Slashdot Mirror
(Solar) Power to the Masses
D3 writes "This report on a solar power tower (pdf) looks extremely interesting. Maybe one day we can have international power lines where all the countries with lots of sunshine provide power to the rest of the world? How cool would that be?" The NY Times has a good article on solar power in Japan.
Google link
PDF Mirror
Visualize the world of wine
...a use for global warming :-)
--This isn't a man who is leaving with his head between his legs.
Discover Magazine just did a story on something like this. Unfortunately the full story is only available in dead tree format. If you wait until next month the older article will be available. You can probably check it out at your Dentist's office like I did if you feel like getting a filling.
EnergyInovations is working on a small version. From the Discover article it discusses how they refined the stirling engine with the best tradeoffs of manufacturing costs to effiency. IIRC they are also making this small enough to make it fit on a roof top.
Geek fact of the day: A stirling engine is an external combustion engine that runs off the pressure created when one side of its engine gets very hot while the other side stays cool. The greater the temperature difference, the greater the pressure, the greater the energy generated.
I hope that someday we will be able to put away our fears and prejudices and just laugh at people. - Jack Handey
then more power to 'em!
Maybe one day we can have international power lines where all the countries with lots of sunshine provide power to the rest of the world?
Great idea, but power simply can't be distributed over that great a distance.
To make up for losses due to resistance in wires, they up the voltage to absurd levels -- decreasing the current level, and, in the process, the voltage drop over a long distance. However, this can only be taken so far, and towers supplying electricity to the rest of the planet is way too far.
In fact, I'm pretty sure that the continental US is too wide for coast-to-coast power sharing (that is, power generated in, say, New York, can only be "shipped" as far west as Indiana, or so).
On the other hand, replace today's wires with some kind of high-current, high-temperature superconductor, and you're golden.
...the US would takeover those sunny countries.
I don't know the percentages, but if you were to transfer power from say Mexico to Canada under this scenario, your energy losses would be huge.
"Learning is not compulsory... neither is survival."
--Dr.W.Edwards Deming
Will the sunshine nations (OSEC) collude to create artificial shortages and drive up prices in the sunless nations. Rolling blackouts, $700 power bills. The best part will be when they say its the fault of the sunless nations for having draconian environmental laws.
I'm really not this bitter in person.
"The plural of anecdote is not data." -- Roger Brinner
If governemnts subsidized people to install these instead of new shingles, this would severely cut down energy concerns.
Of course electric companies would complain, but they will still be needed, solar power won't provide enough power.
hmm...actually then my electric company would just charge more for less so they don't lose profits...damn
Gibble: Descriptive of an emotional state in which one's mind is scrabbling for some purchase on reality
ok so these people have a 17% electricity bill drop (from what to what in Japan?) after buying an 1100 sq. ft. home that has solar panels...
How much did having the solar panels on the home add to the price of an already expesive home? How much will the 17% save over the life of the home?
Are electric rates in Japan like they are here? 17% of my last electric bill (mind you, it's the summer and I have the A/C on at least 8 hours a day and a box fan in the bedroom on at least 10 hours a day) is $4.20 (granted my apt. is 720 sq. ft. instead of 1100).
International Power Sharing/Leasing/Selling is all well and good. However, I truely doubt that the large scale implied by the poster would ever happen. All cables are lossy. Pushing power along cables has energy lost, dependent mostly on how far you're pumping the juice. (Also, voltage, current, resistance of the wire, local EMFs, and all sorts of minor things too)
While it would rock to have clean energy finally adopted... Carting it across long distances still sucks.
Gimme Wind, Gimme Solar, hell, I'll even take Geothermal, just make it clean, unobtrusive, and if you'd like, I can sell you some good land in my back yard. *me mutters about pretentions NIMBY asses*
I assert that my comment is only my opinion, not that of any employer, past, present or future.
I'm sorry, I can't help but smirk and snicker when I think about the Japanese and their
"Solah Powah Towahs!"
*smile*
---"What did I say that sounded like 'Tell me about your day?'"---
We don't really need lines carrying solar power from sunny areas to the rest of the world. There are plenty of environment-friendly ways to generate power; solar in the sunny areas, hydro-electric in areas with lots of waterfalls, etc, windmills in the plains...
Availability of methods isn't slowing down alternative fule sources; people just see no reason to invest the necessary capital to change over, when burning dead dinosaurs is working quite happily.
