Humanity in the process of its development consumes more and more energy to ensure its vital functions. If before dry branches fallen from trees was enough, now we burn huge amounts of fossil fuels, block rivers and split the atom. All these methods are not very friendly to our planet. Sooner or later, we will exceed the strength of the earth and collapse will come. To avoid disaster, people need to reduce consumption and use renewable energy sources. About reducing the consumption we will talk in the next article, and now we will consider the renewable sources and methods of energy extraction available to mankind at the present moment, as well as the reformation of the energy system as a whole.
Electricity is a type of energy that cannot be stored in its pure form in valuable quantities. After the electricity occurs it must do the work immediately and go to other forms of energy. It is advisable to accumulate energy in the form of hydrocarbons (CxHy), alcohols (CnH2nOH) or hydrogen (H2), or biomass.
The modern concept of a large-scale concentrated electric power industry is inefficient from a global perspective. Large power plants have a low unit cost of kWh, but not everything in this world is measured in money. Huge stations require huge equipment which produced in a huge factories which feed from the same stations through huge powerlines which require huge equipment for the transmission, conversion and distribution of electricity with losses at each stage. In addition, a large concentration of power plants adversely affects the environment. Nature can not cope with the processing of such an intense release of harmful substances and carbon dioxide (CO2) locally. Many stations use natural water reservoirs for their needs, which causes thermal pollution and violates the natural biotops of vast territories. A large amount of forest is cut under huge power lines and distribution substations. The risk of electric shock and the harmful effects of electromagnetic radiation increase. The participation of non-industrial consumers in the global energy sector is small. Therefore, the mega stations work mostly for themselves and for those who own the energy system.
The concept of the future is small distributed energy. Many small power plants connected in a single energy system and, if possible, use local renewable resources. The most promising are:
I. Biogas plants.
Bacteria recycle biomass under anaerobic conditions. As a result, we obtain a mixture of methane-based gases. It requires cleaning of impurities. Methane is a universal energy carrier. It is stored in gaseous or liquefied form.
II Mini hydroelectric plants.
They are installed in any river or stream without disturbing the ecosystem.
They produce mechanical energy (mills, pumps, machine tools, etc.) and electricity. Excess energy is converted to hydrogen through electrolysis plants *. Hydrogen is stored in a gaseous or liquid state.
* Water electrolysis is the physicochemical process in which, with the influence of a constant electric current, water breaks down into oxygen and hydrogen.
2H2O + energy → 2H2 + O2.
Before use, the gases in the installation are dehydrated and cooled. The outlet pipe of the installation is always protected by check valves to prevent fires. The efficiency of the facilities stories is currently approximately 60%.
III. Pyrolysis facilities **.
The combustion of wood with oxygen deficiency forms a combustible gas that can act in internal combustion engines. It is stored in a liquid or gaseous state.
** In a gas generator during the thermal decomposition of the firewood under conditions of oxygen shortage, a CO combustible gas is formed. 1 kg of wood produces enough CO gas to generate 1 kWh of electricity.
IV. Solar stations
The sun’s energy is concentrated with special mirrors and sent to steam production or to a Stirling engine. The steam turns the turbine of the electric generator. More effective in arid and polar regions.
Example: Gemasolar. Spain. Seville.
Sunlight is converted into electricity through photocells. It is necessary to improve the technology of production and exploitation of solar panels to reduce environmental stress. Excess energy is converted to hydrogen.
Wind energy is converted into mechanical or electrical energy by rotating wind pick-up mechanisms.
It is necessary to improve the technology to reduce the environmental impact (vibration, noise, energy intensity of exploitation).
Tidal energy has been used by people since ancient times by installing tidal mills on the coasts of England, France, Spain, Russia, Canada, the USA and other countries. Such installations were carried out by forming a pool with dams overlapping small bays, where mill wheels that worked during low tide were located. Tidal power plants use the renewable energy of tides, which is associated with tidal forces arising from the gravitational interaction of the Earth with the Moon and the Sun.
Geothermal energy is energy derived from the natural heat of the Earth. This heat can be achieved using wells. This heat is delivered to the surface in the form of steam or hot water. Such heat can be used both directly for heating homes and buildings, and for the production of electricity. Geothermal energy reserves are inexhaustible. Thermal regions are found in many parts of the world.
The distribution of generation capacities will lead to a decrease in the urban population, the development of peripheral territories and an increase in the number of people employed in the real sector of the economy. The energy will be closer to the people, people will better understand the processes of energy generation and transformation throughout the planet, they will be more concerned with the conservation of energy and the culture of consumption. Distributed energy eliminates the problem of major technogenic accidents. Eliminate the risks of deenergizing a large number of consumers when one station is fall. The threat of terrorist attacks at power plants will disappear because they will no longer make sense. At the same time, we should not refuse to extract and use fossil hydrocarbons, because they are the energy of the sun stored by our planet for millions of years. But at the same time, it is necessary to improve the technology of its production and processing and reduce its participation in the global energy sector.
Therefore, distributed energy based on renewable energy sources is one of the most important components of a sustainable and prosperous future for all mankind.