? about magnifying lens/parabolic mirrors steam turbine electric generator

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Discussion Overview

The discussion revolves around the feasibility and theoretical framework of using magnifying lenses or parabolic mirrors to evaporate water into steam for powering a turbine and generating electricity. Participants explore the potential power output, cost comparisons with solar panels, and the efficiency of heat engines versus photovoltaic cells.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that each square meter of collecting area could capture 1kW of solar power, raising questions about the efficiency of converting that energy into mechanical power.
  • Another participant questions the specific formulas needed for calculations related to the proposed system.
  • There is a discussion about the cost-effectiveness of solar heating generators compared to solar panel arrays, with one participant noting that heating is generally cheaper but heat engines are not.
  • Participants mention government feed-in tariffs in the UK, which incentivize small-scale solar energy contributions to the grid, although there are concerns about the overall profitability of such systems.
  • One participant shares a personal experience regarding the costs associated with integrating solar power into their energy usage, indicating that fees may outweigh potential savings.

Areas of Agreement / Disagreement

Participants express differing views on the efficiency and cost-effectiveness of solar heating versus photovoltaic systems, with no consensus reached on the best approach or the specific formulas needed for calculations.

Contextual Notes

Participants have not fully resolved the assumptions regarding the efficiency of heat engines compared to photovoltaic cells, nor have they established a clear framework for the calculations needed to evaluate the proposed system.

Who May Find This Useful

This discussion may be of interest to individuals exploring renewable energy technologies, particularly those considering solar thermal systems versus photovoltaic systems for electricity generation.

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Ok here's an idea that isn't a perpetual motion machine (it's no more perpetual than solar cells):

Using a big magnifying lens or parabolic mirrors, what are the formulas when either of them are used to evaporate water into water vapor steam to move a turbine to power an electric generator?
 
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To get an idea of the upper limit to the power that such a device could transfer, each metre square of collecting area would capture 1kW of solar power. If you could focus the radiation to produce a nice high temperature then you could perhaps think of getting a small fraction of that in mechanical power. I have a feeling that PV cells would do better; heat engines are not the best way of transferring energy if there is alternative.
 
Sohpie, do you know what the cost comparison is between a solar panel array and a solar heating generator producing equal power?
 
Heating is cheap but a heat engine is not.
And the feed in tarif is good.
 
sophiecentaur said:
Heating is cheap but a heat engine is not.
And the feed in tarif is good.

Feed in tarif?
 
An 'in joke'. The UK government makes the electricity supply companies pay a laughably high rate for small scale feeds to the National Grid.
 
sophiecentaur said:
An 'in joke'. The UK government makes the electricity supply companies pay a laughably high rate for small scale feeds to the National Grid.

I think the power company here does the same thing to people who want to tie their own power into the grid as well. I looked into it and it turned out that I would be paying more just in fees than I would make up for by adding enough solar power to cover 50% of my average power use.
 
In the south UK, if you have no shadows, then you are very much in profit over several years - if the governmen its word.t keep
 

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