The Future of Solar Energy
Off-Grid - Combined Heat and Power Concentrating Photovoltaics
Bradford J. Snipes, Solar Engineer
offgridtexan.net bradford.snipes@yahoo.com

We are downstream of peak oil. As the world's finite oil supply of petroleum is further depleted and the world's demand for oil continues its relentless increase the cost of energy derived from it's combustion will obviously begin to increase at an even more rapid rate than it has in the past
Historically, the cost of energy has been increasing at the exponential rate of about 5% per year. If governments gain control of the energy sector through proposed Cap and Trade mechanisms, they will take money from the fossil fuel industry and give a portion to renewable energy companies, especially companies that feed into the Grid. This would be beneficial to the solar energy industry in the short term, but it will be disastrous for our economy. About 60% of our electricity comes from coal burning power plants. If they are penalized for carbon dioxide emissions they will only pass the burden of the carbon tax to the consumer. Electricity rates and gasoline prices will skyrocket. Do liberals really want this?
Besides, to disprove the junk science of global warming is easy. Historical temperature data prior to 1985 was very meager. Plenty of weather stations collected data for the industrialized areas of the world but data for the oceans and the continents of Africa, South America, was almost nonexistent.
Even today, they could not determine the true average temperature of the world within ½ of a degree without a reasonable margin for error. Think about it, all data would have to be collected and analyzed instantaneously and there would need to be much more data collection in the oceans and undeveloped regions of the world. As an engineer having some knowledge of thermal processes, I cannot accept their conclusions nor can I condone their manipulation of the meager data set.
I am not at all concerned about global warming. I am concerned about a government takeover of the energy sector. I want the solar energy industry to be independent of government control as we end the Age of Fossil Fuels and begin the Age of Solar Energy and a hydrogen Economy.
The present focus of the renewable energy community is obviously to provide electrical power to the grid. But, the most beautiful aspect of solar energy is that it has already been distributed by God. It offers the possibility of energy independence and self-sufficiency to individuals. Why should we feed solar electricity into the Grid for subsequent redistribution? Energy independence and self-reliance is only possible with off-grid or micro-grid renewable energy systems.
The recent advent of multijunction solar cells makes a new approach to the collection and utilization of solar energy possible. These solar cells have the capability of receiving concentrated solar energy and are almost 3 times as efficient as conventional roof mounted solar cell arrays.
A Bradford Collector positions a cylindrical array of Boeing Spectrolab dense array solar cells at the linear focus of a multi-segmented conical reflecting concentrator. This cylindrical array is enclosed within glass cylinder which acts as a secondary refracting concentrator to focus all available energy onto the active solar cell area only. Using this two-step optical concentration, 1000 Suns of solar concentration is delivered to the solar cells. Assuming the reflectance of the conical reflecting surface is 90% and a transmittance of the glass refracting cylinder is 90%, the efficiency of the optical concentration system is about 81%.
The Spectrolab multi-junction solar cells convert 40% of the solar energy they receive to electrical energy. The remaining 60% of the solar energy is converted to heat and must be removed to prevent thermal degradation of the solar cells. Accounting for the optical concentration efficiency of 81%, a Bradford Collector will convert 32% of the available solar energy to electricity and about 48% of the available energy to thermal energy.
Inside the secondary cylindrical glass refracting concentrator, the dense array solar cells are bonded to a flat sided octagonal metal tube . Boiling of water is caused to occur by spraying water on the interior surface of the tube. The resulting low pressure steam may be used for Multiple Effect Desalination of Seawater, Ammonia absorption air conditioning, home heating or hot water. A 32 ft diameter collector will provide about 110 kWh of electricity and sufficient steam to produce about 400 gallons per day of 140 OF distilled and about 2 tons of absorption air conditioning. An off-grid home using this collector will be completely energy self-sufficient.
On a larger scale, solar farms of Bradford Collectors will provide electricity at a cost which will make its use for the electrolytic production of hydrogen practical. As gasoline prices continue to increase, hydrogen can be expected to be the future automotive fuel of choice. A tremendous potential market exists in providing the hydrogen refueling infrastructure. The low pressure steam produced by these solar farms can be used for the multiple effect distillation of seawater.
So, as a fortunate byproduct of the hydrogen production, very large amounts of distilled water will be produced. Enough water will be produced to irrigate thousands of acres of new farm land.
It can be shown that, 32 foot diameter Bradford Collectors may be placed about 50 feet apart with minimal shading. Seventeen Bradford Collectors may be placed on each acre of land with minimal shading. So the expected daily output per acre of a Bradford Collector farm, on the Texas Gulf Coast or South Texas, will be about 1870 kWh per day, 6460 gallons of 140 OF distilled water, and 35 tons of absorption refrigeration or air conditioning.
The United States military is mandated to convert military bases to renewable energy. In particular, the Department of Defense is interested in micro-grid energy systems. If a black-out or brown-out condition exists with the conventional grid, military bases must not be incapacitated. It is a national defense issue. Texan Home Energy Solar Collectors can be used to economically make many United States military bases self-reliant.
The goal is the rapid proliferation of Texan Home Energy Collectors and associated systems.
As the use of solar energy supplants the combustion of fossil fuels many of the world's problems will be solved. Our dependence on foreign oil will be diminished and the waste of a precious limited resource as fuel will be reduced. The falsified fear of global warming will go away. It was completely trumped up anyway. It was never a problem.
But, more importantly, the rapid proliferation of this truly economical approach to solar energy collection will result in the creation of thousands of new jobs. The recession will end and we will enter in to a new age of prosperity, the Solar Age.