After decades dismissed as the province of sandal-wearing cranks, renewable energy - wind power, solar generation and the like - is being taken more and more seriously.
With global warming a mounting worry, a string of countries are investigating whether they can curb what President George W. Bush termed in February's State of the Union Address an "addiction" to oil and other fossil fuels.
Bush, perhaps more than any other leader, has repeatedly professed faith in scientists' efforts to make renewable energies viable. But is he right? There is a long way to go.
The most common 'alternative' energy source, hydro-electric power, amounts for just 2.15% of total global primary energy supply, according to data from the International Energy Agency. Wind power makes up 0.05% and solar less than 0.04%.
Growth in renewable sources, especially for anything other than electricity generation, remains slow, requiring major global efforts for them to have a meaningful impact.
Some proponents of alternative energies argue that technology is not the issue, given that most of the methods have been around for decades. Instead, they say, it is simply the political will that us lacking.
The main forms of renewable energy are:
Hydro-electric power: The longest-established alternative source - water wheels have been used for hundreds of years - hydro power accounts for almost a fifth of all electricity generated worldwide. Harnessing the energy contained in water flowing to a lower elevation, it is highly efficient but limited by the necessity of suitable natural sites. For example, mountainous Kyrgyzstan in Central Asia produces 90 percent of all its electricity by hydropower - not an option in, say, the Netherlands.
Solar: Sunlight contains many thousand times more energy than humans use but harnessing it can be expensive. The most common method, photovoltic cells, which turn light directly in electricity, work at a maximum efficiency of little more than 15 percent and are also expensive to buy. The few existing commercial solar power stations are huge - the biggest, in Southern California's Mojave Desert, covers 1,000 acres. An even bigger facility is being built nearby. Edison International's project uses mirrors to reflect heat onto Stirling engines, a near-200 year old design in which sunlight heats hydrogen, which in turn moves pistons to generate power. When completed the site will generate enough power for almost 280,000 homes.
Wind: The sight of massive wind turbines gently whirring atop a cliff or hill is increasingly common, particularly in parts of northern Europe, such as Germany and Denmark. However, such 'wind farms' have prompted a bitter divide among environmentalists, with some green campaigners arguing long ranks of turbines scar the countryside, can make noise and kill too many birds and bats with their blades. One alternative is to site wind farms offshore, but this makes them more expensive to maintain - not to mention a potential shipping hazard.
Wave and tidal power: Thus far a negligible contributor, with only a few mainly experimental sites worldwide. The most common prototypes use the kinetic energy of ebbing and flowing tides by trapping water in barrages, which then powers turbines.
Nuclear: Even mentioning nuclear power in the same breath as renewable energies is sacrilege to many environmentalists. But proponents argue that modern reactors are safer and more efficient than those used in the past, as well as being powerful enough to have a real impact on fossil fuel use.
Fossil fuels: Still more controversially, Professor Mark Jaccard at Vancouver's Simon Fraser University, insists oil, coal and gas are still the way forward. He argues that there are enough resources to last at least another 500 years and that burning fossil fuels more cleanly - for example 'capturing' carbon dioxide emissions underground - is the most feasible way of saving the environment.
Are renewable energies the future? What is happening in your country?
The underlying factor in this debate is environmental friendly energy sources. But the options in the third world are few. Partly because the safer sources have been looked down upon.
Let's go back to solar, wind and tidal waves forms of energies. They are available to all nations and will never be depleted. Let's compel our governments to adopt energy policies that will work for even those in the lower echelons. Those that are using carbon-fuels have a responsibility of maintaining carbon balance. Lest we do that, humankind will suffer.
Renewable energies can not only provide you with alternative energies, cutting on running expenditures, but can also prevent the world from being further polluted.
In India, though there are technologies available, but only a minimum effort is being taken to harness the power of renewable energies fully.
Much more can be done, in this sector, if better co-ordination and a will to transform is there. This should involve local people, make them realize the power of renewable energies and the benefits, they can get -- cost savings, pollution control.
Tamil Nadu is one of the states where wind power is exploited well. But India, being a nation getting a lot of sunlight, can better harness solar power.
I'm 13 and I don't want to have to grow up with global warming and other pollutants destroying our Earth, and when I have kids I don't want them to have to suffer because of what we have done now an in the past. Any solution to this problem is fine with me.
Renewable energies are the only future. Not much progress is being made, too much bickering on the political level, narrow-minded thinking on how or what forms of alternative energies are the most effective.
I feel ethanol is the wrong approach and more concentration should be put on buildings, using solar, windmill power.
