Hi guys! So much has been said in the last year with a view to increasing climate awareness. I'm hoping that those amongst us making important decisions, determining the fate of our planet and our future, were listening carefully! One of the main contributors to changing environmental effects is energy. It is crucial that we embrace sustainable, efficient and powerful sources of energy for our societies as we step into tomorrow. Here I will summarise several of our primary energy options, past, present and possibly in the future! Hopefully this will get us all thinking about the environment and the steps we need to take to protect our green planet home.
For each energy method, I will point out 5 things: 1: How the method provides us with energy; 2: Benefits of the method; 3: Costs (environmental or otherwise) of the method; 4: Requirements of the method; 5: My personal opinion.
First: The infamous fossil fuels.
1: How fossil fuels provide us with energy: Combustion of carbon-based fossil fuels (coal, oil, gas etc.) releases a huge amount of thermal energy. Using water and a steam turbine, we can convert this thermal energy into kinetic rotational energy. This kinetic energy can be used to rotate a magnet, providing electrical energy.
2: Benefits of fossil fuels: Reliable and releases a lot of energy. Many major industries depend on the use of fossil fuels.
3: Costs of fossil fuels: This method is not renewable, since the fossil fuels needed for combustion are coming from a finite source. Once it's gone, it's gone! Also, for every tonne of carbon burnt, 3.67 tonnes of CO2 are produced. This CO2 is, quite famously, a greenhouse gas. It is a main contributor to global warming.
4: Requirements of fossil fuel combustion: Fossil fuels must be mined from an ever-decreasing source under the ground, damaging or destroying the landscape, sometimes removing green land and habitats.
5: My opinion: Even though we rely heavily on them, we should try to pull away from using fossil fuels as soon as possible.
Then, the Renewables:
1: Solar Power.
1: How sunlight provides us with energy: Photons hit electrons on a metal plate, temporarily exciting them and "knocking" them off the plate. This is called Einstein's photoelectric effect. Normally the electrons return to their original state and re-emit a photon but here, the excited state of the electron is harnessed as a voltage.
2: Benefits of solar power: Provides a DC current, which is suitable for most everyday components. Also, the Sun will emit light for billions of years to come so this method is sustainable.
3: Costs of solar power: Not reliable (humans have not developed/installed enough capacitance to store energy for cloudy days) and solar farms obscure patches of green land. Also, solar cells are only 15% efficient.
4: Requirements of solar cells: Suitable metals must be used to create photoelectric plates and enough land must be provided to create solar farms. Also, the solar cells must withstand extreme conditions (temperature, weather etc.).
5: My opinion: If we can refine solar cell capacitance and strategically place solar farms (i.e. in places with low rainfall), then solar power is definitely an excellent option for generating electric power.
2: Wind power:
1: How wind provides us with energy: Wind directly pushes a turbine, spinning a magnet and generating electrical energy.
2: Benefits of wind power: Requires little land and it is one of the most efficient methods of generating renewable electricity.
3: Costs of wind power: Wind turbines have an efficiency of about 35% (compared to 45% efficiency of coal combustion) and wind turbines are expensive to set up.
4: Requirements of wind power: A windy climate (about Beaufort Scale 6-8).
5: My opinion: This is like the solar power. If we can strategically place wind turbines, then this is a most viable energy source.
3: Hydroelectric Power:
There are two main hydroelectric energy methods: hydroelectric reservoir power and tidal power.
1: How hydroelectric reservoirs provide energy: The gravitational potential energy from water in a highly placed reservoir is converted into kinetic energy of water falling down a channel, ultimately meeting the sea. The kinetic energy is used to turn a turbine and spin a magnet, providing electrical energy.
2: Benefits of hydroelectric reservoir power: They are reliable (there is always going to be water in the reservoir as the reservoir is part of a river), create even flow rates (sometimes beneficial to riverbank cultures), are sustainable (can be used for future generations) and large hydroelectric reservoirs are the most efficient type of electricity generators (90 - 95%).
3: Costs of hydroelectric reservoir power: Can destroy shoreline habitats, create unnaturally even flow rates (sometimes detrimental to riverbank cultures) and are expensive.
4: Requirements of hydroelectric reservoir power: A full reservoir (or a dam).
5: My opinion: We should move towards this direction if we can somehow avoid obstruction/destruction of shoreline habitats.
1: How tidal waves provide energy: When there is a high tide, a reservoir fills up. This reservoir empties at low tide due to a pressure gradient across the reservoir boundary. This emptying of water turns a turbine, converting gravitational potential energy to kinetic energy to electrical energy.
