Give Us A Wave (Power Revolution)

Wave Power Developments

There are several wave power developments that are now being scaled up to generate reliable and clean energy from an abundant and sustainable resource – waves from the sea. The Commonwealth Scientific and Industrial Research Organisation (CSIRO) estimates that wave energy is at least three times more predictable than wind energy. There are great opportunities to expand, and benefit from, wave power that is a reliable source of energy. With almost half of the world’s population living within 100 kilometres of the coastline there will always be a market for clean energy generated by the sea.

This month three examples of different approaches to wave energy converters are showcased from around the world. They are all pioneering the generation of electricity from the waves. Each one utilises a slightly different approach to capturing energy from the waves and each has a different electrical output. The solutions are quite small but are being scaled up and offer good sources of energy for islands. It can remove the need for fossil fuel generators that are typically powered by diesel.

Wave Swell

In Tasmania, Wave Swell is installing a 200kW wave energy device, to be deployed on King Island by the end of 2020. Construction of the device is almost complete, with the unit commissioning expected to begin in the first quarter of 2021. The energy produced will complement existing wind and solar grid, diversifying the renewable sources. It has the benefit of reducing diesel consumption on King Island.

This device uses well-established concept of the oscillating water column (OWC). As water rises and falls inside, air is forced past a turbine at the top of the chamber. The turbine generates electricity which then can be sent back to shore via a cable. The technology operates unidirectionally. This means that the turbine is simpler, than models that operate bidirectionally, more robust and reliable. It exhibits a higher energy conversion efficiency as a result. Details can be seen here: Wave Swell.

Wavestar is a Danish project, dating from 2000, that is looking to harness the power of the waves but also to create a flexible platform that will enable the combination of renewable energy sources. For example, wave power with wind power or with solar panels. Wavestar is requesting European Union (EU) support through its Horizon 2020 program which is aiming for innovation lead sustainable growth. Wavestar, as part of an industrial consortium, is aiming to produce the first full-scale 1 MW Wavestar wave energy converter (WEC) to be tested commercially.

A WEC prototype has been in use at Nissum Bredning in North West Denmark. It creates a regular output of energy from ocean swells and waves (which are typically 5-10 seconds apart). This was achieved with a row of half-submerged buoys, which rise and fall in turn as the wave passes. The design allows energy to be continually produced, despite the periodic nature of waves. There is a built-in protection system that prevents the wave machine being damaged in extreme storms or weather events.

A test 600 kW machine was installed at Hanstholm in September 2009 and has been connected to the grid since February 2010. This is a half scale machine, developed over time, which has been gradually scaled up from smaller prototypes. Designs have evolved to reduce cost and allow deployment to other sea areas. It is estimated that the machine should be adaptable to different types of wave systems around the European coastline. This is a key feature that should allow the technology to adapt and expand. It aims to be a scalable low carbon energy solution for the future.

The final example is another wave power project benefiting from the EU Horizon 2020 program: Arrecife Systems from Spain. Prototypes have been tested in the north of the country in the Cantabrian Sea. It is another company that is developing small energy systems that will support different situations. An example is providing power to small island communities. It has a 75kW, 440kW and 2MW system. The wave energy converters are designed to work with the most common waves, ranging in height from 1 to 5 metres. This represents around 98% of the waves. As a result, there is more efficiency both in the manufacturing and in the energy production which allows the WECs to be working at full capacity during more hours of the day.

These examples show the potential to scale up wave technology and harness energy from the sea which is very reliable and clean source of electric power. The energy being generated is gradually being developed with the different designs are being tested fully to evaluate and improve them. Capturing continual energy will be a big win over solar and wind power. Wave power has a huge potential if it is given the right backing for it to grow and prosper.

