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The deterioration of the environment and the depletion of natural resources make us think about how to get electricity and heat from renewable sources.
In this article, we tell you how alternative energy works and why many countries opt for it.
What is alternative energy?
Energy can be renewable (alternative) or non-renewable (traditional).
Alternative energy sources are ordinary natural phenomena, inexhaustible resources that are produced naturally. Such energy is also called regenerative or “green”.
Non-renewable sources are oil, natural gas and coal. They are looking for a replacement, because they can run out. Their use is also associated with carbon dioxide emissions, the greenhouse effect and global warming.
Mankind receives energy, mainly due to the combustion of fossil fuels and the operation of nuclear power plants. Alternative energy is methods that give energy in a more environmentally friendly way and do less harm. It is needed not only for industrial purposes, but also in simple houses for heating, hot water, lighting, electronics.
Renewable Energy Resources
- sunlight
- water streams
- Wind
- tides
- Biofuel (fuel from vegetable or animal raw materials)
- Geothermal heat (Earth’s interior)
Alternative Energy
1. Solar energy
One of the most powerful types of alternative energy sources. Most often it is converted into electricity by solar panels. The entire planet will have enough energy for a whole year that the sun sends to Earth in a day. However, the annual generation of electricity at solar power plants does not exceed 2% of the total volume.
The main disadvantages are dependence on the weather and time of day. For northern countries, it is unprofitable to extract solar energy. The structures are expensive, they need to be “cared for” and the photocells themselves, which contain toxic substances (lead, gallium, arsenic), must be disposed of in time. Large areas are needed for high output.
Solar electricity is common where it is cheaper than usual: remote inhabited islands and farmlands, space and sea stations. In warm countries with high electricity tariffs, it can cover the needs of an ordinary home. For example, in Israel, 80% of the water is heated by solar energy.
Batteries are also installed on unmanned vehicles, airplanes, airships, Hyperloop trains .
2. Wind power
The reserves of wind energy are 100 times greater than the energy reserves of all rivers on the planet. Wind farms help convert wind into electrical, thermal and mechanical energy. The main equipment is wind turbines (for generating electricity) and windmills (for mechanical energy).
This type of renewable energy is well developed – especially in Denmark, Portugal, Spain, Ireland and Germany. By the beginning of 2016, the capacity of all wind turbines overtook the total installed capacity of nuclear energy.
The disadvantage is that it cannot be controlled (the strength of the wind is not constant). Wind turbines can also cause radio interference and affect the climate, because they take away part of the kinetic energy of the wind – however, scientists do not yet know whether this is good or bad.
3. Hydropower
To convert the movement of water into electricity, hydroelectric power plants (HPPs) with dams and reservoirs are needed. They are placed on rivers with a strong flow that do not dry up. Dams are built in order to achieve a certain pressure of water – it makes the blades of a hydroturbine move, and it drives electric generators.
Building hydroelectric power plants is more expensive and more difficult than conventional power plants, but the price of electricity (at Russian hydroelectric power plants) is two times lower. Turbines can operate in different power modes and control the generation of electricity.
4. Wave energy
There are many ways to generate electricity from waves, but only three work effectively. They differ in the type of installations on the water. These are chambers, the lower part of which is submerged in water, floats or installations with an artificial atoll.
Such wave power plants transmit the kinetic energy of sea or ocean waves through a cable to land, where it is converted into electricity at special stations.
This type is used little – 1% of the total electricity production in the world. The systems are also expensive and require convenient access to the water, which not every country has.
5. Ebb and flow energy
This energy is taken from the natural rise and fall of the water level. Power plants are installed only along the coast, and the water drop should be at least 5 meters. Tidal stations, dams and turbines are built to generate electricity.
The tides are well studied, so this source is more predictable than others. But the absorption of technologies has been slow and their share in global production is small. In addition, tidal cycles do not always correspond to the rate of electricity consumption.
6. Temperature gradient energy (hydrothermal energy)
Sea water has different temperatures at the surface and in the depths of the ocean. Using this difference, get electricity.
The first installation that generates electricity at the expense of ocean temperature was made back in 1930. Now there are closed, open and combined ocean power plants in the USA and Japan.
7. Energy of liquid diffusion
This is a new type of alternative energy source. An osmotic power plant installed at the mouth of a river controls the mixing of salt and fresh water and extracts energy from the entropy of liquids.
The equalization of the salt concentration gives an excess pressure, which starts the rotation of the hydroturbine. So far, there is only one such power plant in Norway.
8. Geothermal energy
Geothermal stations take the internal energy of the Earth – hot water and steam. They are placed in volcanic areas where water is near the surface or can be reached by drilling a well (from 3 to 10 km.).
The extracted water heats the buildings either directly or through a heat exchange unit. It is also converted into electricity when hot steam turns a turbine connected to an electric generator.
Disadvantages: price, threat to the Earth’s temperature, carbon dioxide and hydrogen sulfide emissions.
Most of all geothermal stations are in the USA, Philippines, Indonesia, Mexico and Iceland.
9. Biofuel
Bioenergy receives electricity and heat from fuels of the first, second and third generations.
- The first generation is solid, liquid and gaseous biofuels (gas from waste processing). For example, firewood, biodiesel and methane.
- The second generation is a fuel derived from biomass (remains of plant or animal material, or specially grown crops).
- The third generation is biofuel from algae.
First generation biofuels are easy to obtain. Rural residents set up biogas plants, where the biomass ferments at the right temperature.
The most traditional way and the oldest fuel is firewood. Now for their production, energy forests are planted from fast-growing trees, poplar or eucalyptus.
