Solar Energy from Space Essay

Eric Gillen December 14th, 2012 Physics – SPH3U Summative Assignment – Renewable Energy

For my Renewable Energy Summative Assignment I chose Solar Energy from Space. I chose this topic because I have always been interested in meteorites, stars, planets; anything in space has always sparked my curiosity. Therefore, I took the opportunity to learn more about the wonders of space and also to learn more about the solar energy process since we are using it more and more every day. Solar Energy from Space has evolved immensely in the past few years and has become one of the most efficient ways to obtain and convert energy.

2. Solar Energy from Space, known in short form as SBSP (Solar-Based Space Energy), has been in research since the early 1970’s. How it works is, in space, there are solar power systems that absorb the suns rays and convert them into microwaves. Then it sends these microwaves through the atmosphere to receivers called Rectenna’s. These Rectenna receivers are rectifying antenna’s that are specially designed to convert microwave energy into direct current electricity. This solar collection method saves the losses from when the suns rays travel through the atmosphere and also the downtime due to the earth’s rotation. The frequency of radio waves sent down from an SBSP satellite would be comparable to the ones of cell phones, wireless Internet, or cordless phone signals. Based on several studies done by NASA, this transmission is safe to human, animal, and plant life near the receiving antennas.
SBSP works mostly the same way solar panels do on earth. The only difference is that instead of converting the suns energy directly into electricity, it converts it into microwaves so it can be sent to earth and converted into electricity there. First, the solar panels harness the suns radiation and convert that energy, using photovoltaic cells, into radio waves (microwaves). It does this because it is the best way to get the energy from the satellite in space to the earth’s receivers. When it gets to the Rectenna’s, the microwaves are then converted into direct current electricity.
Solar Energy from Space can be used for multiple things. In fact, some scientists think that SBSP can and may supply nearly all the electrical needs for our planet! The lifetime of the sun is an estimated 4-5 billion years! This makes space solar power a truly long-term energy solution. One very big customer that is interested in SBSP is the Military. They are looking to use clean and natural energy with a low cost to power their bases. The SBSP method is beginning to look like a long-term solution for the military’s energy problems. Also, it can power smaller but just as important customers, like businesses, hospitals, police stations, etc. And not to mention all the regular people can use it as well. They can heat their homes, power their homes (light, televisions, computers, etc.), it could even power all the homes across the globe! Of course we would have to vastly expand the number of SBSP systems across the world. Although it seems like a far stretch, it is possible. The energy is there we just need to build enough solar systems in space to capture it.
3. In Canada, we have used solar energy for many years now and have been expanding ever since. It has been a great way of getting clean energy and has worked very well, but there is always room to improve. Since the 1970’s, we have been working on a better way of using solar energy and a more efficient way to harness the suns radiation. The solution is Solar Energy from Space. Scientists say that the suns rays are five and a half times as strong in space than it is on the surface of the earth! This is because of many reasons, one being; there is no air in space. This means that the sunlight is much more intense than inside the earths atmosphere. Also it does not have to interact with the atmosphere, the weather and also the day and night cycles. SBSP is able to run almost continuously, with only short periods of time when the satellite is in the earth’s shadow. But those downtimes are at most 75 minutes which is nothing compared to the solar systems that are on the earth that have on average a 12 hour downtime due to night time. Canada is beginning to do a lot of research on SBSP and is trying to find ways that they can diminish the costs of these systems so that they can create and launch more of them into space. Scientists say that the process of Solar Energy from Space is 85% efficient. Where as, regular solar systems on the ground range from only 10 to 34% efficient. This is the major reason why we are turning to Solar Energy from Space.

