Solar and wind power on energy efficient buildings
Passivhaus compliant buildings, such as the flat shown above, can have their own solar power. Source: Passivhaus-Institut |
These energy efficient buildings can and should also have their own solar energy, either as solar panels which are expensive, or better still (when available) using spray-on solar film for walls and windows and installing solar roof tiles which I would personally recommend. Such a building would at the very least be zero-energy (or minimal energy), and could even be a net exporter to the electricity-grid, especially if other energy sources are also added. We can also have rainwater collection systems added not only to potentially generate more electricity (especially using nanotechnology), but also to provide water at the same time for gardening, washing machine, car washes, WCs, and (with a suitable filtration system) even for drinking water and showering.
Of course, the main electricity grid can still be used as backup for solar, and if installed, rainwater collection too. And of course the main water supply can still be used as backup for the rainwater collection based water supply.
If every building in your country was constructed to the passive house standard, with solar, and possibly even rainwater collection power generation for each building, imagine how much energy, especially electricity can be generated for the building, and how much surplus could be exported back to the electricity grid. At the very least these type of buildings can really minimise energy consumption, especially when using OLED wallpapers for lighting in the future.
Solar power arrays and solar farms
It is recommended to carry on with existing solar power arrays. This is especially important for places which get a lot of sunshine. Having said that, simply having daylight alone (even on an overcast cloudy day) means a lot more sunshine than one thinks. Nanotechnology can also be used to make photovoltaic solar panels more efficient, this research is happening, as with spray-on solar film which also uses nanotechnology. But the photovoltaic solar panel is not the only solar power technology available.Solúcar PS10 solar power tower in Sanlúcar la Mayor, Andalusia, Spain |
In the long term future, solar panels or solar panel arrays can even be put into space, current designs have the solar panels collecting the light and then transmitting the energy to receivers on Earth using microwave rays. Perhaps an alternative method of transmission might be discovered in the future. Solar panels in space would be consistently exposed to a high amount of solar radiation (significantly higher than on Earth) so is no longer dependent on weather conditions, but other problems would be meteoroid impacts and radiation damage in space.
However today and in the immediate future, solar power arrays are one way of using renewable energy to supply energy to the electricity grid, and their use should be expanded.
Wind farms
Wind farm in Ardrossan, Scotland Author: Vincent van Zeijst Licensed under CC-BY 3.0 |
Geothermal energy
Geothermal power station in Krafla, Iceland |
The obvious place, and where traditionally where the first geothermal power plants were constructed, is to build close to the surface where tectonic activity happens, typically geysers, or near volcanoes. Binary cycle power plants is one modern type of geothermal plant, first introduced in the USSR in the 1960s. A more recent development is in Enhanced Geothermal Systems (EGS) which do not require convective hydrothermal resources, and which involve deep drilling, injecting high pressure water, then extracting the resulting heat from the steam. Depths for the EGS wells can be 3-5 km deep.
Although there can be emissions including carbon dioxide, hydrogen sulphide, methane, and ammonia, as these are obtained via fluids drawn from deep earth, existing geothermal plants emit 33.9 g/GJ (122 g/MWh) of carbon dioxide, which is a small fraction of the emission intensity of conventional fossil fuel power plants per GJ of power generated. Geothermal sources can also contain trace amounts of toxins such as mercury, arsenic, boron, and antimony, but the modern practice of injecting cooled geothermal fluids back to Earth mitigates this environmental risk.
Some caution is advised however with geothermal power plants (especially with deep level heat extraction), as geothermal power plant construction can adversely affect land stability and in extreme cases cause seismic activity (earthquakes) as happened in Basel, so care needs to be taken, especially in or near earthquake zones (Basel is in an earthquake zone). It must be also noted that it is very expensive to drill very deep.
Despite this the usage of geothermal can and should be expanded, and EGS is also worth considering where practical, and where care is taken during construction and/or drilling. Although the easiest method still remains to construct near tectonic boundaries where practical.
Tidal power
SeaGen - world's first commercial tidal power generator, Strangford Lough, Northern Ireland Author: Fundy Licensed under CC-BY-SA 3.0 |
There have been recent design improvements (dynamic tidal power and tidal lagoons for example), and turbine technology (including axial turbines, and crossflow turbines), which shows that tidal power is much more available than was previously thought.
Since the Earth's tides are dependent on Earth's rotation, as well as the gravitational attraction of the Sun and the Moon, this source of energy is limitless. This power source has great potential, and should definitely be considered.
Nuclear fusion (long term future)
Deuterium-tritium fusion reaction |
For fusion reactors, current designs involve two isotopes of hydrogen, deuterium and tritium, which get fused together, and this reaction generates six times as much energy compared to the equivalent fission reaction. 1g of nuclear fusion fuel (deuterium and tritium) would generate as much energy as 11t of coal.
Concerns however include to stop neutrons (a byproduct) from escaping although these would be absorbed by a material (for example a vanadium alloy or some material which can absorb neutrons), as well as tritium which has a radioactive half-life of 12.32 years. This means that having secure and fail-safe systems which prevent any leakage would still be extremely important for fusion power plants, as it is with nuclear fission today.
There is no risk of a major tragedy caused unlike with fission (but industrial accidents are still a risk). Waste products are the radioisotopes which would result from material surrounding the plasma absorbing the neutrons from the reactor core, these radioisotopes would have a comparatively short half life at 50 years as radioactive mater, become low level waste in 100 years, and have the same radioactivity as coal ash in 300 years. However, as with fission, this waste has to be handled. By contrast, nuclear fission produces waste products which can have a half-life of thousands of years at least. A fuller analysis of nuclear fusion is shown in the publication Fusion as a future energy source: Recent achievements and prospects.
Although fusion is technically non-renewable, there is enough deuterium in seawater on Earth to 150 billion years based on the 1995 global power output. However, to make tritium, lithium is required, and the lithium needs to be split in a nuclear fission reaction to make tritium (as well as the helium-4 byproduct. Although lithium is quite abundant on earth, it is still needed for other purposes, including Li-ion batteries for example, and it is not infinite because the known lithium reserves are estimated to last 3000 years, and lithium from seawater would last approximately 60 million years.
The International Thermonuclear Experimental Reactor (ITER) in France, the Wendelstein 7-X in Germany, and the Large Helical Device in Japan, are demonstration proof-of-concept fusion reactors, whose development is in progress. Actual power generation for homes would be expected in the late 21st Century or the 22nd Century. Fusion Energy can also be used to propel spacecraft in the long term future (or could even be used just for spacecraft engines, should renewable energy meet all our energy needs on Earth).
Nuclear fusion is an energy source for the future. There might be also alternative designs for fusion reactors, or new ways of igniting a fusion reaction in the future which have not been invented yet (fusion reactions have to be ignited, and then contained). Having said that, renewable energy will always have a very important role to play in meeting our energy needs, so will need to co-exist with fusion, once fusion is introduced. At the same time, while research continues into viable nuclear fusion energy, there is no need to wait until the first fusion power plant is made, we can have renewable energy now.
I am all for alternative energy but do wonder if it is all too little too late... These new sources should now be overtaking the old but the progress seems a little too slow.
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