What characteristics should solar collectors have, to function in an optimal way?
Why should these properties be fulfilled?
If there is a water flow of 500 g / minute to a solar panel on one m2, how much water is heated up under optimal conditions during the passage of the collector? Expect that the collector is in Gothenburg and the calculation is done for one day in mid-June (noon)
If the calculation is done for a full day, or day-night, you would not use the noon value for the daily average.
Optimal conditions are obtained with a cloudless sky, with panels facing the sun. These conditions would seldom be achieved, and would require that the panels be tilted at variable azimuth and tilt angles during the day. The penels must also be enclosed under clear clean glass to minimize convective heat loss to air.
At optimum conditions in mid June at noon using optimally tilted panels you could, for a few hours, expect to collect about 1000 Watts of solar energy per meter of panel area. Even in Gothenburg.
For the temperature rise DeltaT under these condtions, solve this equation:
(mass flow rate)*DeltaT*(4.18 J/ C g)= 1000 J/s
The mass flow rate should be in g/s, which would be 8.3 g/s in this case. This leads to a DeltaT of 28 C.
24-hour averages for typical weather conditions using stationary tilted panels will probably be less that 10% of that value. There are published average insolation values for various locations in Europe.
i still need help plz
i need more explanation
Hi!
Can you explain how did you get this equation
(mass flow rate)*DeltaT*(4.18 J/ C g)= 1000 J/s
To function optimally, solar collectors should have the following characteristics:
1. High efficiency: Solar collectors should be designed to capture and convert as much sunlight into usable energy as possible. This means they should have a high absorption rate for sunlight and minimize any losses or reflections.
2. Good thermal insulation: Collectors should be well insulated to prevent heat loss, so that the captured solar energy is efficiently transferred to the working fluid.
3. Large surface area: A larger surface area allows for more sunlight to be absorbed, increasing the overall energy output of the collector.
4. Durable and weather-resistant materials: Solar collectors should be made of materials that can withstand varying weather conditions, such as prolonged exposure to sunlight, rain, and snow, without deteriorating in performance.
These properties are essential for the optimal functioning of solar collectors because:
a) Efficiency ensures that a higher percentage of the sunlight is converted into thermal energy, which maximizes the overall energy output of the collector.
b) Good thermal insulation helps to minimize heat loss and maintain a high temperature difference between the collected solar energy and the ambient environment, improving the efficiency and effectiveness of heating the working fluid.
c) A large surface area allows for more sunlight to be captured, increasing the overall energy collection potential of the system.
d) Durable and weather-resistant materials help to ensure the longevity and reliability of the collector, minimizing maintenance requirements and maximizing the lifespan of the system.
To calculate the amount of water heated up under optimal conditions, consider the following:
1. Determine the solar irradiance in Gothenburg at noon in mid-June. This information can be obtained from historical weather data or solar resource databases specific to the region.
2. Estimate the area of the solar panel in square meters.
3. Multiply the solar irradiance by the collector area to determine the total solar energy incident on the collector during that time period.
4. Take into account the efficiency of the solar collector in converting sunlight into thermal energy. This can vary depending on the type and design of the collector.
5. Calculate the heat energy transferred to the water by considering the specific heat capacity of water (4.186 J/g°C) and the mass flow rate of water (500 g/minute).
6. Finally, convert the heat energy into the temperature rise of the water using the equation Q = mcΔT, where Q is the heat energy transferred, m is the mass of the water, c is the specific heat capacity of water, and ΔT is the temperature rise.
Note that the specific calculations would require precise values for solar irradiance, collector efficiency, and other factors, which are not provided in the question.