Solar panels in the built environment: smarter, better, and more attractive
In order to reduce CO2 emissions, we will have to maximise our use of solar energy. But how? By making optimal use of all of the available surface area, combined with the smart integration of solar power and electric vehicles in the electrical grid. Wilfried van Sark, Professor of Integration of Photovoltaic Solar Energy will argue precisely that during his inaugural lecture at Utrecht University on 31 October.
Solar energy is currently on the rise in the Netherlands. In just 10 years, the share of solar energy has increased hundred-fold, and by the end of 2019 the country is expected to have installed around 7 gigawatts of solar panels. Around the world, installed solar power has ‘only’ increased by a factor of 25 in that same time period. And there is still no end in sight: the Dutch market is growing one and a half times as fast as the rest of the world.
Despite this explosive growth, however, solar power currently only supplies around 5% of the Netherlands’ demand for electricity. The majority of this solar power is generated on roofs in the built environment. Unfortunately, most roofs only hold a small number of solar panels. In order to make a real contribution to achieving the CO2 reduction goals in the built environment, as agreed upon in the Dutch Climate Agreement, then the number of solar panels will have to increase by a factor of 30. Van Sark: “To do that, we’ll have to use every available surface, which means facades and perhaps even windows in addition to roofs, because we’ll also have to reorganise our heating and mobility needs to make them fully electric.”
Roofs and facades
There are now many more options available than just the familiar blue solar panels that you often see arranged on roofs like blocks in a Tetris game. According to Van Sark, there are smarter and more attractive ways to do it. “We’ve long had the possibility, and I can’t emphasise this enough, to install solar panels over the entire roof, or even to integrate them into the roof itself. A whole range of colours is available now, and there are even solar panels in the form of roof tiles. We can also minimise the effects of shade from dormers and chimneys using smart electronics.”
The facades of utility and commercial buildings are also ideal locations for solar panels. Van Sark: “Facade panels that generate electricity are available in all sorts of sizes and colours. It’s not hard to imagine that eventually every surface will generate electricity, without anyone noticing that they’re looking at solar panels!”
Smarter integration into electrical grid
The supply of solar power changes from day to day, and even from hour to hour. The same applies to the demand for electricity from electric vehicles and heat pumps. “But our present electricity grid can’t deal well with the fluctuations, and is therefore a limiting factor for the unrestrained increase in solar energy”, according to Van Sark. Reinforcing the grid is also an extremely expensive task. Fortunately, it can be delayed through good management, with the help of big data. “That will give you a good balance between the solar energy generated and the demand for electricity, but then we would have to be able to predict the fluctuations much better than we are able to do at present. You can do that by making intelligent use of batteries at home, in the neighbourhood, or in your car.” Van Sark expects that car batteries with a smart charging station will be especially important in maintaining the balance in the electrical grid.
Wilfried van Sark was appointed Professor of Integration of Photovoltaic Solar Energy in September 2018. His inaugural lecture ‘Integration through Differentiation - the Role of Solar Energy in Society’ will be held on Thursday, 31 October at 16:15 in the University Hall at Utrecht University.