Comments on: California Wants to Draw Energy From the World’s First Orbiting Solar Farm

By: Steve Wahls

Steve Wahls — Thu, 23 Apr 2009 02:52:11 +0000

The earth gets all her energy from the sun. But only what strikes the side facing the sun if we add area in space that would normally allow energy to pass on by then the energy we would send down would increase the energy consumption by that amount and be a net increase in atmospheric temp. This method would be a more direct increase in global temp than any other method. Worst choice so far. jiriz is net right. Electricity gets turned into heat when we use it even when we use it to freeze a burger.

By: Lisette Root

Lisette Root — Fri, 17 Apr 2009 17:50:39 +0000

This concept is very interesting, but we need to get a handle on the growing problem of orbiting space junk first.

By: Adam

Adam — Wed, 15 Apr 2009 22:16:38 +0000

There won’t be a net heating because the rectenna receiver shades the ground below it more than the power it receives from space. Think about it a bit more.

By: veekie

veekie — Wed, 15 Apr 2009 12:39:43 +0000

Well, there’d definitely be indirect heating effects, and these can be cumulative if the sunlight captured would not have reached Earth normally(but not in a solar shade placement, where sunlight intensity on Earth is diminished by the obstacle).After all, the energy is converted to electricity and then lost as stray heat somewhere down the line. This is a linear warming effect though, not like the multiplicative one of global warming through emissions. In the short term, this should result in overall cooling until we get warming under control. Plus, the land it’d have otherwise used up on Earth can be put to other, constructive purposes.

By: Mark D

Mark D — Wed, 15 Apr 2009 09:21:45 +0000

Because you see the word “microwave” do you assume it’s heat? You are forgetting the other way microwaves work… it’s very easy to convert it into electrical energy (just like putting a fork or tin foil into your home microwave makes sparks. No, don’t do this.)

You can debate cost efficiency or lifetime of the solar cells, but it’s not debatable that this is a nearly 0% polluting energy source (I’m sure someone somewhere can argue about the rocket fuel or transmission problems)

By: veekie

veekie — Wed, 15 Apr 2009 06:12:21 +0000

Do it and have double duty as a solar shade then.

By: jiriz

jiriz — Wed, 15 Apr 2009 04:05:58 +0000

What is there in my post not to understand?

The solar farm will capture a lot of the sun energy (perhaps as much as 50%) that would normally NOT reach the Earth surface. That energy gets beamed to the surface and converted to heat.

By: Nick

Nick — Wed, 15 Apr 2009 03:30:11 +0000

Radio frequencies are light. Please see Wikipedia for a refresher on the electromagnetic spectrum. They’re just not a part of the so-called ‘visible’ light that we detect with our eyes. That being said, ionizing radiation is on the opposide side of the electromagnetic spectrum (with visible as the median) as compared to radio frequencies.

Honestly, there’s no magic bullet solution to this problem (power). A combination of things (small scale local wind/solar), treadmills and exerbikes that produce instead of consume energy (what a ridiculous idea, paying for a treadmill, and then paying for power to walk on it when it’s free to walk out the front door – at the very least make them self-powered), piezoelectric floors (and maybe even piezo wands that pull energy out of the wind), keyboards and mice (ever play a frustrating video game on your computer? you’ll get plenty of energy back out of that – especially if you’re a keyboard fist-slammer) and more efficient energy storage devices will be the only solutions.

By: Grant H

Grant H — Wed, 15 Apr 2009 02:32:52 +0000

Well, this certainly beats burning coal. I hope China take a liking to this idea, I reckon they’ve got the resources and funds to develop the tech and start making serious use of it.

By: Stefan

Stefan — Tue, 14 Apr 2009 19:37:29 +0000

Excellent comment,
That’s what I love about this site there’s always at least one informed opinion to counter ignorant posts.

By: David Colton

David Colton — Tue, 14 Apr 2009 18:41:39 +0000

1) Microwaves are radio waves. Clouds are largely invisible to them.

2) An array of large receiving dishes will easily capture the energy.

3) Security wouldn’t need to be any greater than any other industrial property. Actually less because nothing much will be worth stealing around them. .

4) The intensity of the microwave beams will be no greater than what is found on any mountaintop or building with microwave relay stations, and considerably less than is found in home microwave ovens. I’ve not heard of birds or insects getting cooked by open air microwave stations. The dishes will probably pose much less of a collision risk than tall buildings, towers, or bridges.

5) All construction requires concrete and security.

6) We wouldn’t need all this if the earth held a reasonable and sustainable 500,000,000 or less total population. Now, with our over 6,000,000,000 population, it will take all the ingenuity, industry, and infrustructure we can muster to avoid an ecological collapse and a population collapse. The USA would be affected as much as any other country. Millions of us would die violently and miserably in our cities if the power grid goes down, water transport over long distances stops, and food is no longer shipped in. For survival and the continuance of our civilization, we need all the clean electricity we can get.

By: M

Tue, 14 Apr 2009 18:38:56 +0000

more info:

http://en.wikipedia.org/wiki/Wireless_energy_transfer

By: M

Tue, 14 Apr 2009 18:36:26 +0000

jiriz: its radio frequencies that are being beamed down, not light.

By: John Ahlstrom

John Ahlstrom — Tue, 14 Apr 2009 18:06:10 +0000

From the URL: http://www.spaceenergy.com/i/pdf/safety_paper.pdf

SAFETY OF SPACE-BASED SOLAR POWER
Dr James Logan, NASA
Feb 2009

2.45 or 5.8 GHz 1 to 5 GW non-ionizing power.
(non-ionizing means not enough energy to ionize atoms or molecules)

Occupational limit 5mW/cm**2 General limit 1mW/cm**2

Beam size
Approx 2-4km wide.

Beam energy
Center 300 watt/m**2 or 30milliwatts/cm**2
(JKA: compare to 5milliwatts/cm**2 above)

Safety considerations
Except for maintenance personnel, human exposure
would not normally be permitted in these areas.
(JKA:But see size of beam above – 2-4km wide)
What about terrestrial animals – birds and bees he discusses.
How many cubic feet of concrete and how many armed guards are necessary
to “not permit” human exposure?)

Microwave oven leak energy
1-5milliwats/cm**2 5 cm from any oven surface

By: jiriz

jiriz — Tue, 14 Apr 2009 17:56:50 +0000

Let’s see: some of the solar energy hitting the panels would otherwise end up being reflected back into space by stratospheric particles and by clouds. Additional energy absobed by the panels would miss the Earth altogether.
Ergo, the solar farm will be a net contributor to global warming. Way to go, Schwarzenegger! Luckily uncle Al will be able to sell you some carbon credits.