Solar Powered Cars

August 24, 2009 by  
Filed under Wind And Solar Energy

To most, upon glimpsing a true solar powered car they will be strongly reminded of the children’s TV series ‘The Jetsons’. After all, most solar powered cars are oddly shaped – sometimes even flying saucer-esque – and are covered in little mirrors and panels to suck energy from the sun. These cars look odd, but they do exist. In fact, in the Australian Outback (which benefits from glaring sun rays) a car powered purely by the sun was about to reach speeds in excess of 80 miles per hour.

Not particularly impressive given the world’s fastest combustion engine car, the Bugatti Veyron, can reach 250mph – but not bad. The effect that solar powered cars have on the environment is virtually nil, and while the shape and design are still somewhat bizarre, that is something that can be tampered with over time. So, does the future see us starting the solar panels on our cars rather than the engine?

Well, not quite. While 80mph may seem pretty good, the cost of getting to that speed was extortionate – well out of the reach of most household budgets. The other flaw is the design; solar panels on solar powered cars need to cover a large area atop the car to function, which leads to designs including wide wings and flat roofs. Not aesthetically pleasing, and not practical either.

The problem is momentum; rather than just generating steam like traditional panels, the solar panels on cars are trying to create enough force to move a stationary object. While there is a chance in the future someone will see a way around this problem, for now, solar powered cars remain the playthings of scientists – not the new family vehicle.

The PS10 Tower: The Future of Energy Generation?

August 24, 2009 by  
Filed under Wind And Solar Energy

Just outside of the city of Seville in Spain, one can see a monolith that largely resembles something from the Lord of the Rings. A huge, towering eye stands a 115 meter high tower, looking out over a sea of large, shiny reflective objects. To the innocent bystander it is an odd, or even alarming sight, but what is happening in this small corner of Spain could indeed be the future of energy.

The monolith is in fact a PS10 tower, a technical name for what is essentially a huge solar panel. Like many solar panels, it gathers the sun’s heat and boils water to create steam; this, in turn, creates electricity, which can then be used to power anything from a small town to the oven in your kitchen.

What makes the PS10 Tower different, however, is that it does not just receive sunlight directly from the sun. While it would be effective in doing so, the PS10 Tower looks out over 624 movable mirrors, known as heliostats, all of which are positioned to shine the sun’s rays directly onto the solar panels atop the tower.

If it sounds complicated, that’s because it is – but essentially, what the PS10 Tower generates in power which then becomes electricity is 624 times more powerful than your average solar panel. Thanks to the heliostats bouncing the sun’s rays directly on to its receiving panels, the PS10 is able to create steam to drive a generator at a rate previously unheard of for solar technology.

What’s more, the experiment has proved so successful that a second tower and second bed of heliostats – the PS20 Tower – has now been built. The Spanish have capitalized on their natural resource – blinding sunlight – and used it to create electricity. Even more excitingly, it works. So is are the PS10 and PS20 towers the future of solar energy? They just might be.

Solar Panels and Overcast Days

August 24, 2009 by  
Filed under Wind And Solar Energy

There is a general misconception that solar panels, used to generate electricity and energy from the sun, do not work on overcast or cloudy days. This continues into the belief that solar panels are only useful during the summer months, rendering this form of renewable energy somewhat useless for half of the year during winter.

It is easy to understand where these misconceptions come from. Solar panels need solar light (and it is assumed, heat) to function; without sun rays hitting the panels, it would make sense that no energy could be produced.

However, there is a difference in what we consider to be the sun’s power and what is the actual power of the sun. We as humans associate solar rays with strong, yellow sunshine in a cloudless sky; the kind of weather conditions that have you reaching for a hat and for sunblock. While solar panels will flourish in these conditions, just because the sky is overcast or the temperature is low does not mean solar panels will cease to function.

This is because the sun is always casting rays down on earth, even if there is cloud cover interrupting its route to the surface of our planet. Many people each year, much to their surprise, find themselves suffering sunburn on what appeared to be a cloudy and overcast day. This is because the sunlight is still getting through, but it is just more filtered and obstructed than usual.

For solar energy, the important part of the above sentence is that the sun is still getting through. Even when we would consider the sun not to be shining, it is – unless it is night time! Solar panels are therefore able to function in most weather conditions, albeit with reduced output.