www.herald-journal.com
Solar power may eventually be directly 'beamed' to earth

September 28, 2009

by Mark Ollig

“Mr. Scott, can you beam a little sunshine onto the Enterprise’s bridge please?”

Yes, my Star Trek reference is cheesy, but I just couldn’t help myself.

In reality, there is an active energy program being investigated for an earth-orbiting solar power-collecting satellite. The official name is called the Space Solar Power System (SSPS).

Simply put, the sun’s electrical energy is collected from a space orbiting solar-satellite and is sent to the earth via wireless microwave transmissions.

From the concept pictures I viewed, focused radiated waves of energy are beamed from an earth orbiting solar-satellite to a ground based “collector device.” This collection device is actually floating on a platform in the water close to shore. From this device there are transmission wires attached which connects it to the electrical grid we use today for power distribution to our homes.

This solar-satellite powered program originates in Japan and has an estimated cost of $21 trillion yen, which is approximately $230 billion in US dollars.

It is thought that as we move away from our traditional fossil fuels as a power source, an orbiting solar power station in space may become necessary in order to provide a source of electricity in the future. This is according to the Kensuke Kanekiyo, from the Japanese Government’s Institute of Energy Economics.

This SSPS satellite will be in a geosynchronous orbit 22,500 miles above the earth.

The SSPS will house a 2.5 square mile area of solar panels which is projected to generate a 1GW (Gigawatt) stream of electrical power. This amount of energy reportedly could power some 300,000 homes in Tokyo.

The Japanese METI (Ministry of Economy, Trade and Industry), along with 16 companies, including the Japanese engineering group, Mitsubishi Heavy Industries (http://www.mhi.co.jp/en), are taking part in creating the technologies needed to send a stream of solar cell electricity to the earth.

I found much of my information about the SSPS for this column from the Japanese Unmanned Space Experiment Free Flyer (USEF) web site. Fortunately for me, there was a link which had some of the information available in English.

If any of my readers do read Japanese, here is the URL: http://www.usef.or.jp.

The SSPS working group examined an achievable configuration which consists of a large power solar generation and transmission satellite. The upper surface of this satellite is covered with solar cells and a rotating flat mirror. The lower surface area – which is tethered with wires – houses the transmitting phased array antenna elements.

The project will be implemented in four steps:

• First, a demonstration testing satellite in Low Earth Orbit (LEO) that will beam back 100kw (100,000 watts) of power.

• Second, a prototype satellite system in LEO which sends back 1MW (Mega or million watts) of electrical power.

• Third, a so-called ‘pilot system’ has a satellite in Geosynchronous Earth Orbit (GEO). This will be the operational test and will provide actual – although partial – service. This third step is sending back 250MW of power, which will be used in some homes.

• The fourth step is the full commercial operation of the SSPS with 1GW or the equivalent of 1000 Megawatts of power being sent via microwaves to a collector on the earth. This power will be distributed to homes and businesses.

The first step is set to happen around 2015, with the launch of a solar-paneled equipped satellite. This will demonstrate the ability to beam electrical power from space to the earth.

I was highly skeptical when I first heard of something like this a couple of years ago from my oldest son. At the time, I thought it was pure science fiction, strictly something out of a Star Trek episode. “How safe is it to beam microwave electrical radiation to the earth?” I wondered.

From the USEF web site, I was able to convert some of the Japanese and found the issues concerning the safety level of the satellite sending microwaves of radiated power were being addressed. I found this somewhat (but not completely) comforting.

I learned it’s not just the Japanese looking into harnessing the sun’s power.

For over 30 years, our own NASA and the Department of Energy have been exploring ways to bring solar power from space to the earth. In fact, they have spent $80 million researching it.

The acting director of the National Security Space Office released a 75-page report entitled “Space-Based Solar Power as an Opportunity for Strategic Security” Oct. 10, 2007. You can view this report at http://tinyurl.com/327kkl.

One premise in this report states “. . . space-based solar power does present a strategic opportunity that could significantly advance US and partner security, capability, and freedom of action, and merits significant further attention on the part of both the US government and the private sector.”

When will the Japanese space-based solar-satellite system become fully operational and begin beaming electricity back to earth? Sometime during the 2030s, according to the Japan Aerospace Exploration Agency (JAXA).

Be sure to check out the frequently visited and often imitated “Web Site of The Week” for more information, pictures, and video about the Japanese SSPS and NASA’s space-based solar power studies.