If anyone else is as tired as me at hearing about alternate sources of energy – the arguments by billionaire mining magnates, activists who need cold showers and vote-hunting, finger-pointing bickering between our political leaders – then I can imagine you’re not going to want to read this. I’ll tell you what though – give me 5 minutes of your time and I’ll try to cut through as much of the BS as possible so that next time you find someone who wants to climb on their soapbox and rant, you can tell them you know already all about it and they can sod off. Fair trade?
Good to see you’re still reading, I’ll take that as a ‘deal’.
Right, two things to get started:
* Firstly, for the most part here, I’m talking about electricity generation. In some cases it’s more efficient to capture the energy in the form in which it’s produce, such as burning things for heating, but I’m going to focus on electricity because we can always convert this later and its the biggest problem.
* Secondly, what are we talking about when we hear “sustainable” vs “renewable” energy (or RenEn for the lazy typist)? Sustainable energy refers to energy made in a way that means it will keep providing energy for a long time and not make too much a mess of the environment – ie. sustainable means efficient. An example is nuclear power – its clean in producing energy, pumps out heaps of energy and it just keeps going. Renewable energy is replenished without much or any effort by people – that is, it is automatically replaced by some other external force (usually the sun or an environmental condition). It always has to come from somewhere though – energy doesn’t just magically appear. RenEn comes from sources like hydroelectric, solar and wind farms.
Meet the Candidates:
Solar: capturing the sun’s rays on photovoltaic cells
Pros – cheap, RenEn, available almost everywhere, technology is well advanced, low maintenance, can be close to users (on rooftop), very clean
Cons – initial cost for setup, doesn’t work at night, needs storage & supplementing with other sources, best in a sunny climates. England in winter is a bad idea.
Wind: air currents push a turbine around and physical motion is converted to electricity
Pros – cheap, RenEn, technology is well advanced, equipment lasts a long time, very clean
Cons – expensive kit to set up, medium maintenance, limited to windy locations, needs space, possibly dangerous for birds (unproven), high maintenance costs. Communities don’t like having them in their own backyards. Most are happy for them to be in other people’s backyards though.
Nuclear Fission: the nucleus of some big atoms like uranium and plutonium are broken apart and release a lot of energy
Cons – Material is expensive, mining it is messy and disposing of it is worse. Stations are expensive to set up and maintain properly, nuclear material is sought by undesirable people for bomb-making. Mistakes and natural disasters are very bad <looks at Chernobyl & Japan>.
Nuclear Fusion: two small nuclei (like hydrogen or lithium) get jammed together, fuse and release a lot of energy
Pros – Elements are extremely common, all the best things about fission without the mess, risk or hazardous waste.
Cons – We can’t do it yet. It does exist though, the sun has it down.
Fossil fuels: burn fuel made from dead organisms that decayed underground for millions of years.
Pros – its cheap and we are good at making it
Cons – very limited supply that will run out at current consumption rates, not renewable and creates pollution. Has been immensely useful but has had a semi-disasterous effect on our environment.
Biofuel: recovering the energy that living tissue (usually plants) make for itself from food and growth, usually through burning it, such as ethanol extracted from sugar cane waste, vegetable oils, wood or even glucose and oxygen in the body which can be harvested for implanted devices such as pacemakers, valves, sensors & drug delivery systems (see The Conversation).
Pros: convenient, available at any time and produce as required, can fill in the gaps with wind and solar, glucose cells are highly portable and close to user.
Cons: burning can cause pollution, sometimes small volumes of energy produced, isn’t necessarily the most efficient (energy lost in the making). Good use of last night’s leftovers.
Hydroelectric – electrical power from falling or flowing water, most widely used type of RenEn around the world
Pros – cheap, clean, available in large volumes, can be combined with harvesting a water supply for communities/cities, attractive.
Cons – if you have to build a dam and alter water courses, it will massively change the environment & be high maintenance, mistakes can also be bad. Flow turbines can still have some effect the downstream ecosystem with dams slowing the water.
Ocean Currents, Tides and Waves: deep ocean currents, tides and the crashing of waves on the coastline can push turbines.(see
CSIRO’s Energy Transformed program)
Pros – clean, readily available, RenEn, predictable, reliable, not visible, calming ocean areas for industry
Cons – high maintenance cost, limited locations, distribution, calming ocean affects the marine environment
Blue energy: using the difference in electrical charge produced by mixing fresh and saltwater, as naturally occurs where rivers meet oceans (see Science Daily)
Pros – clean, could produce a good amount of energy
Cons – still in research, only produce harvest-able energy at the mouths of rivers, not sure of economic and technological costing
Geothermal – using heat from rocks deep underground, particularly good in locations that are near or above volcanoes and magma such as Iceland.
Pros: clean, efficient for heating, excellent in some locations where magma is near the surface
Cons: expensive if you’re not in one of those limited locations, requires drilling, expensive kit, high maintenance and distribution
Pros – huge amounts of almost free energy available for as long as we’d need it
Cons – it’s completely fictional. Would need an advanced space program, technology and materials that don’t exist, incredibly expensive to make, and difficult to transport energy back to where it’s needed on earth. However, we are looking for evidence of Dyson Spheres in the night sky in the search for advanced extra-terrestrial civilisations (!) (see SETI).
Piezoelectric – energy from touch pressure, can be captured in a film (so could have an iPad that recharges itself as its used) – doesn’t make much energy.
Kinetic – directly captured from movement, such as treadmills, rotors. Kinetic watches have been around for a while, a weight rolling around inside capturing hand motion. Moving parts wear out, low power generation but both can be excellent for low power, portable devices.
Cost – how much does it cost to setup? Maintain? Produce energy? And how long will that investment last?
Storage – most energy systems need some form of battery for storing the energy until it’s needed – are the storage needs short or long term?
Distribution – how close is the energy source is to the customer? Big centralised plants need infrastructure and services to deliver electricity to consumers. (see why closer is better)
Efficiency – In production, can we get a high ratio of energy-out to energy-in for a sustained period?
Waste produces – what are the impacts of the waste products produced? Does it generate pollution like coal or burning carbon, or is there a waste product at the end for disposal, as with nuclear fission?
Consumers’ Energy needs – Different locations have different requirements. For example, colder climate needs more heating, hot climates tend to use air conditioning, big cities use a large amount for lighting and entertainment.
Technology Maturity – Is it ready? Some of the techniques still being tested to see if they economically viable. Fusion is still a long way off and the dyson sphere is .. well, cool for a Star Trek TNG plotline.
Public opinion – “not in my backyard”. Honestly people, suck it up or live without your fridges, freezers, tvs, computers, lighting, hot water, …
Volume of electricity – some glucose, piezo and rotor kinetic can’t make much energy but may suffice to power some devices. It all helps.
Lifetime – a glucose energy cell for a pacemaker in a rat can currently last for one month, whereas 1kg of uranium can provide energy for 100 years. Will the lifetime validate the cost?
Consistency/Reliability – does energy produced drop off at times, say with seasonal changes or day/night? If so, back-ups will be needed in the form of storage or an alternate source for reliable power.
Most Suitable Solution Is …
All of them. Yep, sorry people. There isn’t going to be a one-size-fits-all solution in the near future and its all heavily dependent on location and environmental conditions.
Wind, solar and hydro are the big 3 RenEn sources that are the most advanced and can perform extremely well if the conditions are right, but that won’t be everywhere. There are arguments as to whether these sources could provide the baseload power supply but it looks viable *if* we increase the efficiency in which we currently use energy – we currently waste an awful lot – and if the gaps in service can be backed up with biofuels or another alternative for constancy. Nuclear power can handle the volumes but no one wants a nuclear plant on every corner and until we find a way of jettisoning nuclear waste into the center of the sun, we have to find some safe way of storing it here for thousands of years when its no longer useful. Ocean and blue energy have an enormous amount of potential for large scale energy production with minimal impact on society, and could also fill those gaps but they are years away from production. Fossil fuels are needed to buy us the time we need. If every rooftop had solar panels and houses installed solar hot-water services, we could dramatically reduce our dependence on dirty energy and budget our non-renewable fuels to last until we can get to that 100% solution. All that sunlight is currently just heating up my roof tiles – seems like a shame to let it go to waste.
There you have it. That bring us to the end of the 5 minutes I promised, so here’s my end of the bargain. The next soapbox ranter than thinks they have the solution for everything, ask them for the specs of their Dyson Sphere and a job on the next shuttle out to the sun to make your fortune. If they can’t arrange it, tell them to get working.