Stephen Rees's blog

Thoughts about the relationships between transport and the urban area it serves

Time for BC Geothermal Energy?

with 8 comments

I got some content today from the US Geological Service. It is intended as a “feature” and covers all their services, with a bent towards the upcoming Earth Day. Of course, on this blog every day is earth day, and my content needs to be local. One of the things I have been banging on about is geothermal energy. We have all sorts of hot springs around BC, and I have even spent time around Harrison Hot Springs. It occurred to me then that there must be more that can be done with this resource than just providing hot tubs. So here is the USGS piece on geothermal energy.

USGS geothermal

Deep within the Earth’s crust lies an extremely important but underutilized renewable energy resource: geothermal energy. In 2008, the USGS released a national assessment of geothermal power resources, showing more than 550,000 Megawatts–electric power–generating potential. Since then, the USGS has continued to research and assess geothermal power potential all over the country.

“Interest in geothermal energy has rapidly grown. Recent permitting activity has seen dozens of applications for geothermal leases. All of this is based on the fundamental resource assessment efforts of the USGS – without that basic research, the benefits of this renewable energy resource would be achieved much more slowly and at much greater expense.” — William Glassley, Department of Earth and Planetary Sciences, University of California, Davis

But of course what we need is information about BC – and that is provided by the BC Sustainable Energy Association though their page on the subject dates from 2005, which suggests to me that it probably needs updating. I did hear that there has been a great deal of drilling done in BC in recent years in pursuit of shale gas, and all that information was lodged with BC’s energy ministry. It contains, of course, lots of data about the availability of geothermal energy which was discovered when looking for something else.

This information is available as maps from the Canadian Geothermal Energy Association

Their conclusions are

Key Findings Summary

  • British Columbia has enormous potential to produce geothermal power.  There is a sufficient potential to meet the entire Provinces’ power demand.
  • There is significant room to improve both the Data Coverage and Confidence of the estimates of British Columbia’s geothermal potential.
  • Priority geothermal exploration areas are identified through the confluence of key surface and subsurface data.

So why aren’t geothermal resources a higher priority – here is a Smog Blog listicle

Meanwhile, our provincial government continues with its quixotic search for an export driven economic bonanza from LNG. And refuses to raise its carbon tax. BC and Alberta being the only two provinces that did not attend the recent provincial “climate change summit“.

Written by Stephen Rees

April 20, 2015 at 9:21 am

8 Responses

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  1. I am not (that kind of) engineer, but my understanding is that there are broadly two kinds of geothermal energy: active and passive. Active is the kind that most people think of first, ie, tapping into heat coming from beneath the earth’s crust. And passive is using slight differences in temperature between the surface and a few meters underground to do heat exchange. The first kind needs to happen near natural heat vents but the latter can be used almost anywhere.

    Andrew Eisenberg

    April 20, 2015 at 10:38 pm

  2. You are right. Ground source heat pumps make much more efficient use of electricity for heating, and originally this post had a paragraph about them, but I deleted it to keep the exposition clearer. In future I think cooling is going to be the bigger issue – good if you have a swimming pool to heat up. Heat pumps are being deployed in BC now but mainly for larger institutional installations than domestic, I think.

    The bigger picture is that we don’t need Site C, or LNG export facilities. There are many more jobs that could be created by switching to renewable energy resources, with a bigger economic impact locally, and much less environmental impact.

    Stephen Rees

    April 21, 2015 at 7:38 am

  3. Thank you for posting on this topic, Stephen. I’d like to add my two cents as geothermal is of great interest to me.

    I completely agree that geothermal power has enormous potential here in BC and in other places in Canada. I suspect the main reasons why it hasn’t been developed in this province so far is that the reigning “free enterprise” governments favour private sector investments in energy (run of river, wind, LNG) and don’t want to underwrite the R&D by BC Hydro. Yet they are underwriting Site C at what could be $10 billion in costs. Delivering a percentage of the power to the LNG industry at hugely discounted prices, nonetheless, has yet to receive adequate public consultation or debate in Victoria. One wonders how much will be left for domestic use, and what will be the price differential between the two? Site C will have significant environmental and economic impacts including wiping out a long swath of Riparian habitat, GHG release from decaying submerged organic matter and silt, and loss of agricultural land from flooding. Climate change will eventually affect hydro power capacity through loss of glacial mass and diminished river flows, which is all the more reason to develop sustainable alternatives. Having said that, Site C would be orders of magnitude less damaging than an equivalent coal-fired power plant.

