How can we solve the energy crisis

Let's solve the energy crisis!

Plans for the future. From electricity from urine to sea snakes: the most bizarre methods of generating renewable energy.

It won't be long before fossil fuel supplies will run out - the search for possible solutions is ongoing. Nuclear energy has long been considered an alternative: generating electricity is relatively cheap and space-saving, acid rain and environmental pollution are avoided. But the disadvantages weigh heavily.

Hence, atomic energy is on the decline. In 1998 the share of global energy production was around 6.5 percent, in 2009 it was only 5.8 percent. In September 2011, 433 reactor units with a total output of 366.6 gigawatts were in operation in a total of 31 countries. Meanwhile, science is constantly working on new, sometimes bizarre methods of generating energy. An overview.
• Energy harvesting. Energy harvesting means to obtain energy from the human body. For example, through given body heat or movement of people. This is already happening in a Dutch discotheque. There, the guests' dance movements are converted into electrical energy by means of pressure plates in the floor. In addition, the heat given off by the dancing people is used to heat an office building next door. When the disco is full, up to 40 kW can be generated. Compared to a nuclear power plant, it would take 25 of these discos, which would have to generate 1000 hours of energy per year to replace a single nuclear power plant.
• Electricity from urine. Urine is actually considered a legacy at festivals and open air events, as expensive waste to dispose of. For example, special microbial fuel cells were developed that convert urine into energy with the help of bacteria. The functionality of the urine battery is surprisingly simple: In the small plastic bag of the prototype there is a copper plate and a magnesium plate between which a paper strip that was previously dipped in copper chloride solution is clamped. Wires connect the individual elements and lead to a plus and a minus contact at the top of the bag.

Human urine contains many ions (charged atoms). If you put a drop of it on the paper strip, a chemical reaction begins that generates electricity. The metal plates divert the energy and convey it to the contacts, where a consumer takes it. In Japan, a 1.5 volt AA urine battery was developed that can keep a flashlight glowing for 20 hours.
• The updraft power plant. This power plant consists of a tower (up to 1000 meters high and 120 meters in diameter) and a plastic tarpaulin with a diameter of up to 7000 meters, which is also called a collector. The way it works is very simple: The sun shines through the collector and heats the air underneath. This rises to the center of the collector and operates up to 32 turbines located at the foot of the tower.

These turbines are connected to a generator that generates electricity. A typical updraft power plant with ideal values ​​could generate 200 to 400 MW and would supply 800,000 households with energy for a year. You would need four to seven such power plants to cover the output of a nuclear power plant. The values ​​depend on various variables, such as the tower height.
• Photovoltaics in space. Scientists are currently researching a photovoltaic system for space. Very large sails with mirrors reflect the sunlight and then concentrate it on photovoltaic cells. These cells generate electricity, which is converted into microwaves and sent to the earth. There these microwaves are converted back into electricity. This system would be sent 36,000 kilometers into geostationary space, because there it could always float at the same altitude. The disadvantage is that it would be extremely expensive to build and transport to space. It would cost $ 10,000 to move a kilogram of this construction to its designated location. The big advantage would be that electricity could always be generated, even in bad weather on earth. The first project should start in five years.
• The sea serpent. This power plant resembling a sea serpent (see picture) is used in marine areas, where it uses the energy of the waves and converts it into electrical energy. The structure consists of several individual, individual segments that are connected by joints. The sea snake sways on the surface of the water through the waves. This movement drives hydraulic motors, which are then converted into electrical energy with the help of a generator.

Around 1,333 mechanical sea snakes would be able to replace a nuclear power plant. Some of these wave power plants are already in operation today. 25 plants are operated in Portugal and achieve a total output of 18.75 MW. A sea snake generates 750 kW of power.

("Die Presse", print edition, June 29, 2012)