alternative energy benefits

Alternative energy is frequently brought to the attention of public opinion as a viable and economical source for electricity and thermal energy supply, now and in the future, at the macro and individual levels.


As energy consumption (electricity, heat) increases, fossil fuel resources decrease and pollute the atmosphere. Moreover, at international level, conventional energy is held by a limited number of organizations, which dictate the availability and prices of this resource of strategic importance. In this context, renewable energy, produced by nature, is a saving solution, cheap and with little impact on the environment.

Alternative energy

Alternative energy replaces conventional energy in a sustainable way, increasing energy independence and reducing the negative impact on the environment. In recent decades, public policies have encouraged the production of eco-energy through various incentives. The big producers were encouraged to invest in this area by receiving green certificates for the energy produced, and the population that chose to equip their house with green energy production equipment received funding.

Two of the main directions of the European Parliament, in terms of energy strategy, are: reducing emissions by 20% by 2020 and increasing long-term capacity from alternative energy sources. This denotes the importance and sustainability of alternative energy production.

What is alternative energy?

Alternative energy, also called green energy, is produced through or by unconventional, renewable sources that have a low negative impact on the environment (non-polluting).

A classification of the main types of renewable energy is made from the renewable source involved in the production of energy.

Thus we have the following main types of alternative sources of renewable energy:

  • Wind energy – refers to the energy produced by the use of turbines that convert wind energy (kinetic) into electricity. Wind turbines can be used for individual purposes in a domestic wind power plant to supply the home with electricity needed for lighting. Wind farms feed SEN (National Energy System) so that the energy is distributed to the population.
  • Solar energy – solar energy is used to produce electricity (through photovoltaics) or heat ( solar panels ). Solar energy is a cheap source of energy for anyone, personal or industrial (provided good sun exposure). Solar energy in Romania is particularly exploited in domestic electricity or thermal power systems.
  • Hydro energy – is the energy produced by the flow of rivers. Hydroelectric energy remains a main source of electricity in Romania at the macro level (25% of the energy produced in Romania). At the individual level, micro-plants are not an accessible source for domestic use.
  • Biomass – is used to produce thermal energy by chemical reaction or by combustion of organic waste. This is an alternative primary source globally as any residue (plant, animal, forest, etc.) can be used as biomass.
  • Geothermal energy – production of geothermal energy using heat pumps .

According to Transelectrica , renewable energy in Romania at the macro level comes primarily from hydro, wind, solar and too little biomass.

Alternative energy versus conventional energy

Alternative energy is a sustainable development, environmentally friendly and cheap (even free, if we exclude the depreciation of the investment!). The unconventional energy sources are renewable, exist permanently in nature and can be used for the production of electricity at home, for domestic and domestic heated water, but especially at a strategic level.

Renewable energy in Romania enjoys support through investment incentive programs. The legislation stimulates the production of renewable energy, forcing the energy suppliers to purchase a share of green certificates (Law no. 134/2012) or financing through the Casa Verde program  consumers purchasing heating systems that use renewable energy (solar panels for water heating, photovoltaics). , heat pumps).

Conventional energy is the use of fossil fuels (hydrocarbons, coal, oil and natural gas) for the production of thermal or electrical energy. It is a polluting way, which worsens the greenhouse effect, costly (there are huge costs on two levels: the extraction of fossil fuel, and subsequently the production of energy) and with exhaustible resources.

How to calculate the efficiency of an energy source

The efficiency of an energy source is represented by the ratio of the energy produced for the consumer’s use to the energy consumed by the respective system for the production of energy. Another way to check the efficiency of an energy source is to consider the cost per 1 kW of energy produced versus depreciating the investment.

 There are various formulas to evaluate the energy production and efficiency of the respective source, here are some examples.

A general calculation formula for the efficiency of a solar energy system is (Energy generated in the form of alternating current) / (Total incident radiation on the inclined surface of the photovoltaic panels) – ISB source.

For hydroelectric power , the performance of a turbine is the ratio between the power provided by the hydraulic turbine and the absorbed power (hydraulic power equivalent to the flow measured under the net fall). In order to estimate the overall efficiency, the efficiency of the turbine is multiplied by the efficiencies of the speed multiplier and the alternator. Hydro energy has the best efficiency of all renewable energy resources. (source, Ener Supply).

Wind energy efficiency is calculated as the ratio of turbine power versus absorbed power to produce electricity. The power generated by the wind turbine is given by the formula P = ρ2cpηAv1³, where ρ is the density of air, cp the power coefficient, η the mechanical / electrical efficiency, v1 – wind speed, and A the rotor disk area. The annual energy production is variable and is related to wind speed (which is evaluated with specific standardization software – Wasp).