    Geothermal power plants would initially be relatively expensive because of the requirement for significant R&D to resolve some of the technical issues such as corrosion of well casings and pipes drilled deep underground into superheated salt and mineral-laden water. But I doubt the cost of a geothermal power plant would exceed the cost of Site C while producing the equivalent power. The lack of widespread environmental impacts of geothermal (the impacts are primarily local except for the construction process and the provision of new access roads and transmission lines) will also have value, and I believe lifetime accounting and deep cost-benefit analyses will add much more weight to the positive side of the ledger.

    The greatest benefits of geothermal power production could be:

    – a very long term sustainable, zero-emission, abundant and concentrated affordable energy source
    – a ‘leavening agent’ that can smooth and flatten the peaks and valleys of the intermittency that limits solar, wind and tidal power when delivered to the grid
    – a process that allows centralized concentrated grid power for industry and decentralized renewables for local use
    – a method to develop co-generation potential using waste heat in greenhouses and district heating distribution grids in nearby communities
    – and as a primary or dedicated power source for export to other provinces via a national smart grid, and to the rest of the continent with competitive pricing

    The latter point may be moot because a Trans Canada smart power corridor would arguably be of more economic benefit than developing new power sources (except for replacing coal-fired electricity). It is possible to utilize high voltage DC (HVDC) transmission lines that take advantage of the offsets presented by our time zones. HVDC loses only about 3% of the power through resistance every 1,000 km, so ~90 percent of the electricity transmitted from BC to Ontario will be available during Toronto’s morning rush hour. The rates would be charged at the time of day at the source, in other words power generated at 4:00 a.m. in BC for 7:00 a.m. use in Ontario would be charged at the lower non-peak rate. This would reverse during Vancouver’s peak demand periods. In effect, the inter-provincial trade in power could result in major savings to the provinces through offsetting or limiting the cost of otherwise spending hundreds of billions of dollars to build new generation capacity across the nation over the rest of the century, and by offering cheaper off-peak power. All economies are underpinned by energy. I believe a smart grid with, in part, its content mixed with stable geothermal power will eventually be seen as one of the only methods to achieve a modicum of stability if not growth and maintain at least a semblance of an industrial economy as fossil fuels continue to deplete and solar and wind fail to fill the vacuum, and we enter a period of instability.

    Under this scenario, and especially if national and international treaties are enforced on limiting emissions, BC will be well positioned to not only balance its own domestic power needs, but to develop an industrial strategy to manufacture core materials at home (steel, cement, value added products), shift transportation from private vehicles burning fossil fuels to public transport using zero-emission electricity, grow our food closer to home, to profit from exports of clean power, and to allow decentralized solar and wind at the local basis to offset the cost of larger grids powering up industry. Our emissions will plummet.

    It is assured that there will be a void left by burnt and / or exported irreplaceable petroleum and this will leave a void in the economy and our livelihoods. That’s physics, not economic theory. Its size and duration depends on how quickly the decision makers enable renewables like geothermal to be developed, and how smart we citizens are in defining the issues to the public and electing the right leaders to deal with them.

    Geothermal power generation comes in several forms and is viable in many places across the nation, from tapping hot water and magma-heated rocks as shallow as 2,000 m to deep geothermal in hydro-fractured rock 20,000 m depth. It is most viable in the volcanic and sedimentary basins of Western Canada and the far North. A Geological Survey of Canada report stated that the potential of geothermal power could be as much as one million times today’s total national energy use. Whether that is ever realized only time will tell, but starting to develop it now is essential.

    Here is a link to a very detailed study of this energy source:

    Geothermal Energy Resource Potential in Canada, Geological Survey of Canada, Natural Resources Canada, Grasby et al, 2012, (322 pages)

    http://publications.gc.ca/collections/collection_2013/rncan-nrcan/M183-2-6914-eng.pdf

    MB

    April 23, 2015 at 3:47 pm

  4. Iceland is hotter than Canada on this topic. They have discovered that drilling very close to a magma dome can yield ~10 times the potential of a typical well field drilled 2.5 km deep due to the supercritical nature of the water. In one case a few years back they drilled right into the magma by mistake.

    ***

    http://www.nea.is/geothermal/the-iceland-deep-drilling-project/

    The Iceland deep drilling project
    The Iceland Deep Drilling Project (IDDP) is a long term study of high-temperature hydrothermal systems in Iceland. The IDDP is a collaborative effort by a consortium of Icelandic power companies and the Icelandic government, formed to determine if utilizing supercritical geothermal fluids would improve the economics of power productions from geothermal fields.

