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Trouble in Eden

In a shock announcement, the Eden Project has revealed that it is going to start hydraulically fracturing rocks beneath its site in a bid to extract geothermal energy. They are keen to emphasise the differences between what they are going to be doing and shale gas operations but a glance suggests these are largely distinctions without a difference.

Fracking the rock to create a geothermal heat exchanger is not the same as fracking for shale gas. We will not be releasing fossil fuels for burning. Geothermal developments are much deeper and in granite so there is much less chance of surface damage or contamination to the water table. We have no plans to use proppants or associated viscous chemical fluids to keep the circulation open. France encourages geothermal development but has a moratorium on fracking for gas.

The bit about the developments being "much deeper" than shale is not true. The image on the Eden project puts the depth at something like 4 or 5 km, which is pretty much the same depth at which the Bowland shale sites will be operating. Non-use of proppants - i.e. sand - seems to me to be a diversion rather than a meaningful distinction.

I also wonder if the planners are going to be presented with a dilemma over the noise levels:

Rigs are hired from the oil industry, so drilling will take place 24 hours a day to minimise the cost. It will take around 20 weeks per well. The rig will be one specifically for use in a populated area and heavily soundproofed, producing up to 45dBA at 200m. During operation, the generator will make a constant noise: a maximum of 30dBA at a distance of 200m. But because buildings are low, the noise can be tempered by landscaping.

Readers will recall that similar noise levels were deemed entirely unacceptable for shale gas operations.

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Reader Comments (66)

Has anybody told the luvvies that their geothermal is "nucular"?

Tom Flummery's problems in Australia were not inconsiderable as our geothermal sauce is even less palatable.

Jan 28, 2015 at 4:08 PM | Unregistered CommenterBernd Felsche

Has anybody told the luvvies that their geothermal is "nucular"?

Tom Flummery's problems in Australia were not inconsiderable as our geothermal sauce is even less palatable.

Jan 28, 2015 at 4:08 PM | Unregistered CommenterBernd Felsche

In response to jamesp, they will probably now use polycrystalline diamond drilling bits which don't have the wear rates of the tools used in former times.

But to state that they won't use proppants makes no sense.

PDCs are expensive and will be very slow at drilling through granite. Fine, more days, more dollars for everything and everyone on rental or day rates!

However, as far as I know there are plenty of fractures and fissures in Cornwall granite already and that's what the geothermal guys would try to exploit to get communication between injector and producer wells, rather than small fracs held open by proppant.

That's why I suggested the chances of communication are much greater than with tight shale fracs. In fact there are often total loss zones in these type of wells, where all your drilling fluid disappears into some underground fissure or cavern, making drilling (now without lubrication along the drillstring) very difficult unless you pour massive amounts of water down the annulus .

But still there is a very low to negligible chance of the fracking causing any problem with groundwater near surface and it's extremely deceitful of them to imply that they are better than tight shale ops in that respect, or that it's even an issue.

Jan 28, 2015 at 4:12 PM | Unregistered Commenterkellydown

If the fracking fluid they use is to be mainly water with no proppants or associated viscous chemical fluids, one has to wonder why the need for quarantine lagoons & subsequent fluid treatment.

For the same reason you'd quarantine any untreated groundwater, and the stuff from downhole will be full of minerals I mean "OMG dangerous chemicals!", that it's picked up in circulation. All this guff about groundwater being pure potable water until the evil frackers show up needs to be shown for what it is.

Jan 28, 2015 at 4:20 PM | Unregistered Commenterkellydown

The biggest environmental danger from any mining operation comes from rocks that are brought to the surface and crushed. When this material gets wet, the water that leaches from it often contains toxic metals and other materials. The beauty of fracking is that the crushed rock remains thousands of feet below the surface. Wastewater from fracking is hazardous mostly because of the materials that leach into it from fracked rock, not the detergent and sand that it intentionally added to it. Once the high pressure operation is complete, the only route into the environment is through leaks in the casing where the well passes through drinking water aquifers near the surface.

