Saturday, April 30, 2011
Where is the Future?
While still playing with the opensource charts, I made this one of the RSS global surface temperature data. There is nothing really special about RSS, it just is a smaller data file that is easier to play with. The linear regression for the three plots extends to the year 2100 (2097 actually, I set the scale so that 1998 shows up better.)
My main thing with this blog is hydrogen and alternate energy. The only reason I have any of these climate charts and other climate stuff posted, is that climate change, aka global warming, is one of the reasons hydrogen as a transportation fuel is being considered. Except for saving the planet, hydrogen is pretty limited in most cases. It is costly to develop and risky to use.
More people using hydrogen drives the cost for electrolysers, fuel cells and storage mediums down. Without mass production, hydrogen for residential power storage is just an expensive hobby. The data in the above chart shows why entrepreneurial hydrogen use and production development is lagging. Governments can do a lot to compel citizens to use certain products. Governments though are inefficient. Entrepreneurs, are the real drivers of any capitalistic country. The entrepreneurs that make the best products are smart enough to know when to pull the trigger. The above chart scares the alternate energy guys to death.
The chart indicates the drastic impact of human caused global warming is greatly over estimated. The chart doesn't prove anything, it just is an indication that climate change is not an immediate concern. Without an immediate concern, the entrepreneurs that are investing their own money or reputations are not ready for the risk. There are still niche markets, but they seriously limit the potential profits. Too many players for not, what appears to be, a rapidly expanding market.
Ballard Power and their partner Plug Power have a decent niche which could be some what rapidly expanding. The new battery cars, Chevy Volt for example, have serious limitations. 30 miles to a charge will not appeal to a very wide customer base. It is basically a toy for the wantabe green crowd and government motor pools. The general American public wants a car that gets at least a 200 mile range, is bigger which is assumed to be safer and convenient refueling. Ballard Power's FC Velocity fuel cell for use in material handling is a good upgrade for the Volt battery pack. Even with the cumbersome fuel storage tanks for compressed hydrogen, a Ballard Power upgrade can deliver the 200 mile range and peppy performance. Refilling though is still an issue limiting the potential of the upgraded Volt.
I mentioned before that the Honda Home Hydrogen station was a natural gas reforming unit. Molten Salt fuel cells are designed to run on natural gas, natural gas and propane are much easier to locate now for refueling, so why bother with the Proton Exchange Membrane fuel cell manufactured by Ballard if you have no access to inexpensive refueling? None really.
A molten salt fuel cell for a vehicle is a little more complicated than the PEM. While the molten salt fuel cell generates electricity it generate a lot more heat. That heat, which is a high temperatures (over 500 C) would require co-generation to dissipate the heat and generate more of something while it is at it. A small gas turbine driven generator is the most likely co-generation. Depending on the temperature range and heat available, a turbine using say a refrigerant for its gas, could generate electricity using the waste heat of the natural gas fuel cell. It is entirely doable, but the extra complexity means higher initial cost, more risk for the consumer and higher maintenance cost. So doable or not, it ain't likely to happen. This goes right back to the matter of scale, utilities with government subsidies may give it a go, but consumers needing a cost effective alternative will still be screwed. Without a hydrogen infrastructure, the Volt, Ballard Power and my dreams of a hydrogen RV are dead.
The Home Hydrogen Stations I was counting on could cost less than $4000 with over 100,000 units per year production and less than $2500 a year with 250,000 plus units per year. Manufacturing scale is a really big deal. Right now, you would be lucky to find a high pressure, water splitting home unit for less than $50,000 dollars. If the greens really wanted to put their money where their mouth is, they should be more involved in strengthen this weak link.
There are a number of low pressure PEM based electrolysers that can be used with extra value added design to make home refueling units. Then, low pressure hydrogen production is not exactly rocket science. Dangerous Laboratory's design looks complicated, but that can be tighten up fairly easily. Also, some of the idiots playing with HHO or Brown's gas aka Oxyhydrogen, have some homemade systems that could be modified to produce reasonable quality hydrogen. It is all in separating the anode gas O2 from the cathode gas H2. A fairly easily made plastic part could separate the gas streams. Porous nickle anodes and cathodes with an alkaline electrolyte (KOH) can produce lots of hydrogen reasonably inexpensively.
What is reasonable inexpensive depends on you power source and your needs. Wanting the highest efficiency is admirable, but getting the job done with affordability is the ticket. In the island home example, forty percent efficient is more than acceptable. After spending $10,000 for a 10 KW solar array another $10,000 for storing energy in not a big deal. The cost for gge (gasoline equivalent gallon) can be over $6, but in the island house case, transporting, storing and convenience are worth it when gasoline is damn near $5 a gallon at the fuel dock now. I can make the same case for the RV of the future. No way can I do it for the Tahoe FCV.