    Over the next several years the IDDP expects to drill and test a series of boreholes that will penetrate supercritical zones believed to be present beneath three currently exploited geothermal fields in Iceland. This will require drilling to a depth of about 5 km in order to reach hydrothermal fluids at temperatures ranging from 450°C to ~600°C.

    A feasibility study completed in 2003 indicates that relative to the output from conventional geothermal wells, which are 2.5 km deep, a ten-fold increase in power output per well could result if fluid is produced from reservoirs hotter than 450°C.

    A typical 2.5 km-deep geothermal well in Iceland yields power equivalent to approximately 5 MWe. Assuming a similar volumetric inflow rate of steam, an IDDP well tapping a supercritical reservoir at temperatures above 450°C and at a pressure of 23-26 MPa may be expected to yield ~50 MWe.

    MB

    April 23, 2015 at 3:53 pm

  5. Thank you MB for these really helpful comments. I will certainly read the articles on those links. What happened when they drilled into the magma? Watching the recent volcano video certainly makes one pause before suggesting that we tap into that resource!

    Stephen Rees

    April 23, 2015 at 5:40 pm

  6. I read a report on this by the Icelandic engineers a couple of years but I cannot seem to locate it at present. What I remember is that they lost their drill bit in the magma but were able to withdraw the pipe. They saw the sudden spike in temperature that led to the conclusion they drilled right into the top of the magma dome. The magma chamber wasn’t highly pressurized, obviously.

    What they found significant was that the much higher temps nearer the magma created supercritical steam which has the energy to generate a lot more power than conventional geothermal or fossil-fueled steam turbines. Packing more punch into one plant has very beneficial connotations for clean energy. BC seems to have enormous potential for “hot” geothermal.

    The other idea that stood out to me was that it seems possible to have a closed loop that could use distilled water stored in tanks on the surface that is continually recirculated. Extra-wide diameter holes are drilled down fairly close to the magma dome (which has to be mapped very accurately), then a special pipe liner is inserted (stainless steel? ceramic?). A water-steam pipe with a U-bend at the bottom would then be inserted and grouted in place. Water would be injected into a pipe where it flashes to supercritical steam near the magma before returning to the surface where it powers an array of turbines. The steam would be recirculated into the next pipe or condensed back to water and stored during non-peak power demand periods. This technique would avoid using superheated corrosive salt, metal and mineral ground water.

    Seismic activity could close the holes, but there is no reason why geothermal plant administration buildings, the turbine rooms and water tank farms shouldn’t assume the costs of building on seismic dampers in order to extend their lifespans and ride out all but the most major earthquakes as a public preparedness policy.

    These ideas make too much sense for our current governments.

    MB

    April 27, 2015 at 12:28 pm

  7. One last comment. The April 25th Vancouver Sun published an op-ed column by Wendy Holm, an agronomist who was retained to report on the agricultural potential of the soils that will be flooded by Site C.

    She first chided BC Hydro for underestimating the amount of acreage that will be affected by flooding.

    “It failed to measure correctly the amount of farmland lost. The land BCH claims will be “lost” to agriculture (1,666 hectares) represents only 13 per cent of the impacted land, 26 per cent of all flooded land and 47 per cent of the Class 1-3 flooded land.”

    She then performed an analysis of the economic value of the crops that are currently grown on this Peace River Valley site that contains very fertile soils, currently sown in hay, pasture and canola, then their potential should the planting be changed to more useful crops.

    “Most significantly, it failed to acknowledge the cumulative impact the removal of these foodlands will have on nutrition, health, community resilience and long-term food security. … Vegetables are the key building blocks of human nutrition. British Columbia is 55 per cent deficient in vegetables, making us reliant on imports. California, our major source of fresh vegetable imports, is in the middle of a 1,200-year drought.”

    I found her conclusion astounding: Based on the lower Hydro 1,666 ha., this site is capable of growing enough vegetables to feed one million people every year. The value of fruits and vegetables are orders-of-magnitude higher than pasture. Moreover, if this segment of the Peace grew crops as intensely as the Okanagan or Fraser Valley, the total value would equate to the cost of Site C in less than a decade.

    You can’t talk about hydro projects in BC without hitting head on with the topic of food security.

    Here’s the link:

    http://www.vancouversun.com/opinion/oped/Opinion+damning+indictment+process/11002769/story.html

    MB

    April 27, 2015 at 12:59 pm


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