The need for Non-polluting Power.
     Environmental concerns have brought focus to the need for non-polluting power. Collecting energy from sunlight allows the generation of power without creating any type of air, water, or earth pollution. This is the primary factor for selecting solar-thermal steam electric power production.

 The need for a system that does not require fossil fuel in any respect.
      Several hybrid systems are being used that use fossil fuel to upgrade the quality of the produced steam. Fuel up to 25% of the output is being used as in the case for parabolic trough line focus power plants. This produces pollution and green house gases. Other systems use fossil fuel to keep the energy transport medium (salt) in a molten state during periods without sun. This heating requirement also produces pollution and green house gases. The tower of power system at Daggett California has this problem. 

 The need for high temperatures and its relationship to high concentration ratios.
     When considering thermal cycles that can be used for power generation, the efficiencies of such cycles are related to the temperature differences inherent in the cycle. Therefore it is desirable to achieve high temperatures. Parabolas of revolution can focus direct sunlight so that temperatures at the practical limit for efficient storage and electrical generation can be achieved. 

 The need for separating energy collection from generation can only be done if storage is possible.
     The need to separate energy collection from power production is a key to provide continuous uninterrupted useable energy especially from renewable resources. It is also true of power production from expendable resources. For example, coal is mined and transported (energy collection) and then power is generated when needed by combustion of the coal at a later time. 
    Separating energy collection from power generation is accomplished by a thermal storage vault that stores thermal energy until needed for power generation. Wind and photovoltaic systems are generally referred to as sporadic power sources because they supply power at the same time they collect the power whether it is needed or not. 

 The need for clean power versus intermittent power and the problems of intermittent power on grid control. 
    The hidden costs of keeping standby power in place in case the wind stops or the sun does not shine have not been considered. In fact, if a large portion of power comes from wind or other intermittent power generations sources it becomes very hard to keep the grid from galloping out of control as it did in the country of Denmark, if there is not an equivalent amount of dispatchable power on standby.  

 The need for reasonable power tariffs from solar power.
     Costs of the plant are the dominant portion of the tariff calculation. Plant costs for delivering power from Photovoltaic arrays is very high for a given annual output. Since the fuel cost is zero for solar power plants that do not use auxiliary energy from fossil fuel, the other cost that is included in the tariff calculation is maintenance and repair. For a location with excellent direct sunshine, such as Lhasa, Tibet, the annual electrical power supplied by one CENICOM cluster is 12,300,000 KWHrs. electrical per year.