Your Questions About Solar Panel Efficiency

William asks…

What Solar Panel Efficiency would replace Coal?

A friend sent me an article that a company called Fraunhofer has produced solar panels that can achieve 41.1% efficiency.

Now taking into account the fact that solar do sent work during storms or night and greatly reduced during winters, what % do you think would be needed to supply a “majority” of our power needs as a nation?
Now taking into account the fact that solar “does not” work during storms or night and greatly reduced during winters, what % do you think would be needed to supply a “majority” of our power needs as a nation?

ssadmin answers:

I'm with g.aidono. The efficiency of the panel is not the issue, it's the cost.

I believe photovoltaic panels are hovering at around 14% efficiency right now – when you see high numbers like 41%, that's an exotic cell, and not in a sturdy glass and metal frame suitable for domestic use. But even at 14%, if they cost $2 / watt, they would be a cost winner in a majority of US homes. Even at $4 / watt today, they are a winner in some places, such as supplying the last few, very expensive kWh's on someone's bill. If panels got to $1 / watt, even without any subsidies, people would be clamoring to connect panels – so many, in fact, that it would threaten the stability of the grid, and new architectures would be necessary.

Steven asks…

Why is solar panel efficiency so low?

How much of the inefficiency stems from light being reflected off of the surface?

ssadmin answers:

About 70% of the loss is due to the photons not having the correct energy level to be converted:

Regarding reflections, if the light hits the surface on the perpendicular, very little of it is reflected. As the angle of incidence decreases, more of the light reflects from the surface. Manufacturers of tracking devices that keep the panel pointed at the sun claim that the tracking will increase the panel's output by up to 20%. But a large part of the gain comes from the panel presenting a full surface area pointed toward the sun. At an oblique angle, the panel doesn't intercept as much of the sun's rays. So the 20% increase isn't due just to fewer reflections, but also due to a full interception area. The latter is quantified on some web sites. Subtract that from the 20% and you could attribute the remainder to losses from reflections (as an approximation).

Lizzie asks…

solar panel efficiency in space?

What, if any, improvement in efficiency per square foot or meter is realized by a solar panel in space vs. being mounted on the ground where the light is attenuated by the atmosphere?
In passing, I found a site that gives an output of .89 watts / 4 in. sq for a particular home-mounted panel.

ssadmin answers:

I'm not sure on the exact numbers of solar panel efficiency, however i do know that at the radius of the Earth we should be receiving about 1000W of power per square meter.

This value is lessened by the atmosphere to a value closer to 600W per square meter on the Earth's surface. (on a really hot day)

That's a 40% drop in power due to the atmosphere. I'm assuming that the solar panels being in space don't affect it's efficiency (as in mechanically). So its power generation should increase by about 40% when in space compared with a ground based panel of the same design.

Hope this helps, Sorry it's kinda sketchy info…

Donald asks…

Increase Solar Panel Efficiency?

Is it possible for the everyday person to increase the efficiency of solar panels that they own? If so, how is it done?

ssadmin answers:

There are 3 (simple) ways to increase the efficiency of a solar panel at home – they all work by increasing the amount of light that falls onto it:

1. Have the solar panel track the sun throughout the day so that it always faces it;

2. Place a lens (larger than the panel) in front of the panel that focuses the light from the sun onto it.

3. Have mirrors around the panel than redirect light from themselves onto the solar panel. (e.g. Imagine a satellite dish with the solar panel at the front and the dish being all mirrored.)

Donna asks…

Does anyone have a graph showing the efficiency of a solar panel vs temperature?

I need a graph showing the efficiency (or power output) of a solar panel vs temperature.
I could also use graphs showing the efficiency of a solar panel vs angle of incidence, optimum output voltage,and other parameters.
I want to optimize the output power fromthe panels so I can use fewer panels.

ssadmin answers:


Powered by Yahoo! Answers

Solar Panel

If you enjoyed this post, please consider to leave a comment or subscribe to the feed and get future articles delivered to your feed reader.

Comments are closed.