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Posted

Hi all,

 

I was thinking the other day about applications for sunlight and I remembered seeing videos like this:

 

 

Which made me wonder why we're not using devices like this to cook food or drive steam turbines to produce electricity in places like Africa.

 

Am I missing something really obvious?

Posted (edited)

Am I missing something really obvious?

You miss that people are greedy.

This device can be sold just once. Then customer has energy for "everything".

But when he/she buy normal electric/gasoline/oil engine, he/she has to pay, pay, and pay, every day for fuel, or electricity.

 

ps. This device the easiest is to make using old satellite dish. It has proper curvature. Cover it with glue. Shatter (or cut in pieces) mirror. And glue them to dish.

Or cover satellite dish with aluminium food foil.

Edited by Sensei
Posted

You miss that people are greedy.

 

And also TresJuicy misses that most are lazy to do anything that takes more than only pushing buttons, day or night, rain or cloudy, for the relentless pursuit of comfort, in exchange of paying.

So preference is pushing buttons that cost money while sitting in front of a TV scratching 'tonsills' in comfort with a cold beer.

 

In current use, as many others selling pushbutton comfort----> https://en.wikipedia.org/wiki/PS20_solar_power_plant

Posted

I'm from Scotland. What is this solar power thing? You haven't fallen for this nonsense that there is a sun out there somewhere, have you?

Posted
I'm from Scotland. What is this solar power thing? You haven't fallen for this nonsense that there is a sun out there somewhere, have you?

 

Have to agree with you i'm from Ireland and haven't seen the sun today maybe it is on vacation...

Posted

I'm from Scotland. What is this solar power thing? You haven't fallen for this nonsense that there is a sun out there somewhere, have you?

 

There are an inordinate amount of Solar Global Warming denialists from Scotland.

Posted

Aside from political and financial reasons, are there any reasons that this wouldn't be easily implemented?

 

As it has been implemented, I assume there are no insurmountable technical problems. I guess it is mainly a matter of cost, efficiency, etc.

Posted

OK, let me rephrase that: is there any reason this hasn't been implemented on a larger scale?

 

As a small, mass-produced device for personal use, it's pretty dangerous. You have to convert the raw heat to electricity to be more useful than just heating water, and anything that gets in the way of the beam (flaming birds?) represents a fire hazard. As a large, facility-sized device, I think they already do something like this with solar panels, focusing the light that comes in for greater efficiency. Sky Fuels is fairly close to me, and has some impressive products.

  • 1 month later...
Posted (edited)

I'm from Scotland. What is this solar power thing? You haven't fallen for this nonsense that there is a sun out there somewhere, have you?

 

Danish island Samsø did.

"Now 100% of its electricity comes from wind power and 75% of its heat comes from solar power and biomass energy"

https://en.wikipedia.org/wiki/Sams%C3%B8

And it's not so far from Scotland. You have daylight too?

Edited by haram
Posted

There isn't one best renewable technology. Consider Earthships (off the grid buildings) to be efficient per $ for homes and some other buildings. They typically use solar panels and batteries to run appliances, but heating and cooling the building is done without equipment, similar to adobe houses but better. If every house was an Earthship perhaps 15% of the world's energy budget would be renewable. in addition, the world needs energy for transportation, businesses and industry. Wind and solar panels are good for a big percentage, perhaps they take us to 75%. The about half the remainder is needed for nighttime use, so solar thermal with heat storage or PV with batteries can supply power day and night. The percentages used are not fixed; they depend on the cost of installation and maintenance of various technologies when renewable power plants are built, because technology costs and usage patterns change over time.

Posted (edited)

About solar furnaces from beginning of this thread, they can have variety of applications:

 

"USES:

The rays are focused onto an area the size of a cooking pot and can reach 4,000 °C (7,230 °F), depending on the process installed, for example:

  • about 1,000 °C (1,830 °F) for metallic receivers producing hot air for the next generation solar towers as it will be tested at the Themis plant with the Pegase project[5]
  • about 1,400 °C (2,550 °F) to produce hydrogen by cracking methane molecules[6]
  • up to 2,500 °C (4,530 °F) to test materials for extreme environment such as nuclear reactors or space vehicle atmospheric reentry
  • up to 3,500 °C (6,330 °F) to produce nanomaterials by solar induced sublimation and controlled cooling, such as carbon nanotubes[7] or zinc nanoparticles[8]

It has been suggested that solar furnaces could be used in space to provide energy for manufacturing purposes.

