Talking solar trends and technology with Professor Brian Norton, Principal of Technological University Dublin.
Solar power has come a long way since making its debut in calculators and space satellites. From powering lighthouses to airplanes, it appears that sky is the limit. But what exactly are the current industry trends? Should there be solar farms in the Sahara? And what does the future of solar look like in Northern Ireland and the Republic of Ireland? These were just some of the questions we asked Professor Brian Norton.
Q1) Could you share with us, a little about your background and what inspires you the most about the sector you work in?
Overall, my work surrounds research into solar energy, energy in buildings and the applications of daylight to displace electric lighting. It is an interesting sector to be a part of, and one I have been involved in for over 40 years. I have published numerous research papers, authored a couple of books and contributed to roughly, another 9 books. Research I have completed, now exists in real life systems that are being commercialised and used, particularly in the Photovoltaics (PV) sector, glazing sector and in the design of solar thermal collectors. I have also been able to develop the manpower in this area, having had some 50 PhD students graduate under me.
In relation to what inspired me; I completed my initial degree in Physics at the University of Nottingham, before finishing my masters and PhD in engineering, all with an interest in the use of solar energy, which was not then commonplace. It just so happened that my mix of skills, both in physics and engineering, alongside my interest in solar, was what was needed at that point in the industry. In fact, I was one of the first to look at systems, at a time when others were working on new devices. Subsequently, I have completed a lot of work in this field, looking at all aspects of the system, including; economics, installation, how long it’s going to last and how much CO2 it saves.
Perhaps my original inspiration was when I realised that I had ideas on the topic of solar and its uses that had not already been done. This is something that surprised me initially and piqued my interest.
Q2) What would you say are the top 3 trends in the solar industry that people should be aware of?
First, I would say energy storage is a big trend involving better storage technologies, cheaper storage technologies and more distributed storage – in that the storage in a PV system might be at the cell-level rather than the array-level. So overall, there is a lot of innovation encompassing storage.
Secondly, I would suggest much more design for PV arrays for durability, for plug-and-play and for module replacement. I think the ability to take a module out of an array and replace it, and to have diagnostics to be able to locate failures, are all part of this trend. So overall, the design for durability and operation of maintenance to keep things running is a key trend.
The third surrounds trends in new materials. There are a lot of new PV materials coming through. Right now, they do not produce extremely efficient cells, but the materials used are so intrinsically cheap, that we will get to a point where they will become commonplace. Researchers are always looking for disruptive technologies and enabling concepts in the solar sector that previously wouldn’t have been considered. For instance, I think we will see a mobile phone that never needs to be charged because it is powered by the sun. I can see this causing the concept of plugging in a mobile phone to become as archaic as that of landlines.
In fact, solar originally began in two markets. It started in space through satellites, and in pocket calculators and small devices, which are now coming full circle. Solar will soon be powering mobile devices, smart phones and iPads, and I think overall; the power requirements of these devices will go down and the combination of motion detecting energy sources and heat detecting energy sources and solar energy will be what powers them in the future. This is a trend I see only getting bigger.
Q3) How do you see solar progressing both domestically and commercially across Northern Ireland and the Republic of Ireland?
I think there will be significant growth in both markets, depending on the regulatory and incentive framework. I think potentially, both the commercial standalone market and the building integrated market will grow as things such as interconnections become easier to do, because the way the PV price is going - it is going to be competitive without an incentive to compete as an energy source. However, there needs to be a level playing field to ensure installation is easily accomplished. As soon as that gets in place, we could be looking at PV being 5-7% of the mix on an annual basis. If we can achieve cost effective inter-seasonal storage, higher proportions than that would ensue.
Q4) The Irish start-up, Solar Marine Energy, recently received a grant to develop floating solar technology, but what are the long-term effects of water, specifically salt-water on solar technology?
It may already be known, but all the Irish lighthouses are in fact solar powered. These solar panels are sitting on a highly corrosive salt environment, and so are heavily encapsulated as a result. The main failure mode of the panels happen when tiny expansion and contractions of the lamination of the solar cell, crack the edge slightly, which allows water to get in, causing corrosion. So, in sealing the edges and encapsulating the cell, we essentially have a solar PV design that is durable enough to survive these marine environments, but of course, the costs associated with installing them is higher. Now, with the growth in floating solar, where more cells are being exposed, the key is to choose cells that are designed for that specific application. It is not so much the design of the cell, but the design of the encapsulation that is important to ensure the solar panels stand the test of time in harsh environments.
