Recently, the researcher tended to use Biofeual from algae, it have high lipid level, it is friend to environment , don't need large areas , it can live in salt and fresh environment , may use its wastes in another purposes.

I hope many answers will come, I’ll add a very unconventional one not harmful at all for the environment and which costs least.. it is educating people to decrease their energy consumption, to use energy wisely, to encourage, value and support research aiming at producing more efficient energy use machinery and avoid useless gadgets. There is alot to do in all these domaines. After the Fukushima nuclear disaster , the Japanese government advised the people to reduce their energy consumption by 15% the great disciplined and educated Japanese people did 20% reduction, if we manage to generalize such models, we invented 15 to 20% more of environmentally very friendly alternative source of energy.

Renewable energy or alternative energy is defined as usable energy derived from renewable sources, while non-renewable energy is the sources that are depleted and not renewable, such as fossil fuel sources such as coal, natural gas,

I do not think alternative energy will ever be an efficient alternative to non-renewable energy for technical, economic, environmental and social factors. Currently, there are huge pockets called underground tanks, which are non-renewable energy sources around the world, confirmed by rigorous global studies.

Solar and wind power has enormous harvesting potential

interesting regards

Hydroelectricity

Nuclear energy

Tidal energy

Wind energy

Solar energy

Concentrated solar power

Solar panels

Geothermal energy

Wave energy

Biofuel and ethanol

Hydrogen

Solar energy is one alternative energy source

Lot of sources of energy are yet to discover

Tidal energy is a good source that we need to adopt.

The list provided by Ahmad Alrawashdeh is very good.

Renewable energy can be a source of energy.

I believe that the only source of clean energy is the fusion of hydrogen or its isotopes. The products of the fusion are: a large amount of heat to be used to generate electricity, helium and water. Scientists all over the world they working on controlled nuclear fusion. The currently most advanced international project "ITER" under construction in Cadarache in France is expected to produce the first plasma by 2020. The next project will be "DEMO". Currently, only Europe has given itself a roadmap to fusion electricity. Through EUROfusion, founded in 2013, the design of a magnetic confinement reactor able to produce electrical energy (DEMO, by 2050) has begun, whose construction will begin when ITER demonstrates the production of thermal energy with a net gain on energy consumption for reactor operation.

Alternative energy encompasses all those things that do not consume fossil fuel. They are widely available and environment friendly. They cause little or almost no pollution. There have been several alternative energy projects running in various countries to reduce our dependence on traditional fossil fuels. There are many impressive options that you can take into consideration such as solar tankless water heater reviews. Here in you will learn more about alternative energy sources that you can take into consideration.

https://www.conserve-energy-future.com/alternativeenergysources.php

I think the sun is the best

Regards, azzam

I agree with Artur. The sun starts our day and when it sets begins our night. It represents our future!

Dear Dr. Artur Braun,

Sun is perhaps the ultimate source of all other energy sources; coal, petroleum, alternative sources etc.

But presently we can use Sun rays directly in the work of production of energy only in recharging the batteries/ cells.

There is nothing wrong with solar and wind energy to replace all current polluting methods. Nuclear will always be there and hopefully more will be generated in water currents (in rivers and in the sea). But the most promising for cold countries is the geothermal method pioneered in Canada.

Sun harvesting is the ultimate way for green culture and sustainability.

Alternative energy encompasses all those things that do not consume fossil fuel. They are widely available and environment friendly. They cause little or almost no pollution. There have been several alternative energy projects running in various countries to reduce our dependence on traditional fossil fuels. There are many impressive options that you can take into consideration such as solar tankless water heater reviews. Here in you will learn more about alternative energy sources that you can take into consideration.

Solar Energy:

Solar is the first energy source in the world. It was in use much earlier before humans even learn how to light a fire. Many living things are dependent on solar energy from plants, aquatic life and the animalsز

Wind Energy :

This is one of the energy sources that have been in use for a very long time and for centuries. It was used in powering sailing ships, which made it possible for explorers to sail around their trade routes in distant lands. A single windmill can power the crop irrigation, and the family energy needs, water pumping and electric lights.

Geothermal Energy:

‘Geo’ means Earth and ‘thermal’ means energy. Geothermal energy means energy drawn or harnessed from beneath the earth. It is completely clean and renewable .

Hydroelectric Energy.

Solar energy is produced by sun and wind energy is produced by moving of winds. The heat caused by sun drives the wind. The movement of winds is then captured by wind turbines. Both wind and sun cause water to evaporate.