Thomas Galvin
OK, we'll let Grapple build it, but if any Decepticons ask if they can help, just say NO.
It requires a complete re-think of the utilities infrastructure and removal of idiots that run them.
If a normal neighborhood had 2 stationary panels on each home's roof pointed south that backfed to the utility power and they did the storage, it could be a reality right now.
but it's easier to keep that 1929 Coal plant running and those power commisioners that have no fricking clue or care outside their pocket or circle of power than to change to current technology.
Anyone here can easily reduce their power consumption to 1/10th of what they use now. Couple that with a city wide solar network with some wind plants like in Macinaw city or out west and you can easily have clean power.
it's changing government, and the wasteful companies (running 1500 horse power pumps from 1955-1957 instead of buying noew high efficency pumps) that will be nearly impossible...
Changing to non polluting power will be more difficult than getting bill gates to embrace and use linux.
Do not look at laser with remaining good eye.
"Learning is not compulsory... neither is survival."
--Dr.W.Edwards Deming
Another obvious stirling use is as part of your home heating plant.
British Gas to launch individual CHP boiler for homes
British Gas has announced that it is developing a household boiler that generates both heat and electricity, which will increase energy efficiency and cut costs for customers, allowing them to sell excess electricity back to the Grid.
The new combined heat and power (CHP) boilers, developed by MicroGen Energy
Think about it. You burn gas to stay warm. (if you don't have a heating season....then you don't) Why not burn the gas to do work? You still get your heat. And the work can make electricity.
Australia is building big convection towers. They are just a big (big!) greenhouse sloping up in the center, so the hot air runs up what amounts to a chimney there, and drives a big windmill -- really, a bunch of them -- in the chimney. It has only a few moving parts, and is easy to build with mature technology.
Simple might not help employ physicists, but it's the right way to build.
How short our memories are.. When we get all that solar power the machines will start a war. We'll have to destroy the skies and move the survivors underground to Zion.
Trolling is a art,
I am not a EE, but having a power Co-Op as a major client I know there is a significant line loss (power loss) associated with transmitting power over long distances. There are also major financial, political and citizen factors to overcome when building new transmission lines. The technology looks cool. I think getting the power from a to b will be a bigger issue.
Great ideas often receive violent opposition from mediocre minds. - Albert Einstein
http://www.eere.energy.gov/csp/csp_tech.html Sandia actually did quite a bit of research on solar power towers. When Bush got into power, alot of the funding was taken away. Israel's Weizmann institute actually has a working power tower that is more advanced than the ones made at Sandia. http://wis-wander.weizmann.ac.il/site/EN/weizman.a sp?pi=420&doc_id=731
all i'm asking is for some prudence and a reality check before ecstatically proclaiming "Maybe one day we can have international power lines where all the countries with lots of sunshine provide power to the rest of the world?"
;-)
i think those sunny countries would rather exist than become giant solar panel farm fields for wasteful cloudy northerners
current power demands versus current solar technology efficiency: wouldn't that necessitate something like covering the whole sahara desert with solar panels?
nevermind the gargantuan investment in time and money to build the infrastructure to set this up... and wouldn't covering vast areas of the earth in solar panels have it's own environmental down side?
i mean, don't get me wrong, hydro/ wind/ solar is wonderful, but isn't the power output from these technolgies miniscule compared to burning hydrocarbons, as environmentally unfriendly as that is?
we need fusion man, pronto. i want my mr. fusion damnit!
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
You know, the author of the article would have more crediblity if he quit using phrases like "Berlin Wall of Solar Power" in the article.
Also buried in the article is the fact that this rig is so freakin' expensive to set up and so uneconomic to run, that only nations with massive subsidy programs are the ones looking at it. They are targeting Spain because they signed Kyoto and so the government (read taxpayer) is willing to underwrite the whole thing.
So, who wants to take bets on how long before environmentalists scream that we are destroying the planet by planting hundreds of thousands of square miles of mirrors across the Southwestern desert?
Have they figured in the cost of replacing sandblasted mirrors and the cost of trucking water in to clean the mirrors?
You can tell a great deal about the character of a man by observing those who hate him.
Answer:
Sure but it would suck.
The reason its so cold there is because what sunlight hits does so at an extreme angle.
Its hot at the equator because the sun is beaming straight down.
A square foot of ground in Mexico gets an order of magnitude more light energy hitting it than a square foot in antarctica.