If fracking for natural gas really posed significant danger, think how much risker frack geothermal areas will be. The fracked rock with be leached with superheated water under high pressure that will be brought to the surface. Anyone who has been to a geothermal area (Yellowstone, for example) knows the stench (H2S) and toxic materials that are brought to the surface by water in these regions.

Jan 28, 2015 at 5:12 PM | Unregistered CommenterFrank

Just a couple of points for education. 30dBA is the equivalent of a quiet bedroom at night. Wouldn't even notice it. I think they mean 30dBA over the ambient? That's noisy.

Also the sound pressure level is not as important as frequency, intermittency etc. as described in BS4142.

Jan 28, 2015 at 5:20 PM | Unregistered CommenterDavid Schofield

That planning statement is oh so carefully worded that it totally useless and ambiguous so that it can mean all things to all planning officers and nothing to any engineers which is OK because planning officer is now a political appointment.

The main thing anyone should be looking for in that statement is what is NOT being said because that is where the truth they are trying to cover up lays.

Jan 28, 2015 at 6:30 PM | Unregistered Commenterivan

FWIW: Emily Gosden has an article up at the DT showing where fracking sites are located in the UK. here.

I took the liberty of making a comment that she should add the Eden Project to the piece. That's got the usual suspects jumping up and down.

Jan 28, 2015 at 6:54 PM | Unregistered CommenterHarry Passfield

"not as important as frequency, intermittency etc."

I can testify to that, living next to a car park where alarms go off (ir)regularly. The only common factor is that it is never someone trying to steal the car!

Jan 28, 2015 at 7:18 PM | Registered Commenterjamesp

@ David Schofield at 5:20pm

"I think they mean 30dBA over the ambient? That's noisy."

It's that figure at 200m [presumably free-field (literally!)], so operatives & others working nearby the plant will be need ear-defenders or get deafened.

I note their pre-emptive defence: "But because buildings are low, the noise can be tempered by landscaping." Strange they don't state 'the noise will be tempered by landscaping'; I suspect they hope the authorities miss that one, and don't insist upon hard & soft landscaped noise barriers.

Jan 28, 2015 at 9:39 PM | Unregistered CommenterJoe Public

I've worked on noise-suppressed rigs in several populated areas. The noise of people shouting or clanging with hammers etc can be louder than the machines. So you just warn crews to be quieter at night.

Jan 28, 2015 at 10:41 PM | Unregistered Commenterkellydown

kellydown, maybe you should ask the local population to stop shouting and clanging hammers at night. They would probably get a better night's sleep and be less grouchy with your workforce.

Jan 29, 2015 at 12:02 AM | Unregistered CommenterGolf Charlie

wonder how you get there ? what no charging point !!! -

"3. When you arrive


There is plenty of free parking at Eden. We have lots of car park stewards to help you. All of the car parks are named after fruit, like Banana, Apple, Orange or Strawberry to help you remember where you are parked. You might have to park away from the entrance because the site is so large however this can often be the easiest and shortest way to get to the entrance. There are Park-and-ride buses that will take you from the car parks to the drop off point nearest the entrance and Visitor Centre. There are well signposted footpaths if you would like to walk to the entrance and Visitor Centre. If you have any questions about disabled parking and access issues please call our Access Eden helpline on 01726 8188558 or 01726 811911 for the main switchboard .


The Park-and-ride buses run a non-stop service from the car parks to the nearest drop off point to the Visitor Centre. The buses are fully accessible and all pick up and drop off points have raised kerbs to accommodate access."

Jan 29, 2015 at 12:15 AM | Unregistered Commenterdougieh

What is there to see for visitors anyway? Lions? Tigers?

Jan 29, 2015 at 7:22 AM | Unregistered Commenterkellydown

How would the Scottish Government handle a request like this one in light of their recent pronouncement on freaccing?

Jan 29, 2015 at 7:46 AM | Unregistered CommenterSandys

Green Fracking is good.

Fracking by nasty petrol-chemical companies who are only in it to make a profit is bad!

Jan 29, 2015 at 8:15 AM | Unregistered CommenterRoy

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