Biomass Energy:

This is the process by which an alternative energy is generated through conversion of biological materials and wastes into forms that can be used as energy sources for heating, power generation and transportation.

Ocean Energy:

The earth promises many power sources. Just like the geothermal and solar energy, which have long been used in heating homes and lighting as well when harnessed. Even in the last century these forms of energy was in use.

Hydrogen Energy:

Hydrogen is the most abundant element available on earth but it is rarely alone. Even water contains two third of hydrogen. It is usually available with other elements and have to separated before we can make use of it

In another one question, I proposed some alternative fuel sources. Among them, water derived hydrogen was also there. I am a worker of the field of Biology and asking such question just to enrich my knowledge from others.

Now I come to know about actual condition of use of Hydrogen gas as fuel getting it from water .

Many many thanks, Dr. Artur Braun.

Piero Ginori Conti tested the first geothermal power generator on 4 July 1904, at Larderello (Italy). It successfully lit four light bulbs. In 1911, the world's first commercial geothermal power plant was built there. It was the world's only industrial producer of geothermal electricity until New Zealand built a plant in 1958. In 2012, it produced some 594 megawatts. Italy and the USA are the two players historic geothermal, they still retain an important role in the production of geothermal electricity. Italy is the 5th largest producer. The USA as they are the world's largest producer with more than 2,500 megawatts of power production. Between the USA and Italy are the Philippines, Indonesia and Mexico. The two volcanic islands such as Iceland and New Zealand are behind Italy in terms of geothermal. Geothermal energy today accounts for less than 1% of global energy production.

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

https://en.wikipedia.org/wiki/Geothermal_energy#History

Hydrogen is the fuel of the future. The current thermal engines can work very well with hydrogen with very few and very easy modifications. Hydrogen thermal engines emit only water. The problem is that to produce hydrogen in large quantities it is necessary to have a large amount of electricity. The only way to produce very large amounts of "clean" and renewable electricity is the nuclear fusion I have already mentioned.

Only renewable energy resources can helps us to survive in tommorrows situations.

Dear Dr. Cannizzaro,

The electricity required for production of Hydrogen gas may be produced by sun rays in sunny, hot areas- at least we can assume!

In one hour, The sun send energy to earth equal to that required for all people for one year

Dear colleague Shibabrata Pattanayak

Have a nice time and good day,

Peace be up on you, your question's readers and all RG members.

Future research must be focused on the wave length of IR (48%) of solar spectrum as shown in the attached file.

Even if we cover all the deserts of the world with solar panels, the electricity produced would not be sufficient to satisfy the current consumption of electricity. Try doing the calculations to believe. The use of agricultural land must be dedicated exclusively to the production of food for all and not to make biodiesel or other types of fuel. Undoubtedly solar, wind, hydroelectric, geothermal, tides and the sea in general can also make a significant contribution to the world needs of electricity but this contribution does not seem to be resolutive. While nuclear fusion, (at very high temperatures two atoms of hydrogen or deuterium fuse together they create a helium atom and a large amount of heat) is an absolutely clean nuclear reaction because the only product of the reaction is helium gas. So nuclear fusion alone can meet the electricity demands of the whole world. In other terms it is necessary create many small suns in properly constructed structures. In fact the heat of the sun is produced by a fusion reaction.

But atomic energy production creates dangerous by products!

Atomic energy is of two types: fission nuclear energy and fusion nuclear energy. In very simple and unscientific words: the nuclear fission reaction is due to the fact that a nucleus of uranium235 or plutonium is broken in several parts due to a collision with a proton, in this reaction a very small part of matter is transformed into heat, in addition a large quantity of radiation and many radioactive elements are produced that have a very long life; in a fusion reaction two hydrogen nuclei blend to create a helium atom even in this nuclear reaction a very small amount of matter is transformed into heat, there is no radiation and no radioactive substances are formed. The nuclear fusion reaction can be triggered by a laser beam (clean energy) or by a nuclear fission reaction (H bomb).

Thank you, Dr. Cannizzaro for supplying valuable information.

Physics studies how the universe is made and how the universe works according to the Galileo principles of reproducibility, verifiability and falsifiability. All that today is physics, yesterday was philosophy that is "pure thought". In other words, physics studies the laws of nature both from a quantitative and qualitative point of view, also through mathematics. The laws of nature can be exploited to build instruments of death or to build instruments of life. Radiation is very useful in medical diagnostics and can save many lives and destructive and incredibly devastating if used in the instruments of war. The use that the men make of "laws of nature" does not depend on the physicists.

Only doctors take an oath to Hippocrates. Physicists like all other researchers respond to their own conscience and ethics.