Besides, it's pitch black 6 months of the year at either pole.
I don't need no instructions to know how to rock!!!!
I always wondered what that facility out in the middle of Kirkland Air Base was. It's quite visible when flying into Albuquerque. I thought that they were exerimenting with a way to shoot down terrorist planes using sunlight. (Imagine burning up a terrorist's plane over New York by training all the mirrored windows of the skyscrapers on it.)
Of course, burning up airplanes wouldn't work well at night.
Damn those countries with so much son,.. is there a way for us to replicate thier sun over our heads in washington,..
Yes we can, it take a really big parabolic mirror... but we will have to test the focus first on a city in your state... will Redmond do as a test target?
This post brough to you by the Linux for solar mirrors of doom in space council...
Do not look at laser with remaining good eye.
After reading the article, this plan to use sun-tracking mirrors to melt salt sounds a little more complicated than this Australian plan. Not only that, but the Australian plan scores more points in the coolness department as the project intends to build the world's tallest structure -- a tower 1 kilometer high. BTW, IANAA (I am not an australian)
http://www.powersat.com -- solar power arrays in space (no attentuation by atmosphere or weather) beaming power back to Earth using microwaves. SF author Jerry Pournelle (http://www.jerrypournelle.com) has been advocating these for years.
Brian
Remember Lexington Green!
How do they do that? I thought in England, the electrons went on the left side of the wire!
Hey kids, there's only 5 days left 'til Yak Shaving Day!
Does anyone else think that this is eventually going to end up as an imaginative way of killing James Bond? The villain will incarcerate Bond in the salt-melting room, give him a long, detailed lecture about his plans for world domination, make a sub-Bond witticism and then go away, explaining that Bond has until sunrise to live. Of course Bond will escape (using some sand-powered laser which Q has fortunately given to him) and the fat guy, sans cat we hope, will end up taking a bath in molten sand. Or is it just me who thinks like this?
Reality is defined by the maddest person in the room
--Home on Lagrange (The L5 Song)
(c) 1978 by William S. Higgins and Barry D. Gehm
"Reality is that which, when you stop believing in it, it doesn't go away." - Philip K. Dick
Possibly the best do it yourselfer magazine I have ever read is dedicated to renewable energy and guerrilla solar.
Home Power Magazine
Wax on, wax off baby!
get together in an undeveloped area, far outside the limits of the nearest city, and build something like this from the ground up? Not only will we have a working example of a radically different electric power structure, but think of the implications of a whole town populated with /. readers!
...
Umm... wait. Nevermind. Don't think of that.
Do not read this sig.
Solar insolation is about 1kW/m^2.. Well, except for the earths rotation. Assuming a non-tracking system, we have to divide by a factor of pi, so thats 300 W/m^2.. Well, except that the average efficiency of solar cells is under 15%, so thats 45W/m^2. Now, the average home has what? 2 people in it, and the per-capita electrical usage, averaged over the course of a year is 1kW. So, you need 2kW for that home, and only get 45W/m^2. So, you need 50 square meters of solar cell, correctly angled south. And this is the best case.
Now account for clouds and dirty cells. Unless you clean the cells every few days and pressure wash them biweekly, better increase the square meters of solar cells another 50%. So, thats 60-80 square meters of cell/house..
Now the next question. Where do you store all the energy you'll use at night? If you don't store it, where does it come from? Fancy burying a few ton flywheel in your backyard? How about aa closet filled with lead and sulpheric acid batteries? If you're going to use hydrogen to store it, better double or triple the square meters of solar cell for those inefficiencies.
The same problem applies to 'Solar 2'. You need about 1000 of them to equal the average energy of a nuclear power plant. And another 299000 to equal the mean energy used by the US. To replace all energy used in the US requires about a million Solar 2's.
The problem is not and never has been generating the power, the problem is storing the power. The power companies barely buy power from individuals; It costs several thousand dollars for the required hardware, and even then they pay you much less than you pay them for power.
So, how do I cheaply, safely, and non-annoyingly store electrical energy (in some form) and how do I get it back to being usable electrical power later? It's trivial to build wind generators using automotive generators, and build solar panels out of broken solar cells, and for that matter to build your own gas generators using alternators. They kick out 12V which is useful on its own, and you can always use inverters to spit out 110VAC or what have you.
