Energy of the future: reality and fantasy. Alternative energy sources

Today, the entire world is supplied with electricity by burning coal and gas (fossil fuels), exploiting water flows, and controlling nuclear reactions. These approaches are quite effective, but in the future we will have to abandon them, turning to such a direction as alternative energy.

Much of this need is due to the fact that fossil fuels are limited. In addition, traditional methods of electricity production are one of the factors of environmental pollution. That's why the world needs a "healthy" alternative.

We offer our version of the TOP non-traditional methods of generating energy, which in the future may become a replacement for conventional power plants.

7th place. Distributed Energy

Before considering alternative energy sources, let’s look at one interesting concept that in the future can change the structure of the energy system.

Today, electricity is produced in large stations, transmitted to distribution networks and delivered to our homes. The distributed approach involves gradual rejection of centralized electricity production. This can be achieved through the construction of small energy sources in close proximity to the consumer or group of consumers.

The following can be used as energy sources:

• microturbine power plants;
• gas turbine power plants;
• steam boilers;
• solar panels;
• wind turbines;
• heat pumps, etc.

Such mini-power plants for the home will be connected to the general network. Excess energy will flow there, and if necessary, the power grid will be able to compensate for the lack of power, for example, when solar panels perform worse due to cloudy weather.

However, the implementation of this concept today and in the near future is unlikely, if we talk about a global scale. This is primarily due to the high cost of transition from centralized energy to distributed energy.

6th place. Lightning energy

Why generate electricity when you can simply “catch” it from the air? On average, one lightning strike is 5 billion J of energy, which is equivalent to burning 145 liters of gasoline. Theoretically, lightning power plants will reduce the cost of electricity significantly.

Everything will look like this: stations are located in regions with increased thunderstorm activity, “collect” discharges and store energy. After this, the energy is supplied to the network. You can catch lightning with the help of giant lightning rods, but the main problem remains - to accumulate as much lightning energy as possible in a split second. At the present stage, it is impossible to do without supercapacitors and voltage converters, but in the future a more delicate approach may appear.

If we talk about electricity “out of thin air”, one cannot even remember the adherents of the formation of free energy. For example, Nikola Tesla at one time supposedly demonstrated a device for generating electric current from the ether to operate a car.

5th place. Burning renewable fuels

Instead of coal, power plants can burn so-called biofuel " These are processed plant and animal raw materials, waste products of organisms and some industrial waste of organic origin. Examples include regular firewood, wood chips, and biodiesel found at gas stations.

In the energy sector, wood chips are most often used. It is collected during logging or woodworking production. After grinding, it is pressed into fuel pellets and in this form is sent to thermal power plants.

By 2019, construction of the largest power plant that will run on biofuel should be completed in Belgium. According to forecasts, it will have to produce 215 MW of electricity. This is enough for 450,000 homes.

Interesting fact! Many countries practice the cultivation of so-called “energy forests” - trees and shrubs that are best suited for energy needs.

It is still unlikely that alternative energy will develop in the direction of biofuels, because there are more promising solutions.

4th place. Tidal and wave power plants

Traditional hydroelectric power plants operate on the following principle:

1. The water pressure goes to the turbines.
2. The turbines begin to rotate.
3. The rotation is transmitted to generators that generate electricity.

The construction of hydroelectric power plants is more expensive than thermal power plants and is only possible in places with large reserves of water energy. But the main problem is the harm to ecosystems due to the need to build dams.

Tidal power plants work on a similar principle, but use the ebb and flow of tides to generate energy.

“Water” types of alternative energy include such an interesting direction as wave energy. Its essence comes down to generating electricity by using the energy of ocean waves, which is much higher than tidal energy. The most powerful wave power plant today is Pelamis P-750 , which produces 2.25 MW of electrical energy.

Rocking on the waves, these huge convectors (“snakes”) bend, causing hydraulic pistons inside to move. They pump oil through hydraulic motors, which in turn drive electric generators. The resulting electricity is delivered to the shore through a cable that is laid along the bottom. In the future, the number of convectors will be increased many times and the station will be able to generate up to 21 MW.

3rd place. Geothermal stations

Alternative energy is also well developed in the geothermal direction. Geothermal plants generate electricity by actually converting the energy of the earth, or more precisely, the thermal energy of underground sources.

There are several types of such power plants, but in all cases they are based on the same operating principle: Steam from an underground source rises up the well and rotates a turbine connected to an electric generator. Today, a common practice is when water is pumped into an underground reservoir to a great depth, where it evaporates under the influence of high temperatures and enters the turbines in the form of steam under pressure.

Areas with a large number of geysers and open thermal springs, which are heated by volcanic activity, are best suited for geothermal energy purposes.

