More technical... hydrogen car

[rhetoric]

http://www.youtube.com/watch?v=tt1uN38EcoQ&mode=related&search;=

This is the supplemental video about Steve Strizki's hydrogen power car. REALLY lame video quality, but toward the end you get a bit of flavor for his political side (not that he's some political nut job) -- he's just making it clear that the obstacles are not technical. The impression you get reading around is that the only way we could ever be "off the grid" is to have solar and hydro and wind and gerbils running around in little cages, etc.

 

[rhetoric]

By the way. I normally chafe at the little titles websites give us for X number of posts ( they are dopey and just seem to reward people being big mouths), but "burning chunk?" That's cool. I'd be happy just to remain a "burning chunk" for the rest of my posts at the hearth!

 

[jjbaer]

http://www.youtube.com/watch?v=tt1uN38EcoQ&mode=related&search;=

This is the supplemental video about Steve Strizki's hydrogen power car. REALLY lame video quality, but toward the end you get a bit of flavor for his political side (not that he's some political nut job) -- he's just making it clear that the obstacles are not technical. The impression you get reading around is that the only way we could ever be "off the grid" is to have solar and hydro and wind and gerbils running around in little cages, etc.

The problem with hydrogen is that you have to get it......1) crack fossil fuels to get it (there's that old Middle East reliance again), 2) crack it from water (need large amounts of electricity which may be better used to charge batteries), etc..........

 

[rhetoric]

Well, in fact this guy isn't. If you watch the other video you'll see that solar panels on his shed roof (58 panels) generate 160% of his home's energy needs -- the rest he uses to make hydrogen to get his home through the winter (when solar is less than 100%) and to run his car.

 

[KeithO]

I'm afraid that his ROI is not very good though. If you add up the cost of all of the toys, he could be living in Hollywood for less money.

The solar on its own is OK. He could lose half the solar instalation and still have more than enough to heat his home and provide the power requirement. He could also build a water tower that the solar fills every day and acts as Hydro every night, that would be a lot more efficient than conversion to Hydrogen or charging batteries. Buying a Prius is a lot cheaper and safer and better return on investment than his freaky hydrogen car.

We really have all the technology needed for all of our needs right now. We don't need hydrogen and fuel cells and their cost will insure that they more than likely will not make it to mainstream even in my lifetime. We could today import smaller cars than what anyone is prepared to sell in this market that achieve Prius like efficiency with "old technology" just by scaling down to the bare essentials. The nice thing about it is that it is cheap too. Just that pesky MANDATORY requirement for air bags and crash test safety to block the imported 4 wheel competition....

I see people driving around my neighborhood in golf carts, but its illegal to use them for commuting. At the same time its OK to ride a moped or scooter and in many states you are not even required to wear a helmet ? Why the double standards ?

 

[Corey]

The sad thing about solar is that the cells don't make themselves. There used to be an old wives tale - something to the effect of "it takes more energy to make a solar cell than it can generate in its lifetime" I think new materials have shifted this balance somewhat favorably to the net energy gain side, but for solar cells to be really effective, we would need solar steel mills and solar construction equipment that produce solar powered solar cell factories.

Corey

 

[jjbaer]

I'm afraid that his ROI is not very good though. If you add up the cost of all of the toys, he could be living in Hollywood for less money.

The solar on its own is OK. He could lose half the solar instalation and still have more than enough to heat his home and provide the power requirement. He could also build a water tower that the solar fills every day and acts as Hydro every night, that would be a lot more efficient than conversion to Hydrogen or charging batteries. Buying a Prius is a lot cheaper and safer and better return on investment than his freaky hydrogen car.

We really have all the technology needed for all of our needs right now. We don't need hydrogen and fuel cells and their cost will insure that they more than likely will not make it to mainstream even in my lifetime. We could today import smaller cars than what anyone is prepared to sell in this market that achieve Prius like efficiency with "old technology" just by scaling down to the bare essentials. The nice thing about it is that it is cheap too. Just that pesky MANDATORY requirement for air bags and crash test safety to block the imported 4 wheel competition....

I see people driving around my neighborhood in golf carts, but its illegal to use them for commuting. At the same time its OK to ride a moped or scooter and in many states you are not even required to wear a helmet ? Why the double standards ?

I drove a Scoda diesle in Norway (made by the Checz I think) and it got 50 mpg (I measured it several times throughout Norway). None to be found in the USA!!

 

[KeithO]

Corey, I'm personally suspicious of that old wives tale. But be that as it may, when you compare it to the alternatives (NG, Propane, Heating oil, Coal etc), these other fuels never ever "manufacture" anything, ever. Neither do the heating devices or cars that you power with the fossil fuels. It is simply a one way ticket. There is a lot to be said for anything that makes power for 10+ years without needing much of anything except being kept clean. I think anyone who can use water as a power storage medium will save a lot of long term cost and aggravation compared to batteries. Batteries are still a limited technology that has a relatively short lifespan and low power density. If one goes with the water storage, one can use both wind and solar and any excess pumps water to fill a reservoir. Clean and efficient.

The sad thing about solar is that the cells don't make themselves. There used to be an old wives tale - something to the effect of "it takes more energy to make a solar cell than it can generate in its lifetime" I think new materials have shifted this balance somewhat favorably to the net energy gain side, but for solar cells to be really effective, we would need solar steel mills and solar construction equipment that produce solar powered solar cell factories.

Corey

 

[rhetoric]

Remember that the title to the companion thread (the problem is political, not technical) asserts that our lack of clean energy is political/economic, not technical. We have the technology to do something besides burn fossil fuels -- or at least to burn way less. We just don't have the political willpower.

Of course solar panels are expensive. So are octave mandolins. They are rare. Rare things are expensive. But start mass producing the things and the price of anything will come down. Make a guitar and you use way more wood and etc, but they are cheaper because there is a bigger market. Now that Honda is mass producing solar panels and now that a barrel of oil is over $90.... The price of solar panels will come down (like laptops, calculators, etc...). The really smart people (and people w/ capital) start selling things for LESS than they can make them for, banking on the fact that the price WILL come down (demand and manufacturing innovations).

The guy's home is, in many ways, an experiment. An expensive and "impractical" one. But that's what people said about horseless carriages. Then Henry did some thinking and now we are the car-nation. The big problem, keitho, is that if we wait until it's ecomically viable (and we get a "return on our investment"), we may all be toast.

In a sense, he is storing energy in H2) -- he's just using the H. But I'm curious about the water storage method you're talking about (KeithO). What do you mean?

 

[Nofossil]

When you boil it down to its essentials, there are three basic problems:

1) How do you create energy?
2) How do you store energy?
3) How do you change energy from one form to another?

The answer to the first is pretty simple - either nuclear fission here on earth, or nuclear fusion in the sun. With the possible exception of geothermal, I don't think there are any other significant sources.

The second two are tied together. Storing energy is a big problem. If you want to store it for a long time and carry it around with you, a reversible chemical reaction is about the only way to go. Plants to a horribly inefficient job by using fusion-derived energy to break apart carbon dioxide into carbon and oxygen. Us wood-burners can carry around that latent chemical energy, store it, and release it by reversing the reaction in our woodstoves.

Solar cells generating electricity to break water apart into oxygen and hydrogen is a similar process. More efficient than plants, but MUCH more expensive. Hydrogen is a b*tch to store and carry around, too.

You could also store energy as potential kinetic energy. If you use energy to lift something, you get the energy back when you let it fall. They built a huge hydro plant in Northfield Massachusetts that would pump water from the Connecticut river to a lake up on a mountain. When they needed electricity, they let it flow back down through turbines to generate power. A giant battery, if you want to think of it that way.

Some smart people are playing with artificial photosynthesis - using sunlight to directly produce a reversible chemical reaction.

Automobile engines are just really complicated devices for transforming chemical energy into kinetic energy (motion). Electric motors are much simpler and more efficient IF you have electricity available. Of course, you have to make the electricity....

Energy density is another dimension. One of the attractive things about gasoline / diesel fuel is that it's easy to transport and carries enormous energy per pound and per cubic foot. Batteries, hydrogen, and other techniques don't come close at this point.

Fusion based energy in the form of sunlight is also very low density. It would take a LOT of panels to create the same amount of energy that's stored in a tank of gas - especially up here where the sun is low in the sky this time of year and it's cloudy a lot.

I meet 100% of my hot water needs in the summer with solar panels. After mid-October, I drain them - there's almost no usable energy to be had.