If you get slightly more uppity you can build your own three phase alternators and use them to drive three phase motors, which are commonly used in machine shop equipment.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
I don't know much about microwaves, but this story at ABC News seems like a pretty amazing idea (Summary: cover swaths of the moon with solar panels and beam the energy back to Earth via microwaves). What's 150 billion in the grand scheme of things?
There'll still be the idealists who scream about defacing the surface of the moon, but it would be relatively low maitenance (no elements to damage the panels, except for the occasional meteorite) and wouldn't take up precious space here on Earth, where things can grow or live. As romantic as some of us can be, the moon is still just a big chunk of lifeless mafic rock.
Anybody actually have an idea how well this would work?
Hydrogen pipelines are nearly lossless, also hydrogen allows you to timeshift your production and use of electricity.
Hydrogen fuel cells are being oversold by many people, but this is one thing that they would be great for.
"I'll have a Guinness, no wait, make that a Coors Light" -Grad student I work with, who shall remain anonymous...
Even if technically feasible (others here think it is not, but cheap 'hot' supraconductors could appear tomorrow), rich countries have enough problems securing their oil supply, to add another dependency with power! It would be "logical" to put solar panels in Sahara to 'feed' Europe, but then Algeria, Lybia & so on would have the power to 'switch off' whole countries. I suppose the US would be solar-self-sufficient anyway, and Japan and Europe could put panels on the sea.
There is enough solar power, and wind power and geothermy, and tidal power, and nuclear (even oil or coal), even in winter, for each continent to provide its own energy. If only we REALLY wanted.
Christophe (Don't hesitate to point out my spelling and grammar mistakes, I want to learn - Thanks).
Small is Profitable by Amory Lovins of the Rocky Mountain Institute is about the benefits of generating your electricity using small, modular power systems where you need them. It turns out that grid infrastructure is often well over 50% of the cost of providing power, and that if you simply install systems like microturbines or small-scale combined wind/solar installations (explained below), you can significantly outperform the grid in terms of end-user price and capital requirement.
That's not a big deal here, where we already have a grid, but it's a huge, huge deal in the third world.
The combined solar/wind thing works like this. Electricity demands have a thing called a "load shape" - basically demand graphed against time. It turns out that solar energy supplies match the load shape of things like air conditioners pretty well, but when the clouds come out, your solar supply goes to hell.
However, wind systems work best when there's a sudden change in temperature, causing new low or high pressure areas, so usually cloudy days have ample wind. If you combine local solar and wind systems in a single "local area grid" you get a hybrid system which produces power in almost exactly the same loadshape as your actual demand, reducing expensive overcapacity, and with excellent availability in all weather conditions.
Renewable energy requires a lot more smarts than "this is a huge factory which produces megawatts a day" - you don't see nearly the full benefit unless you actually take advantages of the full range of renewable solutions, using factors like their modularity, size, loadshape matching, low capital requirements, grid independence and many other subtle factors.
Small is Profitable is a hard read: about 400 pages of really densely argued financial and technical analysis, but it's pretty much the definitive work in the area. If you want to know more, it's the book to get.
Hexayurt - open source refugee shelter,
I envision a future where PV homeowners can share their extra power with their neighbors through a P2P system... of course, the local energy company will call it "stealing" and attempt to sue those homeowners who are engaging in the theft from honest, hardworking oil companies.
www.homepower.com is a great site That always offer their current magazine as a free PDF download. Most issues will show several complete setups including diagrams, results, and pictures of several different types of setups. Just in the past I've seen solar, hydroelectric, thermal water heating, and recipies for making bio-diesal from waste cooking oil.
Chika Chik-ah... do-e ow ow.
Buy Steampunk Clothing Online!
Let's see. The article talks about 200 MW plant. At 1kW/m^2 and 17% efficiency this means we need about 300 acres of mirrors. Seems real practical.
You're missing the important point here. It's not that solar power is going to save the Japanese a lot of money. They're desperate to ween themselves off nuclear power using any means necessary. After all, if you had to contend with these three smashing your reactors on a yearly basis, wouldn't you be damn anxious to do something -- anything -- to stop relying on nuclear power?
GMD
watch this
Looking at our electrical bills over the last year averaging between $100 and $150 a month, I decided to look into putting in solar panels and here is what I found out.
For 7K out of pocket (after tax credits, rebates, etc.), I can get a 2KW solar panel system with grid tie installed. This would give me, conservatively, about 496 KW hours a month in production. This would cut my usage by 2/3s. For 12K out of pocket, I can get a 3KW system which would give me about 720 KW hours a month in production and would completely clear my needs.
