This is the Aeromine rooftop wind energy system, rated at 5 kw. Scientists have been developing
this wind system, which could apparently outperform solar panels in many applications.
Reports have been floating around stating that it can generate 50% more electrical energy than solar
panels for the same cost. However, Aeromine's own reports show that they can more than half
solar panel costs, claiming cost reductions as high as 70%. These are some bold claims.
So in this video we'll look in more detail at the scientific papers Aeromine have published
to see if this system is too good to be true. Firstly, let's look at how the Aeromine Win system
actually works, as at first glance it appears to not have any spinning turbines at all. The
fact that there are no external moving parts is actually one of the benefits of the Aeromine,
as it makes it more suited for being mounted on roofs for structural and safety reasons. However,
this doesn't mean that there are no moving parts. To understand the system,
it is first useful to look at a single aerofoil.
As air flows past the aerofoil, it gets redirected and areas of high and low pressure form. Now,
if we take two aerofoils and place them opposite each other, we have something similar to the
Aeromine system. With this, we have now created a low pressure region between the aerofoils,
which is the fundamental principle of how the wind system works. Each of the aerofoils on
the Aeromine also have holes in them. So as air flows through the low pressure regions between,
the aerofoils suck in the surrounding air over a hidden turbine below,
meaning this is still somewhat of a wind turbine.
This action of drawing in the surrounding air is the same principle as a straw. When the pressure
in your mouth decreases as you begin to suck, the water in your glass begins to flow up the straw.
This wind system is a pretty interesting design, but is not necessarily a new idea. In fact,
it reminds me of these ancient air conditioners called windcatchers that have been used in Iran
for the past 3000 years. Similar to the Aeromine, these wind catchers exploit low
pressure regions which are caused by the wind to draw air up into the buildings.
In this example, an underground aqueduct known as a canna is also used to cool the air,
providing the ancient air conditioning. Now, with an understanding of how the Aeromine works,
we can start to look into how valid the reported claims are. Despite some key
drawbacks that I will cover. One benefit is that the Aeromine isn't supported by a tower
and is based on a modular design. This makes it space efficient and helps to keep costs down.
It also reduces the need for steel in the construction, which could be seen as a benefit,
as steel has historically released significant greenhouse gases when it's made. In fact,
steel production makes up 7% of global CO2 emissions, which is why the steel
manufacturer SSAB is creating fossil fuel free steel. SSAB have found a solution to
steel's CO2 problem using their new hybrid technology. Hybrid replaces Coca Cola,
which is traditionally needed for ore-based steel making with fossil free electricity
and hydrogen. In the new process, sustainable hydrogen is used instead of carbon to separate
iron molecules from oxygen molecules in iron ore, which is a fundamental step of steel production.
This new process releases water as a by-product instead of CO2, like when Coca Cola is used.
This is a huge breakthrough as this step is the biggest cause of CO2 emissions in
steel production. The water released is also reused by SSAB and other processes. However,
they have actually bottled some and named it Pure Waste. Although pure waste won't
be sold to consumers, it symbolises the clean by-products of the hybrid process.
The fossil fuel free steel will be available on the market as soon as 2026 and SSAB are
committed to largely eliminating their overall CO2 emissions by 2030. Clearly,
SSAB have learnt a lot about drastically reducing the CO2 emissions of steel manufacturing, so they
are dedicated to sharing knowledge and information about the technology to increase their impact. If
you want to find out more on this, make sure to follow the link in the description to learn
more. Looking back at the Aeromine, we can see that it's designed for rooftop applications.
But as we continue our analysis, we'll see this is actually one of its biggest flaws.
See, the test results are actually very impressive. After successfully showing a
proof of concept design in 2019, a three metre pilot scale rig was analysed in 2022 to see how
the system performs under different conditions. Something I found interesting was how the Aeromine
system tackles winds from different directions, which is important as it cannot turn to face it
like a normal wind turbine. What they found was that the system produced the same amount
of power whether the wind was coming straight on or up to 45 degrees in either direction,
which can be seen in this graph, where the power generation quickly drops off after that. This
may sound counterintuitive, but my understanding is that this works due to the commander effect.
This is the same effect that causes air flow to follow around an aerofoil. As
you can imagine that the wind hitting the Aeromine from different angles is the same
as an aerofoil changing its angle of attack. So that is how the Aeromine deals with different
wind directions. But is 45 degrees enough? A good thing to look at here is a wind rose.
This shows what proportion of the wind at a certain site comes from each direction. If we look
at the wind profile from near where I am in the southwest of England, we can see it mostly comes
from the south westerly direction. By roughly picking the average wind direction and looking
at the area 45 degrees either side, we can see the Aeromine would do a pretty good job here. However,
if we look at some wind roses from other locations, we can see this isn't always
the case and that a lot of potential wind energy would be lost. Another study from Aeromine using
their pilot system looked at how efficiently they could capture power from the wind.
For reference, a standard wind turbine can usually hit a maximum efficiency of 50% in
the right conditions, which is not far off the theoretical limit of 59%, known as the Bets limit.
An intuitive feel for the Bets limit is that if all the energy was extracted from the wind,
it would be stationary behind the turbine and therefore no new wind could flow through. With
this in mind, the Aeromine prototype managed to hit 25% efficiency, up from 18% in their
lab test. Although this maximum efficiency is lower than traditional turbines, Aeromine says
this can be weighed out by the fact the system captures a larger area of wind due to its design.
Importantly, the key aspect of the Aeromine is the comparison of its cost compared to solar panels.
Here is a graph that compares the levelised cost of energy for the Aeromine system and industrial
solar panels at different wind speeds. Here, the levelised cost can be thought of as the price
of captured energy averaged over the system's lifetime. This graph shows how in the Midwest,
where the average wind speed is just below seven metres per second,
the energy from the Aeromine is around 70% cheaper than the upper end of industrial solar. However,
this is where things become a little bit less favourable for Aeromine. The
thing is these average wind speeds come from this map.
Specifically, this map shows the average wind speeds at 30 metres elevation,
where the wind is faster than at ground level. Although 30 metres is generous for most buildings,
it is probably the least of the worries here. This is because the map also has some important
small print which reads the average wind speeds indicated on this map are model derived estimates
that may not represent the true wind resource at any given location. Small terrain features,
vegetation, buildings and atmospheric effects may cause the wind speed to depart. From the map's
estimates, this is very important as objects at ground level impact the wind speed a lot.
The effect of different terrains and buildings on wind speed is captured
in the surface roughness. And if we assume the Aeromine is used near villages, small towns or
agricultural land with hedges, we can see that the ideal seven metres per second wind speed
at 30 metres becomes four two metres per second, with this only getting worse at lower elevations
and with more built up areas. In terms of cost, this means even in the windy Midwest,
the cost becomes higher than the most expensive solar panels. The combination of slow wind speeds
on roofs and the lack of economies of scale means these are also more expensive than getting energy
from a distant wind farm through the electricity grid. Although this isn't great news for Aeromine,
I should mention I don't think any of their claims are false.
They could technically reduce energy costs by 70% compared to solar panels. However, they may
be overly optimistic with where this would happen, but it may be effective in some cases where there
is a very low surface roughness, and I hope they can develop this technology further and find more
applications where it can provide benefits. If you want to know more about Aeromine and
ask specific questions related to this, I'm now going to be doing a live stream related to every
video I upload for this video. The live stream will be at 07:00 p.m. GMT on the 19 December.
But if you want to know more about how energy is stored now,
cheque out this video on using superheated bricks. And don't forget to like and subscribe.