After several weeks, I am back to share with you the third and last part of my debut article (post)! I am sorry for the delay but, meanwhile, we have had the opportunity to enjoy reading some other really interesting posts in the Blog!
So far, we have done a quick review on the concepts that we are dealing with when we talk about Grid-tied Energy Systems + Storage, and we have also described and showed some details about the strategy that is proposed by the authors. Now, it is time to see how our plan works! So, in this post some simulations are analysed in order to present the results of the algorithm when it deals with different meteorological conditions.
One decision to be taken is the way we want to deliver the committed energy to the Electricity Grid during the operation day. In our case, we propose a very simple delivery which will consist of constant values of power, so that at the end of each hour slot the accumulative value of that power curve (integral) will be equal to the energy committed with the Market. In short, applying a constant power of 10 MW during one hour would result on an Energy Supply of 10 MWh, as simple as that. This way of meeting our energy commitments is only possible thanks to the Storage, as it was explained in our first post. Otherwise, our power curve during one day would have the typical shape of an inverted parabola, since we would need to deliver the exact amount of power that our solar panels are producing at any time.
In my last post some background and previous concepts about National Electricity Markets and grid-tied Photovoltaic Plants were introduced. Now, it’s time to go deeper in the issue under consideration by applying that knowledge. In this second part a management strategy based on a Model Predictive Control (MPC) is proposed in order to increase the competitiveness of gried-tied PV Plants when it comes to National Electricity Markets participation and their daily operation.
First of all, let’s remember the last question we were discussing: Do we really need to supply the whole production every hour?
Power Production Curve during a Sunny Day assuming a 100 MW PV Plant (Own Data)
Nowadays, the correct answer would be: NO, as long as the PV Plant is equipped with Energy Storage Systems. From my point of view, this is the key condition to make PV Plants more competitive in the electricity markets. I know that one could think that the idea is not really original, and it is undeniable that this same concept has been used in the past in other Power Plants, such as the Hydroelectric ones. Nevertheless, the simplicity of an idea should never be considered as a drawback.
If someone mentions the term Photovoltaic System (PV Systems), the first thing that one would probably think about is a solar panel installed on top of the roof of a house, like the one shown below. Well, even though this equipment is undeniably the most popular worldwide, this article deals with the current and short-term situation of those huge PV Power Plants which are connected to a National Electric Grid and, therefore, participate in a National Electricity Market.
First of all, I would like to start by providing some background and a number of previous concepts that might be needed later. A simple diagram is shown below, which represents a normal grid-tied PV Plant: