You've heard, of course, of solar panels, wind turbines, and hydroelectric power plants, but did you know there are some other lesser-known renewable technologies currently in the pipeline? From stretchable or paint-infused solutions that can generate electricity from the Sun to ways for you to power your own electronics, the future of energy generation may be a very alien place to live in indeed.
Some technologies may even, finally, enable us to drop our addiction to fossil fuels. Just perhaps.
What are some of the most promising renewable sources of energy?
Before we look at some of the more novel technologies in development, it might be worth spending a little time exploring what more "traditional" renewable power sources have the most realistic potential.
Wind turbines (onshore and offshore), solar panels, solar thermal, geothermal, hydro, and, yes, nuclear, tend to get the lion's share of the news, but there are other renewable technologies of equal, if not more, potential.
While existing "green" technologies shouldn't be dismissed, there are some others that really do deserve more attention. Since these aren't the main thrust of this article, we'll only highlight a handful of examples here.
One of them is hydrogen fuel cells. These devices tap into the chemical energy of hydrogen to produce power efficiently and, most importantly, cleanly.
Hydrogen fuel cells effectively use hydrogen as a fuel source (instead of, say, gasoline or natural gas), and can do all the things more traditional combustion-based power generators do. You can use them to directly generate electricity, or act as a direct, or indirect, heat source.
They work in a very similar fashion to a battery but do not run the risk of being drained or require constant daily recharging — obviously.
These fuel cells can generally be used as direct replacements for more traditional systems like gas boilers in your home (in theory) and have the capability to come in a range of sizes. Such fuel cells could, for example, be used en masse for utility power stations, or be made small enough to power a laptop.
Another very promising piece of sustainable tech is tidal turbines. Working much like wind turbines, these devices, often very large, use the power of the ocean's tides to generate clean energy very reliably. While technologically very challenging, these devices can be kept out of sight (unlike wind turbines), and out of mind, while potentially providing enough juice to power entire cities.
There are, of course, many others, and we'll highlight some of them below.
What are some of the most interesting renewable options for homes?
And so, on the main event. Other than the usual solar PV, solar thermal, micro-wind turbines, and ground or air heat pumps, you may ask, what other novel renewable power sources exist (or are in the pipeline)?
Prepared to be amazed. This list is far from exhaustive and is in no particular order.
1. Solar paint could be a game-changer for clean energy in the home
One of the newest, and very promising, kids on the renewable energy block is something called solar paint. Touted by many in the industry as the "next big thing" in renewable energy, it is actually quite an interesting concept.
As the name suggests, this is a special kind of paint that can actually be used to generate electricity from the power of the Sun. What's more, many of the solutions currently in development are also very durable and keep the elements out pretty well.
While not a new concept (like many renewable technologies, in fact), our technological capability has only now caught up enough to make it practical.
To this end, various organizations are currently exploring the technology, each with its own spin on the basic concept.
One example is a synthetic molybdenum-sulfide and titanium oxide paint currently in development by the Royal Melbourne Institute of Technology (RMIT). Their solution enables the paint to generate power from water vapor. This paint effectively absorbs moisture from the air and uses sunlight to break down the water molecules into their constituent parts (mainly hydrogen and oxygen).
The free hydrogen can then be used to produce clean energy.
Another interesting example is currently under development at the University of Toronto. Using nanoscale semiconductors called "quantum dots", this paint is able to capture light and turn it into a tappable electrical current.
The dots, also called ‘colloidal quantum dot photovoltaics', to give their full technical name, are very cheap to manufacture and also happen to be more efficient than more traditional PV panels.
According to current research, these little dots are, on average, 11% more efficient than the best PV panels on the market. Theoretically, it should be possible to paint them on the exterior of buildings (or anything really), including the roof, to provide a very unobtrusive way to generate your own power.
Yet another example is something called "Perovskite" solar paint. Currently being researched at the University of Sheffield, this type of paint could be used to provide "spray-on" solar cells.
The main ingredient, "Perovskite", is a naturally occurring mineral comprised of calcium titanium oxide, and was first discovered in the mid-1800s. Around a decade or so ago, it was discovered that this material has some interesting properties that make it an ideal candidate for producing efficient solar cells.
The best part is that solar cells made from this material can be produced in liquid form — pretty handy if you want to mix it with paint.
While these are all pretty exciting, it will be a number of years before they become commercially viable.
2. Energy from booze or waste food "kills two birds with one stone"
Some breweries and distilleries have discovered an innovative way to use the waste products from their processes to actually produce useable energy — rather than throwing it away or using it as animal feed.
For example, in Scotland, various whiskey distilleries send their draff (the spent grains produced in the whisky-making process) to be mixed with wood chips to act as a fuel for specially designed combustion power plants. Working much like more conventional fossil-fuel power plants, the only real difference is the fuel source.
