Category Archives: Energy

Mining the Moon

At the 21st century’s start, few would have predicted that by 2007, a second race for the moon would be under way. Yet the signs are that this is now the case. Furthermore, in today’s moon race, unlike the one that took place between the United States and the U.S.S.R. in the 1960s, a full roster of 21st-century global powers, including China and India, are competing.

Even more surprising is that one reason for much of the interest appears to be plans to mine helium-3–purportedly an ideal fuel for fusion reactors but almost unavailable on Earth–from the moon’s surface
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But a serious critic has charged that in reality, He3-based fusion isn’t even a feasible option. In the August issue of Physics World, theoretical physicist Frank Close, at Oxford in the UK, has published an article called “Fears Over Factoids” in which, among other things, he summarizes some claims of the “helium aficionados,” then dismisses those claims as essentially fantasy.

As I stated in January in Helium-3 Fusion Reactor: “This sounds pretty incredible to me and I find the claims of using fuel from the Moon economically to power our needs on Earth. Still it is interesting and just because it sounds fantastic does not mean it can’t be true. But I am skeptical.”

Revolving Doors

Every day I go into work I see about 15 people by bypass a revolving door (those using the revolving door average about 1.5 – including me) and use a standard door (and in fact 90% of those use an automatic handicap door open button – which leaves the door open for a good 5-10 seconds). MIT students have a page about the waste caused by people too lazy to use a revolving door:

On average 8x as much air is exchanged when a swing door is opened as opposed to a revolving door. That’s 8x as much new air that needs to be heated or cooled and that’s why using the revolving door is a great way to reduce energy requirements on campus.
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You’ve probably seen the signs around campus saying “Help MIT save energy. Please use the revolving door.” But does it really make any difference? Absolutely. Our estimates show that if everyone used the revolving doors at E25 alone, MIT would save almost $7500 in natural gas amounting to nearly 15 tons of CO2. And that’s just from two of the 29 revolving doors on campus!

As noted previously, for energy savings (greenhouse gas reduction…), not-so-glamorous conservation works best.

Peak Soil

An interesting article. Obvious the author has a biased viewpoint (that doesn’t mean the conclusions are wrong but it certainly can make one cautious – just as if a drug company shows results that their drug is effective or safe – you just have to pay a bit more attention…). I would be interested in others thoughts on this. My perception (though it is just an opinion based on limited facts) is that topsoil loss is a problem and that using corn for ethanol is more a federal government payoff to buy votes than a wise national policy. I am less inclined to accept some of the more extreme suggestions in the article. Peak Soil: Why cellulosic ethanol, biofuels are unsustainable and a threat to America

“The nation that destroys its soil destroys itself.” – President Franklin D. Roosevelt
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When you take out more nutrients and organic matter from the soil than you put back in, you are “mining” the topsoil. The organic matter is especially important, since that’s what prevents erosion, improves soil structure, health, water retention, and gives the next crop its nutrition. Modern agriculture only addresses the nutritional component by adding fossil-fuel based fertilizers, and because the soil is unhealthy from a lack of organic matter, copes with insects and disease with oil-based pesticides.

I believe it makes sense to research things like bio-fuels. However I am not convinced massive payments to the political well connected is a wise course of action.

Robo Insect Flight

photo of flying robot on a hand

Robotic Insect Takes Off

“Nature makes the world’s best fliers,” says Robert Wood, leader of Harvard’s robotic-fly project and a professor at the university’s school of engineering and applied sciences.

The U.S. Defense Advanced Research Projects Agency is funding Wood’s research in the hope that it will lead to stealth surveillance robots for the battlefield and urban environments. The robot’s small size and fly-like appearance are critical to such missions. “You probably wouldn’t notice a fly in the room, but you certainly would notice a hawk,” Wood says.

Recreating a fly’s efficient movements in a robot roughly the size of the real insect was difficult, however, because existing manufacturing processes couldn’t be used to make the sturdy, lightweight parts required. The motors, bearings, and joints typically used for large-scale robots wouldn’t work for something the size of a fly. “Simply scaling down existing macro-scale techniques will not come close to the performance that we need,” Wood says.

Cool. How annoying are those pop up ads after you follow the link though? Extremely yucky usability.

New York Steam Pipes

About a year ago I posted about the civil engineering report that the USA Infrastructure Needs Improvement. Why the heck does New York have steam pipes, anyway?

It turns out that Con Ed has been piping steam–which is a by-product of power generation, naturally–to buildings throughout lower Manhattan since 1882. (The pipe that blew up dates to 1924.) Incredibly, the system, which includes 7 plants, one with a boiler 8 stories tall, produces an average of one million pounds of steam per hour.

The reason that’s interesting, at least to me, is that this is a prime example of what’s known as combined heat and power generation. It’s an old idea, but one that’s making a resurgence as bills for all our petroleum-dependent energy sources–heating oil, natural gas and electricity–continue to climb. As we all know, the easiest way to “generate” more energy per dollar spent is simply to conserve.

You might also wonder, as I did, why the heck these pipes are pressurized even in the middle of July–clearly the steam isn’t being piped into radiators. Here it turns out that an additional cleverness has been introduced into the system: buildings in the financial district use the steam to power the compressors that run their massive air conditioning units.

The whole thing is rather brilliant–a model of re-use and smart urban planning–that is until disaster strikes. Apparently there have been lethal steam pipe explosions before, the most recent in 1989 in Gramercy Park. There’s a movement to bring these kinds of combined heat and power systems to cities small and large throughout the U.S., since it’s more efficient to combine the two functions and reuse the “waste” products of the power generation process.

