# Temperature of a Solar panel in space

• nithinyes
In summary, the conversation discusses the setup of two 1 square meter marble slabs in space, with one slab having a photovoltaic solar panel and the other having a resistive load. At equilibrium, the power received from the sun is equal to the power lost in radiation. When the solar panel is connected to the load, the net power received by each slab changes, leading to a temperature increase in the load slab and a decrease in the solar panel slab. This can be explained in terms of entropy, with the solar panel converting sunlight into heat and work, thereby limiting the increase in its temperature. However, the presence of black paint and the efficiency of the solar cells adds a complication to the analysis.
nithinyes
Consider two 1 square meter marble slabs each of mass 1 kg floating in space facing the sun such that light from the sun incident perpendicularly on the flat faces.
At equilibrium, power received from the sun 'PS' equals the power being lost in the form of radiation 'PR'.

PS = PR (at equilibrium)

For simplicity, assume the equilibrium temperature TE = 300K.

Let us now install a photovoltaic solar panel on the right slab and resistive load on the left slab.

Assume the mass of the photovoltaic panel and resistive load be 1 kg each.

Connect the panel and load using wires and a switch of negligible mass.

Let the new equilibrium temperature also be 300 K.

At time t = 0, the pv cell is connected to the load by closing the switch. Let the power being transmitted from pv slab to load slab be 'PPV' and all this power is consumed by the load slab.

So the net power received by load slab is PS + PPV and the net power received by pv slab is PS - PPV.

Since PS + PPV > PS - PPV,

So what happens to the temperature of the slabs?

Last edited by a moderator:
nithinyes said:
So what happens to the temperature of the slabs?
You first: what do you think happens, and why?

davenn and phinds
russ_watters said:
You first: what do you think happens, and why?
I think that the power consumed at the load converts into heat and so the temperature of load slab increases.

Coming to pv slab, net power received is reduced due to diversion of some solar power to load power and so the temperature of pv slab decreases.

Am I correct?

nithinyes said:
I think that the power consumed at the load converts into heat and so the temperature of load slab increases.

Coming to pv slab, net power received is reduced due to diversion of some solar power to load power and so the temperature of pv slab decreases.

Am I correct?
Yup!

russ_watters said:
Yup!
If so, Can we say that photovoltaic cell is a device which reduces its temperature and does useful work on surroundings when it is operating?

nithinyes said:
If so, Can we say that photovoltaic cell is a device which reduces its temperature and does useful work on surroundings when it is operating?

Yes, but in order to avoid misconception it is better to say that it limits the increase of its temperature by doing work that would otherwise converted into heat.

DrStupid said:
Yes, but in order to avoid misconception it is better to say that it limits the increase of its temperature by doing work that would otherwise converted into heat.
Can you please explain it a little elaborately in terms of entropy?

nithinyes said:
Can you please explain it a little elaborately in terms of entropy?

Sunlight (with low entropy) is absorbed by the solar panel and converted into heat (with high entropy). If a part of the absorbed energy is converted into work (without entropy) there is less energy left to heat the panel.

etotheipi, nithinyes and vanhees71
DrStupid said:
Sunlight (with low entropy) is absorbed by the solar panel and converted into heat (with high entropy). If a part of the absorbed energy is converted into work (without entropy) there is less energy left to heat the panel.
Thank you

nithinyes said:
I think that the power consumed at the load converts into heat and so the temperature of load slab increases.

Coming to pv slab, net power received is reduced due to diversion of some solar power to load power and so the temperature of pv slab decreases.

Am I correct?
Because this is an intermediate level post I would like, for completeness, to include one complication.. The slab is made of marble which is presumably not very absorbtive (or therefore emissive). Panting (only) the sunward side of the slab black would increase its radiative equilibrium temperature. The solar cells are black and not 100% efficient and so the true answer is unknown because of these competing factors.
But the rest of the analysis is fine.

nithinyes and Dullard

## 1. What is the average temperature of a solar panel in space?

The average temperature of a solar panel in space can vary depending on its location and orientation. However, on average, a solar panel in space can experience temperatures ranging from -250°F to 250°F.

## 2. How does the temperature affect the efficiency of a solar panel in space?

The temperature of a solar panel in space can greatly affect its efficiency. As the temperature increases, the efficiency of the solar panel decreases. This is because the materials used in solar panels have a negative temperature coefficient, meaning that as the temperature rises, the electrical output decreases.

## 3. Can extreme temperatures in space damage a solar panel?

Yes, extreme temperatures in space can potentially damage a solar panel. If the temperature is too high, it can cause the materials to expand and potentially crack. On the other hand, if the temperature is too low, the materials can contract and become brittle, also leading to potential damage.

## 4. How do scientists regulate the temperature of solar panels in space?

Scientists use various methods to regulate the temperature of solar panels in space. One method is to use thermal control coatings or materials that can reflect or absorb heat. Another method is to use heaters or radiators to regulate the temperature. Some solar panels also have built-in mechanisms that allow them to rotate and avoid direct sunlight, helping to regulate the temperature.

## 5. Can the temperature of a solar panel in space be used to generate electricity?

No, the temperature of a solar panel in space cannot be used to generate electricity. While the temperature of the panel can affect its efficiency, it does not directly generate electricity. Solar panels in space still rely on the sun's energy to generate electricity, regardless of the temperature.

• Electrical Engineering
Replies
31
Views
2K
• Mechanical Engineering
Replies
30
Views
2K
• Electrical Engineering
Replies
11
Views
1K
• Thermodynamics
Replies
152
Views
5K
• Electrical Engineering
Replies
28
Views
3K
• Introductory Physics Homework Help
Replies
9
Views
2K
• Other Physics Topics
Replies
7
Views
1K
• General Engineering
Replies
1
Views
2K
• Astronomy and Astrophysics
Replies
12
Views
1K
• Electrical Engineering
Replies
1
Views
1K