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

https://www.researchgate.net/deref/https%3A%2F%2Fwww.conserve-energy-future.com%2Falternativeenergysources.php

It seems to me that the document cited by Ahmed does not mention controlled nuclear fusion. Furthermore, I would like to point out that the bombs fired on Hiroshima and Nagasaki were bombs A, that is, nuclear fission bombs. The nuclear fusion bomb H (hydrogen) seems to have been designed and built in the early 50s. The flammability of hydrogen has nothing to do with nuclear fusion. The H (hydrogen) bomb is triggered by a bomb A (fission bomb of uranium or plutonium) which is the cause of radiation and the production of the radiative elements.

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

Interesting discussion

I think that the future is for renewable energy sources. Like those mentioned by @ Ahmad Alrawashdeh.

Renewable sources like wind, solar, and hydroelectric power have some limitations: they're inconsistent.

There is a long-term solution that overcomes these problem: Nuclear Fusion.

Dear Dr. Mohsen,

The only problem in nuclear energy production is the nuclear waste. 100% safe disposal of these waste is practically impossible.

Human race may extinct by these waste, if accidentally they mix with sea water or environment.

Excellent contributions from RG members.

Solar and wind energies are effective, less costly and more environment friendly alternatives in energy production in Ghana.

Dear,

Alternative energy represents the clean energy source that derives from a natural and renewable source of energy such as solar, wind, geothermal, waves, tides, waste, biomass, hydrogen and so on. some of references add the nuclear energy with renewable energy types.

regards

Best Ethical Alternatives to Fossil Fuels

https://energycentral.com/c/ee/3-best-ethical-alternatives-fossil-fuels

In recent years, ethical issues regarding our energy use and systems have increasingly been at the forefront of the global conscious. Growing awareness of climate change has led us to question how we’re producing and using energy, and how sustainable these practices are.

These ethical considerations are more important now than ever. The IPCC has predicted that global temperatures will rise by up to 10 degrees over the next century, and this is largely due to emissions from energy production. In fact, 90% of all carbon emissions caused by human activity come from fossil fuels. Unfortunately, this shows no signs of reducing, with the International Energy Agency predicting that Chinese emissions will double by 2035.

To keep global temperature increases within manageable levels, we need to leave 80% of our current fossil fuel reserves underground. As such, the need for ethical alternatives to fossil fuels is greater now than ever. Here are 3 of the most promising alternative fuel sources that could help us to turn things around. 

1. Solar Power

Solar power technology has come a long way over the last few decades. Solar panels are now so advanced, they can be used for energy production on an unprecedented scale. Many homes are able to generate all of their required power from solar panels alone.

The only thing holding solar power back from widespread adoption is the upfront costs. The cost of solar power installation is off-putting for many homeowners, which is a shame as they can actually save money on energy bills in the long run.

To combat this, governments around the world have introduced initiatives to encourage more people to adopt solar power. In the US, the ‘Solar Investment Tax Credit’ is one such example.

2.  Wave Energy

Wave energy utilizes the kinetic energy of the sea to generate electricity. Wave energy converters are placed far out in the oceans to harness the power of the waves and use it to produce energy.

The advantage of this is that there is little to no waste produced. It’s very reliable and has a lot of potential. The only potential barrier is that, as of yet, scientists still don’t know exactly how these converters can affect local ecosystems. 

Tidal energy is similar to wave energy and holds equally impressive potential. A recent report predicted that tidal energy alone could provide up to 20% of the electricity demands of the whole of the UK. 

3. Wind Energy

Wind energy is one of the planet’s most promising renewable energy sources. The wind is a limitless source of kinetic energy. Wind turbines can harness that energy by using it to turn spinning blades and generate electricity.

There are thousands of these wind turbines already in place around the globe generating a huge chunk of the global energy supply. According to the EWEA, wind power accounted for 44.2% of the total power capacity installations in 2015 - more than any other form of power generation..

The only ethical issue regarding wind energy centres around the way they look. Many people have raised concerns that wind turbines are an ugly blight on the countryside. However, this seems to be a relatively small compromise for a clean, renewable, limitless energy source.

Currently, 85% of the world’s population is reliant on fossil fuels. While the fossil fuel industry is the leading contributor to climate change, it is also a finite source that will be depleted. In order to continue on, humans must find other sources of energy to rely on. So, what sorts of alternatives are available?

