Hybreds for Green Energy No. 4

It seems that Solar Energy and Wind Energy is catching on among those who can afford it. The cost of solar is coming down and the efficiency is going up. Soon, Solar Energy's cost will soon reach the $0.50 per watt that will make it competitive with commercially produced energy. The same is true, too, for Wind Power but at a lesser extent. There is, however, still one more roadblock that makes both clean energy sources less viable. Solar Cells produce no electricity unless the sun shines and Wind Turbines require the wind to blow. For those times when the sun does not shine and the wind does not blow at least at 8mph, expensive battery systems are require or one must buy electricity from the commercial producers or both.

There is a solution. If the fuel cell, in particular, the Solid Oxide Fuel Cell is used, then one can find complete independence from the commercial electrical power companies, from expensive foreign oil, and from the greenhouse gases that plague us today. With this schema, one can still use his already existing solar cells. But rather than powering his home directly, he/she would use the sunlight to produce hydrogen through electrolysis of water. The produced hydrogen would be stored along with other gases to fuel his/her SOFC. The Solid Oxide Fuel Cell is actually is an almost hands off and maintenance free continuously operating electric power source that runs on a multitude of fuels, all of which can be produce by the home owner.

I would like to propose two skid units, one containing the electrical equipment modules and one containing biomass fuel modules. The modules should be manufactured to several sizes to accommodate a multitude of budgets and physical space requirements. The primary electrical skid would be sized for the modest budget at a basic 3 KW output, with the exhaust heat produced to drive a steam boiler that would service the hot water, heating and cooking needs of the home plus providing the possible process needs of the biomass fuel skid. From this modest size, one can scale up to 5 KW, 10 KW, and beyond to supply a whole community with low cost clean electric power.

The biomass skid will also be designed for a modest budget with up-scaling for larger biomass input. THe basic design should include the use of household wastes including bathroom and kitchen wastes. The bio-digester module for the household wastes would produce a 50-50 mix of methane gas and carbon dioxide. If one wishes, the carbon dioxide can be scrubbed, however, since the CO2 is organically derived, it will be greenhouse gas neutral and safe to allow in the atmosphere. The liquid waste, effluent, from the bio-digester will contain some alcohols and should be sent to the vacuum still module for further processing. All yard and garden wastes would be put into the biomass precondition module where is will be batch treated with enzymes and boiled to extract the starches and sugars. The solids from the precondition module would be sent to the syn-gas reactor module that would use the high temperature steam from the SOFC exhaust boiler (800 to 850 C). The starches and sugars would then be transfered to the fermenter module. The liquids of the fermenter would be supplied to the boiler section of the vacuum still module to extract the alcohols (methanol, ethanol, propanol, butanol, and their isos). Since these are fuel alcohols and not fit for human consumption, the federal alcohol taxes should not apply but a federal alcohol still license should be obtained. The solids from the fermenter will also go to the syn-gas reactor module. All the syn-gas and bio-digester gas will be stored in the 500 to 1000 gal. SOFC input tank on the electrical skid. The alcohol production will be stored on the fuel skid's 50 gal. liquids tank with any access to be sent to the SOFC input tank.

All the fuel produced here are usable to fuel the SOFC. The SOFC is able to reform each of the gases and alcohols for its own uses, with the exhaust being water, carbon dioxide, some nitrogen, and 800 to 850 degree C (1475 to 1560 degrees F) heat. When condensed, the water in the exhaust is pure and safe for human consumption. If fact, the condensed fuel cell water on our space shuttle and space station is saved for use as drinking water for the astronauts. The exhaust water from our SOFC should to into a holding tank for our own use in preference to ground water.

I am too old, at the end of my life, on social security and too poor, or I would actually design and build these skids myself and use them as a demonstration. If anyone wishes, please do sue this process layout and do the design. I suggest, however, that the design follow all of the OSHA regulations, that a process and mechanical flow diagrams be created and used in a thorough hazards analysis prior the construction of the skids and that competent engineers be employed for each phase from the design of the home or retrofit to the home, the installation of the skids and with the start-up of the modules. As we move from fossil fuels and into the hydrogen economy we must take care that we do not cause harm to ourselves and that we might actually enjoy our new found freedoms.

Hybreds for Green Energy

It is time to update again:

After continuing to research the subject, it is still quite clear that the keep to clean(er) energy to run our homes, farms, and factories will come from the use of fuel cells and in particular, the Solid Oxide Fuel Cell. Both Acumentrics and Siemens are preparing to develop such fuel cells in the 5KW range. Both have submitted briefs to the DOE for approval and both will quite affordable, selling at around $2,000 to $5,000 per unit. The units will also be produced for safe installation, complete with hook-ups to the fuel source and directly into the electric grid. Both Siemens and Acumentrics Units are fully capable of using and internally reforming Methane (pipeline natural gas), propane, alcohol, and bio-fuels. They do, however, require the removal of any sulfur from the fuel stream prior to entering into the fuel cell.

