrestrial power plants have energy payback times in the order of months to a few years, with slightly better values for space based solutions;
  • The availability of cheap terrestrial storage capacity has a large enough impact on terrestrial solar plant production costs to render space alternatives competitive under certain circumstances (pumped hydrostorage versus hydrogen storage)
In conclusion, space generated solar power for terrestrial power supply has proven too attractive to be neglected but yet too immature to account for a considerable contribution within the next two decades.
  
 
 Brief Description:
  
Based on the results of the industrial assessments during the first phase and the comparison of European technology assumptions with the ones made by US and Japanese research groups during the SPS’04 conference, several technology areas for focussed research in Europe were identified. Following the logic of the SPS Programme Plan, these are areas:
  • that demand further research and development for SPS to be realized (technology maturation)
  • that show near- to mid-term potential in other areas than SPS (technology synergies)
  • in which European industry and research institutes already have demonstrated international leadership (European excellence)
Taking into account the worldwide recognized excellence of European industry in laser power transmission technology as well as the recently demonstrated, groundbreaking efficiency increase of direct solar pumped laser materials on the “lower” power scale, it is proposed to put one focus of the 2nd SPS phase on the powering of planetary exploration spacecraft / vehicles and small scale scientific missions.

In detail the efforts on laser power transmission will be concentrated on concepts including:

  • direct solar pumped laser technologies, which (especially after recently reported results) offer the option of increasing total laser conversion efficiencies by an order of magnitude
  • innovative beam control and beam steering technologies
  • innovative laser to electricity conversion techniques
  • combination techniques for parallel data and power transmission
A second focus of the activity will be put on the assessment of the integration of space-based solar power plants into terrestrial ones, including innovative approaches to orbit selection, methods for the adaptation of terrestrial solar power plants to serve in addition as receiving station for space solar power plants, offering the reduction of local storage needs and overall higher plant efficiencies (including multiple ground stations with a global option).

These activities are proposed to be combined in one study assessing a laser-based SPS concept for Earth (0.05-10 GWe) power transmission and one for lunar surface or small scale science missions laser power transmission (1-50 kWe). The division into an Earth and Moon systems allows for the derivation of reasonable scaling laws and different conditions for optimal integration into surface solar power plants.
 
 
 References:
  
[1] - EcoFys. Earth and Space based power generation systems; Final Report 07615/03/NL/EC, EEP03020, November 2004
[2] - LBST. Earth and Space Based Power Generation Systems, A Comparison Study. Final Report 17682/03/NL/EC, November 2004
[3] - EADS Astrium. REPOSE - Solar Power Satellites, A Remote Power Source For Space Exploration And Applications, Final Report 17761/03/NL/MV, September 2004
[4] - "High-power Colquiriite lasers with high slope efficiencies pumped by broad-area laser diodes", A. Isemann and C. Fallnich, Optics Express 11, 259 (2003)
[5] - "Space-borne solar laser for power-beaming applications", Ja.H. Lee and B.M. Tabibi, AIP Conf. Proceed. 664, 608 (2003)
[6] - "Model of a pulsed liquid solar-pumped spaceborne laser", A.A. Seregin and E.A. Seregina, Quantum Electronics 34, 99 (2004)
[7] - " A solar-pumped Nd:YAG laser in the high collection efficiency regime", M. Lando et al., Optics Communications 222, 371 (2003)
[8] - ESA. Solar Power from Space and Wireless Power Transmission SPS'04 and WPT5, Conference Proceedings, SP-567, July 2004
 
 
  
Last update: 11 July 2005