So, in California there is an entire geothermal complex called “ Geysers " It unites 22 stations generating 955 MW. The source of energy in this case is a magma chamber with a diameter of 13 km at a depth of 6.4 km.

2nd place. Wind power plants

Wind energy is one of the most popular and promising sources for generating electricity.

The operating principle of the wind generator is simple:

• the blades rotate under the influence of wind force;
• rotation is transmitted to the generator;
• the generator produces alternating current;
• The resulting energy is usually stored in batteries.

The power of a wind generator depends on the span of the blades and its height. Therefore, they are installed in open areas, fields, hills and in the coastal zone. Installations with 3 blades and a vertical axis of rotation work most efficiently.

Interesting fact! Wind energy is actually a type of solar energy. This is explained by the fact that winds arise due to uneven heating of the earth's atmosphere and surface by the sun's rays.

To make a windmill, you don't need deep knowledge of engineering. Thus, many craftsmen were able to afford to disconnect from the general power grid and switch to alternative energy.

Vestas V-164 is the most powerful wind generator today. It produces 8 MW.

To produce electricity on an industrial scale, wind power plants, consisting of many wind turbines, are used. The largest is the power plant " Alta ", located in California. Its power is 1550 MW.

1 place. Solar power plants (SPP)

Solar energy has the greatest prospects. The technology for converting solar radiation using photocells is developing from year to year, becoming more and more efficient.

In Russia, solar energy is relatively poorly developed. However, some regions show excellent results in this industry. Take Crimea, for example, where several powerful solar power plants operate.

It may be possible to develop in the future space energy. In this case, solar power plants will be built not on the surface of the earth, but in the orbit of our planet. The most important advantage of this approach is that photovoltaic panels will be able to receive much more sunlight, because this will not be hindered by the atmosphere, weather and seasons.

Conclusion

Alternative energy has several promising areas. Its gradual development will sooner or later lead to the replacement of traditional methods of generating electricity. And it is not at all necessary that only one of the listed technologies will be used throughout the world. See the video below for more details.

In recent years, alternative energy has become the subject of intense interest and heated debate. Threatened by climate change and the fact that average global temperatures continue to rise every year, the desire to find forms of energy that will reduce dependence on fossil fuels, coal and other polluting processes has naturally increased.

While most of the concepts are not new, it is only in the last few decades that the issue has finally become relevant. Thanks to improvements in technology and production, the cost of most forms of alternative energy has fallen while efficiency has increased. What is alternative energy, in simple and understandable terms, and what is the likelihood that it will become mainstream?

Clearly, some debate remains regarding what "alternative energy" means and what the phrase can be applied to. On the one hand, the term can be applied to forms of energy that do not increase humanity's carbon footprint. Therefore, it can include nuclear facilities, hydroelectric power plants and even natural gas and “clean coal”.

On the other hand, the term is also used to refer to what are now considered non-traditional energy methods - solar, wind, geothermal, biomass and other recent additions. This type of classification excludes energy extraction methods such as hydroelectric power, which have been around for over a hundred years and are quite common in some regions of the world.

Another factor is that alternative energy sources must be “clean” and not produce harmful pollutants. As noted, this most often refers to carbon dioxide, but can also refer to other emissions - carbon monoxide, sulfur dioxide, nitrogen oxide and others. By these parameters, nuclear energy is not considered an alternative energy source because it produces radioactive waste, which is highly toxic and must be stored appropriately.

In all cases, however, the term is used to refer to the types of energy that will replace fossil fuels and coal as the dominant form of energy production in the next decade.

Types of alternative energy sources
Strictly speaking, there are many types of alternative energy. Again, this is where definitions get confusing because in the past, “alternative energy” was used to describe methods that were not considered mainstream or reasonable to use. But if we take the definition broadly, it will include some or all of these points:

Hydropower. This is the energy produced by hydroelectric dams when falling and flowing water (in rivers, canals, waterfalls) passes through a device that turns turbines and generates electricity.

Nuclear power. Energy that is produced during slow fission reactions. Uranium rods or other radioactive elements heat water, turning it into steam, and the steam spins turbines, generating electricity.

Energy that is obtained directly from the Sun; (usually consisting of a silicon substrate arranged in large arrays) convert the sun's rays directly into electrical energy. In some cases, the heat produced by sunlight is used to produce electricity, this is known as solar thermal energy.

Wind energy. Energy generated by air flow; giant wind turbines rotate under the influence of the wind and generate electricity.

Geothermal energy. This energy comes from heat and steam produced by geological activity in the earth's crust. In most cases, pipes are placed in the ground above geologically active areas to pass steam through turbines, thereby generating electricity.

Tidal energy. Tidal currents near coastlines can also be used to generate electricity. The daily change in tides causes water to flow back and forth through the turbines. Electricity is generated and transmitted to onshore power plants.

