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.