Interesting. The event has also resulted in several articles on the deteriorating infrastructure: When Cities Break Down – Explosion exposes NYC’s aging systems

Home Engineering: Windmill for Electricity

photo of windmill

William Kamkwamba’s Malawi Windmill:

I built my first windmill when I was 15. Over the next few years I kept refining the design. I made many modifications to the plans i found in the book. For example, I increased the blades from three to four to provide more power output. The windmill now powers lights for 3 rooms and a light over our porch outside. I also use it to power my family’s two radios. I also can charge mobile phones that the neighbors have.
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Two weeks ago I used a computer for the first time. I learned about Google and searched for “windmill” and “solar energy.” I was amazed to learn how many entries there were for both subjects. My friends showed me how to create an email address and now I am on Gmail. Now I am practicing sending and receiving emails when I have access to a computer.
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On Sunday, my friends from National Solar and I completed the next phase of work on my electrical system. You can see a compete set of (my first) digital photos at my new site on Flickr. I had the following goals:

1. Upgrade the power generation in the windmill
2. Upgrade the battery technology and capacity, to provide more even power for more hours at a time
3. Increase the brightness of the lighting (lumens) to make it easier for my family to accomplish tasks at night, especially to read…

Photo: Back in November, the windmill was only 5 meters (15 feet) tall compared to 12 meters (36 feet) today. I raised the height because I discovered that the best wind was just over the top of the shorter windmill.

World’s First Commercial-Scale Subsea Turbine

Artist's impression of MCT Seagen pile-mounted twin rotor tidal turbine

Earlier this month, Marine Current Turbines confirmed the installation date for its 1.2MW SeaGen tidal current system in Northern Ireland’s Strangford Lough. SeaGen consists of twin axial flow rotors, each of 16m diameter driving a generator via a gearbox much like a hydro-electric turbine or a wind turbine. The twin power units of each system are mounted on wing-like extensions either side of a tubular steel monopile 3m in diameter which is set into a hole drilled into the seabed.

SeaGen is four times as powerful as the world’s previous most powerful turbine, SeaFlow, which Marine Current Turbines has been operating off Lynmouth in Devon since 2003; SeaGen will form the basis for the commercial projects that will follow. SeaGen, which is being assembled at Harland & Wolff in Belfast, will be connected to the local electricity grid and have the capacity to generate clean and predictable power for approximately 1000 homes.

Martin Wright, Managing Director of Marine Current Turbines said: “The new investment partners and the support of our existing shareholders re-affirm the commercial potential for tidal power in the UK and overseas, and recognise our engineering achievements in developing a world-leading technology. With SeaGen set to be deployed in August, we are moving ahead with our plans for a 10MW tidal farm, to be installed within the next three years.”

Each submerged turbines range from 750 to 1500kW per unit (depending on the local flow pattern and peak velocity). And they expect to deploy 10-20 at a time – more can be added for relatively less marginal cost allowing for incremental investment in new capacity. They expect the turbines to have an excess of a 20 year operating life.

We have also added a new energy category to the blog.

Building an Electricity Producing Wind Turbine

How I home-built an electricity producing Wind turbine:

Several years ago I bought some remote property in Arizona. I am an astronomer and wanted a place to practice my hobby far away from the sky-wrecking light pollution found near cities of any real size. I found a great piece of property. The problem is, it’s so remote that there is no electric service available.
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Whether you build your own, or buy one, you will need some sort of controller for your wind turbine. The general principal behind the controller is that it monitors the voltage of the battery(s) in your system and either sends power from the turbine into the batteries to recharge them, or dumps the power from the turbine into a secondary load if the batteries are fully charged (to prevent over-charging and destroying the batteries). The schematic and write-up on the above web page does a good job of explaining it.
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My ultimate goal is to have enough power from wind and solar sources to power a small cabin and observatory on my remote property that will only be occupied occasionally and won’t have much need for electricity. If you need a bigger system, then you need someone with experience with bigger systems to help you out.

Very interesting home engineering project. Related: Awesome CatCam – Engineering at Home – The sub-$1,000 UAV Project

Winter Air Refrigeration

From Freeaire:

“Free Cooling” In colder climates, the Freeaire taps into the greatest source of refrigeration ever created: winter. The Freeaire can use cold outside air to cool the space, simply using what Nature has so kindly made available, to give the entire compressor system a winter vacation.
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In cold climates, this innovative option allows you to utilize a natural resource we have in abundance up here in the North: outside winter air. Rather than relying on the compressor system to produce cold air it simply moves the cold from outside to inside, using just a fraction of the energy.

Seems like a smart idea to me. Their systems are for large walk in freezers.

High-efficiency Power Supplies

High-efficiency power supplies for home computers and servers (pdf) by Urs Hoelzle and Bill Weihl – Google:

Most likely, the computer you’re using wastes 30-40% of the electrical power it consumes because it is using an inefficient power supply. It’s difficult to believe that something as basic as a power supply could be responsible for that amount of waste, but it’s true.
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The opportunity for savings is immense — we estimate that if deployed in 100 million PCs running for an average of eight hours per day, this new standard would save 40 billion kilowatt-hours over three years, or more than $5 billion at California’s energy rates.
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The net result of these changes is a dramatic improvement in efficiency (including the power supply and the regulators) to about 85%, at virtually no cost. In other words, you won’t have to pay more for a higher-efficiency PC, because the power supply is actually getting simpler, not more complicated. By spending another $20 or so extra, it is possible to use higher-quality components and achieve efficiencies well over 90%.