ENERGY FROM SPACE
When will Energy from Space be realized?
The first steps are already made and proof-of-concept systems are in the making. Ground experiments are being conducted and Low Earth Orbit demonstration satellites are already proposed. Launching these is the first big challenge, possibly in the early 2020's, followed by prototype satellites. When proven successful, deployment of the first full-scale Energy from Space system will occur from 2035.
Until now: ground and space experiments
On Earth, many of the technologies can and should be tested and analysed before real-time deployment. These ground experiments include testing:
- Wireless power transmission
- Expandable structures, mainly for solar panels
- Highly durable and lightweight materials
Already in 1975, large scale wireless power transmission using microwaves was proven by NASA at JPL Goldstone. During the test 34 kW was transmitted over 1.5 km with an efficiency of more than 82% (video). More recently, in 2008, tests have been conducted in Hawaii. Further tests are planned by universities and space agencies to increase efficiency and expertise. Also, wireless power transmission is currently developed for charging electric vehicles, mobile phones and household appliances.
Lightweight expandable structures are necessary to allow the Energy from Space systems collect enough solar energy. Space agencies like NASA (video), JAXA and ESA, but also universities like Caltech are conducting advanced research on expandable space structures.
Finally, advanced research on space materials is necessary because it allows the Energy from Space system to operate for more than 30 years.
2020-2025: demonstration satellites
Proof-of-concept is absolutely essential before any large-scale Energy from Space system from technological and financial points of view. It gives more confidence to investors, policy makers and engineers, and it offers unique opportunities for testing the systems with respect to ground experiments.
There are a couple of ways for demonstrating the Energy from Space concept. Two of them are illustrated in the figures on the left. It is very likely all proof-on-concept satellites operate in the lower regions of a Low Earth Orbit, roughly between 400 km and 700 km altitude.
The first possibility involves a module to be attached to the International Space Station (see adjacent figure). The advantage here is that a large part of the infrastructure is already present, like power supply from solar panels and orbit control mechanisms. Also, it offers the possibility to be controlled directly via the astronauts on-board. Such a module would transmit 1 to 10 kW, weigh up to 500 kg and cost around $40 million in total.
The second possibility is to construct and launch a stand-alone satellite (see adjacent figure). Here, the system can be demonstrated as a whole from harvesting energy with the solar panels to generating the power beam. Another advantage is that there is more choice which orbit the satellite is in. As such, the contact time with specific ground stations can be optimized. Roughly speaking, such a satellite would also transmit 1 to 10 kW, weigh up to 10,000 kg and cost a similar amount as above.
Another, perhaps more accessible, option would be to construct and launch a nano-Energy from Space satellite, serving as a first and relatively simple proof-of-concept. The Energy from Space Foundation is pro-actively looking into this.
2025-2035: prototype satellites
After the small-scale to medium-scale demonstration satellites, the Energy from Space technology will be matured with large-scale prototypes. These satellites range in size, power and costs. The first version of these prototypes could be capable of transmitting 1 to 2 MW, would orbit the Earth at roughly 1,000 km altitude and may cost up to $200 million. The purpose of such a satellite is to demonstrate the harvesting and wireless transmission of large amounts of power. Specific energy price would be between $1/kWh to $5/kWh.
The final step towards full-scale deployment of the typical 1 GW Energy from Space systems may be a prototype satellite in geostationary orbit. This would serve as the ultimate reference mission and would be capable of delivering more than 10 MW, possibly even 100 MW, for $1/kWh to $5/kWh. Since it would operate from roughly 36,000 km altitude, it would remain above one location on Earth. As such, the satellite can deliver uninterrupted power to one or multiple places within its 'sight'.
2035 onward: full-scale deployment
The final stage is the development, deployment and operation of full-scale Energy from Space satellites. The preparations are already made before 2030, during the demonstration and prototype phases.
The aim is to have the Energy from Space satellites provide power at a competitive price between $0.10/kWh and $0.50/kWh, and each operating for more than 30 years. Since the satellites remain stationary above one location on Earth, it is possible for multiple power utility companies and even for nations to agree collaboratively on power purchase agreements. For example, Energy from Space systems located above the Atlantic Ocean could power Europe during peak (daytime) and gradually shift the power to the East Coast of the United States when peak demand occurs there. Similarly, for other satellite locations this 'power sharing idea' could hold, for instance, for the East and West coasts of the US, for Japan and India, and for South Africa and Brasil.
How many satellites will be launched is difficult to predict. For Japan, for example, the launch of one Energy from Space satellite per year would deliver roughly 30% of its power by 2060. Some visionaries even consider the placement of 500 Energy from Space systems (each generating some 2 GW) operated and maintained by 2090. That would mean that on average about 8 per year would be installed, beginning with 3 per year from 2035 on and 15 per year during the peak in 2060. It is estimated that would realize an annual deployment on the order of 5 million people, and power entire continents.