There are quite a few categories within the renewable energy sector:
- Biogas
- Earth energy
- Kinetic energy
- Solar energy
- Water energy
- Wind energy
Biogas
In the western world, biogas is mainly used in the bigger farms and factories working with waste (water) and fermentation installations on a large scale. Also there are low-scale alternatives available from companies such as HomeBiogas. In developing countries, it is mainly used by families and communities as an alternative to the more expensive electricity and charcoal needed for cooking. Hivos has provided a really nice short insight in what biogas means for a Tanzanian family.
Earth energy
Here are two examples of how the earth and basic physics can help to generate energy: geothermal energy technology and gravity. Geothermal energy technology uses hot water currents located deep beneath the earth’s surface to generate large amounts of energy in a short amount of time. The second really cool way of producing energy is the GravityLight, a lamp which is powered by the force of gravity and aims to be a low-cost alternative to kerosene lamps. The GravityLight has a clear advantage over solar energy, as gravity “doesn’t go to sleep at night”.
Kinetic energy
Kinetic energy refers to the energy an object or a person possesses due to its motion. Kinetic energy can be transformed into different kinds of energy, think of a cyclist transforming human movement into a bike’s wheels.
One of the first cool examples we came across is this soccer ball by Uncharted Play – it works on a small scale, but it’s great for distribution. An hour of kicking the ball around the field accumulates enough energy to plug in a light at night or to charge other electronic devices.
The company Pavegen takes a bolder approach to its kinetic energy products and has designed this soccer pitch in Nigeria which is lit by the movement of the players. This company has taken it to the next level with their latest product: V3 tiles. Not only does it convert your steps into energy and reward you with digital currency, it also collects data about the users.
Solar energy
The costs of solar energy have always been much higher than more traditional energy sources: wood, coal, gas, oil. However, the energy prices have dropped significantly, leading to the growth in the number of solar energy solutions, especially in electricity-deprived areas such as Sub-Saharan Africa. There are many examples of solar power initiatives that rely on local African entrepreneurs to help the community develop (SolarTurtle and Karibu), but first watch this video to understand why solar energy is spreading so fast in Africa. And if solar power is abundant in Africa, why not use it as a continuous input for a durable water purification system?
Other cool solar initiatives include the Solar Impulse, the first plane to fly without fuel, the Physee PowerWindow which is a see-through solar panel and Norbert Frischauf’s plans to harvest solar energy from space.
Water energy
Transferring the natural movement of water into machine power is only a few centuries old. Think of the water mills where the energy produced rotates the mill stone. Some of these huge water mills are still in operation, only to be used for generating electricity. Luckily there are more manageable solutions for individual use nowadays, such as the Idénergie by Vert&Net.
Other, more large scale innovations, are aimed at turning ocean swell (continuous long waves) into renewable power: Ocean Wave Power Station and the Perth Wave Energy Project even aims to desalinate freshwater at the same time.
Wind energy
Ever curious to see how big offshore wind turbines can get? Check out the Vestas v164-8.0 MW, which is compared to London’s main hallmarks and is claimed to be the largest wind turbine in the world. Also have a look at one of the smaller ones: the AEOLOS 500w is used to power street lights of a mountain town in Brazil.
In designing wind turbines many companies and startups find inspiration in nature (biomimicry). Check out these turbines inspired by hummingbirds and trees.
A last cool example of a machine that generates energy from the wind is by the company AVEtec. They create artificial tornadoes in an atmospheric vortex engine to capture mechanical energy.
Scaling up
In winning the debate for renewables, scaling up is vital. Here are some cool examples of huge plants: the BrightSource solar thermal power plant in the Mojave Desert, U.S.A, the Stanford solar plant that powers half the campus, the portable and flexible solar plant by Renovagen and the Dubai 2020 Solar Park project.
Below are some videos which didn’t belong to the categories mentioned above, but are still worth your while: