I'm guessing you probably don't need me to
give you any clues about what this thing is? Admittedly you don't see too many of them
with lurid green blades or any of this nonsense sticking out the back, but you know,
it's a wind turbine isn't it. And its bigger brothers and sisters are now a fairly regular
site across large parts of many of the countries where you good folks are watching this from.
Generally speaking the grown-up versions all have a very tall mast and three blades, attached
to a central nacelle with a heavy duty gearing system inside to translate the rotational kinetic
energy of the blades into useful electrical energy via a generator. They form part of a sub-category
called horizontal axis wind turbines or HAWTs. But they're not the only way you can get
electrical energy from wind. There's a whole other sub-category called vertical axis wind
turbines or VAWTs. These things are extremely popular among the DIY enthusiast fraternity,
many of whom have rigged up rudimentary versions in their backyards or gardens to
provide useful power for their homes. Now a new company has taken the basic concept of
vertical access turbines to create a commercial model that's designed to work even when there's
no prevailing wind. So how do they do that? Hello and welcome to Just Have a Think. The
science of wind turbine dynamics and efficiencies is pretty much an entire field of
technical expertise in its own right. There have been all sorts of different approaches
and designs over the years, all aimed at achieving the optimal overall performance. Vertical axis
turbines or VAWTS tend to fall into one of two sub - sub categories. Savonius turbines like
this one. or Darrieus turbines like these. And you'll find dozens of very entertaining
DIYers on YouTube who've chopped up oil drums and various other articles to produce
their own homemade energy generators. When it comes to grid scale commercial
wind turbines though, there are various reasons why horizontal axis turbines have
generally been favoured over vertical axis. At those sorts of enormous dimensions early
development prototypes of VAWT systems proved less efficient, and in the days before
we had new-fangled composite materials, VAWTs also proved less reliable as well,
with turbine blades tending to shear off with the constant changing directional forces
from the wind. In-depth comparisons between HAWTs and VAWTs are beyond the scope of this
video, but if you want to dive more deeply into it then I can highly recommend jumping
over to my YouTube buddy Rosie Barnes channel, where you can find two excellent videos
explaining the pros and cons of each turbine type. And you can go straight to the first of those
videos by clicking up there somewhere. VAWTs do have some advantages though. They're
obviously much more compact than HAWTs and they can take energy from the wind
regardless of which direction it's coming from. HAWTs have to have an extra mechanical
setup inside the tower called a YAW system, which turns the turbine into the prevailing wind
so that the blades can keep rotating. So vertical axis turbines have the potential to provide very
useful energy in more urban settings where space is at a premium. Designing a vertical axis wind
turbine that doesn't necessarily require the wind to be blowing though, might seem like a bit of
a crazy endeavour, especially for a commercial enterprise. But that's exactly what a British
start-up called Alpha 311 are planning to do by installing their turbines onto motorway lamp
posts, road bridges and roadside buildings, effectively harvesting the wasted airflow produced
by vehicles driving past. The company was founded in 2018 by business partners Barry Thompson and
John Sanderson. Having researched existing studies of the potential for roadside turbines
they realized that the focus was usually either on placing turbines right at the top of
lampposts where they wouldn't get any benefit at all from oncoming traffic or building entirely
new infrastructure in addition to the hardware that was already there, which of course always
proved to be cost prohibitive. So the initial concept that Alpha 311 pursued was to retrofit
existing infrastructure with low level turbines that would get the benefit of traffic airflow. And
they thought that would probably provide enough power just to run the lamps at the top of the
post that the turbines would be attached to. But when their working prototype was formally assessed
by the Institute of Thermofluids here in the UK, even factoring out any prevailing wind conditions
and assuming no traffic at all between 10 pm and 7am, the results still showed far more electricity
generation potential than originally anticipated. The A311 turbine blades start to turn in an
airflow speed as low as 1.2 meters per second. Typical average motorway traffic speeds of 60
miles an hour produce a residual airflow of 5.4 meters per second, which is about 12 miles an
hour. At that speed each turbine has a generating capacity of just over 2.5 kilowatts with a
30% efficiency, or power coefficient to be more precise. The performance calculations were
based on a 5.4 mile section of the M2 motorway in the southeast of England. Using Department of
Transport data for hourly rates of traffic flow the analysis showed that a single turbine will
produce an average daily energy generation of just under six kilowatt hours. And that particular
stretch of road can accommodate 410 turbines, so the total annual electricity generation along
that section worked out at just over 860 megawatt hours. Which is definitely worth having.