As for the use of solar cells and wind turbine, these are still limited and too costly for the average home owner. Solar panels are rapidly increasing in efficiency, but still sell in the price range of $3.00 to $5.00 per watt. Also, they produce electric power only when the sun shines. The most effective use of solar electric power is to store the electricity produced in some sort of battery system. I propose that the solar power be used to disassociate hydrogen from water, releasing the oxygen into the atmosphere, and inserting the hydrogen into the natural gas pipeline feed to the fuel cell generator. http://www.distributed-energy.com/hydrogen_generation.html is an excellent source for Hydorgen generation for this purpose. This can be done best by placing a tank of about 500 gal. just before the fuel cell. Since the natural gas is at low pressure and the hydrogen is produced up to 200 psig, as the hydrogen is produced, it will displace the natural gas and some of the hydrogen will likely be safely back-fed into the pipeline for others to use.

It is important to understand, too, that the conditions and relative cost of wind turbines is essentially the same as that of solar cells. The difference is that the cost of maintaining a wind turbine is high, after all , it is a mechanical device, and the wind turbine must have a constant wind at a minimum of 8 miles an hour to be effective. I see the wind turbine and the solar cells as being a primary source of hydrogen for use in the Fuel cell and not as the primary producer of home electric power. Eventually, the natural gas pipelines will be converted into hydrogen pipelines. In the mean time, the efficiency of the SOFC, up to 90% if used in co-generation, will markedly reduce the greenhouse gas emissions. In addition, the waste heat produce by the SOFC can be used for home heating and cooking.

So, let's step forward now and insist on our hybrid, the true "high-bred", green energy built home.

Hybreds for Green energy

More news updates:
It continues to appear that the SOFC running on hydrogen filtered from Natural Gas is still the best and most economical option for electrifying our homes, be it a new home or as a retrofit for an existing home. However, there are other options for producing the Hydrogen. The problem is that the options for Hydrogen production, all of them in a state of development. All of the methods are, to date, expensive. Usually, too expensive for the home owner/builder to seriously consider. It looks like the heart of our electrification, the SOFC, will run us as much as a new car, somewhere in the $10,000 to $20,000 area. But keep in mind that there is a payback. Our 5kw unit will supply us with all the electric power we need with some left over for our neighbors, thus saving us our currently high monthly electric bills. There is, also, some payback from the State and Federal governments, too, in the form of subsidy and grants for switching to green energy.
There is one more bonus for using the SOFC. It operates as +/- 50% efficiency at a 800 degree F exhaust temperature. This is hot enough to produce high pressure steam to drive a steam turbine driven generator, thus increasing the total efficiency to near 90%. The water that is condensed is pure and drinkable or can be used as the feed water for a hydrolysis hydrogen generator; more on this later. The water condensing process can also heat water for our household hot water and for home heating, too. Thus, our efficiency goes up to near 95%. These benefits and the multiple fuel capabilities is what makes the chosen tubular SOFC so attractive. As we move toward the Hydrogen economy but still needing the carbon fuels, the increased efficiency alone reduces the greenhouse gases released into the atmosphere.
Let us now consider some other options for producing our fuel of choice, Hydrogen. This will quickly show why getting our Hydrogen from Methane at this time:
Our governments, federal and local, have embarked on a campaign to put Hydrogen into a pipeline system for distribution. This is very feasible, safe, and the most logical idea. Hydrogen in the natural gas pipeline is far safer than the current Methane being distributed now. Methane is heavier than air and settles into pockets as it mixes with air and produces a very powerful explosive mixture, one spark an BOOM, you house is gone. Hydrogen, on the other hand is the lightest of all the gases and quickly rises high into the atmosphere as it mixes with air. The mixture then reacts with sunlight to produce water but is not likely to be explosive nor would it likely find a spark to ignite it if the explosive mixture is achieved. so, until our natural gas pipelines are filled with hydrogen, we will be able to use the methane to give us our hydrogen.
Another method for producing our hydrogen is to use solar cells to drive a Hydrolysis Hydrogen Generator. Distributed Energy Systems has just a system already available. Their system includes not only solar cells but wind turbines, too. The one drawback is, however, they are pointing to the PEM fuel cell rather than the SOFC. I am sure that this is an easy fix, however. The real problem is the costs of the solar cells, the wind turbines which are for windy locations, and for the hydrolysis units. I can see the solar cell/wind turbine/water hydrolysis as a added on scheme for later uses and/or for areas where the Natural Gas/Hydorgen pipelines are not available. One more problem with this method is the storage of the hydrogen. It can be put into tanks with pressures up to 200 psig, stored with metal hydrides and/or in nanotubes that are being developed now. But all of these methods add cost to our home system and we need the least expensive method. Otherwise, we will be stuck with using the fossil fuels we are forced to use today.
There are still more methods for producing hydrogen in development, but none of them hold much promise for mass production or hardware store availability. It is important to note, however, that the SOFC does operate on bio-gases and alcohols, too. These bio-gases and alcohols are also an important source of hydrogen, having more hydrogen per carbon atom than does water have per oxygen atom. Also, the alcohols are normally liquid and even mixed with water up to 50% can be used as a motor fuel as well as a fuel cell fuel.