Curbing carbon

IRL's half-scale wave energy device is undergoing sea trials in Akaroa Harbour near Christchurch.

Wave of the future

Over the past three years, a wave energy generator using technology developed by IRL engineers in Christchurch has demonstrated its potential in trials of a small-scale prototype device off Taylors Mistake in Christchurch and at Evans Bay in Wellington Harbour.

The project received a boost in April 2011 when the US Department of Energy (DoE) invested US$1.82 million in the wave energy project.

The wave energy converter is now being scaled up and tested by Wave Energy Technology NZ (WET-NZ) – a collaboration between IRL (83.8%) and private Wellington-based company Power Projects Ltd (16.2%).

The US funding is through Oregon-based North West Energy Innovations and will allow the research team to get a greater range of data to speed up the development of a full-sized commercial device.

Unlike other wave energy converters, this one extracts energy not just from linear motion, but also from surge and heave, and is anchored to the sea floor in an upright position. It senses and reacts to water movement, and the energy from those movements is converted into electricity by a system of on-board hydraulics.

The original device was recently upgraded to one-quarter size and has been deployed for some months off Taylors Mistake. That model has undergone a lengthy process of risk identification and mitigation and as a result has been granted Statement of Design Feasibility certification by an international certification agency, Det Norske Veritas.

The next step has been to move to a half-scale model and that is being done here in New Zealand and, thanks to the DoE funding, in the US as well.

The half-scale model to be deployed in New Zealand has been manufactured by Stark Bros in Christchurch and will be tested first off Akaroa and then off Moa Point in Cook Strait.

At the same time, the ‘smart‘ high-value components, subsystems and 'brain' of the device will be sent to the US to be installed in a half-sized device manufactured there to IRL’s design.

That will be tested off the Oregon coast and will also undergo wave tank testing, where design concepts to enhance its performance will be tried out. That work cannot be done in New Zealand since no testing facilities are available here, and will demonstrate the TRL 5/6 (Technology Readiness Level) status to accepted DoE guidelines.

“This not only gives us a chance to test the device in a different maritime situation and try out new ideas for advancing the design, but is also an important step in opening up the US market,” IRL General Manager Industry Engagement Gavin Mitchell says.

“The US DoE has a very strict review process for projects it has funded and having its tick that the technology has proven itself would be a significant endorsement and we would expect a lot of interest in licensing the technology there.

“Because the technology is protected by patent, we see all the sophisticated components of the device being manufactured in New Zealand and exported around the world, so future sales could bring in hundreds of millions of dollars to the New Zealand economy.”

Going lime green

CanmetENERGY, a top Canadian clean energy research institution, is to test a new reactivation process developed by IRL to improve the performance of lime-based CO₂ capture processes.

Lime is the sorbent used in a system to capture and then release concentrated CO₂ for sequestration
– a process known as calcium looping – but this absorption capacity diminishes with repeated cycles of use.

The IRL process solves this problem by maintaining the performance of the lime so that it can absorb and release the CO₂ multiple times. This significantly improves the economics of this promising technology for reducing the emissions from coal-and gas-fired power stations as well as other big carbon emitters such as cement works and steel plants.

IRL’s lime reactivation process has been published internationally and has been verified by researchers at Imperial College London. Patents for the process have been filed in the US and Europe. As a result, the IRL process is now attracting attention from international researchers involved in the development of lime-based CO₂ capture systems, such as the team at CanmetENERGY.

IRL will be producing a sample of reactivated lime in reactors that have been constructed with the help of the IRL workshop, in quantities that can be tested at Canmet’s experimental CO₂ capture facility in Canada.

As well as lowering the cost of CO₂ capture systems, the calcium looping process offers the advantage of safety and has low water requirements compared with other systems. The equipment needed is also relatively compact, meaning that it could be retrofitted to existing plants where space is limited.

The IRL research team has also shown that calcium looping using their lime reactivation technology has excellent potential for storing energy in applications such as solar power generation, where supply is intermittent.

The lime-based CO₂ capture process developed by IRL senior research scientist Robert Holt and his team improves the efficiency of a promising new technology for reducing emissions from coal- and gas-fired power stations. Photo by Kent Blechynden, Dominion Post.

Power for the people

IRL’s HyLink distributed energy system for remote communities has been licensed to Lower Hutt-based E Sime Group Ltd. Recently they formed ESG Energy Ltd, a company that will be marketing, selling and installing alternative energy systems both within New Zealand and overseas, with HyLink a significant part of their offering.

HyLink, developed by engineers at IRL Christchurch, is distinctive in that, while it uses sophisticated technology, most of the components are inexpensive and readily available.

Energy generation is from renewable sources and can be wind, solar or small-scale hydro, depending on site resources. Residual electricity is converted, transported and stored by HyLink's hydrogen energy system.
An electrolyser splits water into hydrogen and oxygen.

The low-pressure hydrogen fuel gas is then delivered by pipeline, which also provides storage for the gas, smoothing out the differences between production and use.

A small experimental system has been operating for five years, supplying electricity to a farm in the remote Totara Valley in Wairarapa. An improved pre-commercial system that will further test the IRL-developed electrolyser technology is being installed on Matiu/Somes Island and will provide energy storage for Department of Conservation staff who manage the island.

Malcolm Sime, Chairman of E Sime Group, says the company is very excited about the potential for HyLink.

“We have already been speaking to people internationally who are very keen to commit to trial orders so they can evaluate the suitability of HyLink to their specific requirements, so we hope to have production of these units started sooner rather than later.”

Sime says that, apart from opportunities in the Western world, ESG Energy sees huge potential in the developing world, particularly where the hydrogen can be used as a cooking gas or for boiling water.

“Work is currently going on with an American architect on projects in Uganda and Kenya, where, with Global Volunteer Network, they are going to build the first two international ‘GVN Village Pods’,” he says.

"Within these self-sufficient complexes, there will be a medical centre, a school, homes for orphans, a guest house to accommodate at least 60 volunteers, donor homes and a 2000-m2 building that will include kitchen, dining facilities, conference room, smaller breakout rooms, offices, computers and the Pod management centre.”

Closer to home, ESG Energy is in the process of developing a ‘Green Energy Pod‘, which they believe is a world first, with amazing potential. Sime describes HyLink as “the jewel in the crown” within this unique green energy facility.