Use of electricity through the classical electricity network

The necessary electricity for domestic consumption can be provided by photovoltaic panels in two ways. On the one hand, small photovoltaic systems can be used to provide some of the home’s electricity, reducing costs to the traditional supplier. In this case, the house is connected to the conventional electricity grid SEN.

In this case, the electricity is either directly consumed without being stored, or the national grid is started and it supplies electricity to the national grid. The second option is bureaucratic and time consuming and requires specific expensive equipment.

On-grid monocrystalline or polycrystalline photovoltaic panels can be used, accessible and easy to maintain. A kit for photovoltaic system of 3 kW has a price of about 4500 euros. For a PV panel calculation, you can visit the US Department of Energy’s website.

Use of electricity as an independent system

For homes that can not be connected to the electricity grid, you can choose the off-grid electric solar panel, which ensures the independence of the home, producing electricity for free. The electricity produced is stored in solar batteries and used for home consumption.

As it is the only source of electricity in the house, sizing consumption is essential. A photovoltaic system for an independent house can cost around 15-20 thousand euros, depending on the electricity needs, and the investment can be amortized in about 15 years.

The street lighting system with photovoltaic panels is another example of the use of electricity as an independent system.

Hybrid energy systems

Hybrid energy systems are implemented for off-grid, energy-independent homes. Since the solar energy captured by photovoltaic panels may be insufficient in winter, a hybrid energy system can be used.

It can consist of a system of photovoltaic panels and a small wind turbine, together covering the annual electricity needs. An automatic generator can be installed that starts to detect an electrical consumer, without mounting storage systems, which will support the entire wear. The optimal option is for the energy to be stored in special batteries and supplied to consumers.

Another hybrid system can be composed of solar panels for water heating and electric solar panels.

Alternative electricity storage

In the off-grid green energy systems, the best solution for home users is the energy stored in solar batteries and then used by home consumers through inverters.

The advantages of installing energy storage batteries are the use of all the energy produced.

Technical characteristics of alternative energy

Alternative energy is stored in batteries, which are in direct current. In order for the energy to be used in the home appliances (230V, 50 Hz, AC-AC) an inverter is required.

Some features to consider when purchasing the off-grid inverter: power dimensioned according to household consumption (W), having a pure sine wave and the input voltage (from the photovoltaic panels) must be checked.

Use of alternative electricity

Alternative electricity can be used in conjunction with the energy provided by the local company. Thus, you reduce costs at the supplier and have your own energy source.

Electricity from alternative sources can be used strictly for personal use in homes

off-grid that are not connected to a conventional provider. In order to streamline the consumption versus the production of electricity, we recommend that you use various ways of saving electricity, such as:

  • installation of LED or similar bulbs;
  • full use of natural light;
  • avoidance of resistive household consumers (with resistors);
  • efficient use of large household appliances;
  • the use of efficient and economical heating systems, the completion of the electricity system with solar panels for water heating during the summer.

Alternative energy types

The classification of alternative energy starts from the type of resource used to produce energy, namely: wind, sun, water and bio mass. Specifically, we have the following types of renewable energy:

  • Wind energy – refers to the energy produced by the use of turbines that convert wind energy (kinetic) into electricity. Wind turbines can be used for individual purposes in a domestic wind power plant to supply the home with electricity needed for lighting. Wind farms feed SEN (National Energy System) so that the energy is distributed to the population.

  • Solar energy – solar energy is used to produce electricity (through photovoltaics) or heat (solar panels). Solar energy is a cheap source of energy for anyone for personal or industrial use (provided good sun exposure). Solar energy in Romania is particularly exploited in domestic electricity or thermal power systems.
  • Hydro energy – is the energy produced by the flow of rivers. Hydroelectric energy remains a main source of electricity in Romania at the macro level (25% of the energy produced in Romania). At the individual level, micro-power plants are not the most permissive source of household energy, because of inaccessibility to the river.
  • Biomass – is used to produce thermal energy by chemical reaction or by combustion of organic waste. This is an alternative primary source globally as any residue (plant, animal, forest, etc.) can be used as biomass.
  • Geothermal energy – production of geothermal energy using heat pumps.

The most efficient alternative energy sources

The efficiency of an alternative energy source depends on the position of the consumption place on the globe. For example, in Romania the most efficient source of energy (and the main source) is hydropower. Specifically, now as we write this article, real-time energy is distributed as follows:

  • 28.89% Hydro – 2692 MW
  • 22.29% Hydrocarbons – 2077 MW (na conventional)
  • 22.04% Coal – 2054 MW (na conventional)
  • 14.97% Nuclear – 1395 MW
  • 10.96% Aeolian – 1021 MW
  • 0.62% Biomass – 58 MW
  • 0.24% Pictures – 22 MW

Source – Transelectrica

Biomass is very successful in the rest of Europe, but not in Romania. The Netherlands enjoys photovoltaic energy (on- and offshore), and desert areas around the world have as primary source of alternative energy the sun.