Posted in Climate Solutions, Energy, Energy efficiency, Europe, Islands, Phase Transition, Renewable Energy, Resources, Smart, Sustainable Development, Technology, Tidal Power, Zero | Tagged , , | Leave a comment

The Largest Island Is Melting: Here’s Why It Matters

Greenland’s Increasing Ice Melt

Greenland is the world’s largest island that is not a continental land mass. The Greenland Ice Sheet covers around 80% of the island. The weight of the ice sheet has depressed the central land area resulting in a basin lying more than 300 metres below sea level. Elevations rise suddenly and steeply near to the coast. Generally ice flows are from the island centre to the coast. The Greenland Ice Sheet is losing mass at accelerated rates in the 21st century, making it the largest single contributor to rising sea levels. It is largely caused by retreats of glacier fronts which is now sustaining glacier melting and persistent ice loss. There is also ice melt from a a warming Arctic air mass.

Research highlighted in Nature shows an acceleration in the Greenland Ice Sheet melt with mass being lost at an increasing rate. 40 years of satellite data has been used to reach these conclusions. In the decades leading up to the turn of the century, the ice sheet was in a state of relative equilibrium. The ice lost in a given year would be replenished by wintertime snowfall. This has now changed.

There was a step-increase in decadal-scale ice discharge with around a 60 giga tonne (Gt yr−1), or 14%, increase between the 1985–1999 and 2007–2018 means. There was a temporary decrease for 3 years around 2005. The discharge continued to accelerate, at a slower pace of 2 Gt yr−1, during 2008–2018. A peak annual value of 502 ± 9 Gt yr−1 was reached in 2017 and 2018 which is 17% above the 1980’s average.

This study shows that there is an observed increase in discharge of 4–5% per every weighted mean kilometre of retreat. This means that for each kilometre of ice loss there is an increasing rate of discharge. Such events are clear evidence of positive feedback events that science has predicted at the higher latitudes. This accelerates the ice loss. Totals remained relatively stable at rates near 495–500 Gt yr−1, but this increase was still sufficient to effectively shift the ice sheet to a state of persistent mass loss.

Increased ice melt is due to both increased surface meltwater runoff and ablation of marine-terminating outlet glaciers via calving and submarine melting. This is termed ice discharge. Total mass loss over the 1992–2018 period was due to approximately equal contributions from both but with greater contribution from increased melt runoff after 2000, when mass losses accelerated. Increased surface melt can be shown to indicate a shorter-term response to climate forcing. Within such a large area there are substantial regional differences in behaviour, even at the individual glacier level, that is likely the result of differences in ocean and atmospheric forcing. Every Greenland region displays the 4–5% increase in mean discharge per kilometre of weighted mean retreat.

In late August 2020 the changes to the ice sheet in Greenland saw further evidence of ablation of marine-terminating outlet glaciers, according to this BBC report. A huge area of ice broke away from the Arctic’s largest remaining ice shelf – 79N, or Nioghalvfjerdsfjorden – which is in the north east of Greenland. The section of ice covers around 110 square kilometres. It went on to disintegrate into many smaller pieces. This is further evidence of a rapidly changing climate leading to further changes in ice cover in Greenland.

79N became is now the largest remaining Arctic ice shelf, after the Petermann Glacier located in northwest Greenland was drastically reduced in size over a period between 2010 and 2012. It is not just warming air temperatures that affect the ice shelves here. Oceanographers have documented warmer sea temperatures around Greenland meaning the shelf ice is almost certainly being melted from beneath as well as from above.

A recent report, from the World Economic Forum, notes the consequences for sea level rise from Greenland’s melting ice. It highlights the rate of ice loss over the past two decades as being a rate of around 6,100 billion tonnes per century. If future emissions are very high, it could lose to up to 35,900 billion tonnes per century. Even if global warming can be limited to 2 degrees Celsius, Greenland’s ice sheet could still lose 8,800 billion tonnes per century. The very high scenario would add almost 10cm to global sea levels. This phys.org article notes that the Greenland Ice Sheet was likely to have moved to a state of persistent ice loss at the turn of this century. The ice sheet contains the equivalent of about 24 feet (over 7.3 metres) of global mean sea level rise. It is now considered the largest single contributor to rising sea levels worldwide due to the rapid retreat.

