Hybrid Power – Its advantages and Disadvantages

<p>When we say solar power, the default implication is that of Solar PV based power plants. Starting from roof tops to ground mounted utility scale systems, we have large and small solar power plants installed across the nation. </p><p>These PV based solar power plants generate power during the day light period which starts at or around 6 in the morning and ends close to 6 in the evening. During summer months, the evening times extend to about 30 to 40 minutes past six. However, the generation curve is a standard curves shown in figure 1.</p><p>When we talk of wind turbines, we normally mean an on shore turbine running in sync with the grid. This generates during the wind season. If we look at a day during the wind season and try to check the daily generation of the wind, we will be able to match it appropriately. Please see figure 1 (amber curve), where the wind daily generation curve is shown. The profiles shown are for 0.75 MW wind and solar.</p><p>When we try to match these two power sources daily, they do look so complementing one another. That is, in the mid-day when the solar hits a peak, the wind hits its trough. It is a good match if it is running parallel, all through the day and the year. </p><p>However, there are two major factors that affect the operation in addition to the daily generation curve, particularly, in the state of Tamil Nadu.</p><p>Factor one is the regulation. Ongoing plan of the DisCom was not to allow any banking for newly installed wind turbines. Otherwise, wind turbines generally give you power only in the season and then it slumps during off season. As I write this article, the stand of the DisCom in Tamil Nadu is going through a change, particularly after the APTEL order, thanks to the ever-active lone warriors, TASMA and other associations. There is a strong grape vine that banking will be given even for new turbines or in other words, TANGEDCO has chosen to abide by the APTEL order. I am yet to see an order from TANGEDCO until then we cannot be sure.</p><p>Leaving aside the possible regulatory implications in the operation of the solar and wind together, as a hybrid, the second factor is the annual generation curve of both the power sources. Take a look at figure 2 above.</p><p>Solar is almost consistent across all the months of a year with a marginal trough in the months of June, July, August and September, the rain months of the monsoon. Monsoon itself brings good tidings for the wind generation. Therefore, on an annual basis too, there is a certain amount of synergy between the two. </p><p>The fall in power generation in solar is about 15% in the monsoon months while the increase in wind is over 30% when compared to the previous months. Therefore, the peak generation months will certainly be substantially higher when compared with non-wind lean months of the year. This should keep the users and administrators of hybrid systems on their toes to ensure smooth and complete consumption.</p><p> Most generators were not expecting the opening of the banking for wind. Naturally, the expense for banking is not factored in their workings. Given the other option of lapsing and the long time it could take to realize the payments from the DisCom, there is no doubt generators will jump at the idea of banking.</p><p> The other option which was always planned by us was to push the power in the G-DAM or RTM of the IEX. That would still remain open to push the excess generation out. With COP-26 and the aggressive policies of GoI, we can expect hybrids continuing to rule for some time until storage mechanisms kick in.</p><p> </p><figure class="table"><table><tbody><tr><td><p><i>Hybrid capacities are available for power sale under captive model. Do </i><a href=""><i>contact us</i></a><i> for more information.</i></p><p> </p><p>(*Thanks to ResearchGate for figure 1 and National Institute for Wind Energy for figure 2)</p></td></tr></tbody></table></figure><p> </p>