Normally the efficiency of a solar panel is about a 21%, but some solar panels in space reached 46% of efficiency and some professional solar panels reached 27% of efficiency. These numbers show that the solar panel efficiency should be increased to 60%. If this is achieved, the countries will be able to get a significant part of their total energy from this source.

These are the common parts of a solar panel:

1. Silicon solar cells
2. Metal frame (typically aluminum)
3. Glass sheet for casing
4. Standard 12V Wire
5. Bus wire
6. Plexiglas

It has to be said that some of the materials like silicon that are used to build the parts mentioned previously are hard to acquire.

The solar energy is a renewable source and can be used effectively in the private sector and hence reduce the bills of its users. The solar panels also have diverse applications like heating water or generating electricity. The solar panels have a low maintenance cost and normally goes with a warranty of 20-25 years.

But there are some disadvantages. It requires a big investment. However that should pay off in 10 or 15 years. It is also a weather dependent source of energy, which makes it more difficult to control.

· Tecnologi PERC

· Space solar panels

· Solar roads

Passivated Emitter and Rear Cell.

This image shows the difference in the capture of sunlight in a standard solar cell and in a solar cell with PERC technology. In the normal cell a big part of energy is lost. In turn, in the PERC cell, part of the radiation, which is wasted in the standard cell, is recovered and exploited thanks to a special insulating layer.

In 2018, scientists from the California Institute of Technology announced that they managed to create a prototype capable of collecting and transmitting solar energy from space.

However, one of the biggest barriers may be the amount of congestion encountered when transmitting radiofrequency waves, because these frequencies are the same ones we use for our radios and other things.

Other problem is that we need to lower the costs of environmentally friendly launch vehicles because it's to expensive launch a vehicle to the space

Solar road panels are made with layers of super-strong glass embedded with photovoltaic cells, electrical wiring and LED lights.

The system of solar panels not only collects the power, but it also creates a system of delivery that decreases the possibility of power failures.

It had been calculated that a single mile off highway, if converted to solar cells, would provide enough power to run 428 homes in the US.

However, there are other people that say that the solar roads are too expensive and inefficient. For instance in France with an inversion of 5 millions euros it only produces 409 kilowatt-hours.