Question
The question that we wanted to answer was: How does the ambient temperature increase due to global warming affect solar panel efficiency? This would be an explanatory question because we are trying to understand one of the causes of reduced efficiency of solar panels. This is an important question because it allows the customer or prospective customer to better understand where the energy from their panels is going and where some of it is being lost. On a larger scale, the losses would be much more significant, so the customer can see if it would be viable for them to install cooling.
Methodology
To simulate the incidence power from sunlight over the course of the day, we are taking irradiance data from the course of a day in Needham (July). From this data, we factor in the albedo of the solar panels (how much energy is absorbed by the panel) to find the amount of power it is converting to electricity. We also factored in how many panels we are using, the surface area of the cells, and the time step for each datapoint of irradiance (30 minutes). We then took the specifications of the solar panel (such as maximum power production capacity, the power loss coefficient, and specific heat of the cells) and incorporated them into a set of equations that calculate the energy lost due to inefficiency over the course of the day. From that, we were able to plot the output over time and compare it to the ideal power generation with optimal conditions and visually see the inefficiency of the panel over the course of the day. Taking the integral of that allows us to see the cumilative energy loss over the course of the day.
Results
The chart titled "Kwh total Generated over a day ideal vs heat inefficiency" displays how there is a direct correlation between irradiance, the power generated by the PV panels, and the inefficiency due to heat. It is visable that the graph that accounts for the inefficiencies due to heat is just a scaled down version of the ideal graph, and power generation peaks at the same time that irradiance does. We can also see from the cumilative inefficiency (energy lost due to the inefficiency caused by heat of the solar panels) over the course of the day that there is a total loss of 7.33 KWh or 78.2% of its full potential given the same irradiance. It is very clear that higher temperatures of PV cells have a significant negative impact on their efficiency.
Interpretation
The final plot represents total energy loss over the course of the day due to the inefficiency of the panel (over the x and z axes) and what the irradiance (inefficiency is directly correlated with irradiance) is over the course of the day as well (over the y and y axes). However, as inefficiency peaks during that time of the day, power production also peaks because the energy generated due to the irradiance increase outpreforms the energy loss due to the inefficiency increase. This essentially means that power loss due to inefficency increase has to be accounted for when investing in solar panels as it is an inherent flaw of the technology. This also means that efficiency could be significantly improved with the addition of some passive cooling system. Connecting this to sustainability; since we know that the temperature of a solar cell is directly correlated to the cell's inefficiency and that aggregate global temperatures are also increasing, we can deduce that the aggregate equillibrium temperature the solar panel reaches as it dissipates its thermal energy to the surrounding environment also increases. In other words, global warming is worsening the efficiency of solar panels.