2: Benefits of tidal power: Reliable (the Moon and Sun's gravity will always pull on the Earth and its oceans, whatever the weather), very efficient, like hydroelectric reservoirs (for comparison, tidal power has an efficiency of ~ 90% whereas a solar farm has an efficiency of ~ 15%) and provides a tremendous amount of energy given a large reservoir.
3: Costs of tidal power: Expensive and could destroy shoreline habitats.
4: Requirements of tidal power: A large reservoir.
5: My opinion: This is a very promising method. If we can prevent natural damage and mitigate the costs, this might just be the power of the future!
4: Biomass:
1: How biomass combustion provides energy: Combustion of biomass releases a huge amount of thermal energy. Using water and a steam turbine, we can convert this thermal energy into kinetic rotational energy. This kinetic energy can be used to rotate a magnet, providing electrical energy.
2: Benefits of biomass power: There will always be biomass in the world so this is reliable. Also, the CO2 released by the biomass could be absorbed by the surrounding plant life.
3: Costs of biomass power: To obtain biomass, deforestation is performed. Also, the efficiency is only 34%.
4: Requirements of biomass power: A combustion chamber and a supply of organic material.
5: My opinion: If we invest in more farming land and somehow improve the efficiency of this method, this might be a key intermediary step from the end of fossil fuels to a cleaner future.
5: Natural Thermal Sources:
3 main branches of this area are Solar thermal energy, Geothermal energy and Ocean thermal energy conversion but they all follow the same principle:
1: How Natural Thermal Sources provide energy: Thermal energy is obtained from the source (Solar energy is obtained using parabolic mirrors that concentrate the Sun's rays onto a pipe with water; Geothermal energy is obtained by implanting a water-filled pipe underground (deep enough to obtain heat from magma/mantle); Ocean energy uses both cold deep water and warm water from the surface as a thermal gradient). This thermal energy is converted to kinetic energy in a turbine which is then converted to electrical energy.
2: Benefits of Natural Thermal Sources: Natural, so omnipresent and reliable. Also, these methods are central to certain communities (Reykjavik --> Geothermic, Hawaii shorelines --> Ocean Energy Conversion etc.). Does not require a combustion chamber, so cheap.
3: Costs of Natural Thermal Sources: These methods are extremely inefficient (Solar thermal energy --> 18%; Geothermal energy --> 15%; Ocean thermal energy conversion --> 3%).
4: Requirements of Natural Thermal Sources: High strength glass pipe that does not absorb too much heat and other apparatus specific to the type of source.
5: My opinion: If we can somehow superboost the efficiency of these methods, they would be perfect for natural energy (out of the choices we have already considered).
Then, fuelled energy sources worth your while:
6: Nuclear Fission:
1: How nuclear fission provides us with energy: When a neutron hits an Uranium-235 atom, a new Uranium-236 atom is formed. This is incredibly unstable and the atom instantly splits into a Barium-141 atom, a Krypton-92 atom and three more neutrons, releasing a mountain of energy as gamma rays. Nuclear energy is converted to light energy. The 3 neutrons each bombard another Uranium-235 atom. If this process was not controlled by the refined control rods and graphite moderators of today, we would have created a nuclear bomb (like those dropped on Hiroshima and Nagasaki). However, we control today's reactors with precision incomparable to that of 35 years ago, in Chernobyl (which actually wasn't the effect of a nuclear reactor-turned-bomb, but rather a steam pressure explosion). The gamma rays heat up water and so turn a steam turbine, converting light energy into electrical energy.
2: Benefits of nuclear energy: Clean and reliable given a supply of fissile Uranium-235.
3: Costs of nuclear energy: Non-renewable (have to mine from a limited supply).
4: Requirements of nuclear energy: Expert precision for the control rods.
5: My opinion: This holds great promise for a clean, green future. Also, as humans look to the stars for asteroid mining in the future, we might get virtually unlimited Uranium-235 from space!
7: Proton Exchange Membrane Fuel Cells (PEMFCs):
1: How PEMFCs provide energy: Hydrogen and oxygen combine to form water. Chemical potential energy is lost in this reaction. This lost chemical energy is directly harnessed as electrical energy through a series of electrochemical reactions.
2: Benefits of PEMFCs: Clean and reliable given a supply of hydrogen and oxygen.
3: Costs of PEMFCs: Inefficient (20% efficient).
