Renewable energy sources

Renewable energy sources

COMENIUS HELP

Tjaša Kovačič and Zala Zoran

It is energy derived from renewable sources which are very important for the protection of the environment, because it generally causes less pollution.

•Wind,

•Sun,

•Biofuel,

•Biomass,

•Geothermal,

•Hydroenergy.

•Alternative sources are divided into seven sectors, which have develop very quickly :

WIND ENERGY

• It’s energy generated by wind.

•Wind turbines have propellers, which resemble air propellers, and most of them have a diameter of up to 60 meters and are able to submit 3mW of electrical power. They are intended to fuel the electric generators.

•"Fields" of such wind turbines are built in areas with constant wind. These fields are usually very large and have significant impact on the appearance of the landscape, but the land surrounding it is still useful.

•Wind energy accounts for only 1 percent of the world's electricity produced, but its importance is increasing.

WIND ENERGY – In Slovenia

In the year 2008, there were only two wind turbines placed in Ajdovščina and in Divača, which are connected to the electric network.

SOLAR ENERGY

Solar energy is energy which is derived

from the sun, and obtained with solar

cells. Solar cells convert the sun energy into electricity, with the help of electrons.

The energy radiated by the Sun to the Earth, is 15,000 times the energy we consume. This energy is renewable, non-polluting and at the same time free.

•Due to the high demand for renewable energy, the production of solar cells in the past years greatly increased, it grows so fast that once every 2 years it increases for 50 %.

•Such plants are generally placed on roofs of buildings or on meadows.

SOLAR ENERGY – In Slovenia

In 2012 all of the solar plants in Slovenia produced about 64.000 kW of electric power.

In 2012 there were 2088 solar plants

installed

BIOFUEL

•Biofuel is solid, liquid or gaseous fuel derived from recently dead biological material. But it can also be obtained from various plants and substances of plant origin.

•It’s mostly used for heating households and cooking.

•There is also a technology

which can produce energy

from polluted air.

BIOFUEL-In

Slovenia

With Slovenia in the European union, now there are areas that we can grow rapeseed, soybean and sunflower, but only if its produced into bio fuel. The aim is to introduce 5% of bio fuel consumption.

BIOMASSIs renewable energy source, which consists of the entire plant and animal organism.

Biomass can be used for heating or it can be transformed into solid or gas hydrocarbons, which can be used as fuel.

Example :

• wood biomass

• less quality wood from forests

• wood from agricultural and urban areas,

• scrap wood

• used (uncontaminated) wood

•Wood, straw and organic waste are the most used materials for energy production.

BIOMASS – In Slovenia

In Slovenia there are about 800.000 house holdings, 25 % of them are heated only with biomass.

GEOTHERMAL ENERGY•Geothermal energy is thermal energy generated and stored in the Earth. The Geothermal energy of the Earth's crust originates from the original formation of the planet (20%) and from radioactive decay of minerals (80%).

•We distinguish between high-temperature and low-temperature geothermal resources. In the first the water temperature is above 150 ° C and it’s used to produce electricity, while in the second the water temperature is below 150 ° C and is used directly for heating.

GEOTHERMAL ENERGY– In

SloveniaIn Slovenia, the richest geothermal and also the most studied

are the following areas: the Pannonian basin, Krško-Brežiško

field, Rogaško-Celjsko field, Ljubljana Basin, Slovenian Istra and

a region of western Slovenia. There are currently 79 wells in

Slovenia with a thermal capacity 140 MWh. Approximately 80 %

of this energy is harnessed from the low-temperature laptops.

HYDROENERGY

Water is the most important renewable energy source and as 21.6 % of all the world's electricity is produced by hydropower exploitation or hydropower. In hydro energy plants the hydro energy is converted to electric energy. Hydro energy does not pollute the environment, and its not so expensive.

The negative downside of hydroenergy is that the construction of them is very harmful for the environment.

HYDROENERGY– In Slovenia

In Slovenia there are 27 hydroelectric power

plants. On rivers: Drava, Sava, Soča, Idrijca in Prošček. The plants

produce nearly 24.5 % of all power generated.Hydroelectric plant Dravograd