ENERGY FROM SPACE
What is Energy from Space?
Energy from Space stands for a technology of generating electricity from solar energy using satellites in space and transporting it to the Earth via electromagnetic waves. It can deliver large amounts of electric energy, typically 1 GW which is enough for 1 to 2 million homes. The big advantages of Energy from Space include that the generation of power is independent (the Sun always shines in space), reliable (continuous more than 99.9% of the time), clean (no emissions) and safe (no harmful effects). The challenges are the expensive launch costs, the technology for transmitting energy wirelessly over long distances, and the in-orbit assembly of the structures. More...
How much energy is generated with one Energy from Space system?
One full-scale Energy from Space system typically delivers 1 GW output power on-ground, which is enough to power 1 to 2 million homes. Since the systems are placed in a geostationary orbit (36,000 km altitude), the satellite is always above one location on Earth. This means that the power can be transmitted continuously to ground stations without intermittance. Only during 75 minutes during the spring and autumn equinoxes the systems are in the shadow of the Earth.
What are the costs of an Energy from Space system?
The costs of a full-scale Energy from Space system are estimated on $20 billion. It is anticipated that the energy price is between $0.10/kWh and $0.50/kWh. For comparison, current average electricity generation costs are $0.10/kWh in the United States and more than $0.50/kWh on remote islands in Indonesia. The main reasons for the relative low energy prices but relative high investment costs are the system's the long life time (more than 30 years), the independency of fuel, and the reliability of the energy. Furthermore, it can make countries more energy independent from energy imports. More...
When will Energy from Space be realized?
It is expected that full-scale Energy from Space systems will be realised earliest in 2035. In the mean time, demonstration and prototype satellites will be launched. Already at this moment ground experiments are conducted and the first demonstration satellites are under review. More...
What is the Energy from Space Foundation doing to realize Energy from Space?
The Energy from Space Foundation promotes Energy from Space and works on a proposal to launch the first proof-of-concept. Our mission is to help realize Energy from Space, and we believe that the first step is to create awareness amongst the public and provide proper information. In addition, we look at the possibilities to launch the first proof-of-concept. More...
How can I contribute to realizing Energy from Space?
To realise Energy from Space we first of all need to create more awareness. So, spread the word! In addition, Energy from Space encourages engineers, investors, policy makers, entrepreneurs and ambassadors to come with initiative. If you have good ideas and/or you think you can contribute to the success of Energy from Space , you can always contact us.
How is the energy transmitted from space to Earth?
The energy is wirelessly transmitted from the satellite by microwaves to one or multiple ground stations on Earth. There are also concepts where the energy is transmitted by laser on smaller receiving stations, however this technology is much more susceptible to clouds and other atmospheric disturbances. For microwave transmission, the beam collection efficiency is estimated at about 90%, meaning that the microwave power sent by the satellite only loses about 10% when it arrives at the ground station. It is calculated that only about 2% is absorbed by the atmosphere, the rest of the 10% is mainly caused by inter-wave interference and scatter effects.
Is Energy from Space safe?
According to our knowledge, yes. Energy from Space is safe to the point that the electricity can be delivered to ground stations on Earth without harmful effects on humans, animals and the environment. Moreover, it even saves on emissions (e.g. CO2, H2O, H2S) with respect to traditional power production techniques. Of course, as with all electricity generation technologies, there are risks involved. When transmitting power using microwaves, it is not recommended for living creatures to be exposed by the beam for long periods of time. The energy density at the center of the beam is calculated at about 250 W/m², which is less than 1/4 of the energy density on Earth of the Sun on a sunny day. The peak energy intensity of the beam at the edge is about 1 W/m², which is well within usual legal limits. Of course, the power beam will be pointed at the specific ground stations at all times. It will probably be placed offshore of on deserted areas onshore and will be strictly controlled. Humans will by no means be allowed to enter these premises for safety reasons. Fail-safe systems will be designed to make sure that if, for whatever unforeseen reason the beam is not pointed correctly, the Energy from Space system will stop transmitting or will divert the beam. Also, the ground station will be connected by a radio link to the space system for correct pointing of the beam. When there is a disconnect between the two, the beam is automatically defocused and the power is lost. As for flocks of birds flying through the center beam, research has shown that some birds experience evidence of detecting the microwave radiation at the maximum levels of the energy intensity. This suggests that migratory birds, flying above the antenna, might suffer disruption of their flying paths, but the birds will never be cooked. Even though it is currently believed that microwaves are non-ionizing (meaning not damaging cell structure of living tissue), more research is needed to analyze the effects in more detail. Another aspect of safety is frequency interference of the beam with communication systems, for example on aircraft. Although the passengers will always be protected from the microwaves because of the metal hull around them, the airspace in an around the beam will probably be restricted for airplanes because of the possible disturbances of the communication signals. More studies will have to be carried out to investigate these effects in more detail. The Energy from Space systems cannot be weaponized, because the maximum power density cannot exceed the designed level. Microwave weapons will use much more higher-power pulses at much shorter ranges; Energy from Space cannot create the same effects. Finally, it is intended to prevent disfunctional parts of the system to become space debris by retrieving them to Earth or repair/recycle them in orbit. More...
