Utilities

Renewable Energy Challenges and Solutions

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<p style="text-align: justify;">Renewable energy is booming around the world at a faster pace. Renewable energy is largely considered as a sustainable that means endless. The most popular renewable energy sources are solar, wind, hydro, tidal, Geothermal, Biomass energy. The two most popular renewable energies are solar and wind and its penetration in the energy markets are also significant compared with other sustainable energy sources.We will mostly talk about wind and solar energy and its challenges as alternative energy.</p><p style="text-align: justify;">Solar energy is from the sun that is converted into electricity. Solar energy is the most abundant and cleanest source of energy available in many places like the U.S. and India regions. Solar power can harness this energy for a variety of uses such as generating electricity, providing light or comfortable interior environment, and heating water for domestic, commercial and industrial purposes.</p><p style="text-align: justify;">Wind energy uses wind turbines to generate electricity. Wind is caused when the surface of earth is heated unevenly by the sun. Wind turbines, like windmills, are mounted on a tower to capture the most energy. At 100 feet (30 meters) or more aboveground, they can take advantage of the faster and less turbulent wind. Turbines catch the winds energy with their propeller-like blades.When wind blows through windmill blades, a pocket of low-pressure air forms on the downwind side of the blade. The low-pressure air pocket then pulls the blade toward it, causing the rotor to turn. This is called lift. The force of the lift is actually much stronger than the winds force against the front side of the blade, which is called drag. The combination of both lift and drag causes the rotor to spin like a propeller, and the turning shaft spins a generator to make electricity.</p><p style="text-align: justify;">Both solar and wind energy sources are connected to the electric grid to distributed energy sources. Distributed energy resources refer to a variety of small, modular power-generating technologies that can be combined to improve the operation of the electricity delivery system.Wind and solar powered about a tenth of electricity in China and India. China is now responsible for more than half of all the world&rsquo;s coal power generation. At the same time, India is also replacing coal power generation at a tremendous rate with renewable energy and penetration around 5-10% in the energy market every few years.</p><p style="text-align: justify;">As renewable energy replacing coal and penetration is larger and larger in the power sector, the main challenge is renewable energy is weather dependent and relies on weather forecasting. Accurate weather forecasting is crucial for integrating wind and solar power generating resources into the grid, especially at high penetration levels. It is a crucial, cost-effective tool available to both renewable energy generators and system operators (NREL, 2016).</p><p style="text-align: justify;">For weather-dependent renewable generators, like solar and wind power plants, the most critical scheduling input comes from weather forecasting data. A power generation forecast is a combination of power availability and weather information for the location, as illustrated in</p><p style="text-align: justify;">Figure 1.</p><p><img style="display: block; margin-left: auto; margin-right: auto;" src="https://kradminasset.s3.ap-south-1.amazonaws.com/ExpertViews/figure1.PNG" alt="" width="595" height="299" /></p><p style="text-align: center;"><strong>Figure 1. Schematic diagram for weather and power prediction forecast.</strong></p><p style="text-align: justify;">The main challenges for the power sector is to implement the Integrating weather forecasting system to forecast on short-term and long-term timescale. Every energy forecast invariably starts with numerical weather prediction (NWP) models, which are the accepted baseline predictions being tuned and run by large and mostly government- funded organisations.NWP methods take weather data, such as temperature, pressure, humidity, as inputs to simulate weather conditions inthe future using physical and mathematical laws. The robust integrated weather forecast system system will not only enhance forecast capabilities but also provide valuable information about extreme weather such as high winds, hail storms and heavy rainfall conditions. By contributing to the allocation of appropriate balancing reserves, long-term weather forecasting assists in ensuring safe and reliable system operations. It can also help in better planning the long-termexpansion of the system, both generation and network transmission capacity, needed to efficiently meet future demand.</p><p style="text-align: justify;">The renewable energy forecast based on statistical models is not accurate and has flawed data sets and does not fit in current changing climate for example extreme weather patterns changing, unusual weather patterns and rainfall.The best way to approach the NWP model and forecasting can be improved further by adopting artificial intelligence (AI) and big data. These simulated weather predictions can then be converted to corresponding energy production from wind and solar resources. NWPs are normally used for 15-days-ahead forecasting ranging from a few hours to days-ahead to week-ahead and so as power generation forecasts</p><p style="text-align: justify;">(Figure 2.)</p><p><img style="display: block; margin-left: auto; margin-right: auto;" src="https://kradminasset.s3.ap-south-1.amazonaws.com/ExpertViews/figure+2.PNG" alt="" width="651" height="376" /></p><p style="text-align: center;"><strong>Figure 2. Generation forecast methods and applications.</strong></p><p style="text-align: justify;">Short-term centralised forecasting is useful for applications related to system operations, such as real-time dispatch, market clearing and load following. Furthermore, accurate weather forecasting can also provide advantages in short- term electricity trading and system balancing.This leads to improved grid reliability and enables the efficient use of renewable energy resources. Accurate weather forecasts can enable renewable power generators to better estimate the generation and bid accordingly in intraday or day-ahead markets, reducing penalties imposed for deviations between actual and scheduled power generation. By using a more advanced forecasting solution with NWP models, renewable energy forecasts can be predicted closer to actual generation time.</p><p style="text-align: justify;">Long-term weather forecasts are valuable for system operators in applications such as reserve planning and operation management. Such forecasts may further assist generators and system operators in investment planning for, respectively, power plant construction and system expansion. Long-term weather forecasts can be used by system operators to predict extreme weather events and better plan and prepare for such occasions. A study conducted for the California Independent System Operator (CASIO) shows that improved short-term wind forecasting in the CAISO market can result in annual total cost savings between USD 5 million and USD 146 million (Hodge et al. 2015).</p><p style="text-align: justify;">With more countries moving away from coal and working towards zero carbon mission in the next decade, renewable energy sectors must adopt NWP energy forecasting system with AL approach for accuracy to deal with load forecasting-&gt;scheduling-&gt;grid management to avoid penalties. The integrated energy forecast system that has a hybrid approach with wind and solaravailability offer several advantages over either single system.&nbsp;</p>
KR Expert - Dr. Anil Kumar