Renewables are to be an essential tool in our fight against climate change – where we must keep temperature rise below 2°C while satisfying our growing population's vast energy demand. They’re also now being pushed by the UK’s most powerful energy lobby – Energy UK, which has historically been fossil-fuel focussed. We're all familiar with the classics: wind turbines, biomass, photovoltaics (PV) and hydroelectric power, but is there anything new and different out there? Yes, lots! Here are a few of the most recent and exciting developments.
(An up-close image of the prototype solar roadway panels with heating elements and LEDs built in. Photo credit: Solar Roadways)
There's been talk of solar roads for a few years now, and it seems that they might finally be travelling (sorry...) towards being mainstream. The idea is simple: cover roads in PV cells to allow transport and power generation at the same time, without sacrificing land for solar farms. Too good to be true? Maybe not – following a Dutch pilot test on a 100 m cycle path, it looks like France could soon be roads ahead as the Minister of Ecology and Energy has announced plans to cover a whopping 1000 km of road with Wattway’s seven mm thick panels, which can be laid down on existing roads. This project is hoped to take five years, at which point it should provide enough electricity for five million people - eight per cent of France's population! They're suitable for both cities and rural, off-grid living. If successful, this could pave the way for solar roads all over the world.
Yes, that does say spray-on solar, and yes, that is a real thing. It’s been investigated right here at the University of Sheffield, by the departments of Physics & Astronomy and Chemical & Biological Engineering. This amazing work could lead to the possibility of almost anything becoming a solar panel! We're not there yet, but let's look at where this technology originated from.
It uses perovskite rather than the silicon conventionally used for PV panels. Perovskite systems may be advantageous as they require much less energy to produce than silicon. As well as the spray-on technology, perovskite's use in PV panels more generally has been investigated. Indeed, Science Magazine hailed these as one of the top scientific breakthroughs of 2013. They operate on the same principles as conventional PV, but have the advantage of a coating hundreds of times thinner – a mere 0.3 microns compared to the conventional 150. The technology is rapidly improving – in 2009, these panels had an efficiency of just 3.8%, compared to an average of around 25%. Just a few years later, the efficiency is upward of 20% (Sheffield's spray-on system has an efficiency of 11% at this early stage in its development). Other benefits include the fact that they can be easily implemented on existing infrastructure. There is lots of interest in this technology – a company called Oxford PV is hoping to bring it to a commercial scale in 2017, and the Australian Renewable Energy Agency is investing nearly $900,000 into their development.
Another innovative solar technology is being worked on by CSIRO – a “solar ink” which can be printed onto surfaces. While inefficient for now, with further work these could offer an exciting way to coat existing surfaces at a variety of scales.
Keeping us Afloat
Who said our renewables have to be down to earth? No one – floating windfarms and solar panels are an exciting opportunity.
Floating solar farms already exist – in countries such as Japan, India and the UK. Thames Water recently began constructing Europe’s biggest floating PV farm, at London’s Queen Elizabeth II reservoir. The development will cover an area of eight football pitches, and generate 6.3 MW – enough to power 1,800 homes. It’s part of Thames Water’s goal to produce a third of its own electricity by 2020. Japanese company Kyocera is constructing an even larger facility – a 13.7 MW development to power 5,000 households, following their successful implementation of three smaller projects. Floating solar farms can also conserve water! There are plans to cover 19,000 km of India’s canals with solar panels, which will prevent evaporation from freshwater waterways.
Floating windfarms could make energy security a breeze – they’re ideal for operation further out at sea, which will vastly increase the area available for offshore windfarms and lead to fewer objections from residents as they will be, by definition, further away from homes. In a UK first, Norwegian company Statoil are building a 30 MW pilot off the coast of North East Scotland, which could power 20,000 homes (incidentally, 30 MW is also almost enough for the University of Sheffield to reduce its emissions by 70%). According to an Energy Technology Institute report, this technology could be credible and cost effective by 2025 – the current global average for offshore wind is £112 per MWh, and it’s hoped that floating equivalents on a larger scale could cost as little as £85!
North East Scotland is looking pretty lucrative – another ambitious project, run by Atlantis Recources, is installing 269 “undersea windmills” to generate 400 MW of electricity to power 175,000 homes. The first outputs of this £1bn project are expected this year, and benefits include them being out of sight, tides being extremely predictable, and the ability to utilise vessels from the slowing North Sea oil and gas operations for construction and maintenance. Funding for this project – the largest tidal farm in the world, was awarded by the UK Renewable Energy Investment Fund.