I do a lot of talking on this channel about the
amazing breakthroughs in laboratories and test centres all over the world that are aimed towards
decarbonizing human activity and energy use. The vast majority of them are focused on providing
renewable power and energy storage to our electricity grids but there are still almost
a billion people in the world who don't have access to a national or regional grid and although
the mass migration into cities especially in the developing nations has brought that number down
significantly over the past decade there are still an awful lot of remote locations that will most
likely never receive the infrastructure for a grid connection. So for the hundreds of millions
of folks living in those areas the options are horrible dangerous kerosene lamps to provide light
during the evenings, and noisy generators running on diesel which is an increasingly expensive fuel
that pollutes the air and dumps huge amounts of carbon dioxide into the atmosphere. In recent
years solar PV panels on individual homes have played a significant role in improving the lives
of many of those people but solar does have that inherent and inconvenient intermittency factor
which even with the battery storage can never be completely overcome. So more recently a group of
visionary entrepreneurs had a bit of a rethink and decided to see if there were any other more
reliable ways in which nature could provide energy to those difficult to reach communities and in
most cases the glaringly obvious answer was the water flowing nearby in rivers and canals. But
surely Dave, you're not advocating yet more dams on yet more rivers causing yet more damage to the
local environment and wildlife are you? No I'm not! Hello and welcome to Just Have a Think. Now I
don't think anyone would seriously suggest that harnessing the power of water was exactly
a new concept. The Greeks were using water wheels for grinding wheat into flour more than two
thousand years ago and that exact same technology was still in widespread use right up until
the dawn of the industrial revolution not just for making flower but also for sawing
timber and pulping paper and running looms to make textiles. During the 20th century that constantly
flowing resource was harnessed at breath taking scale to drive hydropower turbines and generators
producing reliable base load electricity in many parts of the world. Hydropower doesn't emit any
carbon dioxide in operation so on the face of it it looks like a great option for any region
that has a major river with a decent gradient. The trouble is though that most governments
are fixated on extremely large centralized infrastructure projects that can supply enormous
quantities of electricity to national scale grids, and they're getting bigger. You think the
Hoover Dam was impressive at a power generation capacity of 2,000 megawatts? Well check out the
Three Gorges dam in China, completed in 2012, capable of more than 10 times that
output. Enough for tens of millions of homes offices and factories. There's lots of
good logical reasons for this approach of course. Large infrastructure projects tend to get
higher levels of investment from commerce and industry. Building large in one location is often
logistically easier than building small in lots of different locations, and once they're up and
running those grand centralized power generators can be easily controlled by power companies and
regulated by the state essentially providing a nice neat and tidy monopoly on a commodity that's
become essential to our modern way of life. But the environmental impact of grid scale hydropower
is a big concern. Building a dam on a river means blocking, diverting or completely
changing the natural course of the water. That often screws up the migration routes for
species of fish that rely on them to get to their annual breeding grounds. The consequence of
that is a drastic reduction in fish populations with big negative effects on the ecosystem,
including food stocks, for indigenous human beings. Water-borne sediment flow is also massively
reduced which means far fewer nutrients for all forms of wildlife further along the river system,
not to mention the obvious consequence of water scarcity or even drought for the folks downstream,
and damming a river also causes upstream flooding. The Three Gorges dam caused a flood of around
a thousand square kilometres, which is about 80 percent of the entire area of Los Angeles,
displacing 1.3 million people as a result. And several recent studies have shown that organic
matter, like dead plants that get trapped in the reservoirs, break down and release carbon dioxide
and methane into the reservoir water. So you know - not ideal! Here's the ideal shopping list then for
several hundred million people living in remote areas of the world. Small scale locally controlled
power generation. Reliable affordable electricity available 24 hours a day seven days a week. Minimal
or even zero environmental impact, and the ability to hook up to a grid system if it's available or
run completely off grid if necessary. All of those criteria are met by a micro hydropower system
developed by a Belgian start-up company called Turbulent, founded in 2015. I recently spoke
with the guys at Turbulent to gain a better understanding of how their system works.
Essentially they've designed what they describe as a vortex turbine that can work in river systems
with a head of water of less than five metres and as little as a metre and a half from the top
of the system inlet to the bottom of the outlet. A channel gets dug to divert a small portion of
the river or canal flow to one side. A sluice gate and mesh filter are installed at the very start of
the channel to regulate the flow of water and to stop any large debris getting in. Once the sluice
gate is opened water flows down into the circular well where the Turbulent turbine is installed, and
as the water passes across the turbine it creates a low pressure vortex. The low rotation speed
turbine blades have soft rounded edges allowing aquatic life to pass straight through the entire
system - possibly somewhat invigorated and keen to have another go but not harmed in any way at all.
