what is the efficiency of the best solar cells today? Also, is biodiesel feasible considering limited land ?

Question

With decreasing oil reserves, alternative energy sources have to be found, while fusion power, if attainable is very promising, it is far from reality (perhaps 20 years if the ITER project is successful). Biodiesel is exciting too. but it would be impossible to grow so many plants to cater to the needs of millions of cars. Besides, we could probably do a better job than plants at capturing solar energy.

Answer 1

I have installed my own solar system and am in the process of starting a solar company. I have included links to all the companies mentioned below. The very first link is to the Energy Blog's Solar PV section. There are dozens of articles about companies that have plans to make or are making solar PV products. The field is very fast growing and there must be well over 100 companies making solar PV products.

The highest efficiency solar cells currently available is about 37% but only under concentrated sunlight about 300X stronger that normal sunlight. This type if cell is intended to be used with a lens or mirror to concentrate the sunlight. They are quite expensive but only a very small number is required compared to normal cells. These cells are made by Spectrolab. There are more than a dozen companies working on making products that use these cells. Most of them will be sold to commercial or utility companies to generate solar power on a large scale.

The highest efficiency normal silicon solar cells is just about 21%. These cells use the highest quality electronic grade silicon wafers and use back side contacts so that the entire front surface collects power. They are made by SunPower.

Normal efficiency crystalline silicon solar cells are about 15% efficient. If you were to buy normal solar panels from a company like Sharp Solar, BP Solar, General Electric etc. That is most likely about the efficiency of the panels. You can buy solar panels made by these companies at the Alternative Energy Store on-line - links below.

There are a number of companies selling and working on several different types of thin-film solar panels. These panels are less expensive ranging from about 8% to 12% efficient but they are also fairly in expensive. Examples include Unisolar, PowerFilm, Kaneka

Answer 2

A long, detailed answer. You asked a lot in your question. First, Solar Cell efficiency rating is about 25% at best it degrades after years of use to 21%, then about 15%, but by that time the owner should notice the difference and wipe the plastic clean, and that should restore it back to about 20%. Solar cells should last about 20 years.

Biodiesel is only feasible in certain areas where agriculture is widespread, like PA (where I am from), but texas and arizona will be better suited for Solar & Wind. Alternative Energy works best when we use different methods, because there are drawbacks to each method. Solar needs the sun, Wind needs strong winds, biodiesel needs arable land. Conservation is something that Americans can do easily because we use about 4x the average of the world. So conservation will play a big part in meeting our energy demand. Biodiesel will also not work everywhere because the industry will be privatized which will only make the large agri-business grow even bigger and we'll still have people starving. Instead of growing corn for food, it'll be for fuel.

If you're interested look into hydrogen, because all the energy sources that you've mentioned are source-point energy, not a mobile source of energy, where hydrogen can be used to power our automobiles. Hope this helps.

Answer 3

The efficiency of solar cells depends on where you live and the season. The latitudes closer to the poles receive less of the suns energy and therefore solar cells are less efficient.

Bio-diesel is also dependent on the area you are in. Plants don't grow well in the desert and tundra areas, so you would have to import bio-diesel, it wouldn't be much different than using conventional diesel.

There is no one great answer for all areas. The absolute best answer would be diversity in production. In coastal areas you might find using ocean tides to run generators is most efficient. In the desert it might be solar cells. In the jungle regions maybe bio-diesel.

Having diversity in energy production also has the added benefit of maintaining a constant supply at a consistent price. If you only use solar cells and next month turns out to be cloudier than normal, energy will be in short supply and prices will skyrocket. However, with a diverse energy supply, bio-diesel or some other source can be used to take up the supply slack.

Answer 4

I agree with most of what Aryan had to say, the only thing I would change is the use of hydrogen. There is no efficent way to make hydrogen as of yet(may change in the future.) Also there is no efficient way to store large quantities of it under pressure. The best bet for storing energy is through the use of Super Capacitors or similar capacitor technology. This type of capacitor has been increasing in storage capacity due to nanotechnology and may hold the key for easy long term electrical storage. In the future their may be some form of capacitant gel that you put in a vehicle to power it up quickly. Is this any reason to stop developing advanced hydrogen tech, definately not. Hydrogen is the fuel of the stars, we should use it if we can.

Answer 5

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Answer 6

ride a bike