What is a Solar Panel?
A solar panel is a device that is used to convert solar energy into an electrical current. They are sometimes called solar cells or photovoltaic cells. When a number of cells are connected to combine into one item it is called a photovoltaic module. When a number of solar or photo-voltaic modules are connected together they are referred to as an array – this method is a way to provide a greater output of electricity.
There are two main forms of solar panels. The most common is a solar electricity cell, but there is also a solar water heating panel that can be used to provide all or part of a home’s hot water supply. Solar electricity panels usually have a battery storage attached to the system to allow the electricity produced through the day to be stored for another time, such as the night. They can help lower your electricity bills and assist in the fight against climate change.
What is Solar Panel Roadways?
Solar Roadways Incorporated is a start-up company that is developing solar powered LED road panels to form a roadway. You can find their website here http://www.solarroadways.com/intro.shtml. By combining a transparent driving surface with solar cells underneath, electronics and sensors act as a solar array generating electricity. Julie and Scott Brusaw from Idaho, USA are the founders of this project, and through grants and fundraising campaigns are now working on making the idea a reality. Scott, an electrical engineer, and his wife even managed to secure a grant from the Department of Transportation. The money was supposed to be used solely for gathering information from experts but the couple also built a prototype.
The Design
Initially the panels were designed by hand, with the original material idea stemming from thinking of the ‘black boxes’ in airplanes, and how they are able to protect sensitive electronics even in crashes. With the backing of funding the couple have been able to hire engineers to improve the design, but it is still yet to be finalised. Using proven technology such as silicon solar cells and LED lighting the design has been met with different, and difficult challenges because of the unconventional installation process.
Initially the design was a 12ft by 12ft square but has since been changed to a hexagon shape, making it easier to lay on a curved surface. The couple paved a space on their property using the hexagons as a first trial. The design sees two pieces of tempered glass, half an inch thick, sandwiching the solar cells, LED and the other electrical components between. Textured glass is used to help to prevent skidding particularly in the rain, giving a similar traction to asphalt. Tempered glass is used because if it breaks it does so into smooth pieces, not sharp like regular glass – it is the same material that is used in car windows.
The Department of Transportation followed up their initial grant with more money, to develop a ‘parking lot’ prototype which demonstrates the product more effectively. This now stands at 108 Solar Road Panels. A crowdfunding source saw a massive donation as it was decided full time materials experts and civil engineers were needed. The prototype has undergone vigorous testing and has been used to identify changes that could make the panels more cost effective. They have two types of surfaces. One is semi-smooth, a walking surface and is capable of stopping a car going 40mph on a wet surface. This can be used on pavements, bike paths and car parks etc. The other is designed for highway use and can stop a car going 80mph on a wet surface.
Efficiency
The couple first got the idea for this project as the topic of global warming became more of a forefront problem that was being discussed. They thought of replacing the regular asphalt and concrete surfaces with solar panels, allowing vehicles to drive on them as they generate electricity. Their vision is that everyone in the future will have power. The demand for fossil fuels would be lower meaning less pollution, and less dependency on foreign oil – in fact in any oil altogether. It would also mean that electric roads will allow electric cars to recharge anywhere, giving them the same range as a petrol or diesel powered vehicle. In order to make their project as green and efficient as possible, they aim to use existing roads as their foundation whenever they can.
The Brusaw’shave said that the road will essentially pay for itself over time. This will be from:
- Generating electricity
- Transporting cleaned storm water
- Leasing the cable corridor to companies such as internet or utilities
- Allowing advertisers to use the LED in the car parks
- Charging people to recharge their electrical cars.
With an integrated system, repair will be quicker and easier than the current maintenance. As each panel contains its own microprocessor it is able to communicate with its surrounding panels – when one stops communicating the other panels are able to immediately report this. It only takes one person to replace the panel with a new one, so this can be done extremely quickly.
The LED lights are there to replace painted lines, meaning a safer road for driving at night due to the lights indicating where a vehicle is, and when it is approaching. But in order to reduce light pollution the LEDs will be designed to dim, or even turn off if no vehicles are on the road.
Potential problems
There are some problems that still need to be worked out. In traffic jams, parked cars will mean the panels will not effectively be sourcing energy, it’s also not known whether there will be much noise at high speeds. Designs are being made so that the panels to be able to take the maximum weight possible, but this is still being modified. There is a heating system in place that will only be used when needed. It is separate to the solar cells because it has to work at night, however the temperature still needs to be worked out fully in order to keep it above freezing. But because the road surface is heated, freeze/thaw cycles won’t affect the road and sopotholes will not exist. A cable corridor runs alongside the road to collect water, in order to combat a large amount of rainfall, grates will be used to pass the water into a filtration area. Through gravity, the water will be passed through a filtration sock and into a storage tank – the water can then be pumped out.
Life expectancy and the future of solar panel roadways
The panels are designed to last a minimum of 20 years, it is the solar cells that have the shortest lifespan of 30 years. The power system will be a decentralised system which means more security and less chance of surrounding homes losing power if the roads are attacked by hackers or terrorists.And it’s not just roads, because of the pressure sensitivity, the panels could also be used as a security measure – if someone steps on a panel it can designed so that an alarm trips. This project has been somewhat controversial, with those doubting whether it will ever make it onto our roads. What can’t be doubted however, is the innovative ideas and technology behind it, and the promise it holds for renewable energy. This article explains further the scepticism this project has been challenged with. http://www.greentechmedia.com/articles/read/Department-of-Transportation-Official-Discusses-Solar-Roadways