More Pumped Hydro Stations?

The phrase “power station” is bit of a misnomer for pumped hydro schemes, as they don’t so much generate power, as store it. The problem with electricity is that if you have too much, you can’t easily put it in a cupboard to retrieve it later. Instead, you have to store it in some other form. Pumped hydro does this by using electricity to increase the potential energy of a large mass of water – by pumping it uphill. To reclaim the energy, you let it flow back and spin up turbines, as in a conventional hydro system.

Naturally, this process is a bit wasteful – for every 4 units of electricity you use to push stuff uphill, you get about three back. But, there’s a big commercial advantage – while the domestic electricity prices are comparatively static, the prices for electricity within the industry follow the laws of supply and demand, typically changing every 30 minutes, and prices at times of peak demand or minimum supply can easily be three times higher than at times of low demand. So you ‘buy’ cheap electricity to pump water uphill, and then ‘sell’ expensive electricity when there’s a TV Pickup.

There are two pumped hydro facilities in North Wales – Dinorwig below Elidir Fawr, and the older and much smaller Ffestiniog. The UK’s other two facilities are in Scotland at Cruachan and Foyers. In particular, Dinorwig is a vital facility because not only can it handle surges caused by a near-infinite number of half-time kettles, it can also be used to ‘bootstrap’ the entire power grid during a Black Start.

Dinorwig was the last to be completed in 1984, and there hasn’t been much interest in additional schemes – until recently: The reason? Renewable energy, in particular wind and solar.

Outputs from both wind and solar power systems are largely unpredictable and highly susceptible to weather conditions. To provide backup power when the wind doesn’t blow requires either extra conventional power stations, or storage schemes. (I’m ignoring power imports here, as that’s really just moving the problem into some other country). Pumped storage is seen as a great solution because it doesn’t burn more fossil fuels, and you can store the excess power that your wind turbines would generate in the middle of the night – which would otherwise simply be lost. (There are other ways of handling this, by demand-side management, but that seems decades away from reality.)

However, there’s a catch. Pumped hydro schemes need very specific geographical conditions: Two bodies of water – an upper reservoir (Marchlyn Mawr, for Dinorwig) and a lower one (Llyn Padarn). The greater the vertical separation between the two, the more energy you can store. In some locations the sea can act as the lower reservoir., but typically the only suitable places you’ll find for these schemes is in mountainous territory. Also, they are huge, expensive and impressive engineering schemes- to build Dinorwig, 12 million tons of rock was excavated from Elidir Fawr.

There are two proposals for new Pumped Hydro schemes in Scotland – Coire Glas, above Loch Lochy , and Balmacaan, where there’s also a controversial wind farm proposal.

But, what about Wales?

When Dinorwig was being planned, two other sites were under consideration – Llyn Cwm-y-Foel below Cnicht in Cwm Croesor, and Llyn Newydd, east of Blaenau Ffestiniog. Llyn Cwm-y-Foel sits in a hanging valley, and already has a small conventional hydro generator. There’s no lower lake, so a new reservoir would need building below. There are suggestions that these sites could be reconsidered for new developments. I suspect that’s a long way off, but it’s another reminder that heavy reliance on wind and solar power can bring a whole new set of problems and challenges in its wake.


Glyder Fawr via Gribin Ridge

Snowdonia, 25 June 2012

It’s been too long since I’ve blogged – and also too long since I’ve been out in the hills. The weather seems to have been nothing but rain since a trip to the Carneddau in mid May, but today’s forecast was good enough to deserve a day trip to the heart of Snowdonia. And as I’ve just replaced my tired and leaking (but much loved) La Sportiva Trango Alps with a pair of Trango Evo’s, something rocky rather than peaty was required.

Tryfan and Llyns Bochlwyd. Llyn Ogwen and the Carneddau beyond

The Gribin Ridge seemed to fit the bill. An easy scrambling route onto the Glyderau plateau, and I could head over Glyder Fawr and then down into Cwm Idwal via the Devil’s Staircase.

It’s always surprising how quickly you leave the A5 (and the crowds) behind as you climb away from Llyn Ogwen. First stop was Llyn Bochlwyd, which is a great viewpoint for Tryfan and back across the valley to the Carneddau. I headed west, picking up the path that heads up towards the Gribin. there are a few rocky steps you can play on in the lower part of the route, but a path follows the line of least resistance and brings you out to the ‘football pitch’ where the rocky crest of Y Gribin  can be properly appreciated.

Y Gribin

The path keeps on, below and to the right of the crest, with great views down into deserted Cwm Cneifion and the winter climbing routes on Clogwyn Du. I should probably have left the path earlier than I did, as the cairn marking the descent route came into view quite quickly. The new boots were great -grippy, and confidence-inspiring when edging, and felt a lot more ‘tactile’ than the Trango Alps. Also, the shockingly bright blue finish is now toned down with a subtle layer of dust and dirt.

The path across the plateau to Glyder Fach is heavily cairned, but visibility was good enough today not to need them. A bit of high cloud was blocking the sun, making photography far from ideal, and there was a good cooling breeze. I’d been on Glyder Fawr twice before – but only in winter, with good snow cover and crampons. It’s actually a lot harder work when there’s no snow, and the screes down to Lyn y Cwn (which had been easy in winter) were something of a slithery nightmare.

Towards Llanberis from Glyder Fawr

The positive side is that it’s a lot easier to locate the Devil’s Kitchen path when there’s no snow. I’d spent 15 minutes trying to find it on a previous visit… The path down below Twll Du is steep and rocky, but very well maintained. I took the left fork to take me round the quieter western side of Llyn Idwal. Plenty of wild flowers out, including Butterwort and Mossy Saxifrage, and a couple that I haven’t identified yet.

Mossy Saxifrage
Cwm Idwal, with Cwn Cneifion and Y Gribin above
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Days 4 and 5: Last days of winter…

Due to rain the camera stayed buried in the rucksack all day yesterday, and the rucksack, in turn, was buried under several tons of snow. This was intentional – part of the process of building a ‘shovel-up’ shelter. In a couple of hours our team of eight had built a shelter big enough for eight people (and one dog) to stand up inside. Inside was the right place to be, as the weather outside was just continually wet. We’d taken a gondola ride up onto Aonach Mor, and done more work on avalanche assessments before getting out the shovels and digging. We also looked at the use of avalanche probes, hunting for a buried drybag in the snow.  Some photos on Rob’s blog here.

Today was the last day, and with a forecast for ‘incessant’ rain and high winds I didn’t have very high hopes. We headed into Glencoe, and up onto a rainy Buchaille Etive Beag. We found what was probably the last decent snowpatch left on the hill, and refreshed ice axe arrests and step cutting, and admired the remains of the snow-holes built by the SARDA Wales team as part of their winter training week in January. By the time we’d finished there was blue sky in evidence and the clouds were parting around us, giving great views down the glens and the occasional rainbow.

We followed the ridge south to Stob Dubh, braving some serious gusts on the way, before heading back to the col, followed by the cars and the Clachaig. A great day to finish on!

And by the time I was back at my B & B, the view across the Loch was stunning.


Hillwalking, and other frivolous pastimes