Their reliance on sunny weather is a limiting factor as a source of renewable on Earth but could be tied to thermal energy storage systems* for energy production through these periods and into the night.

 

SMALLER SCALE DEVICES

The solar furnace principle is being used to make inexpensive solar cookers and solar-powered barbecues, and for solar water pasteurization. A prototype Scheffler reflector is being constructed in India for use in a solar crematorium. This 50 m² reflector will generate temperatures of 700 °C (1,292 °F) and displace 200–300 kg of firewood used per cremation."

 

https://en.wikipedia.org/wiki/Solar_furnace

 

 

*such are solar thermal power plants Andasol:

https://www.rwe.com/web/cms/mediablob/en/1115150/data/0/1/Further-information-about-Andasol.pdf

and Ivanpah:

http://breakingenergy.com/2015/06/17/ivanpah-solar-production-up-170-in-2015/

and many others, experimental or commercial:

https://en.wikipedia.org/wiki/List_of_solar_thermal_power_stations

- advantage of those facilities, compared to photovoltaics, is that they can store Sun's energy in thermal form during cloudy periods or night.

 

 

Tremendous power of the concentrated sunlight:

 

 

Another variant, middle-sized system -solar powered Stirling engine:

https://en.wikipedia.org/wiki/Solar-powered_Stirling_engine

http://www.real-world-physics-problems.com/stirling-engine.html


There isn't one best renewable technology. Consider Earthships (off the grid buildings) to be efficient per $ for homes and some other buildings. They typically use solar panels and batteries to run appliances, but heating and cooling the building is done without equipment, similar to adobe houses but better. If every house was an Earthship perhaps 15% of the world's energy budget would be renewable. in addition, the world needs energy for transportation, businesses and industry. Wind and solar panels are good for a big percentage, perhaps they take us to 75%. The about half the remainder is needed for nighttime use, so solar thermal with heat storage or PV with batteries can supply power day and night. The percentages used are not fixed; they depend on the cost of installation and maintenance of various technologies when renewable power plants are built, because technology costs and usage patterns change over time.

 

Agreed. Choosing the most appropriately tec depends on many factors... for instance, in Denmark is better to harvest wind energy, in Arizona direct sunlight, in many coastal areas best choice are OTEC plants*... and that energy could be stored on several vays (mechanical, thermal, chemical...) which all can affect on effectiveness and costs.

 

 

*https://en.wikipedia.org/wiki/Ocean_thermal_energy_conversion

 

 

===============================================

 

 

There is another interesting, but not well examined idea yet.

 

Why waiting winds to blow, why depending on their fluctuations? Why not artificially make them? It's an old idea, which was revived by a canadian inventor Louis Michaud - and Atmospheric Vortex Engine, or Tornado Power Plant, was born. :D

The idea is to collect the heat, whether from Sun or from waste heat of some industrial facility, transform it in steady air motion, and amplify to tornado-sized controlled whirlwind. So far, smaller scaled experimental models given the proof of the concept.

 

http://news.nationalgeographic.com/energy/2015/12/151204-louis-michaud-breakthrough-tornado-energy/

http://vortexengine.ca/index.shtml

 

 

 

 

In fact, that is a variant of solar updraft tower/solar chimney, but without expensive and fragile tower.

https://www.youtube.com/watch?v=eE4B3YCo5Vo


Also are some huge steps maked in artificial photosynthesis

http://nocera.harvard.edu/SolarEnergyConversion

http://newscenter.lbl.gov/tag/artificial-photosynthesis/

and using ammonia (which can be produced cheaply using renewable energy) as a fuel is an old fact

https://en.wikipedia.org/wiki/Ammonia#As_a_fuel

Edited by haram

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