4. There are many positive environmental impacts of Solar Energy from Space but there are also some negative impacts as well. Here are the positive impacts: * By placing the satellite into their proper orbit, natural fuels like H2, O2, etc will be made use of.
When the SBSP system is working properly, it will have zero carbon emissions therefore making the environment free from mercury and sulfur. The SBSP ground receivers (Rectenna’s), which convert microwave energy into electricity, does not require fresh water for thermal cooling and power generation. * Unlike oil, gas, ethanol, and coal plants, space solar power does not emit greenhouse gases.
Greenhouse gases have been a major problem in the last 20 to 30 years and are getting increasingly worse. It is one of the main causes of global warming. * Unlike coal and nuclear plants, Solar Energy from Space does not need fresh water resources.
This relates back to my first point where I mentioned that the SBSP system does not require fresh water for thermal cooling. The accessibility of fresh water is getting substantially lower and we are always trying to find ways to cut down our water usage. This is a very big advantage to SBSP. * Solar Energy from Space does not require the limited earth-based energy resources such as: coal, gas, ethanol, etc.
Earth’s resources have always been very important because they are so limited, but yet, power so many things on our planet. There has always been conflict between countries because of the lack of fossil fuels. If most countries, if not all of them, had there own SBSP systems, there would be no more conflicts for fossil fuels. * Elimination of plant and wildlife interference.
Since Solar Energy from Space does not require the burning of fossil fuels, there will be no longer any toxic gasses that can harm plants or animals.

There are not nearly as many negative environmental impacts than positive ones, and also they are not as consequential. The main negative environmental impact is: * Solar photovoltaic panels may contain hazardous materials
These hazardous materials could be released when a panel is damaged or disposed of improperly. Solar Energy from Space systems may also use potentially hazardous materials like oils and molten salts, creating the potential for spills, which could result in contamination of surface or groundwater.

5. Solar Energy from Space may not seem like a very hard task. If you think about it, mostly all you need to do is take a solar panel from earth, and launch it into space. Also build a few Rectenna’s on earth. Simple right? No! The technical part of it is but that’s not the most worrisome part. It’s the cost! The cost is not so much for making Solar Energy from Space systems but launching them and getting them into space. In a 2007 study on SBSP by the National Security Space Office (NSSO): it would take 10 years to develop an SBSP system, cost $10 billion, and generate 10 megawatts. The power it generated would not be cheap, but also would not be as costly as one would think. It would be between $1-5 per kilowatt-hour. The cost in Canada today is on average 7 cents per kilowatt-hour. This is quite a bit lower than the cost for SBSP electricity but over time, the cost for SBSP electricity will decrease. As of today, Solar Energy from Space is not economically feasible, but every year it is getting less and less expensive and is becoming to look like a very strong alternative source of energy for the entire planet!

Reference:

Foust, J. (n.d.). Retrieved from http://www.thespacereview.com/article/1978/1 Space, E. (2012). Sbsp_overview. Retrieved from http://www.spaceenergy.com/SBSP/SBSP_Overview.htm

National space society. (2006, october). Retrieved from http://www.nss.org/settlement/ssp/

Wikipedia. (21 1). Retrieved from http://en.wikipedia.org/wiki/Space-based_solar_power NRCAN. (2009, January 27). About renewable energy. Retrieved from http://www.nrcan.gc.ca/energy/renewable/1297

Solar-based power satellites. (2011, November). Retrieved from http://www.spacecanada.org

Solar energy. (n.d.). Retrieved from http://education.nationalgeographic.com/education/encyclopedia/solar-energy/?ar_a=1

Murphy, T. (2012, 20 03). Space-based solar power. Retrieved from http://physics.ucsd.edu/do-the-math/2012/03/space-based-solar-power/

Dvorsky, G. (2012, Novemeber 28). How space-based solar power will solve all our energy needs. Retrieved from http://io9.com/5963955/how-space+based-solar-power-will-solve-all-our-energy-needs Hubpages. (2011). Retrieved from http://tonks21.hubpages.com/hub/Positives--Negatives-Of-Solar-Energy

William, C. (2011, March 23). The race for solar energy from space. Retrieved from http://www.consortiumnews.com/2011/032311b.html