For domestic consumption, photovoltaic energy (especially high-rise photovoltaic panel systems installed on homes) is an efficient and available source all year. The efficiency of an alternative energy system is given by the presence of the respective source, and this is a first selection criterion for choosing the right source (of photovoltaic panels in sunny areas, and wind turbines in coastal areas).

Wind energy

Wind power is booming in Romania, being the next alternative energy source after hydropower and nuclear power. Wind power is efficient in coastal or hill areas. The disadvantages of this type of energy are due to the lack of wind in the areas of high-speed, high-speed wind in the mountainous regions.

In order to make a correct investment in the generation of electricity at home, the wind potential must be estimated and the turbine must be correctly sized, based on the wind speed. Domestic wind turbines can be installed in a hybrid system.

A home wind turbine kit has a price starting from about 10,000 euros (at a power of 3 kW, at a wind speed of 11 m / s). There are cheap wind energy generators on the market, produced in China (which is a big alternative energy producer, so their systems are being tested).

Geothermal energy

Geothermal energy is used for direct heating, when the water temperature is less than 90 degrees Celsius (for temperatures above 13 degrees Celsius, geothermal energy is used to produce electricity).

When the temperature is below 40 degrees Celsius, the thermal water is used to heat or cool the interiors by means of heat pumps. Heat pumps are different from 12V submersible pumps, those being designed only for surface water extraction.

The efficiency of the heat pump is given by the ratio between its heating power and the electric power absorbed from the grid for the production of thermal energy.

High-temperature geothermal systems are used to generate electricity, at 10 kg of steam producing one unit (kWh) of electricity. The geodesic works to identify the geothermal source are expensive.


For Romania, hydropower is the main source of renewable energy, thanks to the country’s wealth in river courses and high capacity plants (Iron Gates 1,2, Lotru, Râul Alb, Stânca).

Hydro energy in Romania represents over 20% of total production, thus elevating our country to the European ranking for alternative energy.

Nuclear power

Nuclear power is an efficient source of electricity generation, only in a regulated and well-monitored environment. In Romania, the Cernavoda power plant is built in the CANDU system, with reactors with natural uranium and heavy water.

Currently, reactors I and II are operating, which produce over 14% of Romania’s electricity.

Solar energy

Solar energy is the radiant energy released by the sun. Electricity is produced by capturing solar energy through specific collectors (solar panels). The efficiency of a photovoltaic installation is given by the region in which the photovoltaic system (sun intensity) is mounted and the positioning of the panels. In Romania, the Black Sea coastal area has the highest solar intensity, suitable for both photovoltaic and wind power plants.

Solar energy in Europe is between 100W / sqm (cloudy day) and 1000W / sqm. The efficiency of a photovoltaic kit is given by the material used for the collector, the intensity of the solar energy, the positioning of the solar panel with respect to the azimuth angle and the inclination angle to the horizontal.

Other alternative energy sources

As electricity consumption increased, new alternative energy sources were used. The water of the seas and the oceans began to be used, the Japanese created electricity systems generated by the body’s movement, and the fitness rooms began to generate their own energy in the cycling rooms. In the Internet age, server-generated heat is reused in alternative energy systems.

The challenge that scientists are launching is that by 2052 the planet will be powered only by renewable energy, and this challenge stimulates innovation.

Wave energy

In recent years, scientists have developed sensors to convert wave energy into electricity. The waves carry kinetic energy (due to the speed with which they propagate towards the shore).

Thus three types of energy capture systems were invented: pressure pipes, starting from the ascent of the liquid to the shore and the system of the liquid piston (water pumping). The disadvantage of these new technologies is that they affect the marine microclimate from the shore.

The energy obtained from seaweed

Marine algae are developed in systems that multiply to the solar energy in a controlled way offshore, where the shore life cannot be affected. Microalgae are used for water purification and for biofuel crops.

The benefits of using algae as a fuel source are multiple: zero negative impact on the environment, is a clean source of biofuel, and crops grow rapidly without involving the consumption of other conventional energy resources.


Bioenergy or biomass energy occupies an important place in global development strategies from alternative resources. Biomass is of two types: energy crop or vegetable, forestry, animal farm, including urban waste. In Romania it takes land, but it is not fully exploited.

There are several ways to generate energy from biomass, mainly through chemical reaction or combustion. A recent example of the use of biomass in a new way, is given by the use of coffee beans for London buses on the floor.

The energy generated by the movement of the body

Through movement the body generates energy, and Japanese researchers have exploited this by inventing the pavers that generate energy at every step of the passage.

Scientists want to get a more direct way than that, by mounting devices designed to capture the energy produced by each movement of the body.

Nuclear fusion

Nuclear fusion is the challenge of scientists since the discovery of the energy obtained from fission (nuclear energy). In the German nuclear fusion reactor Wendelstein 7-X, scientists tested in 2016 the production of energy from nuclear fusion.

At the base of these new energies lies the nuclear fusion of hydrogen atoms, similar to the way solar energy is produced.

Carbon capture and storage in industrial areas

An Icelandic energy-producing company has developed a carbon dioxide capture system, which it then injects into basalt rocks.

Following the injection of carbon dioxide into the soil, new minerals develop. This reduces the negative impact on the environment. A similar project is being developed in Romania at the Turceni Energy Complex.

Space technologies for hydrogen capture

Harvard researchers have succeeded in 2017 with an incredible experiment. During the 100-day research, they managed to convert hydrogen into metal. This new resulting material has powerful driving properties and could be used in a variety of applications (levitating train or ultra-high performance computers, aeronautics, etc.).

The experiment was done in the laboratory, under conditions similar to those in space. The concern of scientists is that this metal may not be stable at the level of natural pressure on Earth, but research is ongoing.

Alternative energy sources with minimal investments

For consumers, solar panels for hot water, affordable photovoltaic systems, domestic wind turbines remain an alternative energy source within reach.

Through the classic Casa Verde program, it offers applicants up to 3000 lei for non-pressurized solar panels (solar panels for water heating), 6,000 lei for pressurized panels and up to 8,000 for heat pumps.

Wind energy for own consumption

Wind energy for own consumption is a solution in areas where the wind is an important and constant resource. For a home wind turbine to produce energy, the wind speed must be between 6-10 m / s (at 11 m / s the peak power is reached). There are people who have built small wind turbines for the house, but there are some concerns regarding the standardization of measurements, the safety of the turbine pillar and the accuracy of the operation of such an improvised system.

The off-grid domestic wind turbine can be used in a hybrid system with photovoltaic panels and equipped with solar panel batteries. To ensure full green energy for the home, you can install a system of solar water pumps, consisting of a storage tank, a 12V submersible pump and small photovoltaic panels. 

Photovoltaic panels

Photovoltaic panels remain the main option to provide electricity independently. The best solar panels are monocrystalline photovoltaics (they are good collectors of solar energy).

To give you an image of the costs involved we give you some price benchmarks for photovoltaic panel kits of different capacities. A photovoltaic kit of 2 kWh / day is priced around 2500 euros; a 3 kw photovoltaic system is priced around 4000 euros (3 kW is sufficient for a small or medium dwelling, and in a plant there are 12 panels of 250 W); a 10 kW photovoltaic system is priced around 20,000 euros (40 photovoltaic panels are included for collection).


Micro-hydroelectric plants can be an alternative source of energy when the property is crossed by a stream, with hydro power being the most efficient source. There are companies in the market for such systems. However, at the micro level, hydroelectric plants can be expensive, difficult to exploit, and the location of such a system on the water course can be prevented by environmental activists (even if it is environmentally friendly).

The water course for green energy requires the development of a thermal power plant on water courses. In 2012, Hidroelectrica tried to privatize the micro-hydroelectric plants in the portfolio, but the project was not successful, as they require high repair and maintenance costs.

Advantages and disadvantages of alternative energy

The advantages and disadvantages of alternative energy continue to be the subject of analysis, sometimes disputed. It is obvious that renewable energy sources are ecological and unlimited. A study in 2009 showed how different types of conventional fuels will decline in the period 2020-2050.

So the early use of green, inexhaustible resources is an obvious solution. Solar energy will last billions of years, as will wind energy. The diversification of sources, their use and the manufacture of equipment with low electricity consumption is part of a comprehensive, global plan to contribute each to a sustainable environment.

The advantages of alternative energy

  • The main characteristic of alternative energy is sustainability. It can be produced in the long term, without contributing to the greenhouse effect and without creating limited resources.
  • Alternative energy is renewable, and energy consumption by the population does not lead to depletion of resources.
  • Ecology – the alternative energy is green and does not affect the environment. There is no emission of pollutants, so the impact on the environment is minimal.
  • Zero costs for alternative resources. The wind, the sun, the geothermal water and the energy of the watercourse are free sources and, in a healthy eco-system, unlimited.
  • Easy maintenance of photovoltaic panels and wind power plants.

The disadvantages of alternative energy

The disadvantages of alternative energy are few, but they slow down the development of green projects. Access to renewable resources is limited area. Not all solar panels can be installed that are efficient. The wind turbines are dependent on constant wind, with speeds over 6 m / s.

Initial investment in green energy is another impediment. For a 2 kW photovoltaic system, 8 panels are required (a calculation of the PV panels can be made simple, dividing the total power by the power of a panel – 250W), inverters and batteries. In addition, additional, costly and time-consuming opinions and assessments are required for renewable energy systems.



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