Swiss-born Thomas Hinderling believes his floating solar islands will produce sufficient quantities of low cost energy to make a real contribution to the world’s energy needs.
A prototype floating solar island under construction in Ras Al-Khaimah in the UAE aims to revolutionise solar technology as we know it.
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The project is the brainchild of Thomas Hinderling, a former NASA employee. “It is an idea I had 15 years or so back, when we had the first sort of oil crisis and people really started to think about energy for the first time in a big way and we started trying to conceive how the energy problem could be solved,” he says.
His theory is relatively simple: that a large flat construction of mirrors floating on the sea will be able to focus the sun’s rays onto a central pipe containing water.
The water evaporates with the heat, turning into a vapour that is taken away via a high-pressure pipe to a nearby generating plant, where it is used to produce electricity. Rather than making each individual mirror adjustable as in conventional solar projects, the entire island will rotate to follow the sun.
“What is different with this concept is that it is a system approach, it is not a technology push. Most solar energy today is pushed by technology, but my opinion has always been that we should have something that allows us to provide solar energy at very low cost, so you have to have a complete system and not just focus on the design of one panel or something like that and this is how I developed the idea,” Hinderling explains.
As a native of landlocked Switzerland, a country also not renowned for its sun, it is no surprise Hinderling found his way to the Middle East to progress his idea.
“It was an intuitive decision to come here because I felt the time would be right and they would start to think in that direction too and as a matter of fact they did,” he adds. He found the authorities in the UAE were receptive to the concept and willing to take risks and experiment with new ideas.
“I didn’t realise back then the dynamic attitude here, but it is a fact and it is the thing that makes this region so interesting for me. Switzerland is a very highly developed country probably one of the most developed countries in the world, everything works well. You have an infrastructure, which is impeccable, but people lose their thrust – they are getting content and there is no sense of urgency in any direction and that is not good for a country. Here, it is wonderful that some people say that’s a good idea, let’s do it,” Hinderling enthuses.
The project is being overseen by CSEM UAE, an innovation centre set up by the Ras Al-Khaimah government and Switzerland’s CSEM around three years ago.
CSEM is a not-for-profit research and product development company, headquartered in Neuchatel, which specialises in micro and nanotechnologies. The firm’s CEO is Hinderling, which prompted it to take on the solar scheme.
The Ras Al-Khaimah Investment Authority has given US$5million worth of funding to develop the floating island project.
Prototype phase
The aim of the prototype is to prove the concept. At this stage, generating substantial amounts of electricity is not the goal, but rather perfecting the design and method of constructing the islands.
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This first model is being built inland in a specially constructed water channel to facilitate observation and modifications. The prototype island will measure 80m in diameter and will comprise 80 mirrors, each with a surface area of 60m2 and weighing more than one tonne.
A local company in Ras Al-Khaimah is supplying the mirrors, which will be sent for glass treatment in Dubai. The island is expected to be able to produce some 0.5 MW of power.
“If we can show that it works we can go larger,” Hinderling explains. “Phase two is going to go ahead in terms of planning, but we will start the construction only once we have proved the concept with phase one.”
Phase two will be the construction of an island 500m in diameter, which will be floated at sea. The reason for positioning the island out at sea is quite practical; primarily, it is a question of space. To produce power on a large scale, Hinderling estimates islands up to 5km in diameter will ultimately be needed.
The only place where such a land mass with high solar radiation would be available would be in a desert, and, as thermal concentrator systems require access to water, a desert location by the sea would be the ideal setting.
But as such land usually comes at a premium, siting the solar islands on the sea is the obvious solution, according to Hinderling, even though it is more difficult to execute. This also removes the problems associated with sand particles covering the mirrors, which reduces their efficiency.
Better than PV
One of the benefits of the solar island design with its mostly horizontal alignment of mirrors, when compared to conventional tilted photovoltaic (PV) panels and parabolic troughs, is that the mirrors can be automatically cleaned using a robot.
Another significant advantage is that the mirrors are much cheaper to source than solar panels. Hinderling estimates the cost per kwh produced is as much as five times lower using his method. Furthermore, the energy, or rather the vapour, generated by the solar islands is storable.
“One of the problems with solar energy, if you look at PV systems for instance, is they produce electricity when the sun shines but not at night and it is very difficult to have an electricity supplier which is unreliable in that sense,” Hinderling says.
“What you need is a supply where you can turn it up and down and draw energy as you want, independent of the sun. If you do solar energy you need some way of storing the energy and this is what we are doing – we are taking the vapour and we are storing the water at very high temperature in a big tank – it’s very simple. You can store an incredible amount of energy just by heating water and having it in a tank and you can take the energy when you want it and use a heat exchanger to drive a steam turbine.”
Of course, locating the islands out at sea brings its own challenges, such as wind and high salinity. But Hinderling says computer simulations with winds up to 70kmph have shown no adverse effects and the material components are all designed to be robust: the plastics used are UV solid and corrosion resistant, while the mirrors are being surface treated.
The life expectancy of an island is up to 20 years. And there is no danger of the islands floating off over night as the plastic membrane supporting the construction will be held in place by electric overpressure pumps every 50m and electric motors every 10m.
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The islands do need be sited away from strong currents, though.
Proof of concept
Hinderling expects to achieve proof of concept by the middle of this year and to generate the first energy before the year-end. “There is no need to prove converting vapour into electricity; it is known technology. What needs to be proven is the floating island – the fact that we can have this thing not only floating, but turning in a very precise manner to follow the sun,” he says.
The project is already catching the attention of governments around the world. The UK, Malta, Monaco and north African countries, such as Algeria, Libya and Tunisia, are said to be interested.
“I have had an amazing amount of interest,” he reveals. “We already have a project going on in the north of Chile; we are doing a feasibility study there to plan what we should be doing and to propose a project.”
Hinderling says his system could help to ensure independent energy supplies, even for countries without access to sea or intense sun, as islands could be located in international waters near the equator and the energy could be converted into hydrogen, which is then transportable. He sees potential for high-voltage undersea cables taking energy to Europe using islands located off north Africa too.
There are also opportunities for coupling the islands to water cooling plants or desalination facilities, as well as making hybrid islands that include some PV panels, when storage capability is not a requirement. In this way, the mirrors would concentrate the sun’s rays onto PV cells instead.
Market potential
Patents for the solar island concept have already been applied for and, as a not-for-profit company, CSEM has created a startup company to pursue its commercialisation.
All the intellectual and industrial property rights have been transferred to new firm Nolaris, which already boasts a portfolio of potential orders worth almost Swiss francs8million (US $7.8million). CSEM currently owns the majority stake in Nolaris, but its shareholding will be diluted as more investors come on board.
A second company called Nolaris Middle East is being set up in the UAE, which will have an exclusive manufacturing licence for the Near and Middle East. The RAK Investment Authority will be the majority shareholder.
Hinderling believes there is a huge potential market for the solar islands in the Arabian peninsula. “If everything goes well, they will make a lot of money from their US$5million investment,” he comments.
And Hinderling is sure he is onto a winner: “I think this project will be a success – we have done all the simulations and we haven’t found a problem, although that doesn’t mean there is no problem.
“If it is a success, it will be an important project because then we can supply large amounts of energy at low cost, which is not possible by any other technology today. I am convinced it will work, but then I am not objective.”