In fact, there is currently a lot of research being done on designing solar cells for all types of difficult environments, especially those where the panels will not be maintained. For instance, if you look at Bangladesh where they have typhoons, all the warning stations are solar powered. However, as the solar panels must survive the typhoon, there is a lot of ongoing work being done to design durable and disaster-proof systems. Overall, there is a lot of work aiming to create systems that can survive without maintenance in extremely amorous conditions.
Q5) Recent reports have highlighted that there is potential to place solar panels in the Sahara Desert. However, with the recent ‘Sahara dust’ making its way over here, just how important is it to wash your solar panels?
This introduces two separate issues. The first, is the idea of putting solar panels in the desert and powering Europe. That, I would not support because it exploits other countries resources. It might be better to have panels in the desert to power people who live in the desert and improve their economic development. In fact, you can achieve the same energy by placing the panels where we are geographically. Overall, I do think solar panels in the desert are a good idea, but for the people there to improve their economic prospects.
Now, looking at the second issue of dust and solar panels, what happens is you get dust accrual and then overtime, the wind blows most of that away and you end up with only a very thin layer. You then have two choices; you can clean those periodically or you can oversize the system. For instance, if you have a thin layer of dust on the panel and it reduces efficiency by 5%, you can just make the array 5% larger, which might be a cheaper option than employing people and systems to keep the panels clean. So, it is less of a problem than you might think because the wind that blows the dust on, also blows it away. If you know your reduction in efficiency, you then have the economic choice of making your system slightly bigger or cleaning it. There are waterless cleaning products currently in the market such as air blowers, but they can end up being quite expensive and even cleaning with water, assuming it is available is still not necessarily cheap. Often, the simple option is to know what the reduction in power is, depending on the amount of dust that accrues, and oversize the system accordingly.
An interesting side-line to that as well, is for example Jordan in the Middle East – the irrigation systems in the desert supply water for nomadic tribes are solar powered. So, what they do there is oversize the water tank, so it pumps and collects more water than is necessary and stores the water so that efficiency of the panels is irrelevant as long as enough water has been pumped.
Q6) Do you think it is necessary for domestic homeowners in Northern Ireland to wash their solar panels?
The reason we clean windows is because they become unevenly dirty. Rain will clean off the middle part of the window, but the top part gets rain shade and so dust accumulates. A solar panel is on an incline, and an inclined surface cleans very uniformally. So there is no need to clean a solar panel in Northern Ireland. Actually, the interesting thing about solar panels in Northern Ireland is that when PV becomes hot, efficiency goes down about 0.5% every degree C in temperature rise. However, as Northern Ireland has a cooler, wetter climate, panels are not as affected by hot weather and rain actually has a cooling effect on the panels. So, overall Northern Ireland has very good conditions for PV to work.
Q7) According to industry reports, the next step is Building Integrated Photovoltaics (BIPV) – such as solar tiles, windows and cladding. Do you think these technologies will soon become a viable option for NI and Ireland?
You will soon see developments where solar panels are no longer black. You will be able to purchase them in other colours. So, you will no longer be able to notice the solar panel. Immediately this makes the product more flexible in terms of building integration. In fact, in Germany, France and Spain – you already see a lot of excellent integrated solar PV, in façade elements and windows of buildings.
However, I think the solar tile market is over-hyped. There might be some applications for it, but trying to make a solar panel look like something else is not necessarily the best thing to do. With solar tiles, you end up with a lot of connection which means lots of points of possible failure. There is a potential niche market for this product in relation to heritage buildings. Overall, solar on walls and roofs is a big market, and one which is becoming increasingly integrated on an international level. I think we will eventually see it make its way more significantly over here too.
Q8) And finally, what are your hopes for the future of solar power and its place within the renewable sector within NI and Ireland?
I think the building integrated PV market is certainly going to grow. I feel that solar power is going to become less dependent on any type of subsidy intervention as the costs of the panels go down, it allows the product to compete well with other fuel sources. However, you do need to ensure that the regulatory requirements in terms of how panels are connected and installed are as easy as possible, as a lot of the cost can be associated with that area.
The standalone market has growth opportunities in Ireland, but has a natural plateau due to the availability of sites. This is a limiting factor because there are many more sites available on the roofs of buildings in terms of total gross area than there are available sites for standalone systems. The other area of growth is micropower applications. Currently, this can be seen happening at an international level, where solar is powering wireless devices, even used in offices to power equipment. Overall, I think we will witness substantial growth in the building integrated PV market, growth to a natural plateau in terms of the standalone market and growth in solar powered handheld devices such as mobile phones, which will eventually mean no longer having to plug in devices to charge.
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