All the water and fish are then returned straight back into the main flow of the river system to
continue on their journey entirely unaffected. So now you've got a spinning turbine driving
a generator producing electricity in exactly the same way as its larger scale hydroelectric
cousins. That supply can either be hooked up to a grid if there's one available or simply run
through a standalone electrical consumer unit to provide power for the building or community
that it's been specifically designed for. The whole thing is controlled autonomously by
electronic wizardry in the electrical cabinets that turbulence engineers install on site, and
of course there's an app for it so that all the performance parameters can be monitored remotely
by the turbulent team and the owners of the system. The smallest installation has a capacity of five
kilowatts which in remote areas of developing nations is enough to supply 50 rural households,
plus water treatment at night and businesses during the day. Larger installations
can be up to 200 kilowatts per turbine and those turbines can be linked up into a
network generating multiple megawatts of power. Off-grid communities get the benefit of
effectively free electricity 24 hours a day 365 days a year for the entire lifetime of the
turbine, which is rated at 30 years. If they do decide to get hooked up to the grid then they may
even generate a small income through grid 'feed-in' payments - which brings us nicely to cost. Well the
guys at Turbulent pointed out that these are very much bespoke systems constructed to fit precisely
into each selected and carefully surveyed site, so that means that every project will have its
own cost structure, but as a rough rule of thumb a 15 kilowatt grid tied installation
would come in at around 75 000 euros and a similar off-grid system would be about
90 000. If that was installed in Europe it'd be enough constant base load power to run 30 typical
European homes, which equates to a cost of about 3000 Euros each. Compare that to a typical
solar panel installation that could cost as much as 10 000 euros, and which would only provide
intermittent power, and the numbers start to look pretty favourable. And the larger 50 or 70 kilowatt
systems have even better economies of scale than that. And it really becomes very enticing indeed
if you compare it to the cost of diesel, which is the fuel source that Turbulent will be
competing against on most of their projects. A 15 kilowatt system will be generating 360
kilowatt hours of energy every day. That's 131 400 kilowatt hours every year for 30 years, which
is very nearly 4 million kilowatt hours of energy over the lifetime of the turbine. If you divide
that into the off-grid installation cost of 90 000 euros you get a unit cost of less than 2.3
Euro cents per kilowatt hour, compared to a typical diesel fuel cost of more like 50 Euro cents per
unit. That's a pretty compelling business model! Turbulent now have 10 fully installed or in
progress projects at various sites around the world. This installation in Bali Indonesia was
commissioned by The Green School - one of the most eco-friendly schools in the world and a pioneer
of sustainable education. The turbine sits on the Ayong river, famous for its white water rafting.
The system provides the school with about 80 percent of all its energy requirements, with the rest
coming from a small existing solar installation. The school spent 11 years trying to develop their
own micro hydropower system by trial and error . Their most recent construction was destroyed by
a flood that carried debris downstream. So one of the main design objectives for the Turbulent
team was to create mechanical components that were capable of withstanding whatever
our changing climate could throw at them, including severe flooding. The turbines are
all fitted with a fully submersible gearbox and induction generator with mechanical
face seals plus a secondary sealing system with multiple layers of projection against
fresh and brackish water debris and sand, designed specifically for use in continuous heavy
duty harsh environments. All the components for The Green School were boxed separately and taken to
site on the back of a relatively small flatbed vehicle and because the water diversion channel
and the circular vortex well already existed, installation only took a day to complete
without the need for any heavy machinery. The whole system sits within a nice small
neat footprint just outside the school. A solar installation generating a similar output would
have taken up the space of four tennis courts. One of the key benefits of the constant base load
supply of these vortex systems is that they can run essential services like hospitals and other
public buildings that absolutely must guarantee permanent uninterrupted power. Those institutions
currently spend a large amount of their budgets on diesel generators to ensure the lights and
life support systems never switch off. And then there are commercial businesses like nature
parks, eco resorts and agricultural centres that are often located far from standard power
grids but typically very close to a source of running water making them ideal candidates
for these sorts of standalone power generators. Micro hydropower can be an attractive option
for governments as well. Rural electrification and development programs are a key priority of
the United Nations Sustainable Development Goals, and grants are available for those sorts
of initiatives, both from the European Union and the World Bank. The grand scale hydropower
dam projects that I talked about earlier are horrendously expensive and many are
currently on hold in developing nations as a result of increased project costs. Turbulent
turbine projects can be built in phases to decrease initial investment and risk, and
part of the energy can be directly used in the areas immediately adjoining the site which
helps to gain the support of local communities. Developing and constructing a large-scale
hydropower plant can take up to 10 years while multiple linked up micro hydropower installations
can be completed within months and could well have paid for themselves entirely in less time
than it takes to build and commission a dam. Regular viewers of this channel will
know I'm a big fan of these sorts of lateral thinking approaches to solving
some of our planet's trickier problems, and I for one would love to see
many more of these brilliant devices installed in remote areas around the world. In fact
if I ever do retire and realise my own little pipe dream of a timber framed passive house next to
a river in the middle of the woods somewhere, then I'd be very tempted to invest in one of
these things myself! Jump down to the comment section below to share your thoughts, but that's
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Very interesting. Was looking for some information on required flow rates. We have a slow meandering creek that crawls in summer time and ices up in winter. Can we make this work for us?
Why not get connected with Coanda screen for those debris flow prevention designs? I applied a Coanda Screen to a micro hydro electric project and it makes a huge difference to on going maintenance costs.