Biomass. This applies to fuels that are obtained from plants and biological sources - ethanol, glucose, algae, fungi, bacteria. They could replace gasoline as a fuel source.

Hydrogen. Energy obtained from processes involving hydrogen gas. These include catalytic converters, in which water molecules are broken apart and reunited through electrolysis; hydrogen fuel cells, which use gas to power an internal combustion engine or drive a heated turbine; or nuclear fusion, in which hydrogen atoms are fused under controlled conditions, releasing incredible amounts of energy.

Alternative and renewable energy sources
In many cases, alternative energy sources are also renewable. However, the terms are not completely interchangeable since many forms of alternative energy sources rely on a limited resource. For example, nuclear power relies on uranium or other heavy elements that must first be mined.

At the same time, wind, solar, tidal, geothermal and hydroelectric power rely on sources that are completely renewable. The rays of the sun are the most abundant source of energy of all and, although limited by weather and time of day, are inexhaustible from an industrial point of view. The wind is also here to stay, thanks to changes in pressure in our atmosphere and the rotation of the Earth.

Development
Currently, alternative energy is still in its youth. But this picture is rapidly changing under the influence of political pressures, worldwide environmental disasters (droughts, famines, floods) and improvements in renewable energy technologies.

For example, as of 2015, the world's energy needs were still predominantly supplied by coal (41.3%) and natural gas (21.7%). Hydroelectric power plants and nuclear power accounted for 16.3% and 10.6% respectively, while “renewable energy sources” (solar, wind, biomass, etc.) accounted for only 5.7%.

This has changed dramatically since 2013, when global oil, coal and natural gas consumption were 31.1%, 28.9% and 21.4% respectively. Nuclear and hydropower accounted for 4.8% and 2.45%, while renewables accounted for just 1.2%.

In addition, there has been an increase in the number of international agreements regarding curbing the use of fossil fuels and developing alternative energy sources. For example, the Renewable Energy Directive, signed by the European Union in 2009, which set targets for the use of renewable energy for all member countries by 2020.

At its core, this agreement requires the EU to meet at least 20% of its total energy needs with renewable energy by 2020 and at least 10% of transport fuels. In November 2016, the European Commission revised these goals and set a 27% minimum consumption of renewable energy by 2030.

Some countries have become leaders in the development of alternative energy. For example, in Denmark, wind energy provides up to 140% of the country's electricity needs; the surplus is supplied to neighboring countries, Germany and Sweden.

Iceland, thanks to its location in the North Atlantic and its active volcanoes, achieved 100% dependence on renewable energy as early as 2012 through a combination of hydropower and geothermal energy. In 2016, Germany adopted a policy to phase out its dependence on oil and nuclear power.

The long-term prospects for alternative energy are extremely positive. According to a 2014 report by the International Energy Agency (IEA), photovoltaic solar energy and solar thermal energy will account for 27% of global demand by 2050, making it the largest source of energy. Perhaps, thanks to advances in fusion, fossil fuel sources will be hopelessly obsolete by 2050.

Power plants are connected to each other and supply electricity to the power grid of a region or country. From this system, consumers of various composition, power, operating mode and other indicators receive electricity. Such integration into the energy system allows: to reduce the total installed capacity of power plants; reserve power due to the possible maneuvering of stations of different types; reduce overall fuel consumption; increase the reliability of power supply to consumers through additional mutual connections; increase the efficiency of electricity generation by optimally distributing electrical loads between stations of various types.

Fig.1.14.

The total electrical load of a group of consumers connected to the electrical power system depends on many factors: the composition of consumers, their power, operating mode, technology and equipment used, time of day and year, climatic conditions, etc. An approximate daily schedule of the electrical load of an industrial area is presented in Fig. 1.14. It is characterized by a constant daily (basic) load P3; weakly variable (half-peak) load from P3 to P2; peak load P1. At each moment in time, there must be a balance of generated and consumed power in the electrical power system (taking into account losses). Otherwise, the operating mode of the power system as a whole and its individual elements may become emergency, even to the point of “collapse,” i.e. complete disconnection of all sources and consumers of electricity from each other. To maintain power balance, it is necessary to regulate and change the power generated at power plants. The different power and inertia of power units determine certain patterns of their use, both from a technical and economic point of view. The base load is borne by the most powerful and inertial power plants - nuclear power plants and large thermal power plants, state district power plants. The half-peak load is covered by maneuverable units of hydroelectric power plants, pumped storage power plants and thermal power plants. Peak load is provided by hydrogenerators, gas turbine units, and combined cycle gas turbine units.

The specific composition of power plants in the region may partially change the load distribution option considered, but the general principles remain unchanged.

Use of alternative energy sources

Population growth, industrial and social development of society require a significant increase in energy production. At the same time, by the middle of the twenty-first century, an acute shortage of organic energy resources, which today provide about 80% of all demanded energy, will become quite real. The cost of extracting and transporting fuel is constantly growing, and this process will continue, because... new deposits are often located in remote, hard-to-reach areas, at considerable depth. The rise in fuel prices is also due to the fact that oil, gas, and coal are important raw materials for many industries, and the statement “heating with oil is the same as heating with banknotes” does not lose its relevance.

Therefore, work is being carried out to search for new, alternative types of energy sources, including renewable and environmentally friendly ones. Some of these developments are discussed below.

Magnetohydrodynamic (MHD) installations. The operating principle of these installations makes it possible to directly convert thermal energy into electrical energy (Fig. 1.15). A jet 2 of ionized gas is passed between metal plates 1 located in a strong magnetic field. In accordance with the law of electromagnetic induction, an EMF is induced, causing the flow of electric current between the electrodes inside the generator channel and in the external circuit. The absence of moving parts in the MHD generator makes it possible to achieve a working fluid temperature of 2550...2600 0C at the inlet and ensure a thermal cycle efficiency of 70...75%.

MHD installations can operate according to different schemes. One of the options is with a closed-cycle nuclear reactor (Fig. 1.15.b.). The working fluid (argon or helium with the addition of cesium) is heated in a nuclear reactor or in a high-temperature heat exchanger 3 and enters the MHD channel 4, where the thermal energy of the moving plasma is converted into electrical energy. The gases exhausted in the MHD channel, having a temperature of about 1500 0C, enter the steam generator 5, which ensures the operation of the steam turbine unit 6. The MHD cycle is closed through the compressor 7, which returns the gas to the reactor or heat exchanger 3.

Fig.1.15.

a - operating principle of the MHD generator; b - MHD installation with a nuclear reactor.

The power of the pilot industrial MHD installation is 25 MW. A 500 MW installation is at the technical development stage. There are a number of difficulties in this process that hinder the pace of implementation of MHD generators: the creation of magnetic fields with high induction; achieving high plasma conductivity at temperatures up to 2400...2500 0C; creation of thermo-heat-resistant materials; obtaining alternating current, which has to be inverted from direct current generated by the MHD installation. Nevertheless, the development and implementation of MHD generators has quite good prospects.

Thermonuclear installations. The creation of industrial installations of this type can almost completely solve the problem of obtaining the required amount of energy. The supply of deuterium and tritium isotopes, the initial fuel for thermonuclear reactors, on Earth is practically unlimited. During a thermonuclear reaction, colossal energy is released. This happens on the Sun, as well as during the explosion of a hydrogen bomb. To control such a process, a number of conditions must be ensured: fuel density of at least 1015 nuclei per 1 cm3; temperature 100...500?106 degrees. This state of the fuel must be maintained for a fraction of a second.

Work on the creation of a thermonuclear reactor was intensively carried out in the USSR, USA, and Japan. Certain positive results were obtained, for example, the TOKOMAK installation at the Institute of Atomic Energy named after. I.V.Kurchatova. However, technical and scientific problems have not yet made it possible to create a real industrial thermonuclear installation.

Solar power plants. The Earth receives 1017 W of energy annually from the Sun, which is 20,000 times more than the current level of consumption. It is natural to convert solar energy into thermal energy. Such installations have been used by man since ancient times. There is also a fairly simple way to convert solar energy into electrical energy - using photocells. Therefore, work on the creation of solar power plants (SPP) is carried out in many countries. Of particular importance is the environmental cleanliness and renewability of such an energy resource. As a result, over the past 50 years, dozens of solar power stations have been built in the USA, Australia, Italy, Oceania and other climatically suitable regions. In the USSR, the Crimean solar power plant with a capacity of 5 MW was built, and a station in Central Asia with a total capacity of 200 MW was designed.

However, there are significant difficulties in creating and using solar power plants, which do not yet allow solar power plants to fully compete with thermal power plants and hydroelectric power plants. This is the variability of solar radiation by time of day, year and depending on weather conditions; low radiation density at the Earth's surface; insufficient technical characteristics of existing photovoltaic cells and the difficulty of their disposal. The efficiency of SEL installations is currently about 15%, and obtaining significant capacities is associated with the placement of equipment over large areas of tens of square kilometers and the corresponding consumption of materials. However, work to improve SELS continues.

Geothermal stations (GeoTES). Such stations use the heat of the earth's interior as an energy source. The main types of geothermal power plants operate on hot water under pressure, water with steam, dry steam or gas (petrothermal energy).

On average, for every 30...40 m deep into the Earth, the temperature increases by 1 0C and at a depth of 10...15 kilometers it reaches 1000-1200 0C. In some parts of the planet, the temperature is quite high in the immediate vicinity of the surface. In these places powerful hot underground waters, steam, and gas flow. Geothermal power plants can be located here. For example, in the Valley of Geysers in the USA, the total capacity of the GeoTPP is 900 MW, the Lardello GeoTPP in Italy has a capacity of 420 MW, and the Wairaket station in New Zealand has a capacity of 290 MW. Quite powerful geothermal power plants operate in Mexico, Japan, Iceland and other countries. The Russian geothermal power plant in Kamchatka has a capacity of 5 MW.

Environmental cleanliness, renewable thermal energy of the Earth, and sufficient simplicity of design are the undoubted advantages of GeoTES.

The disadvantages of geothermal stations are their rigid connection to the place where heat escapes to the Earth's surface and limited parameters of the working fluid in terms of pressure and temperature.

Tidal power plants (TPP). Modern TPPs use the phase of ebb and flow, their units (turbines) are reversible and operate when water moves from the sea to the bay and vice versa (Fig. 1.16). Such installations are capable of operating in turbine and pump modes.

PES operate in Russia (Kislogubskaya, 400 kW), Japan, France and other countries. The most powerful TPP is located at the mouth of the Rance River in France - 240 MW.

Fig.1.16.

a - top view; b - section

VGP - highest tide horizon; VGO - the highest low tide horizon

Tidal energy is environmentally friendly, renewable, unchanged in annual and long-term periods, however, it changes significantly during the lunar month and can only be used in specific geographic locations on the coasts of seas and oceans if the necessary relief is available.

Power plants using marine energy. The energy of waves, currents, temperature and salinity gradients in seas and oceans can be converted into electricity. Several types of conversion plants have been designed and tested. For example, the 80 MW Coriolis turbine is designed for stations using ocean currents.

Wind power plants (WPP). Man has always used wind energy. Converting this energy into electrical energy is fundamentally very simple. In the USSR, already in the 20s, the Kursk wind farm with a capacity of 8 kW was built. The world's largest installation with a capacity of 1050 kW in one unit has been operating in the USA since 1941.

However, despite certain advantages (ecological cleanliness, renewability, simplicity and low cost of use), wind energy also has significant disadvantages that limit the construction of wind farms. This is a large unevenness in the density of wind energy, dependence on geographical, climatic, meteorological factors, etc. Therefore, at present, wind farms of limited power for local use are economically justified.

Prospects for the dynamics of development of power plants

The dynamics of global and domestic energy development indicate that in the near future the existing balance between thermal power plants, nuclear power plants and hydroelectric power plants will be approximately maintained. In this case, priority will be given to the gas-coal strategy, and the use of fuel oil at thermal power plants will be reduced. World energy prices, influenced by numerous factors, are capable of adjusting this strategy to varying degrees and at different time intervals.

PGU and GTU will be further developed. Of the relatively new areas, MHD installations are the priority.

Non-traditional energy will develop (solar, tidal, geothermal), using environmentally friendly renewable natural resources. Research and development work will continue on the creation and development of thermonuclear installations, thermoelectric, radioisotope, thermionic, electrochemical generators and other units. A separate and very important area of ​​work is energy saving of all types of fuel and energy resources, thermal and electrical energy.

Why pay energy companies for electricity every month if you can provide your own energy? More and more people in the world understand this truth. And that’s why today we’ll talk about 8 unusual sources of alternative energy for home, office and leisure.

Solar panels in windows

Nowadays, the most common alternative energy source in everyday life is solar panels. Traditionally, they are installed on the roofs of private houses or in courtyards. But recently it has become possible to place these elements directly in the windows, which allows the use of such batteries even by owners of ordinary apartments in multi-storey buildings.

At the same time, solutions have already emerged that make it possible to create solar panels with a high level of transparency. It is these energy elements that should be installed in residential windows.

For example, transparent solar panels were developed by specialists from Michigan State University. These elements transmit 99 percent of the light passing through them, but have an efficiency of 7%.

Uprise has created an unusual high-power wind turbine that can be used both at home and on an industrial scale. This wind turbine is located in a trailer that can be pulled by an SUV or motorhome.

When folded, the Uprise turbine can be driven on public roads. But when deployed, it turns into a full-fledged wind turbine fifteen meters high and with a power of 50 kW.

Uprise can be used when traveling in a motorhome, to power remote sites or regular private residences. By installing this turbine in his yard, its owner can even sell excess electricity to neighbors.

Makani Power is a project of the company of the same name, which recently came under the control of a semi-secret innovation laboratory. The idea behind this technology is both simple and ingenious. We are talking about a small kite that can fly at an altitude of up to one kilometer and generate electricity.