Nuclear is too dangerous, especially now, and what are you going to do with the waste?
Communities should create programs (starting at the lowest level) and concentrate on better and more effective conservation methods. There are so many available tools in the conservation areas, it's just a matter of people from all walks of life getting together and getting the job done.
Simply, wind and solar and conservation. No need to complicate the issue with impractical solutions such as expensive -- and taking up earth space as well as pulling nutrients out of the soil -- massive plantings of ethanol. Also, this goes for witch grass too.
Some geo-thermal projects could work but I fear that would be very expensive and would be limited to certain areas. However, it should be looked into. Ocean wave, methane gas, coal; too many problems, coal and gas with emissions and expensive as well. The ocean wave concept -- expensive, and most impractical for many reasons which I could get into but I wont bore you any further.
Yes, renewable energies are the future. It makes us sick that people don't even think about the fact that in doing what we are doing we are destroying our planet and ourselves.
We need to act now, because the evidence is there. We can see what's going to happen.
You don't have to be a rocket scientist to understand that global warming caused by our addiction to fossil fuels is having a severe impact on our planet, from massive species extinctions to extreme weather events. Read the news - it's happening now.
Yet, by making small changes to our own lifestyles - investing in solar or wind power, hybrid cars, bicycles etc, we can cut our carbon footprints by 50% - easily!
Governments have proved they are too slow with too many vested interests and business leverages to make the changes needed in the time required. They will not solve the problem. Individual people, making small adjustments can and will.
I believe we have to take personal responsibility for our lifestyles and by so doing, collectively, we can make a HUGE difference. One person at a time. One step at a time. What are you waiting for??
In my country, the U.S., there is a very low percentage of energy from the wind. In the country of my birth, India, there is a lot more sensitivity to such things.
Al Gore had eight years to change things. We expect less from Bush. The governor of California is somewhat more interested in this. But I think that a recognition that the Third World is doing more than its fair share is needed.
I can't understand why governments aren't taking any action before it is too late. I think this is a serious subject.
I have been working since 1975 in the field of renewable energy sources, but am very sorry to say that in my country this subject has become a fool's paradise. The only solution is if affordable, cheap manufacturing for such technology to be made available.
With all this warning we are having about climate change, and with burning fossil fuels liable to be the cause, I just can't understand why governments aren't taking any action before it is too late!
Certain parts of our country seem to be more worried about extracting oil from the soil than about finding alternative energy sources. There are efforts in other parts of our country to push forward with hydroelectric and wind energy sources. Critics say this is not viable. But neither was oil at one time.
It is really time now to pour money into research into alternative energies. And it is also time for local governments to take the bull by the horns and force developers to build alternative energies into their infrastructure. If the federal governments won't do it, then it's up to the local authorities. Just because a few of our so-called "leaders" (Canada's Prime Minister Stephen Harper and US George W. Bush) seem to believe Kyoto is not viable, it doesn't mean the rest of us can't pull our act together and do what's right.
Current alternative energies are a poor replacements for oil. The only one that is really viable is nuclear. Solar is the most abundant but collection technologies for it are so poor, it's almost pointless. Nuclear energies are the only way to supply power to things such as space flight.
I live in the heart of the oil Industry in Canada. I keep reading day after day how the "big bad oil companies" did this and did that, all because they make lots of money.
But that's the root of it isn't it? Money? Here is a simple idea...Create a market. Buy lots of solar cells. If lots of people buy lots of solar cells, it will create a successful business model and draw the attention of companies with the resources to create/produce/innovate on these products. Cell phones are an excellent example. They started out not very effective/efficient and now every day they get better and last longer. If there is a way for somebody to make money doing something they will, and so will their competitors, creating more and better options for everyone.
Are renewable energies the future? True, it is so. but certain lobbies do not want to be sidelined -- I mean the petro lobby.
Here is the problem with renewable energy. Our present day energy use is so large (about 907 gigawatts in the USA each day) that no amount of renewable energy will ever be able to replace the conventional power sources without energy conservation on a massive scale.
It is not that RE systems (wind/solar) are so ineffective, just that we are relying on the wrong parties to oversee the implementation of these systems along with the tendency of Western and emerging Asian load centers to equate a particular lifestyle (the term I hate most - our American way of life) with unlimited energy which never existed.
Wind generators are nice but sometimes the wind is not available; solar panels are nice but the sun does rise and set, leaving large load sectors without alternative power sources for significant periods of time.