Which steps have to be overcome for Energy from Space to become real?
For full-scale Energy from Space systems to become technologically and financially feasible, there are a couple of challenges that are top-priority:
Cheap and reliable launch vehicles. Currently it costs around $20,000 per kg payload to launch into geostationary orbit. This should come down to less than $1000/kg. This could be reached by mass-transportation to low Earth orbit (LEO), followed by transportation to geostationary orbit over longer periods of time (several months). For LEO, this means the launch vehicles should be able to carry around 25 metric tons by reusable or cheap dispensable launch vehicles. Currently, heavy launch vehicles like the SpaceX Falcon 9 or the Russian Zenit can launch around 10 metric tons per vehicle.
Efficient wireless power transmission equipment. The current end-to-end efficiency of wireless power transmission is 40% and should double to about 80%. This can be achieved through research and development by institutes and universities. Also increased interest of private companies in commercial wireless power transmission products will improve the costs and performances. In addition, the actual transmittance and receiving of large amounts of energy should be tested in more detail. Some experiments were already conducted and more are currently carried out now and in the near future.
Light-weight and efficient solar power systems. Since conventional thick film solar panels used on Earth are too heavy for Energy from Space systems, light-weight and possibly flexible solar cells will be used. Examples of these so called thin-film space solar cells include amorphous silicon (a-Si), poly-silicon and CuInGaSe. These are much lighter, but their efficiency is generally lower. Typical current state-of-the-art space solar panels have an efficiency of around 25% to 30%, which should improve to more than 35% for the thin-film panels. Advantages of these types include increased flexibility and very low degradation over time. Alternatively, instead of arrays of solar panels, a concentrator photovoltaic (CPV) system can be used, which utilizes solar mirrors that reflect and focus the sunlight on a concentrator. This concentrator might involve the use of high-efficient, multi-bandgap PV cells that at this moment already achieves 30% to 35% efficiency. Advantages include increased fold-ability and weight of the structures (i.e. mirrors), high-efficient conversions, and reduced impact of panel (i.e. mirror) failure on the performance. Disadvantages include the more difficult deployments of the structure and the large dependency on the concentrators itself.
In-orbit assembly and maintenance of components. Tele-operated and fully autonomous robotics are required for assembly and maintenance, because the in-situ presence of astronauts would make the Energy from Space systems needlessly costly and complex. For these robotics to work, advanced beacons, visual cues, and regular features for image recognition are needed. The development of such systems requires coordinated design with existing space structural technologies, as well as the design of interconnects, avionics and platform dynamics, and attitude control systems.
These challenges require significant developments, but achievable within the coming 10 to 20 years. More... Before full-scale Energy from Space systems are realized, there are plenty opportunities out there for enthusiastic people to participate in and contribute to this endeavor. More...
Who will pay for the Energy from Space systems?
In the end, as with all power plants, the end consumer will eventually pay. However, upfront costs like those made by research and development, experiments and launching demonstration satellites will probably be born by space agencies, governments, universities, and institutes. Also companies may invest in the road map in order to initiate or strenghten their strategic position. The expected costs of one typical Energy from Space system are $20 billion. The system is designed to produce 1 GW of power for at least 30 years for an anticipated price of $0.10 to $0.50 per kWh. More...
Frequently Asked Questions
Links for more information:
- Wikipedia: Space Based Solar Power (http://en.wikipedia.org/wiki/Space-based_solar_power)
- JAXA: interview about Space Solar Power Systems (http://www.jaxa.jp/article/interview/vol53/index_e.html)
- ESA: Space Based Solar Power (http://www.esa.int/gsp/ACT/nrg/op/SPS/index.htm)
- NASA: Space Based Solar Power (http://www.nasa.gov/offices/oct/early_stage_innovation/niac/mankins_sps_alpha.html)
- National Space Society: Space Solar Power Library (http://www.nss.org/settlement/ssp/library/index.htm)
- Change.gov: document (http://change.gov/open_government/entry/space_solar_power_ssp_a_solution_for_energy_independence_climate_change/)
- Space Faring Institute: Space Solar Power video (http://spacefaringinstitute.com/)
- The Space Review: Space Solar Power (http://www.thespacereview.com/article/1364/1)
- Scientific America: Solar Energy in Space (http://www.scientificamerican.com/article.cfm?id=farming-solar-energy-in-space)