**5.3 Solar PV**

Solar power may be concentrated, better known as concentrated solar power (CSP), through mirrors or reflective lenses that focus sunlight onto a collector containing a fluid to heat the fluid to an extreme temperature; then, the heated fluid flows from the collector to an engine, where a little of it is converted to electricity, and a few kinds of CSP allow the warmth to be stored for several hours. One kind of collector is termed "*long parabolic trough mirror reflectors,* **"**and therefore, the second type is "*central tower receiver* "with a field of mirrors surrounding it. Within the central power, the focused light heats a circulating storage fluid known as concentrated solar power (CSP). CSP is a dispatchable form of solar power, whereas PV is not to be dispatched. PV only works while the sun is shining. CSP can be dispatched on demand, much like flipping on a solar switch. So, CSP is not competing with PV [23]. During days without sun, a storage plant additionally produces electricity but only for few hours, so basically without storage, the CSP ability to store is around 25%. With storage availability, the capability element raises to around 65%. CSP is great for helping to satisfy the power need and power requirements, and importantly, CSP collectors can ramp their power manufacturing up and down quicker than coal or nuclear plants [24].

Photovoltaic systems demand more maintenance than other forms of energy generation. Solar systems has a tendency to become the greatest source of power generation by boosting the efficiency of solar cells, which is now around 43%, although manufacturing these cells has not yet been accomplished. A battery will never drain below 50%, preventing the cells from deteriorating and thereby increasing the battery's life expectancy. It is evident that a battery with double the amperage must be utilized instead of a battery with the same power as required. All of these elements influence solar system efficiency; therefore, by boosting solar system efficiency, power system stability may be enhanced. As a result, we might claim that this strategy is still one of the most expensive.

#### **5.4 Bioenergy**

Bioenergy (from conventional Greek bios, life) is extracted from organic materials such as wood, agricultural products, or organic waste and is originated from a recently produced organic material, known as biomass, as an anti-fossilized biomass fuel. It is also used in electricity, heating, cooling, and transport. It can be used in liquid forms, including biofuels; in gaseous forms, like biogas; or in solid forms. Bioenergy is the oldest form of energy used by humans, but it is also at the forefront of Europe's new attempts to step away from fossil fuels and decarbonize our economy. As a result of European climate and energy policies, the use of bioenergy is increasing exponentially [25]. European policies consider all bioenergy to be renewable energy and the foremost important measure from the EU within the fight against temperature change, so much hope currently lies on the performance of bioenergy. The sustainable use of biomass for heating/cooling and the generation of electricity will result in a variety of energy, economic, employment, and environmental benefits. Biomass can be processed at times of low demand and can be used to provide energy as required. Depending on the type of conversion facility, biomass will also play a role in managing the growing share of intermittent renewable energy from wind and solar energy in the electricity system. The possibility to store biomass enables the production of heat to satisfy seasonal demand. In addition, biomass enables the production of high-temperature heat that cannot easily be provided by other low-carbon sources [26]. In 2011, 95% of bioenergy was consumed as heat, 4.7% as transport fuel, and 72,700 kWh as electricity [27]. As far as bioenergy storage is concerned, the sufficient way to store biomass is to accommodate seasonal production and to ensure daily supply to the biomass utilization facility [28]. Wet storage systems may be used for higher yield intended for wet use, such as in brewing and anaerobic digestion systems, with tight monitoring of storage times to prevent unnecessary depletion of feedstock. Storage structures usually used for dry agricultural residues should be secured against spontaneous combustion and excessive decomposition, and the actual storage moisture depends on the type of storage used [28].

The effectiveness of various biomass-to-energy conversion processes varies greatly. For example, producing electricity from pure biomass is only about 30–35% effective; however, producing heat from the same material is frequently more than 85% efficient. In general, utilizing bioenergy for heat and electricity is a far more efficient approach of decreasing greenhouse gas emissions than using bioenergy for transportation fuel. Organic waste and agricultural or forestry residues are more resource-efficient than many other types of feedstock because they do not place additional strain on land and water resources and offer significant greenhouse gas savings.
