Wednesday, January 2, 2008

Technology Challenges: Power

There are a number of technology challenges to be addressed by any serious attempt to colonize Antarctica. This post aims to touch on only the power or electricity generation aspect.

Power

In order for humans to survive in Antarctica we will need ample power. A system to generate more than is needed and store the surplus energy for peak demand times would be optimal. However, this is easier said than done. There are several options available. Although, if we are to adhere to Antarctica Treaty we will need a power solution that is green and pollution free. This rules out Nuclear, Coal and Oil.

Geothermal

Geothermal power would be a good option for an Antarctic colony. However, it has a number of drawbacks. A geothermal power plant's high initial cost (est. $20-30 million) and inability to scale being the main obstacles.

The benefits being a clean and constant flow of both power and heat should not be overlooked. For those reasons it should be researched and kept as an open option for further debate.

Wind

Harnessing the power of Antarctica's natural wind power would seem like an ideal solution, as Antarctica is the highest and windiest of the continents. Wind power much like geothermal also has it's drawbacks. These being a lack of power in low wind conditions, wind generators freezing up, and possible breakage and other equipment failure in the extreme Antarctic conditions.

Overcoming The Drawbacks Of Wind Power

With adaptations to present technology it may be possible to overcome the drawbacks of conventional wind power technology deployed in Antarctica.

Low wind conditions could be compensated by building wind generator platforms on multiple sites. When the wind is low in one location it will most likely still be blowing in another location. It may be as simple as spreading out wind generators over a large enough area to provide constant power flow.

Freezing up can be avoided or minimized by the installation of defrosters on the wind turbines themselves. Also, it may be necessary to occasionally send a maintenance crew to clear ice and snow from the generators and platforms.

Breakage and damage to the wind generators can be reduced or minimized by using VAWTs (vertical axis wind turbines) instead of conventional HAWTs (horizontal axis wind turbines). VAWTs, although, not as efficient at producing energy as HAWTs are far more durable, especially in high wind conditions that is prevalent in Antarctica. Also, the base of the VAWTs being on the ground makes maintenance much easier.

VAWTs are cheaper to build, install and maintain than HAWTs, which is yet another advantage. The downside being that they will have to be built in minimum groups of three, as the tops will need to be linked together for support. Otherwise a large and expensive support frame would need to be constructed for each wind turbine.

Of course many of you reading this may be curious as to why if VAWTs are so good, why are they not already being used widely? The answer is simple, HAWTs are far more efficient in low wind conditions. Also, HAWTs are usually built on towers that increase height, allowing access to higher wind speeds at higher elevations. This is simply not as much of an issue in the wind swept high elevation regions of Antarctica.

Power Storage

Another major hurdle to overcome will be storing the excess power generated. As any storage solution will need to be environmentally friendly. For that hydrogen gas would seem like an ideal choice. If the colony is located near the ocean, salt water can be drawn up into tanks and the extra electric power can be used to convert the water into hydrogen and oxygen gas. The hydrogen gas can then be compressed into tanks for storage and use. It could be used to power everything from vehicles to stoves to electric generators. This may well be the best viable option for a backup and power storage system.

Alternative Technology

Because of the vast temperature differentials present in Antarctica. This may be a golden opportunity to explore an alternative technology like the Stirling engine. The Stirling engines can run a motor or electric generator off of two plates, as long as a temperature difference exists between those two plates. The ocean water, the ground or even the ice itself and the surface air above could be used to run motors and create power with no other inputs.

These technologies describe here all exist today. More information on them can be found readily at sources like Wikipedia and others. All one needs to make them work as described is proper funding, a little ingenuity, some hard work, plus the drive and determination to get things done and this could become a reality.

3 comments:

al fin said...

A sustainable colony in Antarctica needs heat--lots of heat. If it can tap into the nuclear powered heat coming from the earth's mantle into the crust, fine. That would be the cleanest most sustainable heat source.

Unfortunately, the nuclear powered heat coming from the sun is in short supply at such high latitude.

Since it is too early to take advantage of clean, safe nuclear power from controlled fusion processes, you are left with a limited selection.

Ordinary unmodified wind turbines are not likely to stand up well to conditions in Antarctica. But a good design engineer should be able to build a custom wind installation that would provide sustainable electric power in the megawatt range. But you would need good energy storage--like redox flow cells.

If your people are very good, technically, useful quantities of methane clathrates may be burned relatively cleanly without significant environmental risk. If your people are typical environmentalists--not good technically--they'd better stay away from anything requiring expertise.

Advanced modular nuclear fission designs are the obvious choice for cogeneration of heat and power, and colonies willing and able to utilise such sources of power would naturally run rings around colonies that placed advanced fission designs off the table. The seawater contains plentiful uranium oxide using clever seawater absorption "wicks".

Colonize Antarctica said...

al fin, Thank you for the comment, you bring up some very interesting points.

You are correct that a large amount of heat will be needed. However, if enough electricity can be produced that in itself will solve that problem. Also, in future posts the heat and shelter issues will be addressed more directly.

A redox battery system would be great for an output balancer and backup UPS for core systems. However, it may not be the best for a large long term power storage solution due to the fact that it uses sulfuric acid. Unless sulfuric acid can be produced locally in sufficient quantities, it would have to be imported. Importing vast quantities of sulfuric acid in itself would be difficult. Hydrogen gas on the other hand can be produced locally and stored long term in tanks for future use.

Regarding geothermal energy. While I do agree that would be the most sustainable of available power sources, the main issue with it is it doesn't scale. If a ten megawatt geothermal power plant was built, it would provide a year round constant flow of power and heat. Unfortunately, if the colony grew beyond the needs of that initial ten megawatts there would be no way to increase output without building a second geothermal plant or enlarging the first at considerable cost. Also, the local geology (depending on where the colony is located) may rule geothermal out as an option all together.

A decentralized power grid would likely be more stable in the long run. If all systems in the colony were tied to one central geothermal power plant and that plant had to shut down even temporarily for whatever reason, that alone may be enough to doom the colony as the sole/primary source of power and heat would be gone.

Ordinary unmodified wind turbines would not be used. What is proposed is the use of heavily modified specially engineered VAWTs (vertical axis wind turbines) to survive in the extreme Antarctica conditions. In addition as was touched on in the blog post, a number clusters of VAWTs could be built in different areas near the colony. That way if there was a partial failure or low wind conditions a fairly constant flow of power could still be achieved.

If each cluster of VAWTs produced several hundred kilowatts of power each, it shouldn't be too difficult to generate power well into the megawatt range, with the ability to easily scale it much larger.

As for methane clathrates, I'm not familiar with that and will have to research it further.

As for nuclear power, it would be fantastic if clean controlled nuclear fusion was developed. However, the goal is to design and eventually build a self-sufficient colony with existing technology using creative engineering to overcome the hurdles, all the while abiding by the Antarctic Treaty which prohibits pollution. Current nuclear technology produces nuclear waste, which likely would be seen as a significant source of pollution and may give cause to the international community to take action against the colonists.

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