Direct current is the future

With the rapid development of new technologies, such as solar panels, LED lamps and electric cars, we are seeing a growing use of power electronics. THUAS is an international pioneer in developing education and applied research around this promising development. An exchange with students from South Africa helped us to promote this knowledge on a global scale.

We are turning away from gas, using more solar power and our cars are increasingly powered by electricity. ‘It started with the demise of the light bulb and the arrival of LED,’ explains project leader Pepijn van Willigenburg. ‘But in this energy transition we are seeing the growing use of direct current in a large variety of applications, instead of the still commonly used alternating current.

Smaller, stronger and cheaper

Pretty good, isn’t it! Direct current offers numerous advantages over alternating current. Equipment uses less power and lasts longer. ‘A classic transformer used to weigh more than a kilo, today’s version weighs only 100 grams. The semiconductors, that transmit the power, are also becoming smaller, stronger and cheaper. Before we used expensive heavy copper semiconductors, whereas today’s versions use the much lighter and cheaper silicon.

Savings

On top of that, direct current creates opportunities for new products. Look for example at the greenhouse industry. Replacing regular light bulbs by LED lamps results in an annual savings of € 15,000 to € 20,000 per hectare. The expectation is that in the near future, USB outlets will be integrated into the walls, replacing regular power outlets. That means new constructions can use thinner and cheaper wiring.

Future

The growth of direct current also involves some problems. Today our power grid is entirely based on alternating current. We lose power when we convert from direct current to alternating current. Van Willigenburg: ‘Thanks to power electronics we can now also build direct current transformers. This will enable us to build a power grid based on direct current. And that is important: direct current technology is the future.’

Research

The Hague University of Applied Sciences is not the first knowledge institution in the Netherlands to do research on power electronics. ‘But we are one of the pioneers among universities of applied sciences in its application,’ explains Van Willigenburg. THUAS is currently partnering with TNO, Siemens and ATAG Nederland to adapt kitchen appliances for the use with direct current.

A new curriculum

Education at THUAS is also taking a leading role in the latest developments in the field of power electronics. In 2014, we launched the new module Power Electronics 1, focused on DC-DC transformers and in 2015/2016 we started the follow-up module Power Electronics 2, focused on AC-DC/DC-AC transformers.

Exchange with South Africa

As an international networking school, THUAS attracts a large number of international students. And this specialisation in particular is drawing a lot of interest from abroad. As part of the project DCT-REES, which stands for Direct Current Technology Renewable Energy Education and Skill development programme, THUAS is working in partnership with seven South African research universities and universities of applied sciences. A total of 22 students in eight different groups will visit THUAS.

Great potential

Van Willigenburg is very excited about the exchange project. ‘Currently the Netherlands uses more solar power than all of South Africa. That sounds strange, because the yield per panel in South Africa is twice as high. Solar power has much greater potential in South Africa than in the Netherlands. That means there will be a huge potential market in South Africa for solar power.’

Lack of electricity

In South Africa there are still millions of people who are not connected to the power grid. ‘So using direct current would be the most logical step for them,’ continues Van Willigenburg. You can build new structures from the ground up there and apply direct current on a large scale. At the same time there is great demand for electricity. ‘As a result, South Africa has a huge demand for this knowledge. And THUAS is able to supply that. It is a wonderful win-win situation.’