Pros and cons of alternative energy
The main prospect of alternative sources is the existence of mankind even in conditions of a severe shortage of oil, gas and coal.
Advantages:
- Availability – no need to own oil or gas fields. True, this does not apply to all types. Landlocked countries will not be able to receive wave energy, and geothermal energy can only be converted in volcanic areas.
- Environmental friendliness – when generating heat and electricity, there are no harmful emissions into the environment.
- Savings – the resulting energy has a low cost.
Disadvantages and problems:
- Construction and maintenance costs – equipment and consumables are expensive. Because of this, the final price of electricity rises, so it is not always economically justified. Now the main task of developers is to reduce the cost of installations.
- Dependence on external factors: it is impossible to control the strength of the wind, the level of tides, the result of processing solar energy depends on the geography of the country.
- Low efficiency and low capacity of installations (except for hydroelectric power plants). The generated power does not always correspond to the level of consumption.
- Impact on the climate. For example, the demand for biofuels has led to a reduction in acreage for food crops, and hydroelectric dams have changed the nature of fisheries.
Renewable energy in the world
The main consumer of renewable energy sources is the European Union. In some countries, alternative energy generates almost 40% of all electricity. Various support measures have already taken root there: discount tariffs for connection and a refund for the purchase of equipment. Do not lag behind the countries of the East and the United States.
Germany
40% of electricity in Germany comes from renewable sources. It is the leader in the number of wind turbines that generate 20.4% of electricity. The remaining share is accounted for by hydropower, bioenergy and solar energy. The German government has set a plan to generate 80% of energy from alternative sources by 2050, but does not want to close nuclear power plants yet.
Iceland
Iceland has a lot of hot water because it is located in a zone of volcanic activity. The country provides 85% of homes with heating from geothermal sources and covers 65% of the population’s electricity needs with them. The power of the sources is so great that they want to export energy to the UK.
Sweden
After the oil crisis in 1973, the country began to look for other sources of energy. It all started with hydroelectric and nuclear power plants. Swedes have often been criticized for Greenpeace because of nuclear power plants, but since the late 80s, the share of energy from nuclear power plants has not been growing.
Since the 1990s, Sweden has been building offshore wind farms offshore. An additional tax has been introduced on carbon emissions by enterprises into the atmosphere, and there are incentives for producers of wind, solar and bioenergy.
Sweden is also actively using energy from waste processing and even plans to buy it from neighboring countries in order to abandon oil. Some cities get their heat from incinerators.
China
In China, the most powerful hydroelectric power plant in the world is the Three Gorges. As of 2018, this is the largest building by mass. Its solid concrete dam weighs 65.5 million tons. In 2014, the station produced a world-record 98.8 billion kWh.
The largest wind resources are also here (three quarters of them are delivered to the sea). By 2020, the country plans to generate 210 GW with their help.
There are also 2,700 geothermal sources here and make 63% of devices for converting solar energy. China ranks third in the production of ethanol-based biofuels.
Alternative energy in Russia
The different geographical location of the regions and the specifics of climatic zones in Russia do not allow the development of this industry evenly. There is no investment and there are gaps in the law.
Types of renewable energy in Russia
solar energy
It is used both on an industrial scale and by the local population as a backup or main source of heat and electricity. The capacity of all solar installations is 400 MW, of which the largest are in the Samara, Astrakhan, Orenburg regions and the Crimea. The most powerful solar power plant is Vladislavovka (Crimea). Projects are also being developed for Siberia and the Far East.
wind energy
Wind renewable energy in Russia is slightly worse than solar, although there are industrial installations here. The total capacity of wind generators in our country is 183.9 MW (0.08% of the entire energy system). Most of the installations are in the Crimea, and the most powerful one is located in Adygea – “Adygei wind farm”.
hydropower
This is the most popular alternative energy source option in Russia. About 200 river hydroelectric power stations generate up to 20% of all energy in the country. Since 1968, there has been a tidal power plant in the Kislaya Bay in the Murmansk region – the Kislogubskaya PES. The largest hydroelectric power station is located on the Yenisei River – Sayano-Shushenskaya.
geothermal energy
Due to the abundance of volcanoes, this type of energy is widespread in Kamchatka. There, 40% of the energy consumed is generated by geothermal sources. According to scientists, the potential of Kamchatka is estimated at 5,000 MW, and only 80 MW of energy is generated per year. There are also geothermal stations in the Kuriles, the Stavropol and Krasnodar Territories.
biofuel
Our country is one of the three exporters of pellets in the European market. In Russia, there are factories that create pellets and briquettes from the remains of wood, which heat boilers and stoves.
Agricultural waste is converted into liquid fuels and biogas for diesel engines. But landfill gas is not used at all, it is simply thrown into the atmosphere, causing damage to the environment.
Companies dealing with renewable energy sources
Rising investment in renewable energy and government support is helping many companies to do business successfully.
First Solar Inc.
This American company was formed in 1990 and became famous for the production of solar panels. Now it is the largest company that sells solar modules, supplies equipment and is responsible for technical services.
Vestas Wind Systems A/S
The oldest manufacturer of wind turbines from Denmark. The company was founded in 1898 and has so far installed more than 60,000 wind turbines in 63 countries. Vestas sells individual generators, complete stations and services devices.
Atlantica Yield PLC
The London-based company owns conventional power lines, solar and wind farms in North America, Spain, Algeria, South America and South Africa.
ABB Ltd. Asea Brown Boveri
A Swedish-Swiss company known for automotive engines, generators and robotics. Since 1999, the brand has been involved in the conversion of solar and wind energy. In 2013, the company became the world leader in photovoltaic equipment.
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