Interestingly, with the Island Home or the RV of the Future, I may be able to make a case for a FCV boat or a FCV convenience vehicle for the RV. More likely, a hydrogen fueled Internal Combustion Engine (ICE) would be better despite the lower efficiency.
So now the focus needs to be on reasonably affordable hydrogen production. Since we need pressurized hydrogen, the compressor is the one component that has to be absolutely right. I am fairly confident that the metal diaphragm pump will prove to be the best for overall safety and efficiency.
A multistage diaphragm pump doesn't have a lot of moving parts. Reed valves direct the gas flow and are not very complicated. The diaphragms are flexed by a rotational motor shaft with cam lobes. That is about it, the cam lobes push on the center of the metal diaphragm to displace the gas volume forcing the gas out of the discharge reed valve while the intake reed is forced closed. When the diaphragm relaxes, the discharge reed closes and the lower pressure opens the intake reed valves. The discharge of a lower stage is piped to the intake of the next stage. Simple and elegant design with no piston rings or lubrication required in the gas stream. Just to make the pump last longer, teflon coated metal diaphragms would be nice. The teflon would absorb the energy of the tiny hydrogen molecules reducing damage to the metal diaphragm. The cams and motor shaft can be lubricated outside of the gas stream or oil free shaft to cam surfaces can be used. A non-sparking electric motor adds to the cost, but not significantly. The motor can be either really beefy for higher flow, higher pressure, or not so beefy for low flow, medium pressure. The cost of the storage tanks is a limiting factor. 4500 to 5000 psi is the maximum cost effective pressure currently for storage, with the 3000 psi range considerably more affordable.
The 3000 psi range for storage also extends the life of the unlined storage tanks. Aluminum cylinders (tanks) have a burst pressure nearly twice the 3000 psi range. So the wall thickness is great enough to handle the constant bombardment of the active little hydrogen atoms at medium pressure for a reasonable number of years. As a guesstimate, approximately ten years, so figure eight years to allow a safety margin.
For the Island Home, the size of the electrolyser is not very important. It is more important for the RV of the future. Considering that, I will start looking at electrolysers designed for 4 kw input power (the rough size of the RV of the Future solar array) and a total space required of 4 cubic feet. A target efficiency of 50% will be used but after all the what ifs, 30% to 50% will probably be enough to justify the design.
That 30% to 50% range will drive most mechanical engineers nuts. After conversion to useful energy, the actual system efficiency would only be 15% to 40%. They can handle the 40%, but 15% they would laugh at. Remember though, we are using fixed cost solar energy. Any power not used is lost, so recovering 15% of something wasted can be a big deal. We have to compare the initial cost, weight, maintenance cost and replacement cost of batteries plus the cost of energy conversion from stored battery energy to useful work. Some of the work we may want, transportation, is a key factor.
So I am off to research affordable ways to make hydrogen under medium pressure. I have seen a lot of websites with big promises, but are there any that really have the goods? With a $10,000 budget and $6 gge goal, let's see if it is doable today.
- Where is the Future?
- Our Hydrogen Home - Is it Worth it?
- The Trends?
- Scale Matters
- That Simple Greenhouse Effect
- It is Time to Pull the Trigger on Synfuels!
- More on that Whacky Tropopause
- More Natural Gas Pains
- Nuclear Power Thoughts with Fukushima in Mind
- Future Farming in Fukushima Prefecture
- The Zonal Potential Temperature plot above is fro...
- Things that Go Bump in the Twilight
- More on the Greenhouse Effect
- Sensitivity To Radiation - Things We Find When We ...
- That Silly Troposphere
- What the Frack! Now They Quibble About Natrual Gas...
- Even More Radiation Stuff From Japan
- Livin' in a Spherical World
- What's Going On?
- More on the Troposphere Sink
- How Did I Screw Up My Energy Budget Answer and Wha...
- My (incorrect) Answer to the Energy Budget Puzzle
- The Energy Budget Puzzle
- How to Take Something Simple and Really Complicate...
- Pondering Climate Change
- The Wind and the Pickens' Plan
- Back to the Future - Hydrogen Power Motor Coach
- So Where Did the Back Radiation Go?
- Fuel Cells, Electric Drives and Other Fun Stuff
- My Fuel Cell Tahoe
- More on Fukushima Response
- The RV of the Future
- More on Synthetic Fuels
- ▼ April (33)