August 09, 2007

tax breaks for renewables

My military nanotech article posted with pictures

Space carnival week 15

Star Stryder hosts the 15th carnival of space

Spacedev, who built the engines for SpaceshipOne, believes they can make a moonbase for $3 billion instead of the Nasa figure of $100 billion

Benson's plan links technology already being developed. Bigelow Spacehab modules would be prepositioned between Earth and Moon. A crew would shuttle from Earth in the orbital version of Benson's Dreamchaser. Upon reaching lunar orbit, 4 astronauts would descend to the Moon in Lunar Human Access (ALOHA) chairs. What a ride that would be! These open vehicles would be much simpler than the Lunar Surface Access Module NASA is designing. The crew would stay in Spacehab modules already landed on the Moon.

My own contribution on more $500/kg or less launch options

Colony worlds discusses the use of Callisto as a base

Centauri Dreams discusses using radio frequency waves to trap antimatter instead of magnetic fields

This site will be hosting next weeks carnival of space.

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August 07, 2007

Cheaper space launch $500/kg or less: Ram accelerator, magnetic launch and plasma hypersonic

The cheapest chemical rocket currently flying is the Russian Dnepr rocket ($1000/lb, $2200/kg) Most other commercial rockets are two to four times as expensive. Without cheap access to space it is impossible to achieve anything useful in space.

I will review some alternative launch proposals, which might be easier to fund than my favorites (photonic mirror laser arrays, nuclear pulsed propulsion, nuclear thermal). The ram accelerator is a variation on a big gun. It has the advantage of a low development and validation cost. It has the disadvantage of high-g acceleration. The magnetic launch ring system is similar and would ultimately be more efficient but has a higher development cost.

Here is a 21 page pdf on the technical risks of the Ram Accelerator (big chemical gun)

The ram accelerator is a chemically powered hypervelocity mass driver that operates with intube propulsive cycles similar to airbreathing ramjets and scramjets. The launcher consists of a long tube filled with a pressurized gaseous fuel-oxidizer mixture in which a subcaliber projectile having the shape similar to that of a ramjet centerbody is accelerated. No propellants for this launch process are carried aboard the projectile; it effectively flies through its own propellant “tank”. The ram accelerator at the University of Washington has been operated at velocities up to nearly 3 km/s and in-tube Mach numbers greater than 7 in methane-based propellant mixtures. This Mach number capability corresponds to muzzle velocities greater than 7 km/s when using fuel-rich hydrogen-oxygen propellant. The combination of hypervelocity muzzle velocities and the ram accelerator’s inherent scalability to multi-ton payload sizes makes it suitable for direct space launch.

Although it resembles a conventional long-barreled cannon, the principle of operation of the ram accelerator is notably different, being closely related to that of a supersonic airbreathing ramjet engine.

The total propellant mass used per ram accelerator launch to 8 km/s is ~20 times the mass of the projectile; e.g., ~40 metric Tons for a 2000 kg projectile.

A cost estimate of a baseline ram accelerator launcher system having a 500-mm-bore and length of 800 m that is capable of launching a 300 kg projectile at 6 km/s. The upper cost boundary for a ram accelerator launch facility is represented by the
SHARP/JVL light gas gun effort. Public data on SHARP is scant; nonetheless, a published estimate for a proposed 1520-meter-long JVL light gas gun cited a cost of $298M (Gilreath et al. 1998, 1999). The basis for this number comes from an estimate provided by Morrison-Knudsen, the company that built the Alaskan Pipeline. Proportioning this cost to an 800-meter-long ram accelerator launch tube results in an estimate of $157M. It can be argued, however, that the ram accelerator facility cost will be significantly lower than that of a light gas gun because it is
inherently a much simpler device.

The $16M per 800 m of Alaskan Pipeline is considered the lower bound of scaling the ram accelerator launch system cost. The only firm conclusion that we can reach is
that the true system cost is somewhere between $16M and $157M; however, this number is likely closer to the lower bound due to the vastly lower system complexity of ram accelerator compared to the SHARP/JVL light gas gun. The authors propose that a system cost in the range of $40 to $50M dollars is not unreasonable.