The Makani Power aircraft is equipped with built-in wind turbines that will actively operate at altitudes where wind speeds are significantly higher than at ground level. The resulting energy in this case is transmitted through a cord connecting the kite to the base station.

Energy will also be generated from the movements of the Makani Power aircraft itself. By pulling the cable under the force of the wind, this kite will make the dynamo built into the base station spin.

With the help of Makani Power, it is possible to provide energy to both private homes and remote sites where it is impractical to install a traditional power line.

Modern solar cells still have very low efficiency. Therefore, to obtain high performance indicators from them, it is necessary to cover fairly large spaces with panels. But a technology called Betaray allows you to increase efficiency by about three times.

Betaray is a small-sized installation that can be located in the courtyard of a private house or on the roof of a high-rise building. It is based on a transparent glass sphere with a diameter of slightly less than one meter. It accumulates sunlight and focuses it onto a fairly small photovoltaic panel. The maximum efficiency of this technology is a stunningly high 35 percent.

Moreover, the Betaray installation itself is dynamic. It automatically adjusts to the position of the Sun in the sky to work at its maximum capacity at any time. And even at night, this battery generates electricity by converting light from the moon, stars and street lights.

Danish-Icelandic artist Olafur Eliasson launched an unusual project called Little Sun, which combines creativity, technology and the social commitment of successful people to the disadvantaged. We are talking about a small device in the shape of a sunflower flower, which during the day is filled with energy from sunlight in order to bring illumination to the darkest corners of the planet in the evenings.

Anyone can donate money to bring the Little Sun solar lamp into the life of a family from a Third World Country. Little Sun lamps allow children from slums and remote villages to spend their evenings studying or reading, without which success in modern society is impossible.

You can also purchase Little Sun lamps for yourself, making them a part of your own life. These devices can be used when going out into nature or to create a stunning evening atmosphere in open areas.

Many skeptics laugh at athletes, claiming that the force they expend during exercise can be used to generate electricity. The creators followed this opinion and created the world's first set of outdoor exercise machines, each of which is a small power plant.

The first Green Heart sports ground appeared in November 2014 in London. The electricity generated by exercise enthusiasts can be used to charge mobile devices: smartphones or tablet computers.

The Green Heart site sends excess energy to local power grids.

It’s paradoxical, but even children can be forced to produce “green” energy. After all, they are never averse to doing something, playing and entertaining themselves somehow. That’s why Dutch engineers created an unusual swing called Giraffe Street Lamp, which uses children’s restlessness in the process of generating electricity.

The Giraffe Street Lamp swing generates energy while it is being used for its intended purpose. By rocking in the seat, children or adults stimulate the operation of the dynamo built into this design.

Of course, the resulting electricity will not be enough for the full functioning of a private residential building. But the energy accumulated during a day of play is quite enough to operate a not very powerful street lamp for a couple of hours after dusk.

Mobile operator Vodafone realizes that its profits increase when customers' phones work around the clock, and their owners themselves do not worry about where to find an outlet to charge the batteries of their gadget. That’s why this company sponsored the development of an unusual technology called Power Pocket.

Devices based on Power Pocket technology need to be as close to the human body as possible in order to use its heat to generate electricity for household needs.

At the moment, two practical products have been created based on Power Pocket technology: shorts and a sleeping bag. They were first trialled during the Isle of Wight Festival in 2013. The experiment turned out to be successful; one night of a person in such a sleeping bag was enough to charge the smartphone battery by about 50 percent.

In this review, we only talked about those alternative energy sources that can be used for everyday needs: at home, in the office or during leisure. But there are still many extraordinary modern “green” technologies developed for use on an industrial scale. You can read about them in the review.

Limited reserves of fossil fuels and global environmental pollution have forced humanity to look for renewable alternative sources of such energy so that the harm from its processing is minimal while maintaining acceptable costs of production, processing and transportation of energy resources.

Modern technologies make it possible to use available alternative energy resources, both on the scale of the entire planet and within the power grid of an apartment or private house.

The rapid development of life over several billion years clearly demonstrates the Earth's availability of energy sources. Sunlight, subsoil heat and chemical potential allow living organisms to carry out multiple energy exchanges, existing in an environment created by physical factors - temperature, pressure, humidity, chemical composition.

Cycle of matter and energy in nature

Economic criteria for alternative energy sources

Since ancient times, man has used wind energy as a propulsion device for ships, which allowed trade to develop. Renewable fuel from dead plants and waste was a source of heat for cooking and producing the first metals. The energy of the water difference drove the millstones. For thousands of years these were the main forms of energy that we now call alternative sources.

With the development of geology and subsoil extraction technologies, it has become more economically profitable to extract hydrocarbons and burn them to produce energy as needed than to literally wait for the weather by the sea, hoping for a successful coincidence of currents, wind direction, and cloudiness.

