Solar Panel Operating Temperature? Call in the Boffins

It may be possible to drive up solar PV plant output with better panel heat dissipation, but a better thermal model is necessary first.

A great way to reduce the cost of solar power is to increase the output of the solar plant. Solar photovoltaic (PV) panels lose efficiency when they operate at higher temperatures, and unfortunately, they generate heat and operate well above ambient temperature. So, a potential opportunity to boost power plant output is to dissipate heat better to drive up efficiency. After recently seeing a not-uncommon 7% thermal loss in a PVsyst simulation, my intention was to write about the value proposition for better panel heat transfer. However, it seems that panel thermal behavior in an operating plant is not very well understood. What seems to be needed first is further scientific study to understand what governs panel temperature in real solar plants. Then, a clear assessment could be made for the potential to boost output from better heat dissipation. Before the design engineers get to work, perhaps the boffins should have another go at it.

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Reducing the Cost of Solar Power by Boosting Solar Panel Power

The Economist recently highlighted a few promising developments in high-efficiency solar photovoltaic (PV) cells, specifically naming Oxford PV’s tandem cell technology, but the article neglected the punchline of what the impact would be (“Solar’s new power,” May 23, 2020). In fact, it could be quite significant. Some years ago, the cost of a solar plant was dominated by the cost of the panel, but now project costs are spread among a variety of categories. In the industry’s current stage, increasing the yearly power generation of a solar plant can be one of the most substantial ways to reduce cost since this affects the full stack of costs. To get the “$/MWh” to go down, boost the “MWh” in the denominator. Furthermore, there are several remaining major opportunities for boosting power generation for solar plants, including perhaps with Oxford PV’s technology.

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What Is and Is Not Competitive about Concentrated Solar Power Technology

A nagging issue with solar power plants is that they generate power according to a schedule driven by irradiance, sun position, and characteristics of the power plant, but not according to the customer’s demand. Wouldn’t a great solar power plant product cater to a customer’s schedule? In many places, people use more power during the day than at night so daytime generation roughly meets demand well – at first. As more and more solar is added to a grid, the peak net demand shifts into the evening, and the value of the contributed solar power falls during the day. (Some nice analysis on this by Bollinger, Seel, and Robson at LBNL among others shows this.) The importance of responsiveness is increasing where there is copious solar on the grid.

Concentrated solar power (CSP) technology with integrated thermal energy storage promises to provide solar power that can more closely cater to customer demand. Coming in at ~1% of the total solar install base, CSP, well, lost the race to PV over the last decade. This is superficially explained by high cost. A quick look at why the cost is so high suggests that performance at a high level does not seem as much of an issue as practical matters. Continue reading “What Is and Is Not Competitive about Concentrated Solar Power Technology”