HYDRO AND GEOTHERMAL ENERGY

Mini and Small hydro plants

MHP mini hydro power plants - the potential energy of water (the transformed energy of solar radiation) is converted first into kinetic energy of water, which hits the turbine and then is transformed into mechanical energy - angular velocity, of turbine shaft and finally via electromagnetic induction is transformed to electrical energy in the generator. Hydropower technology is considered to be the best known and most developed at the global level, compared to other RES. By being technically the best known is considered to be BAT is one of the best available technologies, with a high level of energy efficiency (calculated from the total potential energy difference of water before and after passing MHP - a system of hydroelectric power generation has efficiency of over 90%). Small hydro is defined as a facility that uses the energy of rivers with the output of electric power 10 kW to 10MW.

Types of Small and Mini Hydro power plants

The advantages of installing MHP:

·         MHP are environmentally friendly, electricity generation has no emissions of carbon dioxide into the atmosphere, which is extremely important.

·         Reduced consumption of fossil fuels,

·         Help protect against floods, do not require the use of large areas,

·         A safer and more reliable distribution of electricity, the degree of efficiency up to 90% and operating costs are low,

·         A positive social impact on the region (employment, etc.).

Mini hydroplants - capacity from 2 MW to 10MW

 Flow through Mini Hydroplants of smaller capacity up to 2MW

Energy from movement of large water mass – seas and oceans

Tidal Energy -electricity production based on the rotation of the propeller in the water mass passing through the dam a flow through system that closes estuaries or bays of the great open sea or oceans. This requires high technology and large construction efforts to achieve stable production, but the energy that is obtained by this RES is abundant. Implementation costs are high, since project of this RES are large, from 100MW to 10GW. Also, the inexhaustible energy and the period of operation of these dams is very long (several hundred years), it is needed to repair blades and generators. The problem can occur if the living world an influence on the work (migration of fish, coral, sea grass ...) and these factors reduce power during operation, a set of alternative energy systems affecting the limited wildlife estuaries or bays. Therefore, it is difficult to estimate a suitable location for this type of plant. It is assessed that there are only 20 suitable locations for installing such systems. In order to use this type of energy it is necessary to make a dam (similar dams that allow passage of ships through the bay and waterways with different levels of height), which shall focus on water mass propellers system. The influx of energy is 10h day, but the energy is constant movement of water masses. Note that this energy requires low operating costs.

Systems for producing energy from tidal power and sea currents - Hydra system

The energy of waves - sea waves is also very good source of energy. The most effective model is the reverse system of the machine that made artificial waves in pools. As the blown air chamber is moved, the air rises, and as the chamber moves by moving a large mass of water and artificially generated wave. For the case of power plant which would use wave energy, water, would enter in a special chamber (set on the coast) to the arrival of the waves increases their level, and under the power of water air would compress as big cylinder under pressure and it would generate mechanic force. If there is turbine on the narrow outlet of the air it would be possible to generate electricity. The problem would be high maintenance costs due to the sludge that would easily clog the entrance. Also the problem was the noise that would be created on exit and entry of air into the chamber. The energy of waves in the open sea can be used separate floating tube, which is approximately 150 m, and which segments of the melt with water. Stretching energy system transforms compounds into electricity generators, the system is called Pelamis.

Pelamis system - generating power from sea waves

Geothermal Energy

Geothermal energy can bring significant cost savings for heating around 40%, and if there is sufficient energy, geothermal energy may be the only source of heat energy in the household. According to the analysis for Serbia, the total production capacity of geothermal energy is about 1.2GW, but it is necessary to properly regulate this field of energy and thoroughly investigate all the existing sources of geothermal water. Depending on the mass and temperature of geothermal water it can be used to produce electricity through geothermal power plant. The use of geothermal power plants is very profitable, but the condition that there should be appropriate legislation to use this type of alternative energy, and above all, the condition is the existence of geothermal water or geothermal water at reasonable depth for the exploitation of energy. Price performances of these plants are very small compared to the profit and limit the production of energy available to the mass of geothermal water and its temperature.

Picture of Geothermal mud digger and types of geothermal pipes placement

Thermodynamic cycles of usage of geothermal energy with heat pumps, in summer-cooling and in winter-heating