With a grid tie system, I run my meter backwards when my production is greater than my demand. This means that any electricity that I generate is credited against my bill at the rate in play (I believe you also get peak pricing withi this setup) at the time I generate it.
Bottom line, is that for a 12K investment, I can clear an average bill of $150 a month. This means that in a little over 6 1/2 years I have paid off the system. Or you can think of this as giving me an annual return of 12.5% on my initial investment. That is pretty damn good!
But of course it is all far too late. If realistic predictions are anything to go by, world oil production will peak in the next decade and then begin to fall at about 2 percent per year soon afterwards. Even if the US started building wind turbines (the most promising renewable energy source) at a rate of 20,000 a year right now, there would still be major problems. As it is, it looks like everyone is going to carry on as usual until the energy shortages begin, at which point there will not be enough spare energy available to undertake a massive renewable energy building program. Given that more than 4 billion of the worlds 6 billion people are only alive because of the energy subsidy of fossil fuels, which allows chemical fertilizers and mechanised agriculture, the resulting resource wars and famines are likely to be very bad.
"No Blood For Sunlight"
"US forces secure African sunbelt, restore stability"
Doesn't anyone get it? Forget what the submitter tossed in, and the sunny-country factor, this tech is potentially the real deal for one reason:
STORAGE
That is, the plant they describe makes it possible to generate electricity any time, day or night, rain or shine. The only limit is that you can't run more than 13 hours without sun at one go.
This means you can throttle it up and down according to need like a real power plant.
According to their numbers (which aren't explained, but I assume are based on the 4 years they've been running the prototype plant) they can produce at $.05/kWh, which is below the retail price of electricity in the US, and probably much cheaper than in oil-hungry places like Japan. Also, since those costs are largely (wholly local) construction, land, and maintenance, sunny countries with low labor costs and some desert (India, Pakistan, Brazil, Mexico, Egypt, etc.) would realize an even better price.
Then there are circumstances they don't mention working in their favor, like:
World oil production is levelling off and may decrease if more easy reserves aren't found.
Natural gas supplies aren't as plentiful as hoped.
No one is building power plants at anything like the rate needed to keep up with demand, and
Nuclear is still politically untouchable.
Throw it all together, and a new plant that can produce at that price is a steal.
Now, if they could float the mirrors around an offshore platform, even the land costs would disappear...
"You can't get something for nothing." - my grandfather, on the stock market and Reaganomics.
Obviously, that isn't going to happen now, tomorrow or ever.
At the same time, using fossil fuels is clearly destructive and a Very Bad Idea.
So, we have to look at other non-carbon producing energy sources. Nuculer?
We could run breeder reactors that generate their own fuel - plutonium. Unfortunately, plutonium is also very handy for making really nastly bombs, and given the number of assholes in the world, this makes breeder reactors politically unfeasible for universal implmentation.
So, then regular nuke plants? There's only so much Uranium on the planet and it is a fairly limited resource. I saw someone on Frontline say that if we converted over to nukes for 100% of the world's power, we'd run out of Uranium in less than 30 years.
I'd also point out that we'd then be saddled with tons of nasty toxic crap that no one would want anywhere near them, and this nasty toxic crap will likely remain nasty toxic crap until sometime well after the next ice age. So, nuculer isn't going to do it to it.
But we still have to power up 15 or 16 terawatts of Mr Coffee machines, hair curlers, computers, and all kinds o' junk and useless nonsense we clutter our lives with. So WHERE is the juice going to come from?
1. by changing the needs base. removing automobiles from the fossil feul food chain by cracking water with solar energy to make hydrogen for hypercars will extend the life of fossil fuel energy production, and by reducing the demand for it, reduce its price.
2. by maximising efficiency of use. devices that use less juice will be at a great advantage in the market place when:
3. Energy markets are opened up to speculators who greedily distort energy prices to their own advantage, driving the need for greater efficiency to reduce dependency on the vampiric rat bastards.
4. Homes are made to be energy self sufficient. Getting people off the grid is the most important thing we can do to reduce energy consumption. when people have to pay for their own power and have to live on an energy budget, they will wildly seek out hyper efficient appliances, and this will encourage non-fossil fuel devices. It will also encourge people to sell energy back to the vampiric grid.