Inflatable space structures and Mylar backed solar arrays can survive the high-g (2000g) launch.

Comparison to air breathing rocket

The firing sequence of a ram accelerator

Different from a regular big gun

Multiple stages of acceleration

Projectile mass and launch speed determine the cost per kilogram

Another alternative is the magnetic launch ring system by Launchpoint. I had covered this before.

The first magnetic launch systems are expected to propel payloads into orbit at a cost of roughly $750/lb (1650/kg). The total cost to orbit might eventually drop below $100/lb ($220/kg). New Scientist had more details

The launch ring would be very similar to the particle accelerators used for physics experiments, with superconducting magnets placed around a 2-kilometre-wide ring. The cost per pound to orbit is about $6,000 for the space shuttle; it is estimated that if the Launch Ring is used 300 times per year, the cost would be about $745 per pound. If the launch rate reached 3000 launches per year, they calculate that would drop to $189 per kilogram.

There is some plasma hypersonic technology which might also be developed for cheap launch. It has some secret CIA and other technology. Some secret black program version of hot structures technology to control the heat problem. Paul Werbos is a champion of this plasma hypersonic technology Paul is a program director at the NSF and has a history with NASA and the IEA

This would take $30 million to maintain existing research and $150 million to make significant progres and $10-15 billion for full development. The near term design has passed peer review.

Space based solar power technical brief

State of the rocket launch vehicle part 1 at space review

Widely deployable Incremental improvements

Physorg talks about smaller nano-boric acid particles that can be added to motor oil within 2 years for a 4-5% fuel consumption reduction in all cars. If the new nano-particle motor oil was mandatory or added at low cost to all motor oil than at the next oil change after its introduction there would be reduced gasoline usage.

A software patch could save 2.6% of fuel for modern cars Adapting batteries and the engine starter to take advantage of more fuel efficient computer control would save 5-6% of fuel.

Being able to shift travel patterns can have a big impact
1. Drive less
Arrange a shorter commute, being able to telecommute more (skype video)
2. Carpool more and use more public transportation
3. Bike and walk more
Folding bicycles and electric bicycles can be combined with public transportation to make a travel system that is less fuel intensive but does not waste time. Some people may also consider all electric mopeds and motor bikes.
4. Buy a more fuel efficient vehicle when you do switch your car
An interesting alternative to an SUV are vehicles like the Honda Fit The Honda Fit has seats that completely fold down so large objects like surf boards can be placed inside it. It has 41 cubic feet of cargo space with the seats folded down. Comparable to a full size SUV that still has the second row of seats up.

Kessels' software dynamically switches the dynamo, which charges the car battery, on and off. However, the software is not quite ready for release. "We don't yet know how much it might degrade the battery". A more significant fuel saving of 5% to 6% could be achieved if the car engine itself were to be rapidly switched on and off, but this would mean serious adjustments to the engine, including the addition of a powerful starter motor to ensure the car gets going quickly after each engine shutdown.

The EPA discusses the importance of fuel economy and how society has chosen to trade efficiency for performance and vehicle weight This also applies to electricity usage in the home. If you get more efficient light bulbs and appliances but then plug in another TIVO, Blue ray recorder, two more big screen TVs and other new devices, just get a bigger home then your total energy consumption went up and you burned up your negawatts (see what Amory Lovins has been saying incorrectly for thirty years)

Wide adoption of ecodriving techniques could make a bigger difference

One of the best ways to optimize mileage (both hybrid and non-hybrid) is to keep up with vehicle maintenance. Key parameters to maintain are tire pressure, tire balance, and proper motor oil weight and level. Inflating tires to the maximum recommended air pressure ensures that less energy is required to move it. Under-inflated tires can lower gas mileage by 0.4 percent for every 1 psi drop in pressure of all four tires per gas tank.

Minimizing mass
Beyond purchasing smaller vehicles, drivers can also increase fuel economy by minimizing the amount of luggage, tools, and equipment carried in the car, including such things as unneeded snow chains in the summer and outdoor sporting equipment in the winter.