If there is a 2 Celsius temperature increase scenario, southwestern Greenland could add 2.4cm to global sea levels per century by 2100. Under a high emissions scenario, this could rise to 9.9cm.

This World Economic Forum Video shows that 11 billion tonnes of ice melted in just one day from the ice sheet. It highlights some of the other factors that are influencing the rate of acceleration of the Greenland ice melt.

Greenland itself may ultimately be transformed into a series of smaller islands should the ice sheet or parts of it melt. The impact of melting ice sheets here will affect many people as global sea levels rise. Even these apparently small changes can make a difference to localised flooding in low-lying areas when there is a storm surge or low pressure weather system further increasing the wave heights.

The rate of ice sheet destruction is increasing at a greater rate as both the Arctic air and water temperatures rise. This will have an impact of the rest of the ice sheet, potentially opening up currently protected parts of the sheet to increased risks of ablation. The potential of the full 7 metres of increase in global sea levels is why it is important to prevent further warming and lessen the risks that would be much more severe under high emission scenarios. Greenland’s ice melt will have an impact many miles away and will affect the rest of the world through sea level rises.

References

King, M.D., Howat, I.M., Candela, S.G. et al. Dynamic ice loss from the Greenland Ice Sheet driven by sustained glacier retreat. Commun Earth Environ 1, 1 (2020). https://doi.org/10.1038/s43247-020-0001-2

https://www.bbc.co.uk/news/science-environment-54127279

https://www.weforum.org/agenda/2020/10/greenland-ice-century-climate-change-holocene-environment-sea-level/

https://phys.org/news/2020-09-greenland-ice-sheet-years.html

Posted in Arctic, Climate Change, Earth Science, Geography, Greenland, Islands | Tagged | Leave a comment

Mayflower 400 And The Citizen Climate Assembly Reports

This month sees the 400 year anniversary of the sailing of the Mayflower to the New World, from England to America. This year sees a high-tech ship also named Mayflower, sailing the Atlantic to collect scientific data. This ship has no crew on board.

The first UK citizen climate assembly reported its findings after several meetings held since last year. It is part of public engagement with climate change. Several solutions have been proposed.

Climate Assembly Report

The UK has held a unique citizen based climate assembly. It was formed of 108 assembly members taken from the general population, as a cross-section of society. It has been working on addressing questions relating to a net zero climate policy from 2050 such as:

  • how will we travel?
  • what will we eat?
  • what will we buy?
  • how will we heat our homes?
  • how will our electricity be generated?
  • how will we use the land?

The key question that needed to be answered was “How should the UK meet its target of net zero greenhouse gas emissions by 2050?”

Assembly members were clear on the principles that should govern policy choices. They included the importance of information and education and the need for fairness, to support those who might be adversely affected by the transition to net zero. Government had to lead the debate and take the actions necessary to reach net zero. A cross-party consensus was needed, to give long-term certainty on the policy choices made. The path to achieve a net reduction in carbon dioxide is, essentially, a collaboration between the UK Parliament, the population, Government and business.

Key findings from the climate assembly members, from across society, are as follows:

  • There is a need for information and education for everyone.
  • The solutions to climate change are neither easy nor free, but they need to be fair.
  • It is important to maintain, wherever possible, freedom and choice for both individuals and local areas so that they can choose the solutions that work best for them.
  • Co-benefits: tackling climate change could bring with it many advantages. It could see benefits for local communities, high streets and local businesses. It could boost our economy and promote innovation, including technological innovation.
  • We need to protect and restore our natural environment, and our access to it.
  • There is an imperative need for strong and clear leadership from Government – leadership to forge a cross-party consensus that allows for certainty, long-term planning and a phased transition.
  • Achieving net zero will require a joined-up approach across society – all of us will have to play our part.

