There Are Always Alternatives
During the last years and recently more often I hear that there are no alternatives to conventional coal, natural gas, and atom power plants. This is not true.
There are three major reasons why we should search alternatives: Global warming due CO₂, the safety concerns about oil and atom energy, and finally the problem with the atomic waste .
Of course we can’t just turn off those power plants over the night. But it’s possible in the near future if we really want. There is plenty of energy out there: Sun, wind, tides, geothermal heat, and plants.
Let’s have a quick look over them.
Sun
Alone the sune shines with more energy than a multiple of the whole world consumes. This is easy to calculate:
According to Wikipedia the annual world energy consumption is about 132’000 TWh (for 2008). The average sun insolation per square meter is about 250 W/m^2^
If we assume a poor efficiency factor for solar panels of 10%, we can calculate the required area required to provide the energy the world consumed in 2008:
132000 TW/h / (1000^2^ m^2^ * 250 W/m^2^) / (365 * 24 h) * 10 = 602740 km^2^
This is 14 times the area of Switzerland. While this is a huge area, we have plenty of desert space (with probably more than 250 W/m^2^). And more important: Not the whole area is required as we can collect energy with other sources.
When we talk about solar panels the critics always throw up the gray energy:
Producing conventional silicium based solar panels requires vast amount of energy: Usually a panel has to run about 5 to 10 years to collect more energy than it required to build. This is affortable as a panel is intended to work more than 10 years up to 50 years.
Besided that there is no need to use those silicium based panels:
- Before we even install electric solar panel we should install panels for warm water (with much less gray energy).
- Huge heat based solar power plants with presswater or molten salt produce more efficent with less gray energy
- Huge heat based solar plants produce more efficient using presswater or molten salt based plants (and allow to store heat energy)
- Sunlight reactors produce fuel directly: Science Magacine and Caltech
- Self assembling and self healing solar cells: MIT
One of the biggest problem with sunlight alone is the availability during day only. Energy storage is required.
Wind
There is a big potential for wind energy. As the wind wheels are quite loud they need some distance from populated areas (both men and animals). This calls primary for offshore plants. Unfortunately the wind blows irregular. The consequences are that either massive amounts of the wind energy needs to be stored or to build continental wide smart grids to distribute the wind better.
Tides
This is an upcoming energy source. The tides contain a massive amount of energy in a regular manner.
Geothermal
Another possibilty as long as they don’t trigger earth quakes. Iceland make heavy use if it. A part of it could be exported to Europe. Other geothemal zones in the world could do the same.
Plants
Plants could be used to produce biogas. Beside that plants could produce fuel. But here we have a ethical problem: The rich people will always have enough money to play for fuel that is produced on agricultural areas instead food for the poor. We must stricly forbid to produce bio fuel on areas that could be use to grow food. There are other possibilities to get biofuel: From bio waste and from algae. Last one could be produced in tubes in unfruitful deserts or on contaminated areas.
Energy storage and the grid
A central part of the variable renewable energy sources is a smart grid along with storage capacities. A continent wide smart grid routes the energy from the current available sources to the consumers. Storage power plants stores energy surplus and provides them later during phases of energy deficit.
There we see why it’s important to have a good mix of energy sources: The more energy is available, the less needs to be stored. Not only the sources should be mixed but also the sizes of the power plants: Starting from small solar panels on the roof of every individual building and ending with power plants the size of multiple square kilometres there should be different sizes.
While there are some more capacities for storage lakes in Europes north (Norway, Finland, Sweden) the capacities are limited without resettling millions of people or destroying valuable nature.
Beside the already known water storage power plants there are new developments:
- Using stone storage hills instead of storage lakes
- Sun power plants can use molten salt to store the sun energy as heat before it is transformed to electricity. This is more efficient than to store the electic energy.
- Using phase change material storage. For example a paraffin wax based storage can store the sun energy as heat and provide it in the winter (using a heat pump).
- Store the energy with high temperature heat storages
- Hydrogen storage plants
Conclusion
We see there is still some research and engeneering required. If the demand is high enough this is solvable. The mankind has solved bigger problems already.
posted at: 18:15 | path: /politics/energy | permanent link to this entry
