Energy sources fall into two broad categories:
- traditional (coal, oil, natural gas, uranium);
- non-traditional / alternative (RES, which use the energy of the Sun, wind, biomass, tides, rivers, seas and oceans, geothermal, thermonuclear energy, etc.).
The energy crisis has boosted demand for alternative energy sources. However, their insufficient widespread use is currently caused by a number of technical problems.
6. Variability of renewable energy sources, dependence on weather and time of day
This circumstance creates the problem of the reliability of the autonomous supply of electrical and thermal energy to consumers. Thus, an autonomous power plant with renewable energy sources must necessarily include batteries for storing energy, or additional backup equipment on traditional fuel. This inevitably leads to an increase in the cost of the system as a whole.
5. Low specific density of incoming alternative energy
The limiting solar radiation flux density does not exceed 1 kW / m2, the energy density of the wind flow at 5 m / s is about 70 kW / m2, and at 10 m / s - about 600 kW / m2. That is, to obtain high power, a RES installation must have large dimensions, which also leads to an increase in the cost of the system.
4. Low efficiency of conversion of alternative energy into heat and electricity
The efficiency of installations with wind generators is no more than 30-40%, solar energy conversion 30-35%, biomass - 30%, hydropower - 60%.
3. Low power RES
Currently, modern technical capabilities make it possible to cover up to 10% of the required energy from renewable energy sources.
2. High equipment price and long payback period
To form an autonomous system of electricity and heat supply, it is not enough just to install a RES source and storage batteries. In this case, the installation of an inverter, controller and other auxiliary equipment is required. Despite the perspective and clear advantages of alternative energy sources, they have a long payback period due to the high initial cost of installations and the complexity of installation work.
1. Occupation of large areas, impact on the environment
First of all, this applies to solar and wind power plants. To obtain energy from renewable energy sources, commensurate with energy from thermal power plants and hydroelectric power plants, installations must have large dimensions and occupy large areas, which can lead to a decrease in the temperature of the soil and the surrounding air. For example, large-scale construction of solar power plants contributes to the disruption of the thermal balance, changes in wind direction, soil and vegetation characteristics.