The turbines are made from durable recycled composite materials and have a hollow internal
sleeve designed to be very easily retrofitted around existing posts. Each unit will be up to two
metres in height and they'll be extremely light, weighing between three and a half and
eight kilograms, depending on the model. That doesn't just improve efficiency, it
also makes them extremely easy to install. The blades themselves will be partly
shrouded to ensure the optimum energy harvesting from air flows in both directions
and to avoid any cancelling out interference. Unlike horizontal axis turbines Alpha 311's
turbine doesn't need a bulky YAW system because it can use airflow from any direction,
and it has no heavy gearing system either, just a neat little static magnetic stator housed
in the base of the unit with a stainless steel rotor inside it which is attached directly to
the base of the turbine. As the rotor turns within the stator it generates an electrical
current that gets sent to a charge controller via the cabling that already exists to supply the
lamp post with power. The charge controller then sends that current through an inverter and back
into the local grid with far smaller transmission losses than other remotely located power sources.
The space allocated for the magnetic stator also houses a centre array for data collection from
sensors that can be mounted onto the lamp post, which means that Alpha's system can also monitor
air quality weather conditions and traffic statistics, all of which can be sent out via an
internet of things, or IOT, gateway to monitoring stations in real time via a 4G or 5G wireless
connection. Now you super smart technically minded types out there might be thinking all that
apparently free energy is coming from vehicles that all require energy to make them move in the
first place and in the vast majority of cases at least today anyway that energy will have come from
fossil fuels in the form of diesel or petroleum. But those vehicles are all punching a hole
in the air and causing airflow around them regardless of whether there's a turbine or a
building or anything else at the side of the road, and that airflow is essentially just wasted
energy. So scooping it up into turbine blades that can drive a generator to produce electricity
is a smart use of already existing resources. that will be sited on the round towers surrounding
the 02 centre in East London. After that Alpha 311 will be supplying 54 turbines to a New
York development called Green Asphalt. The medium-term goal is to get these turbines
installed on motorways and trunk roads all over the United Kingdom and the wider world, but
Alpha 311 have longer term aspirations beyond that too. Although the quoted performance figures
are based on traffic airflow, the turbines obviously do work just as well in prevailing
wind conditions, and one obvious secondary application for compact lightweight turbines
like these is on telecommunications masts. There are hundreds of thousands of those things
across the globe, enabling our mobile phones to work wherever we are. A typical 5G mast uses
about seven kilowatt hours of energy every day. One of these turbines installed on each of those
masts will provide very nearly all the power they need, removing a significant load from our
national grids. And as long as the relevant regulations are adhered to there's no reason
why smaller versions of these turbines couldn't be installed on domestic homes, possibly even in
conjunction with solar power and battery storage to provide a much wider time window of
power generation for the householder. That sort of system would pull a lot of people,
even here in the UK, out of fuel poverty. And in developing nations it would be yet another
option for people in remote off-grid areas to consider alongside solar and micro
hydropower that we looked at in a recent video. It is very early days with the first
production run only just going through now, and I know that one of the criticisms these
start-up companies get is that they're unproven and might not achieve the numbers they're
predicting. And I get that. It's a perfectly reasonable challenge. But companies like Alpha
311, and so many others all over the world, are all working towards the same basic end
goal, which is to develop working alternatives to the existing dominance of fossil fuels on our
electrical grids. Alpha 311 installations will never replace onshore or offshore wind turbines
and they're not designed to, but they can provide a very valuable complementary power source that'll
improve the diversity of renewable energy inputs onto those grids, and for that reason I
for one think they should be applauded. No doubt you've got your own views
on this one though. If you have, or if you work in related industries and
you've got insight that you can share, then jump down to the comment section
below and leave your thoughts there. That's it for this week though. Thanks as always
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on that icon there. As always thanks very much for watching. Have a great week ,and remember
to just have a think. See you next week.
Clever