Integration of Renewable Energy Sources with Smart Grid

Three gauges project in China on the Yang-Yang river is the largest power station in the world having installed capacity of around 18,200 MW. Tehri hydropower complex is built across the Bagirathi River in Uttarakhand with a proposed capacity of 2,400 MW is the tallest hydropower project in India. The hydropower plants of less than 25 MW come under Ministry of New and Renewable energy and above 25 MW are under the Ministry of Power. The construction of massive dams submerges large areas that may lead to the color change of the land. Some hydro project submerges rain forests which will add to global warming impacts. Because of heavy construction requirements, it needs high capital cost and long gestation period compared to thermal plants [11].

The pumped storage plants are used to store hydro electrical energy. This scheme has an upper and lower reservoir. During peak power generation, electrical energy is used to pump water from the lower reservoir to the upper reservoir. During peak load period, energy in the upper reservoir is used to generate the power.

The western region of India with steep gradients of rivers has the largest potential for the development of pumped storage plants. A potential of 96,524 MW was identified by CEA during studies conducted in 1978–1987.

Synchronous machines in these plants can be made to act as synchronous condensers for voltage support. It helps in the straightening of load curve by act load during low load period and as generating source during peak periods which improves the overall economy of power system operation.

As we know, the sun is the biggest source of renewable energy for the Earth. The part of solar energy is enormously large even though the earth receives only a part of the energy generated by the sun (i.e., solar energy). There are two forms of solar energy, namely, light and heat, which the earth receives. The solar power can be converted to electrical energy using either photovoltaic (PV) or concentrated solar power systems.

PV directly converts solar energy into electricity. When certain semiconductor materials are exposed to light, they absorb photons and release free electrons. This phenomenon is called the photoelectric effect. Direct current (DC) is produced by the PV effect based on the principle of photoelectric effect [12].

Solar cells or PV cells convert sunlight into DC electricity. But a large amount of electricity cannot be produced by single PV cell. Therefore, several PV cells are electrically connected to form a PV module or solar panel. Solar panels range from several hundred watts up to a few kilowatts and are also available in different sizes. Solar panels or modules produce current which is directly dependent on the incident light. Since most of the applications require AC power, the solar power system consists of an inverter too [13].

There are different types of PV systems:

PV direct system: This is the simplest type of PV system. Because they do not use batteries and not tied up to the grid, they power the load only when the sun is shining.

Off-grid system: This is also called as stand-alone systems which is independent of the power grid. When the sun is not available, batteries are used to store energy.

Grid connected system: Here solar PV systems are tied with grids so that the excess required power can be accessed from the grid. They may or may not be backed up by batteries.

In this type of solar power system, sun rays are focused on a small area by using mirrors or lenses. Due to this, a large amount of heat is generated at the focused area. This generated heat is used to heat the working fluid which, in turn, drives the steam turbine. There are three main types of concentrated solar power systems, namely, parabolic trough, power tower, and dish sterling system.

Advantages

Solar power causes no pollution.

Renewable energy resource and can produce clean power throughout the year.

Return on investment unlike paying for utility bills.

In case of grid connected excess power can be sold back to power company.

Helps the economy by creating jobs for solar manufacturers and installers.

Less safety risks.

Disadvantages

Initial cost is high for installation and material.

Requires additional equipment like inverter to convert dc to ac.

Efficiency is generally low.

Cloudy days do not produce as much energy.

Size of the solar panels varies depending on the geographical locations for the same power generation.

Large battery bank is needed to store the power.

Government Initiatives: Since solar energy has started to light up the lives of millions of peoples. Government has taken various initiatives to enable an increase in solar power at a subsidized energy cost. There are some top government initiatives which is listed below:

Solar park scheme [13].

Viability Gap Funding scheme (VGF).

Government Yojana solar energy subsidy scheme.

Ujjwal Discom Assurance Yojna scheme (UDAY) [13].

Rooftop scheme.

Jawaharlal Nehru national solar mission.

1 Kurnool Ultra Mega Solar Park: It covers a total area of 5,932.32 acres in the Gani and sakunala villages and utilizes 4 million solar panels with capacities of 315 and 320 Watts. This solar park is able to generate more than 8 million KWh of electricity, which is enough to meet the total demand in Kurnool district.

2 Kamuthi Solar Power Park: It is the world’s sixth largest solar park and covers a total area of 2,500 acres in Kamuthi, Ramanathapuram district. This solar park is able to generate 648 MW at a single point [14].

3 Gujarat Solar Park: It covers a total area of 5,384 acres in the Charanka village, Patan district and installed capacity is 274 MW. It has also capacity to generate 100 MW of wind power. So, this is the biggest solar-wind hybrid park in the world.

4 Pavagoda Solar Park: It covers a total area of 13,000 acres in Pavagada Taluk, Tumkur district and planned to have a capacity of 2,000 MW at the end of 2018 and will be the world’s biggest solar park.

5 Punjab Solar Park: It is located in Bhatinda village, Punjab and installed capacity is 5 MW. The new concept of solar plus organic farming was introduced in this park.

6 Ujjain Solar Park: It is located in Ujjain, Madhya Pradesh and can able to generate 75 MW of solar energy [14]. Panel cleaning is done through the rain water harvesting.

7 Uttarakhand Solar Park: It is located in Maheswari village, Haridwar district and can able to generate 5.5 MW.

8 Ananthapuram Ultra Mega Solar Park: It covers a total area of 7,924.7 acres in Nambula Pulakunta, Ananthapuram district and has a capacity to generate 750 MW.

Mankind has always been fascinated by the power of wind. Wind energy is one of the most exploitable forms of energy. From time immemorial, wind power is used for mechanical applications such as water pumping and milling. Professor James Blyth was known to be the first person to successfully produce electricity from wind power in 1887. As of 2019, the total installed capacity of wind power has grown to 651 GW [15].