Comments on: FAQ: A concentrated power boost for solar energy

Using very different designs, several companies are focusing the sun's energy onto solar cells to lower the cost of solar electricity.
Photos: More solar bang for the buck

[Joe Real]

Efficiency doesn't increase!!!

Concentrating the sun's radiant power into smaller cells do not increase the overall solar to electric energy conversion efficiency.

Often, in the city where the piece of land is prime real estate, you are limited with the amount of space for sunlight capture. If you are intercepting the sunlight that would have otherwise fallen into other areas, you are in fact stealing solar energy from them and diverting it for your own solar cells.

What the net effect of PV solar concentration is to increase the energy output per unit amount of silicon used, and in no way in Physics you can call this as improvement of solar conversion efficiency. The perceived increased is only for marketing purpose, and to declare that there is an overall increase of efficiency is very misleading.

The real inquiry or the bottom line then would be to know if by concentrating the solar beams, will it result to lesser cost of production per unit energy output per unit area of land.

[Bubbasolar]

conversion efficiency is an important issue with some type of solar conversion. i.e., solar thermal. If you can concentrate the suns energy more efficiently then you can produce more heat per area of sun gathering.

This has big implication for the effectively using the sun... not as sun to electricity directly, but sun to create steam to turn generators. Now you can not only create new powerplant based on solar, but you can lessen the need for fossil fuels in traditional steam turbine plants by using solar thermal as a co-generation source.

[rdbarahona]

Solar concentrators make sense...

... for large solar electricity production farms. Where land is cheap, the sun shines all day, and there are no construction constraints (e.g., pitched roofs), this approach makes a lot of sense. It's clear that these technologies offer greater output per square foot, and at lower cost.

This leads to the next question of whether it makes more sense to do solar in a distributed (roof by roof) or centralized model. Much of the legislation seems to be encouraging distributed energy production - large subsidies are available to residents who put solar on their roofs. Technologies like concentrators just don't really apply here. The cost goes way up, and the extra weight and equipment may be impossible to mount on most roofs.

The biggest barrier to widespread residential solar is information. Most people find this topic so complex that they just don't bother, despite having high interest in being 'green'. Sites like www.solar4sf.org help in cutting through the complexity to make the information accessible to non-solar geeks.

[SiXiam]

Not Information... Price Rules

There is tons of information on the internet and in libraries if one actually wants to learn about solar.

The true barrier to solar is cheap panels and accessories. Also I'm gonna take a gamble and say that until hydrogen fuel cells replace batteries, there is no hope of people adopting solar power widely.

Installation costs are too high also. What we need is a cheap (under $3000 in current 2007 US Dollars) kit from WalMart that includes everything you need to get power from the Sun and could be easily self-installed....

[sonnyle30]

Actually, you can build your own solar panels to power your appliances and reduce your energy bill by 80% for less than $200. You can buy most of the materials and supplies at local hardware stores.

Go to this site and download the ebook guide and video. It has easy step by step instructions to show you how you can build your own solar panels for your home.

Here's the website: http://7peter7.earth4.hop.clickbank.net

[sonnyle30]

Actually, you can build your own solar panels to power your appliances and reduce your energy bill by 80% for less than $200. You can buy most of the materials and supplies at local hardware stores.

Go to this site and download the ebook guide and video. It has easy step by step instructions to show you how you can build your own solar panels for your home.

Here's the website: http://tinyurl.com/solarpw

[pan cheng]

I agree with most of the comments. The equipments for the solar power is expensive, and there are many issues about how to efficiently collect the solar power. However, I think that the solar power is still valuable to the human's life. Everyone would agree with me that the solar power is renewable and pollution-free. We must find a way to use it efficiently. The project, "Apple's solar strategies", is a great example of how to use the solar power efficiently. We should always try to discover and create new solutions. I believed that, in the future, humans will fully manipulate the solar power.
http://pctechedu.blogspot.com/

[fireofenergy]

Rooftop is inherently more expensive (more labor and pricy parts per watt). Also, in keeping with the laws of passive solar energy, it may be more efficient to use shade trees for cooling (and CO2 absorbtion). Also, most people don't live in a desert, the perfect place for very large arrays of mirrors and molten salt heat resevoirs (for 24/7 power generation).

Personally, I think it would be cheaper to let (inforce) the utilies to pay the extra for largescale than to do it all myself on my roof top.