A very practical model
It was in May of last year that imec announced it had developed a simulation model. This model uses the weather conditions to predict how much energy a solar panel will ‘actually’ produce. Typically, a solar cell has a specific conversion efficiency that is expressed in %. This percentage is measured in a laboratory under standard conditions. But when this solar cell is used in a module or panel - whether it is installed on a roof or as part of a solar farm - and it has to operate in all sorts of weather conditions, the actual yield of the cell is sometimes very different. For the managers of solar farms, energy providers, developers and investors, etc. it is important to know how much power a solar panel, when installed in a particular location, will generate on an annual basis. For them, the most important parameter is not the conversion efficiency of the panel, but the euro per kilowatt hour it generates. And this is precisely where the simulation model can help them. Below, we have set out some of the applications for which the simulation model can be of value:
- Load management. To be able to guarantee the stability of the energy network, it is important for supply and demand to be balanced at all times. This can be difficult when renewable forms of energy – such as solar – are included in the network. This is because the amount they generate is very much dependent on the weather. Using imec’s new simulation model, it is possible to predict how much solar en will be produced – right down to a 15-minute window of accuracy. In the short term, the model can be used in this way for (micro-)grids, such as islands, large manufacturing facilities, residential districts – and so on.
- Negotiating energy prices. Energy is traded between countries. To negotiate from as great a position of strength as possible, it is important to know exactly how much energy your country will produce over a particular period of time. The actual amount of solar energy you are going to produce can be computed accurately using the simulation model. As a result, solar energy is becoming less and less of an ‘unpredictable’ factor in the supply of energy.
- Technical adjustments to the solar cell. The simulation model also makes it possible to calculate how much a specific change made to a solar cell will produce ‘in reality’. Imagine, for instance, that you want to use a different type of material in the cell, or that you want to replace the glass cover with film, etc. The model computes how much the altered cell would produce in the solar cell farm under weather conditions typical for the area where it is located. This enables PV researchers and solar cell manufacturers to make the right choices when optimizing a solar cell, module and panel. And they can do this without actually having to produce the cells, saving a great deal of time and money.
- Installing the solar panel. In countries such as Belgium, solar panels are typically positioned at an angle of 36° to achieve the right light level. But what if you were to place it at 30°? If you did that, you might have less light exposure, but you might also achieve more cooling by the wind – and hence enable the solar panels to function better. This could mean that it might generate more energy at 30° than at 36°. Optimizing scenarios such as this are straightforward enough with the new simulation model.
What makes this model so unique?
Imec’s new simulation model is holistic in that it takes optical, thermal and electrical parameters into account. It also looks at how these parameters interact with each other. For example: if more light hits the cell (optical parameter), this has an effect on how the cell heats up (thermal parameter) and also on the production of the charge carriers within the cell (electrical parameter). Which means there are lots of scenarios in which this interaction of parameters is able to produce the end result.