If only there were inexhaustible energy sources that didn’t produce harmful emissions, were cheaper to generate, and gave us a domestic energy source we can rely on….. Well, it turns out these forms of energy already exist, and have for decades:

• Wind 
• Solar
• Hydroelectric

1. Wind Power

When the blades on the windmill are exposed to wind forces, they begin to rotate the turbines, converting the kinetic energy in the wind into mechanical energy. This then powers a generator to create electricity. Wind power is a clean energy source and costs about 7 to 15 cents per kWh to produce. Wind turbines can stand 328 feet tall and higher, making lots of open space a necessity to generate electricity.

2. Solar PV

Solar photovoltaic panels are able to convert sunlight into usable energy for your home. The benefit to solar is the ability to install panels on your roof and turn your own home into a clean energy source while eliminating your current electricity bills, adding equity to your home, and allowing you to save money while doing so. The cost per kWh for electricity from solar power is about 12 cents on average in the US.

3. Hydroelectric

Hydroelectric power uses the energy from flowing water to generate electricity. Typically water is trapped into a reservoir or dam. When released the flow of water rotates a turbine, which in turn powers a generator to create electricity. The average cost per kWh to operate hydroelectric power is 3 cents, making it the least expensive form of clean energy.

Now let’s compare these with some fossil fuel sources.

Coal

Burning coal produces heat which turns water into steam, which is then used to power a turbine, in turn powering a generator and producing electricity. Burning coal also results in the emissions of toxic greenhouse gases and localized air pollution. This contributes to global warming, smog, acid rain, asthma, heart disease, cancer and much more. The cost per kWh of electricity from coal power plants is between 10 to 15 cents. There are other costs to factor in though. Reports from Harvard Medical School found that an added $500 billion (about 17 to 27 cents per kWh extra) should be factored in as well for external costs of coal, including increased health risks and disease as well as negative environmental impact. So why haven’t you switched to clean energy like solar?📷

Natural gas

Natural gas is released through a process called hydraulic fracking, in which water, sand, and other chemicals are forced at high pressure under the surface of the earth. Fracking results in increased earthquakes where the earth has been opened up through this process. Though natural gas produces fewer emissions than other fossil fuels, it still emits toxic emissions when it is burned. Natural gas costs about 7 to 14 cents per kWh, not including the added health costs and environmental impacts, which range on average about 16 cents per kWh.

Comparing All Your Energy Options

Comparing the costs of different forms of energy can become a bit convoluted when you’re thinking about the cost going into building a power plant, transmission of energy, distribution, etc. The levelized cost of energy is a good indicator to compare the real costs of these forms of energy. Lazard recently conducted a wide study on the levelized energy costs, showing how renewable forms of energy cost much less than fossil fuels without subsidies or external cost factors included.  

The main alternatives to oil and gas energy include nuclear power, solar power, ethanol, and wind power. Fossil fuels still dwarf these alternatives in global and domestic energy markets, but there is considerable public momentum to increase their utilization as industries shift towards sustainability and more green business practices.

Fossil fuels--comprised primarily of energy sources from coal, oil, propane, and natural gas--account for more than 80% of total energy consumption in the United States. Alternative forms of energy have, to this point, proven to be uneconomic substitutes; they are less efficient and more expensive (or, in the case of nuclear power, completely restricted from expanding) than fossil fuels. As a result, the government currently provides a lot of subsidies for consumers who choose cleaner forms of renewable energy either for their house or for their vehicles. The many oil alternatives are ballooning as more research and development occurs in this space, and as supply and demand laws of economics eventually push down prices to be competitive with traditional fossil fuels.

More details here

https://www.investopedia.com/ask/answers/060415/what-are-main-substitutes-oil-and-gas-energy.asp

The Economics of Solar Power

Fossil fuels—namely crude oil, natural gas, and coal—are the world’s number one source of energy. Despite being a non-renewable source, there is still a high demand for fossil fuels due to their affordability and reliability. From heating and lighting homes to fueling vehicles, fossil fuels play an integral role in energy production and the global economy.

Here

https://www.investopedia.com/articles/investing/061115/economics-solar-power.asp

Renewable and Alternative Energy Sources

The quest for energy independence, economic growth, and environmental sustainability increasingly suggests the importance of renewable energy sources. Renewable energy is gained by tapping into “existing flows of energy” and “natural processes” in ways that generate more usable energy than is expended in the production process.

Most “renewables” harness the sun’s energy in some fashion, either directly (solar power) or indirectly by:

• Burning plants that lived by photosynthesis (biomass);
• Capturing the air currents that are created when the sun heats parts of the atmosphere differently (wind power); or
• Channeling flows of water that are created through the sun-driven cycle of evaporation, condensation, and rain (hydropower).

Alternative Energy

Renewable energy sources are not exactly the same as alternative energy sources. Alternative energy is a broader category encompassing all non-fossil-fuel-based energy sources and processes, of which renewable energies are only a part. Forms of alternative energy not covered under the renewable label include hydrogen power and fission power. Since current levels of hydrogen and fission power generation are extremely low, renewable energies are now of greater interest to us.

Additional details here

http://www.globalization101.org/renewable-and-alternative-energy-sources/

Forms of energy not derived from fossil fuels include both renewable and alternative energy, terms that are sometimes used interchangeably but do not mean the same thing. Alternative energy broadly refers to any energy that is not extracted from a fossil fuel, but not necessarily only from a renewable source. For example, nuclear power generation most commonly uses uranium, an abundant but not technically renewable fuel. Renewable energy, on the other hand, includes sources such as sun and wind that occur naturally and continuously. 

There are five main renewable and alternative fuels.

• Wind power is created when wind spins a turbine, or a windmill, which can be located on land or offshore. 
• Solar power harnesses the sun’s energy in two ways: by converting the sun’s light directly into electricity when the sun is out (think solar panels), or solar thermal energy, which uses the sun’s heat to create electricity, a method that works even when the sun is down.
• Hydropower is created when rapidly flowing water turns turbines inside a dam, generating electricity.
• Nuclear energy is produced at power plants by the process of nuclear fission. The energy created during nuclear reactions is harnessed to produce electricity.
• Biofuels, also referred to as biomass, are produced using organic materials (wood, agricultural crops and waste, food waste, and animal manure) that contain stored energy from the sun. Humans have used biomass since they discovered how to burn wood to make fire. Liquid biofuels, such as ethanol, also release chemical energy in the form of heat. 

Renewable and alternative energy sources are often categorized as clean energy because they produce significantly less carbon emissions compared to fossil fuels. But they are not without environmental footprint.

Hydropower generation, for example, releases lower carbon emissions than fossil fuel plants do. However, damming water to build reservoirs for hydropower floods valleys, disrupting local ecosystems and livelihoods. In another case, biofuels are renewable but are cultivated on huge swaths of land and sometimes generate more carbon emissions than fossil fuels do.

More details here

https://world101.cfr.org/global-era-issues/climate-change/sources-energy-comparison

Renewable energy sources (which includes biofuels, biomass, geothermal, hydropower, solar and wind) account for about 13 percent of electricity generation. In producing that electricity, they had minimal effects on the environment, minuscule effects on global warming and negligible effects on air quality. Additionally, renewable energy sources like wind, solar, hydropower and geothermal—unlike fossil and nuclear energy—incur no fuel costs. We do not pay for the wind or the sun, the heat from the Earth or the flow of water.

Additional details here

https://www.triglobalenergy.com/climate_change

All energy sources have some impact on our environment. Fossil fuels—coal, oil, and natural gas—do substantially more harm than renewable energy sources by most measures, including air and water pollution, damage to public health, wildlife and habitat loss, water use, land use, and global warming emissions.

However, renewable sources such as wind, solar, geothermal, biomass, and hydropower also have environmental impacts, some of which are significant.

The exact type and intensity of environmental impacts varies depending on the specific technology used, the geographic location, and a number of other factors. By understanding the current and potential environmental issues associated with each renewable energy source, we can takes steps to effectively avoid or minimize these impacts as they become a larger portion of our electric supply.

Despite these environmental impacts, renewable energy technologies compare extremely favorably to fossil fuels, and remain a core part of the solution to climate change.

Details in this link

https://www.ucsusa.org/resources/environmental-impacts-renewable-energy-technologies

The movement of wind and water, the heat and light of the sun, the carbohydrates in plants, and the warmth in the Earth—all are energy sources that can supply our needs in a sustainable way.

A variety of technologies are used to convert these renewable resources into electricity. Each comes with its own unique set of benefits and challenges; collectively, they represent our best hope in the fight against climate change.

Other technologies

Renewable energy isn’t just limited to the sun or wind. Geothermal plants gather heat from the earth to generate steam and produce electricity. Hydroelectric dams exploit the movement of water to turn turbines. New hydrokinetic technologies harness the power of ocean’s currents and tides. And bioenergy—the burning of biomass to generate power—may offer a sustainable use for crops and waste wood.

The key thing tying all of these technologies together is their ability to create electricity with minimal harmful side-effects. The alternatives—fossil fuels—are neither sustainable nor safe.

Additional details here

https://www.ucsusa.org/energy/renewable-energy