
Could We Dredge the Netherlands Without Fossil Fuels? - helb
http://www.lowtechmagazine.com/2018/08/could-we-dredge-the-netherlands-without-fossil-fuels.html
======
jws
The horse powered dredge boats are interesting to compare to today's
technology. They don't specifically give dimensions, but considering the space
it takes one horse to walk, plus some extra space for dredging and boat
functions, it is easy to place 750 watts of solar panels in the same space.

You could make solar powered dredge boats which would be functionally
equivalent to the horse boats. You'd only dredge when the sun shines, but you
also wouldn't have to stop and change horses every hour and maintain dozens of
horses per boat.

You would get a good 4-5 months of dredging 4 hours/day, and you'd get to take
December and January off! (or operate a fraction of an hour a day).

You'd need about 20 thousand of the boats to keep up with current demand, so
that might be a traffic congestion problem during the summer months.

~~~
equalunique
Interesting ideas! Might want to take into account the customarily rainy
weather in the Netherlands. The graph here shows roughly 50% of the time
conditions are rainy, so your estimates might be somewhat over-estimating.
Luckily there are other opportunities for green energy in the Netherlands,
like wind power for example.

------
throwaway5752
It's an interesting article, but a better title would be "How the Netherlands
were dredged without fossil fuels".

The article makes note of how wind power was used pre-electricification at
several points (windmills, specialized sailboats) so they're not oblivious to
that obvious answer.

Since it can be periodic and during daytime surely electric dredgers with
umbilicals could do some of the heavy pumping based off a wind and solar
powered grid. Would be interesting to see the dredging power requirements vs
local renewable resources.

------
jaggederest
Anywhere you'd really need to dredge, you can run power lines and dredge on
tethered power electrically.

I think it's interesting from the standpoint of understanding human capacity
and thinking differently about how we allocate our time and effort though. I'm
not sure that typing 24/7 is the ideal way to build a life.

------
roywiggins
Simplest to use biofuels or hydrogen cells for this sort of thing?

~~~
Arbalest
Biofuels has always been and should only be considered as a bridging solution.
Crops use a bunch of elements that we really don't need for energy transfer
but really do need for nutritious food. Phosphorous most significant among
them, but plenty of other soil minerals too. Put them in an engine and poof,
they're in the air not being good for much.

~~~
jagger27
What about algae-based solutions?

I'm curious where the phosphorus and mineral losses come into play. Is it not
totally feasible to repurpose the waste products of fuel production back into
fertilizers?

~~~
Arbalest
I have my doubts as to whether it would be cost effective enough to filter out
everything but the long chain hydrocarbon molecules (in the case of
biodiesel), though ethanol based fuels might be better as they already have to
be fairly well purified. Really depends on the individual chemistry I guess.
Hopefully the waste isn't too contaminated.

------
torpfactory
Wind power and a long extension cord....

------
Robotbeat
Just put a big battery on a boat. If it gets good utilization and can charge
inexpensively, it should pay for itself in fuel savings.

