Last night began the start of this years Institute of Physics Merseyside Branch Events 2013-2014.
This years programme kicked off with a talk from Professor Ken Durose in the Surface Science Research Centre.
There was a great turn out for this event, more than anticipated, including A-Level students, undergraduate students, lecturers and various others.
Ken Durose joined Liverpool University in 2011 and is a research leader for photovoltaic materials in the new Stephenson Institute for Renewable Energy.
He delivered a very interesting talk on the history behind solar electricity, the achievements and the problems faced by photovoltaic materials.
The photovoltaic effect was discovered by Adams and Day in Britain in 1879 and it is basically the creation of electricity from exposure to sunlight.
Since 1879 a lot of research has been undergone in order to efficiently harness this property of certain materials.
These days the limit on the efficiency from solar cells has reached 40%.
Although there is a lot of research into this area there are still main problems being faced which include developing solar cells which are: low cost, sustainable and which approach and exceed the Shockley-Quisser limit (the maximum theoretical efficiency of a solar cell).
One of the biggest hurdles are the materials that the solar cells are made from.
Silicon solar cells are the world leaders, as ~80 % of all solar cells are made from this material. Silicon solar cells are the most efficient, however manufacturing costs are a big problem.
The purification of silicon in order to be suitable for photovoltaic materials is a long and expensive process.
As well as the purification process being expensive, there is an increase in global photovoltaic production every year.
This has led to a global oversupply in which 100 out of 350 silicon manufacturing companies have gone bust.
Furthermore, solar cells are are being sold at a cheaper price than it takes to manufacture.
In order to resolve this issue, solar cells can be made from alternative materials such as thin films. Wafer Silicon can be replaced with thin films such as CdTe.
This uses less material but the process of developing films that are thin enough to be used is a costly process.
Other alternatives include nanowire photovoltaics, using organic materials (although these degrade in the sunlight so are really not efficient), as well as techniques such as quantum dot cell – a lot of research in this process is going to be undergone in Stephenson Institute by the end of this year.
In addition to the above, a new material known as Perovskite has recently come on to the scene.
The reason Perovskite solar cells are bec0ming so popular is due to the fact that there has been a 15% rise in efficiency in 1.5 years.
There is going to be a lot of research going into this material in the following years.
Although there are a lot of cost issues in terms of manufacturing solar cells, data shows that the expense from photovoltaics will be cheaper than household electricity prices in 2020 – 2030; much earlier for countries in southern Europe due to the fact that their climate is better for solar cells than ours is.
However it has to be noted that this data does change continuously.
The global solar energy potential is 900 kwh/yr/m^2.
Overall there is a future for photovoltaics but a lot of work has to go into resolving the cost issues.
We’d like to thank Ken Durose for a stimulating talk on solar electricity.
The next IOP talk is on the 15th of October and it is about Acclerator Magnets.
The talk will take place at 6:30 pm at the Barkla Lecture Theatre.