Solar Wind Energy Tower: A Hybrid Solar-Wind Energy Technology Gets The Official Nod

Replies

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  Rajni Jain

  Great to see that Solar Wind Energy Tower Inc. had got an approval for the Solar Wind Downdraft Tower.
  
  My thought is even though the tower has the capacity of generating 1250 megawatt / hours, and an average of 435 megawatt / hours. Still, Can a county or state be fully dependent on this for the usage. Arizona is one of the warmer state of USA, and generally sun shines through out the year. Still what about the rainy / winter seasons?
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  Satya Swaroop Dash

  Rajni Jain

  Arizona is one of the warmer state of USA, and generally sun shines through out the year. Still what about the rainy / winter seasons?

  Yes, finally someone raised questions about its feasibility. 😀
  And the answer to your question is: Yes, it does but in low quantities.
  The company's statement is as follows:
  

  Under the most recent design specifications, the Tower designed for a site near San Luis, Arizona, has a gross production capacity on an hourly basis, of up to 1,250 megawatt hours. Due to lower capacities during winter days, the average hourly output per day for sale to the grid for the entire year averages approximately 435 megawatt hours/hr.

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  Rajni Jain

  Under the most recent design specifications, the Tower designed for a site near San Luis, Arizona, has a gross production capacity on an hourly basis, of up to 1,250 megawatt hours. Due to lower capacities during winter days, the average hourly output per day for sale to the grid for the entire year averages approximately 435 megawatt hours/hr.

  I read that earlier as well,
  However my question was average has gone down significantly by >60% that suggests that atleast 2-3 months they may not be producing electricity or in very less amount.
  
  So if Arizona will be dependent on this plant (solely👀), then how come they will be getting electricity during the winter and rainy season?
• 

  Void Runner

  Rajni Jain

  then how come they will be getting electricity during the winter and rainy season?

  Note that this is a power plant that operates on vapour absorption cycle to create motion in turbine to generate electricity. It is a solar thermal, not solar photovoltaic, power plant.
  
  Unlike solar photovoltaic systems which directly convert photons into electric current, solar thermal systems work on heat generated due to IR radiation from the sun. Materials can easily be constructed which store heat easily and conduct heat easily. It is likely that the heat-up rate difference during rainy seasons is compensated by the enhanced wind energy and speed on such days. As such, sensible heat storage systems such as a collection of pebbles in a tank also work to extract heat by passing water through it. The process always occurs, the rate of the process changes as per the weather conditions. At no point will the plant stop producing electricity, and using heat storage systems, it is quite possible to regulate the rates.
  
  To ensure a consistent output to the consumer, all generated electricity can be stored in battery banks - the generated current thus charges the battery bank which delivers the actual power to the user via transmission lines.
  
  Source: Engineering Physics major 😀
• 

  pinank

  Void Runner

  Note that this is a power plant that operates on vapour absorption cycle to create motion in turbine to generate electricity. It is a solar thermal, not solar photovoltaic, power plant.
  
  Unlike solar photovoltaic systems which directly convert photons into electric current, solar thermal systems work on heat generated due to IR radiation from the sun. Materials can easily be constructed which store heat easily and conduct heat easily. It is likely that the heat-up rate difference during rainy seasons is compensated by the enhanced wind energy and speed on such days. As such, sensible heat storage systems such as a collection of pebbles in a tank also work to extract heat by passing water through it. The process always occurs, the rate of the process changes as per the weather conditions. At no point will the plant stop producing electricity, and using heat storage systems, it is quite possible to regulate the rates.
  
  To ensure a consistent output to the consumer, all generated electricity can be stored in battery banks - the generated current thus charges the battery bank which delivers the actual power to the user via transmission lines.
  
  Source: Engineering Physics major 😀

  battery banks!! you are suggesting to store 1250MW of electricity in batteries!
  This is economically not at all viable! See the generators will be producing AC electricity. Now to store such huge amount of energy firstly you will require huge battery banks.Thus increasing the cost of the entire power plant! Also it has to be noted that batteries have their own life time which is 5 years if you use the new technology lithium ion ones. Secondly, Converting AC to DC would require converters as well as inverters (to convert DC-AC). Converters use thyristors valves, again increasing to the cost of the overall plant!
  Hence batteries is a bad option.
  
  As per the viability of the project, I have concerns with the output power the plant will generate during winter or rainy seasons. Agree the output will be drastically low, but taking the return on investment and the total project cost, it would be a challenge for Solar Wind Energy Tower Inc to supply electricity at low cost! Arizona being a desert state, the radiation from sun is pretty high, so using PV cells is more advisable. Arizona has around 12 hours of bright sunlight. So it will definitely be a challenge to supply cheap power.