The instability and variability of weather conditions, as well as the relative cheapness of engines running on fossil fuels, have forced progress to develop towards the use of energy from the bowels of the earth.

Chart showing the ratio of fossil and renewable energy consumption

Carbon dioxide, assimilated and processed by living organisms, resting in the depths for millions of years, is returned to the atmosphere when fossil hydrocarbons are burned, which is the source of the greenhouse effect and global warming. The well-being of future generations and the fragile balance of the ecosystem force humanity to reconsider economic indicators and use alternative energies, because health is more valuable than anything.

Conscious use of alternative energy sources renewable by nature is becoming popular, but, as before, economic priorities prevail. But in a country house or country house, using sources of alternative electricity and heat may be the only cost-effective option for obtaining energy if running, connecting and installing power supply lines turns out to be too expensive.

Providing a house remote from civilization with the minimum required amount of electricity using solar panels and a wind generator

Possibilities of using alternative types of energy

While scientists are exploring new directions and developing cold fusion technologies, home craftsmen can use the following alternative energy sources for the home:

• Sunlight;
• Wind energy;
• Biological gas;
• Temperature difference;

For these alternative types of renewable energy, there are ready-made solutions that have been successfully introduced into mass production. For example, solar panels, wind generators, biogas plants and heat pumps of various capacities can be purchased along with delivery and installation in order to have your own alternative sources of electricity and thermal energy for a private home.

Industrially produced solar panel installed on the roof of a private house

Each individual case must have its own plan for providing household electrical appliances with sources of alternative electrical energy, according to needs and capabilities. For example, to power a laptop, tablet, or charge a phone, you can use a 12 V source and portable adapters. This voltage, with a sufficient battery volume, will be enough energy for lighting using.

Solar panels and wind turbines must charge batteries due to the variability of lighting and the strength of wind energy. With an increase in the power of alternative sources of electricity and the volume of batteries, the energy independence of autonomous power supply increases. If you need to connect electrical appliances operating on 220 V to an alternative source of electricity, then use voltage converters.

Diagram illustrating the power of household electrical appliances from batteries charged by a wind generator and solar panels

Alternative solar energy

It is almost impossible to create photovoltaic cells at home, so designers of alternative energy sources use ready-made components, assembling generating structures, achieving the required power. Connecting photocells in series increases the output voltage of the resulting source of electricity, and connecting the assembled circuits in parallel gives a greater total current of the assembly.

Connection diagram of photocells in the assembly

You can focus on the intensity of solar radiation energy - this is approximately one kilowatt per square meter. You also need to take into account the efficiency of solar panels - at the moment it is approximately 14%, but intensive development is underway to increase the efficiency of solar generators. The output power depends on the radiation intensity and the angle of incidence of the rays.

You can start small - purchase one or several small solar panels, and have a source of alternative electricity at your dacha in the amount necessary to charge a smartphone or laptop in order to have access to the global Internet. By measuring current and voltage, they study the volume of energy consumption, considering the prospect of further expanding the use of sources of alternative electricity.

Installation of additional solar panels on the roof of the house

It must be remembered that sunlight is also a source of thermal (infrared) radiation, which can be used to heat the coolant without further converting the energy into electricity. This alternative principle applies in solar collectors, where, with the help of reflectors, infrared radiation is concentrated and transmitted by the coolant to the heating system.

Solar collector as part of a home heating system

Alternative wind energy

The easiest way to create a wind generator yourself is to use a car generator. To increase the speed and voltage of the source of alternative electricity (the efficiency of electrical energy generation), a gearbox or belt drive should be used. An explanation of all sorts of technological nuances is beyond the scope of this article - you need to study the principles of aerodynamics in order to understand the process of converting the speed of air mass flow into alternative electricity.

At the initial stage of studying the prospects for converting renewable sources of alternative wind energy into electricity, you need to choose a wind turbine design. The most common designs are the horizontal axis bladed propeller, the Savonius rotor, and the Darrieus turbine. A three-bladed propeller as an alternative energy source is the most common DIY option.

Types of Darrieus turbines

When designing propeller blades, the angular speed of rotation of the windmill is of great importance. There is a so-called propeller efficiency factor, which depends on the speed of the air flow, as well as the length, cross-section, number and angle of attack of the blades.

In general, this concept can be understood as follows: in low winds, the length of the blade with the most favorable angle of attack will not be enough to achieve maximum energy generation efficiency, but with a multiple increase in the flow and an increase in angular velocity, the edges of the blades will experience excessive resistance, which can damage them.

Complex windmill blade profile

Therefore, the length of the blades is calculated based on the average wind speed, smoothly changing the angle of attack relative to the distance from the center of the propeller. To prevent blade breakage during hurricane winds, the generator leads are short-circuited, which prevents the propeller from rotating. For rough calculations, one kilowatt of alternative electricity can be taken from a three-bladed propeller with a diameter of 3 meters at an average wind speed of 10 m/s.