4: Requirements of PEMFCs: Hydrogen and oxygen (i.e. from water) separated from each other (with displacement reactions etc.)
5: My opinion: This might be a good method but I prefer other methods that have already proved successful (other renewables, etc.).
8: Microturbines:
1: How microturbines provide energy: Microturbines utilise the same process as any other fuel combustion method but the excess heat generated is also used to turn the turbine, whereas in other methods some heat is lost to the atmosphere.
2: Benefits of microturbines: Keeps oil companies employed, produces way less emissions and is more efficient (up to 88% more efficient) than conventional fossil fuel combustion (45% efficient). Also the microturbine method can use any carbon-based fuel and requires very little space.
3: Costs of microturbines: Emits greenhouse gases.
4: Requirements of microturbines: A fuel supply and a recuperator are required to boost efficiency.
5: My opinion: This is probably an incredible short term solution, to power the world whilst we refine renewable power for global use.
9: An unexpected but impressive candidate: Municipal waste combustion:
1: How municipal waste combustion provides energy: This method is like all the other combustion methods but uses un-recycled waste.
2: Benefits of municipal waste energy: Municipal waste energy produces less than 1/24th of the emissions of fossil fuel combustion; The byproducts of this combustion are ash for landfill (artificial fertiliser), metal ashes (which can eventually become recycled metal) and aggregate that can be reused for buildings; Municipal waste energy reduces waste volumes by 90%.
3: Costs of municipal waste energy: A bit inefficient (25%).
4: Requirements of municipal waste energy: A supply of waste and that is rampantly increasing.
5: My opinion: This is the best non-renewable fuelled energy source I've seen so far!
Then, some potential energy sources of the future!
10: Fusion Energy:
1: How fusion energy provides us with energy: Fusion of deuterium (an isotope of hydrogen) and Helium-3 at really high temperatures recreates thermonuclear reactions in the Sun's core, releasing astronomical amounts of energy.
2: Benefits of fusion energy: Emits 0 emissions and would last for an indefinite amount of time.
3: Costs of fusion energy: It is very very expensive!
4: Requirements of fusion energy: Helium-3 from the Moon, which we could mine when humanity builds a moon base; Deuterium from the sea.
5: My opinion: It's definitely worth it, but humanity must start living like "lunar-tics"!
11: Dyson Sphere:
-1: But why bottle a star when we can have the one we orbit?
0: What is a Dyson Sphere? A megastructure that is theoretically designed to obtain/use the whole of the Sun's energy.
1: How a Dyson Sphere provides energy: The megastructure cannot be a single encapsulating mirror as radiation is reflected back into the Sun's core, which could turn the Sun into a premature supernova. Instead we could apply a swarm of mirrors to deflect sunlight. The radiation pressure of that abundance of photons could be used to push new anemometer-style turbines to create more energy sources, not to mention that there is now an option for all year solar farms.
2: Benefits of a Dyson Sphere: As above, the radiation pressure can be used to push things without fuel. Also, that abundance of light energy can solve our energy crises.
3: Costs of a Dyson Sphere: The construction of a Dyson Sphere will take a lot of time and resources.
4: Requirements of a Dyson Sphere: Sturdy mirrors that are very thin.
5: My opinion: If humanity can surmount such a task, then Homo Sapiens will be a race beyond compare, but I think we should focus first on other megastructural plans (Stellar engines, etc.).
In my mind, a possible energy scheme over time could be like this:
A: The point at which we have refined renewable energy so much that there is no more profit from combustion energy.
B: The point at which humanity has built its first moon base.
What do I mean by this diagram?
Well, the diagram shows that currently, Fossil Fuels are the main energy source and that Renewables and Nuclear Fission follow suit. It shows that I think that we should change our fossil fuel combustion chambers to Municipal Waste combustion chambers (since there are many more environmental benefits and will keep the combustion industry afloat). While we are supported by MWE, we should try to refine the renewable energies that we already use. Eventually, the renewables (such as solar farms, tidal plants, biomass chambers and natural sources) will be so refined that we do not even require combustion energies. Then renewables and nuclear fission would be the predominant energy sources. Further in the future, humanity would go out to space and would probably like to build a moon base as a second space station. There, we could mine Helium-3, which is necessary for Nuclear fusion energy. With this fusion energy, as well as the renewables and fission energy, we could power the world for eons.
We could use other energy sources that we have discussed already, but I just focused on the top sources of energy.
Please share your thoughts in the comments below and C u soon!