That leaves me with only two choices - stored fusion energy (I have a pile of it under my deck), or fission energy from my neighborhood nuclear plant. Note that coal and hydro plants are just converting stored solar energy. In the case of hydro, the heat from the sun causes water to evaporate and rise up into the atmosphere. When it falls down, some of it lands at high elevation where we can exploit its potential energy.

 

[KeithO]

Here is a schematic on the "water battery". It is powered electrically, either by a solar array or by a wind turbine or both.

During the day, when solar yield is at its peak, the array will generally yield far more than that household consumption is (if you have a high efficiency home). Anything in excess of what is consumed on a minute by minute basis is directed to the water pump, which pushes water "up the mountain" into the high level storage tank. Elevating water is simply storing potential energy. The only losses in the system are from the resistance of the wires and the small amount of heating that takes place in the pump and from friction losses along the length of the pipe.

An ideal system is vertical, just like every towns water tower. The formula for potential energy is m*g*H where m = mass in kg, g = 9.81 and H = the difference in height that the water is lifted. So here is how the math works: Assume that the average solar array output from 8am-4pm is 3kW. Lets also assume that during that period the home power consumption is 1kW. That leaves 2kW "spare". 2000W will apply a force of 1Nx2000m or 2000N x 1m or any combination that yields a result of 2000 in 1 second. Lets assume for simplicity that our storage tank is elevated 100ft or 33m. So dividing 2000 by 33 we get 60.6 and dividing this by 9.81we get 6.178kg (or liters) of water that can be lifted 100 ft per second. Just a bit less than 2 gal/second or about 120 gal / min.

By understanding the power requirement of the house at night, one can "size" the storage tanks appropriately. To store a full days worth of water with the example above would need a storage tank holding 46k gallons. But if you are able to double the height of the storage tank, you can cut its size in half for the same energy storage. Now putting 80 tons of water on a structure 200 ft tall doesn't sound like everyones cup of tea, nor cheap. But, depending on the situation with your aquifer (pressure) it may not be neccersary to have a high tower. One could instead "lift" water from the aquifer at 200 ft below ground level, and at night "return" it down the well into the aquifer, while spinning the pump.

To be fair, the power numbers quoted in the above example are over the top. Looking at my last energy bill, I consumed 545 kwh for the month of September. I have 1800 sq ft of finished home with another 800 sq ft of garage (in the basement). Since there are 720 hours in a month, that means that my average household power consumption is 0.75kw (and that was with the air conditioning running more than 12 hours per day). Assuming a power consumption of 1kW and assuming a 200 ft deep well, a storage tank with a 15 ft diameter x 9ft deep would more than suffice to store more energy than could be used in an entire day.

Folks living in mountainous areas may find it entirely practical to build a reinforced concrete tank up on the hillside, it all depends on the terrain. Town folk would need to have a "communal" project, with dedicated supply and demand lines to a dedicated watertower. The "net metering" principle could be applied to both outgoing and incoming lines to measure whether you made a contribution or were only consuming power.

I'm sure this is not a thorough explanation, but hope you get the idea. The "hydro" companies do this exact thing just on a much bigger scale.

 

[wg_bent]

When you boil it down to its essentials, there are three basic problems:

1) How do you create energy?
2) How do you store energy?
3) How do you change energy from one form to another?

The answer to the first is pretty simple - either nuclear fission here on earth, or nuclear fusion in the sun. With the possible exception of geothermal, I don't think there are any other significant sources.

The second two are tied together. Storing energy is a big problem. If you want to store it for a long time and carry it around with you, a reversible chemical reaction is about the only way to go. Plants to a horribly inefficient job by using fusion-derived energy to break apart carbon dioxide into carbon and oxygen. Us wood-burners can carry around that latent chemical energy, store it, and release it by reversing the reaction in our woodstoves.

Solar cells generating electricity to break water apart into oxygen and hydrogen is a similar process. More efficient than plants, but MUCH more expensive. Hydrogen is a b*tch to store and carry around, too.

You could also store energy as potential kinetic energy. If you use energy to lift something, you get the energy back when you let it fall. They built a huge hydro plant in Northfield Massachusetts that would pump water from the Connecticut river to a lake up on a mountain. When they needed electricity, they let it flow back down through turbines to generate power. A giant battery, if you want to think of it that way.

Some smart people are playing with artificial photosynthesis - using sunlight to directly produce a reversible chemical reaction.

Automobile engines are just really complicated devices for transforming chemical energy into kinetic energy (motion). Electric motors are much simpler and more efficient IF you have electricity available. Of course, you have to make the electricity....

Energy density is another dimension. One of the attractive things about gasoline / diesel fuel is that it's easy to transport and carries enormous energy per pound and per cubic foot. Batteries, hydrogen, and other techniques don't come close at this point.

Fusion based energy in the form of sunlight is also very low density. It would take a LOT of panels to create the same amount of energy that's stored in a tank of gas - especially up here where the sun is low in the sky this time of year and it's cloudy a lot.

I meet 100% of my hot water needs in the summer with solar panels. After mid-October, I drain them - there's almost no usable energy to be had.

That leaves me with only two choices - stored fusion energy (I have a pile of it under my deck), or fission energy from my neighborhood nuclear plant. Note that coal and hydro plants are just converting stored solar energy. In the case of hydro, the heat from the sun causes water to evaporate and rise up into the atmosphere. When it falls down, some of it lands at high elevation where we can exploit its potential energy.

Gas may have a lot of energy density, but gas engines are horribly ineffieient. Electric is a lot more efficient. Even if we used highly efficient and small diesel engines to keep batteries charged, and fun the car off electric, that would be more efficient.

 

[Corey]

Keith - you bring up a good point. I simply wanted to show that solar power is far from free. If we have to burn a 10 ton pile of coal to refine sand into silicon, assemble the cells and create all the infrastructure to run them, then the cells finally generate an energy equivalent of a 12 ton pile of coal before they die, we have netted a little energy, but far from ideal.

Your water battery has some merit, but even that has quite a few stages - even if you assume everything is 90% efficient, it still starts to eat into your total. Solar Cells > power regulation, power regulation> electric motor, motor>pump, pump>stored water, stored water>turbine, turbine>generator, generator > power regulation. I count at least 7 steps to store the energy and get it back out. .90^7 = about 50%. Suddenly everything needs to be a little larger.

 

[Nofossil]

The sad thing is that efficiency is poor for almost all forms of energy conversion. In KeithO's excellent illustrated example, it's unlikely that you could get a pump that would give you a sustained efficiency greater than 50% over the range of operating conditions. Add a little piping loss and assume a conversion efficiency of 50% when you turn the potential energy back to electricity, and you might only get back 20% of what you started with - not to mention that the solar cells are probably less that 10% efficient at turning sunlight into electricity in the first place. This means that you get 2% of the original sunlight back as usable electricity at the end.

The good news is that lots of smart people are working on improving all of these numbers. There are pumps now that are 90% efficient, and solar cells that are 40% efficient. Photosynthesis itself is less that 10% efficient at transforming sunlight into stored chemical energy. However, we can retrieve that energy with better than 80% efficiency.

For cars, the real challenge is the combination of conversion efficiency and storage density. A diesel driving the wheels directly is more efficient than a diesel driving a generator driving an electric motor driving the wheels, but the electric subsystem provides the possibility of regenerative braking as well as running from batteries which can be in turn charged from some more efficient source.

I'm hoping for an order-of-magnitude leap in battery technology - 10 times the power per pound.

 

[KeithO]

Some info on the energy payback for PV systems

http://en.wikipedia.org/wiki/Solar_cell#Four_generations_of_development
Start quote
Solar cells and energy payback
In the 1990s, when silicon cells were twice as thick, efficiencies 30% lower than today and lifetimes shorter, it may well have cost more energy to make a cell than it could generate in a lifetime. The energy payback time of a modern photovoltaic module is anywhere from 1 to 20 years (usually under five)[9] depending on the type and where it is used (see net energy gain). This means solar cells can be net energy producers, meaning they generate more energy over their lifetime than the energy expended in producing them.[10][9].[11]

End quote

9 = http://www.nrel.gov/docs/fy05osti/37322.pdf
10 = http://jupiter.clarion.edu/~jpearce/Papers/netenergy.pdf
11 = (broken link removed to http://www.csudh.edu/oliver/smt310-handouts/solarpan/pvpayback.htm)