To create an optimal blade profile, you will need computer modeling and a CNC machine. At home, craftsmen use available materials and tools, trying to recreate as accurately as possible the drawings of alternative sources of wind energy. The materials used are wood, metal, plastic, etc.

Homemade wind turbine propeller made from wood and metal plate

The power of a car generator may not be enough to generate electricity, so craftsmen make electrical generating machines with their own hands, or remake electric motors. The most popular design of an alternative electricity source is a rotor with alternately placed neodymium magnets and a stator with windings.

Homemade generator rotors
Stator with windings for a homemade generator

Alternative energy biogas

Biological gas as an energy source is obtained mainly in two ways: pyrolysis and anaerobic (without oxygen) decomposition of organic substances. Pyrolysis requires a limited supply of oxygen necessary to maintain the reaction temperature, while flammable gases are released: methane, hydrogen, carbon monoxide and other compounds: carbon dioxide, acetic acid, water, ash residues. Fuel with a high tar content is best suited as a source for pyrolysis. The video below shows a visual demonstration of the release of flammable gases from wood when heated.

To synthesize biogas from waste products of organisms, methane tanks of various designs are used. Installing a methane tank at home with your own hands makes sense if the household has a chicken coop, pigsty and cattle. The main output gas is methane, but large amounts of hydrogen sulfide and other organic compounds require the use of purification systems to remove odor and prevent clogging of burners in thermal generators or contamination of engine fuel lines.

It is necessary to thoroughly study the energy of chemical processes and technologies with a gradual gain of experience, going through trial and error, in order to obtain combustible biological gas of acceptable quality at the output of the source.

Regardless of the origin, after purification, the mixture of gases is supplied to a heat generator (boiler, oven, stove burner) or to the carburetor of a gasoline generator - in this way, full-fledged alternative energy is obtained with your own hands. With sufficient power of gas generators, it is possible not only to provide the home with alternative energy, but also to ensure the operation of small production, as shown in the video:

Thermal engines for saving and obtaining alternative energy

Heat pumps widely used in refrigerators and air conditioners. It was noted that moving heat requires several times less energy than generating it. Therefore, cold water from a well has thermal potential relative to frosty weather. By lowering the temperature of running water from a well or from the depths of an unfrozen lake, heat pumps extract heat and transfer it to the heating system, thereby achieving significant energy savings.

Saving energy with a heat pump

Another type of heat engine is the Stirling engine, powered by the energy of temperature differences in a closed system of cylinders and pistons placed on the crankshaft at an angle of 90º. The rotation of the crankshaft can be used to generate electricity. The network contains a lot of materials from trusted sources that explain in detail the principle of operation of the Stirling engine, and even provides examples of home-made designs, as in the video below:

Unfortunately, home conditions do not allow us to create a Stirling engine with energy output parameters higher than those of a fun toy or demonstration stand. To obtain acceptable power and efficiency, it is required that the working gas (hydrogen or helium) be under high pressure (200 atmospheres or more). Similar thermal engines are already used in solar and geothermal power plants and are beginning to be introduced into the private sector.

Stirling engine at the focus of a parabolic mirror

To obtain the most stable and independent electricity in a country house or in a private home, you will need to combine several alternative energy sources.

Innovative ideas for creating alternative energy sources

No expert will be able to fully and completely cover the entire range of possibilities of renewable alternative energy. Alternative energy sources are available in literally every living cell. For example, chlorella algae has long been known as a source of protein in fish food.

Experiments are being carried out on growing chlorella in zero gravity, for use as food for astronauts during long-distance space flights in the future. The energy potential of algae and other simple organisms is being studied for the synthesis of flammable hydrocarbons.

Accumulation of sunlight in living chlorella cells grown in industrial installations

It must be borne in mind that a better converter and battery for solar energy than the fluoroplastic of a living cell has not yet been invented. Therefore, potential renewable sources of alternative electricity are available in every green leaf that carries out photosynthesis.

The main difficulty is to collect organic material, use chemical and physical processes to extract energy from it and convert it into electricity. Already, large areas of agricultural land are allocated for the cultivation of alternative energy crops.

Harvesting miscanthus - an energy agrotechnical crop

Another colossal source of alternative energy can be atmospheric electricity. Lightning energy is enormous and has destructive effects, and lightning rods are used to protect against it.

altThe difficulty in harnessing the energy potential of lightning and atmospheric electricity is the high voltage and discharge current in a very short time, which requires the creation of multi-stage systems of capacitors to store the charge and then use the stored energy. Static atmospheric electricity also has good prospects.