Another interesting, and growing, potential renewable energy tech in this field is anaerobic digestion. By using waste to feed bacteria (and other microbes) that produce methane, houses and some commercial enterprises could literally turn their old food waste into a potential energy source.
For farms to distilleries and even individuals at home, this technology could let you redirect your waste food from the trash into a potentially unlimited source of combustible energy gases like methane. By connecting the digestors to an existing gas boiler system, you could severely reduce your drain on the need for natural gas.
Some local authorities are also getting in on the biomethane act, albeit with rotting oranges rather than the byproducts of booze production.
The best part about this solution is that commercial options are currently available for domestic setups. The systems are also highly scalable and can theoretically be installed anywhere that generates enough waste organic material.
Also known as "biogas", this would be a game-changer for places not connected to gas grids — from remote parts of the UK, USA, to rural regions in Africa, etc.
3. Piezoelectricity — making 'you' the power plant
Piezoelectricity — perhaps one of the most underrated technologies ever developed. You use it every time you turn on your stove and it is the thing that keeps your quartz watch tracking time.
The term is derived from the ancient Greek piezein ("press" or "squeeze"), and the piezoelectric effect is the ability of certain materials to generate an electric charge in response to applied mechanical stress.
When it comes to renewable energy, this could be a very interesting and potentially very promising way to provide power.
From generating electricity as you walk on a surface, or potentially topping up the battery to your mobile device or laptop as you type, it could prove to be an important way of generating power on the fly.
For places with a high throughput of people, like sidewalks, public buildings, nightclubs, shops, etc, incorporating piezoelectric systems into floors could provide an innovative way to reduce the need to draw energy from the grid. In fact, one club in the Netherlands called Club Watt, now sadly closed, did just that.
If installed on a smaller scale, say, in your own home, such a system, if production and installation costs were heavily reduced, could potentially help cut your energy bills significantly.
3. In the future, micro-nuclear reactors could be installed in your back garden (if you dare)
Nuclear reactors might be coming to a town, or neighborhood, near you very soon thanks to breakthroughs made in small, modular nuclear reactors. Coming pre-fabricated, and being relatively easy to transport and install, micro-nuclear reactors could be the future of domestic power generation.
Presently, a few companies are working on designs for micro-reactors, with several having been approved by regulators in a number of countries. Development is holding a steady pace, with some estimating that they could become a reality within 10 years.
Most designs are small enough to be transported on the back of a truck, and they are touted by many as a potential game-changer for self-generation of power for commercial sites, individual communities, and even military installations. Obviously, safety is one of the primary concerns with this kind of technology, but most, if not all, have critical fail safes that enable the reactors to shut off automatically in case of a problem — often using passive systems like relying on gravity to "power" the movement of control rods.
Most tiny reactors in development are incredibly safe, and are pretty much self-regulating, eliminating the need for a large number of specialist engineers to constantly monitor the reactor's status and intervene should they run too hot.
Existing designs for reactors do vary, but most should be able to produce 50 to 300MW of electricity, compared to the typical 1,000MW of traditional large-scale reactors — energy that can be harnessed to provide heating, hot water, or, of course, run turbines to generate power.
Such reactors can be used directly for heat and power supplies, or, could find uses for supplementing existing renewable installations, like wind turbine farms or solar farms. They could also be used as a form of backup generator following disaster events.
Being nuclear, these little power plants should be able to run for at least a decade without needing refueling and are designed to be safely removed or swapped out if needed. Some designs are even being created that can run on nuclear waste from larger-scale, existing, nuclear power plants.
If current designs prove successful, you may find that your future home is powered or heated, either directly, or indirectly, by some form of communal/community mini-nuclear power plant.
4. Make the most of "wasted" surface area with solar windows
Another promising renewable energy tech for homes are solar windows. These devices, as the name suggests, are specially designed windows that act both as a traditional window for viewing the outside, and at the same time as a way to generate electricity.
Given the amount of glazed area of domestic, and many commercial buildings (especially curtain walled buildings), this kind of tech could significantly improve the energy self-generation potential for buildings without affecting its cosmetic look.
This could also be a game-changer for the adoption of renewable tech in existing buildings.
Current existing and in-development solutions range from solutions to allow retrofitting of existing windows, as well as completely new units that can be fitted to new buildings.
One example, developed by a company called NEXT Energy Technologies, is one of the former. They have developed a transparent PV coating that can be used to turn any existing windows into energy-producing surfaces with little to no effort.
According to the company, its first generation PV coatings can produce anywhere between 10% and 20% of an installed building's energy needs. The application is also relatively cheap, enabling any company that uses them to have the initial investment paid off in as little as one year. Not only that, but the coatings, once installed, should be good for 30 years, or so.
