Renewable energy is energy that is derived directly from the sun or heat generated deep within the earth. This is energy that is naturally replenished. Renewable energy often provides energy in the area of air and water heating or cooling, transportation, electricity generation and off-grid energy services. There are five common sources of renewable energy and they include; solar, wind, geothermal, hydropower and biomass which includes ethanol, biodiesel, biogas, wood and wood waste. These forms of energy are constantly replenished and can never run out. Renewable energy systems have over the years rapidly become more efficient and cheaper and their share of total energy consumption is increasing.
Rapid deployment of renewable energy would lead to significant energy security and economic benefits. This is as a result of reduction in pollution resulting from burning of fossil fuels. Renewable energy is much more efficient and reduces significantly primary energy requirements.AnalysisRenewable energy sources which are integrated into electric power systems connect to existing grids at a range of voltage levels. Increase in penetration of renewable sources has a significant impact on reliability and performance of the electric grid.
This due to the fact that renewable sources are variable and lack large-scale economical storage capability. The penetration of these renewable sources comes with technological challenges that have to be met to satisfy reliability standards of the electrical grid. Variability of renewable sources requires measures to accommodate fast generation changes incorporation of renewable sources comes with no fuel costs but is associated with increased maintenance and operational costs.
The inclusion of storage devices for renewable sources alters unit commitment. ; A procedure by which the entire ensemble of generating units is examined to produce subset of generators that satisfy the load. Unit commitment and economic dispatch are the operational functions most impacted by penetration of renewable sources. Feed-in fluctuations are induced by renewable energy sources are one amongst the key challenges to stability and quality of electrical power grids. Wind and solar power possess intermittent increment on time scales and their short term fluctuations disturb the system on time scale on which load balancing does not operate. Electricity grids are set up with operating reserves that allow the grid to maintain stability. Changes such as adding more distance transmission can be made to the system to allow it to be more flexible. Using a smart grid to make changes can also be applied and this may include turning off water heaters and all air conditioners when electricity supply is low or inadequate.
Relative to the intermittent electricity that can be added because of their implementation; all these changes tend to be high in cost and slow to implement; leading to instability of the electrical power grid.A greater proportion of wind and solar in total generation leads to higher electricity prices for consumers. This is because when all costs are included, including indirect costs such as need for additional storage and grid costs, the cost of intermittent renewable sources of energy becomes high.
The generation sources of renewable energy causes frequency deviations larger than permitted by regulations. This is because of use of active and reactive power associated with renewable energy besides intermittency problems. As electricity is transmitted over long distances, a lot more costs are incurred.
When it comes to renewable sources of energy, there is uncertainty in predicted output. This is as a result of fluctuations in flow of wind or inconsistency of heat from the sun due to both weather and climatic changes. In winter for example, the heat from the sun reduces drastically and at given times no sunshine is experienced. This causes deficit in electric generation and would thus lead to instability of the electrical grid. Wind on the other hand is unpredictable and at times during calm seasons no wind is experienced or blows at all.
Generating power from the wind at such periods or times becomes a problem and would lead to major blackouts for those who depend on wind generated power. Renewable sources of energy lack flexibility and this would lead to instability on the electric grid. Due to the smaller size and more distribution of installations of renewable energy sources, accounting of renewable energy is more demanding and complex. Renewable energy generated band consumed at subsistence level outside formal markets is often not measured. This is because it does not feed into the power grid. Incorporating it into the power grid would generally increase the power supply even though on large scale it would be accompanied by extra cost such as installation of storage facilities and other maintenance costs. Production of electricity on large scale from renewable sources is costly and comes with technological challenges that renders it unreliable.
Although it has led to significant reduction in usage and demand of fossil fuels, it’s expensive and costly on large scale production.