The only solution is to abandon large grid schemes and concentrate on removing all coal fired plants (if we want to save our planet) and replace them with distributed low-scale generation while mandating home and business PV systems with energy storage (batteries) to cover the night time loads and mandate energy efficiency everywhere.
If we can do this with cars why not our homes. Large systems only concentrate wealth and do not benefit all. I can prove this anytime to anyone.
The destruction of the environment is a human rights issue of epic proportions. All of humanity must take responsibility, and endeavor to restrict our use of energy, unnecessary products from it, wastage etc.
This should be individual decisions by all of us, don't help governments go for power grabs. Boycotting companies and products who do damage would have a powerful effect.
Solar power-generating satellites are the way to go. Once built and placed in orbit, there is no longer an urgent requirement to search for more energy sources until either the sun diminishes in its old age, or our civilization has expanded enough to require more energy than the sun outputs. I dare say this will not happen for many millennia.
They say hydrogen is the future of fuels since the only pollutant it produces is water vapor. If the majority of vehicles and factories used hydrogen, we will get other environmental problems that we have not yet discovered due to too much water vapor in the environment. Will hydrogen production/extraction cause pollution?
I believe that renewable energy is the key to sustainable development. In the Philippines, our country is very rich in natural resources that, when harnessed properly, can address the energy needs of the Philippines.
And yet due to lack of funding in research and development and the lack of political will, our country is heavily dependent on conventional sources of energy, primarily coal-driven power generation, whose fuel we import. Thus the Philippines is not self-sufficient and is heavily dependent.
Alternative energy is the only way to save our environment from global warming and eventual destruction.
Renewable energies are definitely the future.They will not only foster cleaner and better technologies, but in developing countries like India offer a huge avenue for fresh investments, especially in the manufacturing that takes place in countries like China and India.
Technology and investments respond to what markets and prices signal, so if the legal and regulatory climate in India is changed such that it encourages such technologies, these will prosper.
In the long run, the environment is a safer investment than fossil fuels.
Alternative energy is the obligatory future, not only because of the greenhouse effect, but because oil and gas will eventually run out. There are many other considerations but we won't go into those now.
So what are the alternatives? Wind, sun and water are the obvious ones to the simple eye, so why are we not getting on and doing something about it? I'll tell you. The oil companies have been too lazy to develop them and even worse, greedy about letting go of their control of the world's energy and subsequently, the big bucks they collect. Have you ever had a good look at the homes and cars that are owned by the presidents of oil and electrical companies?
People have forgotten the advent of the nuclear fusion reactor. All reactors today are currently based off of nuclear fission, the generation of energy from the breaking down of radioactive materials.
However, nuclear fusion involves the same process of the sun, the generation of energy from the fusion of hydrogen atoms to form more complex compounds.
The first prototype reactor is already under construction in France, and should it prove successful, it will be clean, efficient energy, without the stigma of fission reactors.
Even then, fission reactors are still extraordinarily decent. Most people do not seem to know that Chernobyl was the result of not only ancient nuclear fission technology, but the technicians were doing an experiment which resulted in the explosion. One must be responsible with nuclear fission, and the Chernobyl incident is where everything went wrong.
In addition, it may be our only option as it is being found out, and feared, that wind, tidal, and hydro-electric power plants tend to affect the natural enviornment in a negative manner.
Ethanol? What an ethical solution! Let's grow food that could feed billions and burn it!
If the U.S. spent $20 Billion of its $400 billion defense budget on finding renewable energy sources, it would eliminate many reasons for war, save the environment and be a model for the rest of the world. But alas!!!Nobody wants to take the road least travelled.
This section seems to focus too much on the supply side of the energy equation. What about energy efficiency? Perhaps a 'Daughter of Kyoto' agreement could set minimum standards for efficiency of energy consuming devices.
One can also think of regulation of advertising in connection with energy-related products. Too many people bought SUVs because of the sales pitch rather than out of direct need.
On the subject of advertising, I am very skeptical about claims for 'clean, safe' nuclear energy. How do they measure safety, what design are they using to zero-base their comparisons, what percentage improvement have they achieved, and how have they solved the disposal problems associated with long-lived radioactive waste products? And how will we handle the thorny issue of uranium enrichment for fuel rods?
The only 'clean, safe, nuclear energy' that I am aware of is cold fusion!
Battery technology has not kept pace with the other technologies. Solar energy is free and with the proper batteries, we can have transportation that will be, at least, partially electric.
The only way renewable fuels will become a reality is to ban the burning of fosil fuels for energy and see how quickly renewable fuels appear when the "big money" goes into their production.