POWER March 2014 - 18

4. An impermeable effort. Statkraft's project to produce power
by exploiting the salinity gradient between seawater and freshwater
has been shelved because it wouldn't likely become competitive. The
effort, which it passed on to the " global market, " means the company
won't expand its prototype facility (shown here) in Tofte, Norway,
which produced 2 kW to 4 kW. Courtesy: Statkraft
5. Ice and steam. The Icelandic Deep Drilling Project has successfully
drilled down into molten rock and fed superheated steam from the
well to the 60-MW Krafla geothermal power plant. This image shows the
drill site of IDDP-1 well, which is near the volcanic explosion crater Viti.
Viti last erupted in 1724. Courtesy: Guðmundur Ó. Friðleifsson
IDDP-1, has led to the development of a unique geothermal project
that supplies heat directly from magma.
" Drilling into magma is a very rare occurrence anywhere in the
As early as last September, Statkraft was reportedly assessing a
location for a possible 1-MW to 2-MW pilot osmotic power facility.
In December, however, the company declared it was discontinuing
its efforts and leaving the technology development to " other players
in the global market. "
" Our main challenge has been to make the technology efficient
enough to achieve energy production costs on par with competing
technologies, " said Statkraft department manager Stein Erik
Skilhagen. " There are other technologies which have developed
enormously in recent years. These are more competitive and relevant
investments for us in the future, " he said.
Statkraft, which is Europe's largest generator of renewable
power, noted investor interest in osmotic power has been sluggish
since the idea to exploit osmotic pressure for energy was
conceived by a U.S. scientist in the 1970s. " A quarter of a century
had to pass before market conditions made several independent
public and private enterprises take up the idea and start developing
the technology further, " it said.
Yet, the company stressed that it had proven that the technology,
which it had substantially improved, " works. " It also said
that the technology can be used in other applications such as the
production of potable water. " We are now leaving the process of
maturing the technology to others, as several independent public
and private enterprises around the world are looking into this
already, " Skilhagen said.
Developing the Word's First MagmaEnhanced
Geothermal System
In 2009, when the first borehole in a series of wells was drilled as
part of the Icelandic Deep Drilling Project (IDDP) in Krafla, northeast
Iceland (Figure 5), it unexpectedly penetrated into magma
with a temperature of between 900C and 1,000C at a depth of
only 2,100 meters (m). Further investigation of the borehole,
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POWER | March 2014
world, and this is only the second known instance, the first one, in
2007, being in Hawaii, " noted Wilfred Elders, a professor emeritus
of geology at the University of California, Riverside who edited
a special issue of the international journal Geothermics that was
dedicated to the scientific and engineering findings arising from a
two-year-long observation period at the unique borehole.
Bearing part of the substantial costs involved, the IDDP-comprising
HS Energy, Reykjavik Energy, Iceland's National Power Co.,
and the National Energy Authority of Iceland-pumped cold water
into the hole to fracture rock near the magma and create high permeability.
Next, they cemented a steel casing into the well that was
perforated in the bottom section closest to the magma. Then, they
allowed the hole to heat slowly. Eventually, high-pressure steam at
temperatures of more than 450C, a measured output that was sufficient
for 36 MW, was allowed to flow out of the hole for two years
until July 2012, when it was closed due to a valve failure.
6. Not just hot rock, magma. This image shows the flow test
of the IDDP-1 well. Courtesy: Kristján Einarsson
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POWER March 2014

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