Pulse and glide
This method is a trick that can be used with some hybrids to minimize internal combustion engine waste. The idea is to optimize acceleration in order to reach the optimal threshold of the hybrid engine. At this point, some vehicles (when the accelerator is minimally pressed) will glide consuming almost no power from gas or electric motors.[3]

Speed and acceleration
Maintaining an efficient speed is also very effective in keeping mileage up. Optimal efficiency can be expected while cruising with no stops, at minimal throttle and with the transmission in the highest gear. For most cars these conditions are satisfied at a speed of approximately 35 miles per hour although, this is below the minimum permitted on most roads that have no stops. Therefore, maximum efficiency is obtained while driving the minimum legal speed on a freeway. When accelerating, the engine should be kept in the peak of the torque curve, this is usually at around 75% throttle. A slow acceleration is less efficient. Brakes are designed to dissipate energy and should be avoided whenever possible.

Fuel choice
The efficiency of a gasoline engine is related to the fuel's octane level. Differences in cleaning agents between brands of fuel and between loads of unbranded fuel can also have a noticeable impact. Drivers may also weigh the fuel efficiency of multiple fuels for flexfuel vehicles and diesel vehicles, as the use of biofuel can result in marked changes in fuel economy in the same engine.

Edmunds discusses how much fuel can be saved by changing driving habits

Test #1 Aggressive Driving vs. Moderate Driving

Result: Major savings potential

The Cold Hard Facts: Up to 37 percent savings, average savings of 31 percent

Recommendation: Stop driving like a maniac.

Test #2 Lower Speeds Saves Gas

Result: Substantial savings on a long trip

Cold Hard Facts: Up to 14 percent savings, average savings of 12 percent

Recommendation: Drive the speed limit.

Test #3 Use Cruise Control

Result: Surprisingly effective way to save gas

Cold Hard Facts: Up to 14-percent savings, average savings of 7 percent

Recommendation: If you've got it, use it.

Test #6 Avoid Excessive Idling

Result: More important than we assumed

Cold Hard Facts: Avoiding excessive idling can save up to 19 percent

Recommendation: Stopping longer than a minute? Shut 'er down

Edmunds tests show tire pressure and air conditioner usage are not that big a factor.

A lot of links on the end of this article about optimizing MPG for a 2006 Jeep

August 06, 2007

Comparison Energy returned on Energy invested

Wikipedia on (EROEI) energy returned based on energy invested.

In physics, energy economics and ecological energetics, EROEI (Energy Returned on Energy Invested), ERoEI, or EROI (Energy Return On Investment), is the ratio of the amount of usable energy acquired from a particular energy resource to the amount of energy expended to obtain that energy resource. When the EROEI of a resource is equal to or lower than 1, that energy source becomes an "energy sink", and can no longer be used as a primary source of energy.

This an important issue because oil used to have a very high energy return on energy invested but it has been falling. Those who forecast a bad energy future claim that this EROEI will fall to cause a collapse or irreversible decline of civilization. If there are replacement energy sources with good EROEI then the claims of a future energy catastrophe are debunked. I think the doomsday scenarios of all fuel falling below EROEI 1 or longterm unending decline scenarios are wrong. We should and will do more to fix energy sources and infrastructure and we have the money (46 trillion in international bonds, 6 trillion more each year, plus about 33% of worldwide 45 trillion GDP in government federal, state and local taxes) and resources to do it.

Here is a chart of energy sources with their energy returned based on energy invested. The sources and dates of the studies are listed. The list was compiled by the nuclear energy regulatory agencies, but the sources can be referenced for methodology and assumptions.

The nuclear industry claims energy return ratios of (diffusion enrichment) 17.5 and
(centrifuge enrichment) 58.

The assumptions do not include that about 80% of reactors are being extended to 60 years of usage instead of 40 years and that current operating efficiency is 90% and not 80%.

The environmental activists claim that the EROEI for nuclear is only 5 to 1. 5 times as much energy as invested. Another Green environmental source is conserve magazine

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