Ballymore Eustace is a place I pass through frequently, on cycles from more distant parts. During the summer, I decided to check out the new 5 km loop walk
Ballymore Eustace Golden Falls Walking Loop
This
trail has been developed over the last few years and runs from the
historic woollen mill (now being restored and developed as a craft
distillery), along the river, through woodland and up to the dam. It
then skirts the Golden Falls reservoir before heading north past the
water treatment plant and through another wooded and hilly area. There
are nice views of the surrounding countryside from this elevated
section. Finally the trail passes through a fenced off section that
isolates it from open farmland, to exit onto the access road to the
plant.
Entry
to the trail is through the pedestrian gate of the woollen mill
entrance, adjacent to the Liffey Bridge in the village. The 5k loop is
shown as a dotted red line on the map in the comments below. Some of the
trail can be navigated by bicycle. Unfortunately the gates on the loop
aren't bicycle friendly like those on the Blessington Greenway and a
bike must be lifted over them.
Note
that the mill and adjoining agricultural land is private property and
out of bounds, but the owners allow pedestrians to walk the trail.
The Golden Falls Dam and Hydroelectric Power Plant
© Eugene Brennan
The dam was spectacular during the summer, and the roar of the water could
be heard before it was seen (the sound on the video doesn't do it
justice and this was a small release of water) as it was released
through the sluices to cascade down the spillways into the river below.
Because of continuous wet weather, at peak times the water release rate
was almost 40 m³/s (cubic metres per second) which is equivalent to 40
tonnes per second. Water normally flows through large pipes called penstocks to the turbine which in turn spins the alternator
to make electricity. However the ESB had temporarily ceased generating
at the plant due to essential maintenance and instead, flow exited
through one or more doors or sluice gates at the top of the dam, the
water effectively making up most of the flow in the River Liffey as far
as Kilcullen. This dam has a single 4 MW alternator (plus a smaller 250
kW one), similar to the output from a windmill. The larger Poulaphouca
Dam upstream has a much greater output, employing two 15 MW alternators.
The Golden Falls lake serves two purposes: It’s a source reservoir for
Dublin City Council’s water treatment plant, supplying 50% of the
Greater Dublin Area’s drinking water supply and part of Kildare. It also
acts as a compensation reservoir, smoothing out the surges due to
larger releases at the Poulaphouca Dam. Without this compensation lake,
the "Flood" in Kilcullen would be much more extreme.
A compensation lake acts as a buffer and is analogous to how in a mechanical system flywheels
in times past were important on single cylinder steam engines for
storing energy and smoothing motion. Your lawn mower and some other
rotating machinery still uses such a device. Capacitors do the same
thing in an electrical power supply, storing charge as the electrical
waveform rapidly fluctuates in amplitude (after it's converted from AC
to DC) and releasing it milliseconds later.