Another example comes from a company called SolarWindow Technologies. They have developed a product called "Liquid Electricity", which is another form of transparent and lightweight window coating. Being so light, it could be fitted to any transparent or translucent material from glass, to plastic, and other films.
An independent study of the technology found that it was able to generate electricity with an efficiency of almost 15%.
Thinking slightly outside the box, yet another company, called SolarGaps, has found a way to reuse the existing surface of windows to generate power too. Their solution is to produce a special kind of blind that can double as PV panels.
These blinds can be readily fitted to any building, are even able to track the movement of the Sun to maximize the amount of electricity they squeeze out of daylight. According to the technology's manufacturer, the blinds are able to produce around 100W of electricity per hour for every m2 of blinds installed.
These blinds need to be installed outside, but they should last for at least 10 years and can be controlled remotely using iOS and Android apps. Being blinds, they can also help reduce cooling costs during the height of summer as they help reduce unwanted passive solar gain.
5. Microbial fuel cells have some very serious potential
Another form of novel power-generation tech of the future is a technology called microbial fuel cells. Ostensibly similar to the anaerobic digestors we previously discussed, this technology is able to actually create electricity directly from microbes in situ.
A form of a bio-electrical chemical fuel cell, systems currently in development divert electrons produced by microbes using a pair of specially designed electrodes. The technology is not entirely new, but it has some very serious potential for the future.
The technology essentially uses special types of microorganisms that are able to "breathe" in metals, thereby generating free electrons in the process as waste. By tapping this supply of "free" power, it should be possible to provide viable sources of renewable power.
The best part is that such fuel cells could be filled using wastewater. At present, MSCs are still only small-scale and can be used to power small electrical devices (like calculators or LEDs). Once the technology is refined and scaled up, it could prove to be a very real, innovative, and exciting way to power our buildings in the future.
6. Solar-generated fuels might have some potential too
Another interesting area of research for novel potential power sources are solar fuels. The basic idea is to use solar energy to turn carbon dioxide and water into a hydrocarbon-based fuel that then is used to fuel conventional combustion engines.
This is similar to what plants have been doing for millions of years — apart from using the fuel to drive cars, obviously.
Such fuels could be generated en masse or, theoretically, at a domestic scale, and then stored for future or immediate use. Current research by the likes of Harvard’s Nocera Lab, MIT’s Grossman Group, and the University of North Carolina’s Energy Frontier Research Center, has shown great promise over the past few decades, or so.
With a potentially commercially viable system, carbon dioxide would be extracted from the air and split into its constituent parts — primarily the carbon atoms. Next, hydrogen would be liberated from water molecules, and the two products would be combined to make fuel.
If a way can be found to really scale up this kind of technology, it should be possible to constantly generate fuel whenever the Sun is shining.
The technology is still very much in its infancy, but there is no reason such a system couldn't become part of the energy mix in many countries around the world.
7. Coming full-circle — a return to "manpower"
"Manpower" was one of the primary energy sources of our species for most of our history, and which has only fairly recently been supplanted by the use of chemical and nuclear energy. But there might still be room for tapping into this ubiquitous power source too.
Such developments in this field would not only be poetic (in a fashion), but also potentially groundbreaking. The ability to tap most of the "wasted" energy produced as a byproduct of human activities could be a rich supply of energy for many applications, especially inside the buildings we occupy or the devices we carry with us every day.
Apart from the piezoelectrical installations mentioned earlier, various researchers are looking into ways to harness the heat created by people as they go about their daily business. Far from the dystopian future of "human batteries" in films like the "Matrix", breakthroughs in this area could offer ways to provide effectively "free" energy with little to no interruption of our daily lives.
Well, there is the cost of fueling your body of course, but we do that anyway.
From special clothing that generates power kinetically from your movements, to ways to harness, reuse and concentrate the thermal energy we radiate 24 hours a day, human-derived power sources could become commonplace in the future.
One interesting example is a special wristband that contains a thermoelectric generator (TEG) which uses your own body heat to actually generate small amounts of electricity. At present, such technology is only able to produce enough juice to power an LED, but it may be possible to improve the technology enough to power small electronic devices — like a smartwatch, say.
This kind of technology could have other interesting applications, like using your own internal heat to power medical devices like pacemakers, or even nanomedical robots.
Such solutions would, in a pinch, remove the need for batteries entirely — so long as you keep the tech on, or in, your body. Who knows what potential avenues for new personal electronic devices this could open doors for?
And that, novel renewable energy enthusiasts, is your lot for today.
Any one of these interesting novel technologies could prove to be truly revolutionary in changing the way we generate, and use, energy in the future. With innovations like these, and those that they inspire in the future, it might just be possible for our species to finally go "cold turkey" with our addiction to fossil fuels.