5. population reduction. We need to get rid of people. Gently and gradually. If we had one tenth the number of people roaming this shattered little planet, light use of carbon fuels (wood, methane, etc.) would even be permissible.
So, that's what needs to be done if we ever expect to have a sustainble future that includes something resembling an industrial civilisation. Get rid of people, make energy expensive, and make people responsible for their energy consumption.
RS
Shoes for Industry. Shoes for the Dead.
- a "typical" residential system (2.4kW AC peak output) is going to run $9000-12000 after the state rebate
- there's also a 15% state tax credit
- the utility buyback of power is called "net metering" and they actually pay the retail price for the power (i.e. they credit you for power you produce at the same rate they charge you for what you use)
As to one of the original, unaswered questions: if you don't have batteries (and you don't need them if you are grid connected), the only maintenance required is hosing off the panels a couple of times a year. The panels are warranteed for 25 years, and generally good for much longer.
"Research is what I am doing when I don't know what I am doing." -- Wernher von Braun
"Maybe one day we can have international power lines where all the countries with lots of sunshine provide power to the rest of the world? How cool would that be?"
You mean Saudi Arabia and Iraq? Damn, they have all the energy!
Opinions change daily as new information arrives. Stay tuned.
For utility installation, you need capitalizations of at most $2000/kW (comparable to hydro and nuclear power plant capital investment requirements) - wind is there now, but solar has some distance to go to be usable as a utility power source. Currently solar photovoltaic systems go for about $2.00/PEAK Watt at best; given night time, solar angle, weather effects etc. and costs beyond the PV cells themselves, that translates to a $8000 to $10,000/kW capitalization requirement right now. PV systems have been dropping in price by about a factor of 2 every decade lately, so we have likely 30 years more development before they will be competitive at the utility installation level.
A lot of this information is available from the Department of Energy's Energy Information Administration.
On the other hand, if the cost of putting stuff in space was low enough, you would get peak watts all the time with a solar power satellite, so in principle that could be a feasible utility option in the near future.
Energy: time to change the picture.
Well, There's always a chance someone on Slashdot doesn't know this, but... Global Warming / Cooling is junk science. The proponents have blocked appropriate measures of earth's temperatures, which involve measuring the ocean's aggregate temperature, and have done so for about a decade now. The measurement would have involved a solitary underwater explosion, and the sound wave would determine the ocean's temperature (although salinity has an effect, it is far from a trivial science). This would be a tremendous mass of ocean water.
The "Save the whales" crowd resurfaced decrying the untold damage to aquatic life by doing this, which is ridiculous compared to doing nothing to find out what is happening to our planet.
Air temperature measurements are a waste of time, especially in urban areas, which have an elevated measure of heat because of the asphalt roofs, roads, etc. Measuring the ice caps is also silly, because their size changes seasonally, like with weather cycles. Everyone remembers the Halloween blizzard in Minnesota. And the 65 degree day in late December 15 years later. The only useful measurement would be of a volume of water (not a tiny pocket of air) the size of the ocean, at the equator. But that's being blocked bye environmental activists; they must have something to hide; what's a few deaf gray whales if it will save the planet?
Did you bother to mention that the various "greenhouse gasses" are mere precursors to tropospheric ozone, which is the hazardous smog that is discussed at the Weather Underground ? All of the sudden, ozone is bad and good.
I read a statistic once that in order to be entirely solar with our power, we would cover the earth 11% over with the dumb cells. Considering the nasty chemicals involved in the manufacture of solar cells, and that solar cells are not simply recycled, and fail in a decade or so (fragile materials), I can't imagine why any earth-first crowd would want yet another major source of toxic waste.
I have long thought that the only solar cells of any use on our planet (since the stuff in space is pretty handy, I'll admit) are the green ones in my lawn and garden. They produce oxygen, which every living animal needs. If you live in a newly developed neighborhood (like in suburban USA), the best thing you can do for your environment is plant plenty of trees on your lawn. Sure, it means raking, but in my neighborhood, I have 100+ year-old oak trees, and they are positively enchanting. They keep the sun off my lawn so I don't have to water, and they keep the sun off my roof (remember, these are mature oak trees) which reduces my AC costs. McDonalds passes out seedling trees on Earth Day, so it really doesn't cost you anything. Sure, it'd make more sense if they passed them out on Arbor Day, but no one remembers when that is, despite it being the more venerable day of commemoration by a good century or more.