Towards the end of the report an additional section was added for Covid-19 recovery and the path to net zero. Assembly members thought that steps should be taken as part of the recovery to use the opportunity to commit to net-zero emissions. Almost 80% of assembly members thought that Government could re-think its investment to support the transition to net zero. There should be support to stimulate or support, economically, further low-carbon economy growth. Changes are required to encourage lifestyles that are more compatible with reaching net-zero.

Covid-19 impacts included: changes happening to air travel (people may continue to fly less); homeworking becoming more acceptable; the impact on public transport (people are currently less willing to use it); increases in cycling and walking or active travel options.

The ten recommendations that received most support with the most recommended first, all of which included support of 85% of the assembly members, were:

  1. The transition to net zero should be a cross-political party issue, and not a partisan one.
  2. More transparency in the relationship between big energy companies and Government support.
  3. Get to net zero without pushing our emissions to elsewhere in the world.
  4. Incentives to accelerate progress to net zero and conditions attached for organisations seeking Government financial support.
  5. A robust media strategy on the outcomes of the Assembly.
  6. An independent neutral body that that monitors and ensures progress to net zero, including citizens assemblies and independent experts.
  7. Move away from fossil fuels and transition to new energy sources.
  8. Products and services labelled to include their carbon footprint.
  9. A follow up on the outcomes of the Assembly covering what has been taken into account, what hasn’t and why.
  10. Harness the response to Covid-19 and next year’s UN climate conference, COP26, to drive international coordinated action on climate change.

Interestingly a slight majority of the assembly did not see ambitions to bring net zero before 2050 as an option. The points above include one on having products and services report their carbon footprint. This would certainly show how much carbon is embedded in a product and allow consumers to adapt due to greater awareness of a product’s climate impact.

A full overview is available in the executive summary of the Climate Assembly report.

Mayflower 400

400 years ago the Mayflower ship left England for the New World in September 1620. English puritans were on board – they became known as pilgrims. These people had left England for exile in the Netherlands two years earlier as they believed that the Church of England was beyond redemption. They left Leiden, Holland for England before going on a treacherous journey across the Atlantic Ocean. This journey left Plymouth in south west England on 6 September 1620 with around 130 people on board. The journey concluded in the “New World” after a challenging sailing over the Atlantic Ocean in a time of autumn storms. Only one life was lost on the voyage. Resources were low upon eventual arrival, in November, off Cape Cod. The Mayflower Compact, an agreement as to the rules that would be followed, was signed before landing and establishing settlement. The immigrants were not used to the cold and freezing conditions that they found. The new arrivals probably only survived their first winter due to the indigenous people helping and teaching them. Around 45 pilgrims died in the first winter.

The pilgrim ship the Mayflower became an important symbol of European colonisation of America. It was not the first group of European emigrants, but a significant one due to the Compact declaration agreed before the pilgrims landed. The Mayflower Compact with its just and equal laws later influenced, and were a precursor of, the United States Declaration of Independence. Plymouth Colony was established from the New Plymouth landing site. By 1622 the indigenous tribe of the Patuxet were extinct. One of the last tribe members, Tisquantum or Squanto, died in November 1622.

Mayflower 2020: Autonomous Research Ship

A new fully-autonomous, artificial intelligence powered marine research vessel, also named the Mayflower, has been launched to coincide with Mayflower 400. Its full name is MAS or Mayflower Autonomous Ship. It has a job to do: undertake cutting edge marine research.

The World Ocean contains more than half of all life on Earth, covers over 70 per cent of its surface and contains 97 per cent of its water. It regulates the Earth’s climate and acts as a crucial sink of excess heat and carbon.

MAS has 6 artificial intelligence powered cameras, 30 onboard sensors, 15 edge devices and 0 humans on board. With no human onboard MAS uses artificial intelligence and automation to traverse the ocean. It is used to collect data and, like the original Mayflower, undertake discovery. Certainly there is a contrast from the conditions on the original Mayflower heading to the New World.

This ship will continue a tradition and provide much scientific data, remotely, from around the world. Full details on MAS can be found here. There is a wide range of experiments that the ship will undertake and data will be returned from automated experiments whilst at sea.

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