Offshore wind is becoming a key component of energy transition strategies in many Asia Pacific (APAC) countries, as they focus on developing low-carbon economies. Countries like China and Japan have already achieved early success, while others like South Korea, Taiwan and Vietnam are actively promoting offshore wind. Various investors and renewable energy developers from across the world have now started exploring opportunities in these attractive emerging markets. Ireland-based Mainstream Renewable Power is one such developer which has significant experience in the offshore wind space in the European region, and is now developing its expertise in other geographies including APAC.

Despite all the developments, grid-related challenges for both onshore and offshore transmission infrastructure continue to hamper potential offshore wind development in many regions. Thus, innovative and cost-effective solutions are urgently needed to resolve these issues and ensure robust grid systems. Against this backdrop, Bernard Casey, Chief Operating Officer APAC, Mainstream Renewable Power spoke about the company’s plans, grid concerns and possible solutions at Global Transmission Report’s conference on Offshore Wind Transmission in APAC. REGlobal presents edited extracts from his address…

Mainstream Renewable Power is a renewable energy developer with headquarters in Dublin, Ireland. We’re growing in numbers with currently about 500 staff worldwide. Since our founding 14 years ago, we have raised about 3 billion Euro in project finance. In Chile, we have 1.3 GW of wind and solar projects under construction at the moment. In South Africa, during the later part of the last year, we won more than 50 per cent of the auction capacity for renewables, which is about 1 GW.

Last year we announced that Aker Horizons has taken a major stake in Mainstream Renewable Power. And earlier this year, Mitsubishi has taken a minority stake in the company. With the financial strength and complementary experience of these two companies, we plan to take Mainstream Renewable Power to the next level as a renewable energy major in the coming years.

We have a long history in the offshore wind space, and we have developed the world’s largest offshore wind farm in the UK, which is now owned and being built out by Orsted. In the APAC region, we are currently developing offshore wind projects in Vietnam and Japan as well as tracking various opportunities in the Philippines.

The biggest challenge for offshore wind transmission often seems to be the onshore grid capacity. Meanwhile, the best locations for these projects are often remote from the load centers as is the case, for example, in Vietnam.

The biggest challenge for offshore wind transmission often seems to be the onshore grid capacity. Meanwhile, the best locations for these projects are often remote from the load centers as is the case, for example, in Vietnam.

We can take learnings from our early development experience in South Africa and the related grid solutions. South Africa is a huge country, where the highest population and biggest energy generation centers are mainly in the northeast. This is where the base load power stations of the national power utility are located. Another factor is that there is only one time zone across this huge country. So, morning and evening peak demand happens at the same time.

The country has high ambitions for renewable energy development up to 2050. Interestingly, the renewable energy source potential of wind and solar is the best in the region of lowest energy demand. However, there are vast distances of about 1,400 kilometers from the best renewable energy sources to the load centers. In the Eastern Cape, Mainstream Renewable Power built one of the first commercial wind farms in the country at Jeffreys Bay.

So, what’s the solution? The South African utility ESKOM is planning major grid upgrades and planning more new ultra high voltage transmission lines and substations. This is a 10 to 15 year program and is a major concern towards meeting the requirements of the country’s ambitious renewables program. They have also allowed developers to participate in grid works and we were the first developer to build a grid substation there. Thus, this represents the perceived best solution so far – high voltage lines over long distances, involvement of the private sector and grid upgrades.

Significant research has gone into getting more from existing grids and this is the focus of several countries seeking a quick fix to deploy more renewable energy. A new US company Smart Wires has adopted power electronics to create flexible AC transmission devices that optimises the existing grid to bring more capacity online. This can bring more renewables into the grid and avoid generation curtailment and reduce cost for customers. A number of grid operators around the world are now deploying this technology to increase the local capacity of their grids and facilitate increased renewable penetration.

So, what about the future? We see after COP 26, that countries are now planning for vast increases in renewable energy capacity, both onshore and offshore. There is not enough copper in the world for all this additional transmission capacity that will be required to meet these targets.

There is not enough copper in the world for all this additional transmission capacity that will be required to meet these targets.

This is where superconductors come in, and that’s the focus of our sister company, Supernode, founded by Dr Eddie O’Connor. So, what are our superconductors? Well, superconductors are materials that allow zero electrical resistance when brought down to a critical low temperature. They are much more efficient than conventional cables. They have a much higher power density meaning much smaller cables are needed for the same power.

Further, a lower voltage can be used to carry the same amount of power as a copper cable.

The cables, the superconductors, can carry transmission levels of power at distribution voltage. Thus, this can bring considerable benefits as the offshore substation platforms can then be much smaller. For comparison of cable size, we can say that 1 gram of superconductor yttrium is equivalent to 30,000 grams of copper for the same load current capacity.

There are numerous small projects with superconductors already in operation over relatively short distances in urban areas in Germany and South Korea. These are cables over relatively short lengths. The limiting challenge of superconductors is the technology required to keep the cables cool, which is essential to maintain zero electrical resistance.

The cable design being developed by Supernode is based on liquid nitrogen cooling and the design concept is aiming for cable lengths of a 100 or more kilometers without intermediate cooling. The ultimate goal is an integrated super grid with super conductor cables. This technology and the work of Supernode has received EU support so it is quite an exciting development phase and has reached technology level 5.

The key advantages of superconductors include a much more efficient approach for power transfer. They are ideal for underground installation and therefore have scope for greater public acceptability. And finally, the lower voltage reduces the size and therefore the cost and consent risk of substations.

The applications of this technology are wide. The key application is that they can help to solve urban congestion of transmission assets. Further, large scale offshore renewables can be delivered more efficiently to remote load centers. And finally grid reinforcement at scale can be achieved.