By increased use of complex devices, our electricity consumption is growing. There’s also increased decentralized power generation. The current AC voltage network is not equipped for this. This is why one of the world’s first DC voltage network was built in Dutch greenhouse area PrimAviera in Haarlemmermeer with input of renewable energy. This pilot project shows that DC voltage can provide a solution for the existing energy problems.
Yield
You can’t tell from the rows of Bouvardia flowers at nursery Vreeken, but the growth lamps above them are powered by the first DV voltage network in the world. Making the pilot project in Haarlemmermeer in 2013 an international first. Founder Harry Stokman of Direct Current BV: "When we started, there was zero knowledge about DC. Now our system is the basis for DC projects that we are setting up worldwide. In developing countries 1.2 billion people lack access to an electricity grid. Why would you build a power network that’s a hundred years old, when we have a cheaper, sustainable and safer alternative available? We are working hard to make DC a standard in countries like India and South Africa. Just like phone lines were never installed there but people just started using smartphones."
Meanwhile the pilot was domestically successful with street lights on DC, an opportunity that arose during the pilot period. Stokman: "We are now earning our money with the spin-off. Streetlights on DC are already a fact in other Dutch cities." In the meantime Direct Current BV has become a major knowledge partner in the area of DC. And Stokman is happy to share that knowledge. "We are developing teaching materials for colleges and universities to make students aware and to create ambassadors. Formerly DC was a forgotten topic, but now it is high on the agenda."
Lessons learned
In Haarlemmermeer more customers in the greenhouse area want to switch to DC. Expanding the DV voltage network is also favorable because of the arrival of a large solar farm. Solar panels generate DC, which is currently first converted to AC for transportation, and then back to DC for use. This conversion results in efficiency loss. Because of all the developments, the system operator that had taken a cautious attitude before is finally on board. Stokman: " Network operators are responsible for the most efficient and cheap possible grid management with public money. So they cannot just swim with every tide. That the system operator wasn’t involved from day one was a problem for our pilot partners. They had to invest heavily in the pilot project without knowing who would become network owner after. These agreements should actually be made in advance: an important learning point." In the meantime the cooperation with Alliander is coming along. Stokman: "Their own research shows that even a combination of DC and AC voltage is only 10 percent more expensive than just AC. A good solution for parties who don’t dare to fully transfer to DC immediately: both are also possible."
Future Plans
There’s no end to ambitions and plans for after the experimental period. Nursery Vreeken has rented an adjacent greenhouse to expand the DC project. Vreeken will also optimize its CHP for the DC voltage network and there will also be a link to the new 2 hectares solar park. Furthermore Direct Current BV is involved in the project ‘de Stroomversnelling' [the Rapids] to make social housing in Soesterberg energy-neutral. Stokman: "If you apply all sorts of measures such as solar PV and electric cooking, the AC voltage network would have to be increased. An expensive matter. By conversion to DC you create more capacity for less cost. Residents can continue to use devices that operate on AC with Siemens converters. There are about 2.4 million homes in total so it offers great opportunities for large-scale DC applications."
Stokman sees DC as the key to a future-proof, sustainable energy supply. "There’s interest around the world. Even from Germany, which is normally more advanced than the Netherlands in terms of renewable energy. With DC the tables have turned."
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Source: RVO.nl