The Saint’s guide to renewable energy

0
wind farm
A wind farm near Caen, France. Wind is one of the most commonly used forms of renewable energy today

Last month the Intergovernmental Panel on Climate Change (IPCC) published their latest report after nearly seven years of scientific research. The report, which is based on contributions from thousands of experts around the world, states that “warming in the climate system is unequivocal” and that the main cause has been human action.

This has obvious implications for energy industries. Governments around the world have agreed to reduce greenhouse gas emissions, so we cannot continue to rely on fossil fuels, even to burn the reserves that remain. This will have huge implications on the way we generate electricity in the future. St Andrews finds itself experiencing this first-hand, the University’s Kenly wind farm project having finally been given the go ahead this month. With this in mind, The Saint has brought together the facts on the future of energy production. From tidal and waves to solar and wind, everything you need to know about alternative energy technologies is here.

Wind

wind farm
A wind farm near Caen, France. Wind is one of the most commonly used forms of renewable energy today

For Scotland at least, wind energy might seem an obvious choice when looking to the future of electricity production. After all, it is hardly in small supply here (except when you are trying to get that kite airborne) but even somewhere as windswept as St Andrews there are genuine obstacles to harnessing that energy effectively. The overwhelming majority of wind energy currently comes from turbines. Wind spins the blades, which turn a shaft connected to a generator that produces electricity. Although some pollution is created during the manufacture and installation of a wind turbine, once it is built the energy it produces causes no air or water pollution. Modern technology is allowing for more and more efficient capture of wind energy and operational costs are near zero once the turbine has been erected.

But wind power does have one critical shortcoming: it is unpredictable. The strength of the wind varies enormously, from zero to storm force, and if it is not blowing there is no electricity generation. Air currents offshore are more reliable, but this significantly increases construction costs. Some industry experts are concerned that wind power could never be consistent enough to meet all of our energy needs.

This is not the only problem facing the industry. Wind farms have a huge effect on the surrounding area. Even modern turbines are noisy; each one can generate the same level of noise as a car travelling at 70mph, and many people find them unsightly and feel they destroy the countryside. This is exacerbated by the fact that turbines need to be placed on high ground, so they can be seen for miles around. The rotating blades also kill birds and bats, but the effects of turbines are negligible when compared to cars, power lines and even tall buildings. Studies have shown that wind farms do not affect local bird populations at large.

Research into innovative technology is overcoming some of these problems. As turbines are becoming more efficient, fewer are needed to provide the same amount of electricity, so their environmental impact is reduced. Interest and investment is also growing in alternatives to traditional turbines, which has produced some promising results. Wind power technology is very versatile. For example, turbines are available in a range of sizes, meaning single households and small villages not connected to a national grid can benefit from wind energy as well as countries, such as the UK, with a vast power network to supply. Wind turbines have also been designed that allow agriculture to continue on the land below.

It is this versatility that has led to global wind turbine use increasing at more that 25 percent per year for the last decade. Currently, however, wind power only provides a small fraction of the world’s energy. Germany has the most installed wind energy capacity, followed by Spain (where, at times, wind power produces 45 percent of the country’s electricity), the US and India. If the current level of growth continues, scientists predict that by 2050 nearly one third of the world’s energy will be found blowing in the wind.

Solar

solar panel operation
A large-scale solar panel operation in the United States supplying power to a town

In 2008, the University of St Andrews committed to renewably sourcing 47% of its energy. In an attempt to produce some of this energy itself, the University has utilised geothermal energy and is in the process of developing wind power at Kenly farm. The University has also installed photovoltaic (or solar) panels at MUSA, its museum on the Scores, to provide energy. These panels trap sunlight inside the cell, where it is then converted into electricity. Photovoltaic cells are especially efficient means of harvesting solar power because they can easily be fitted onto roofs, requiring no extra space while taking advantage of daily sunlight. Solar panels do not require direct sunlight, so they continue to generate energy even on cloudy or rainy days. This makes them perfect for Fife.

Once up and running, solar panels have many benefits. In addition to generating energy and cutting energy bills, the panels may produce surplus energy, which can then be sold back to the grid. Likewise, any energy generated by the panels entitles its owner to a government tariff, which pays individuals for electricity generated by solar panels. Savings, thus, are multiple. According to Energy Saving Trust, a charitable foundation committed to renewable energy, a typical home solar in Scotland is expected to generate around 2,750 kilowatt hours of energy per year – about two thirds of a typical household’s electricity needs. Additionally, such a system would save over a tonne of carbon dioxide annually. The average domestic solar photovoltaic system costs around £7,000. In the past year, though, costs have dropped as demand has increased. While the University requires substantially more energy than a typical home, it would benefit from having a larger solar system in place. Though initially more expensive, larger systems are typically more cost-effective than smaller ones and they obviously generate significantly more energy. In fact, the University has already implemented a larger solar system on campus. Four Fife Park residences are now equipped with solar panels to help produce the hot water used in the flats’ showers and kitchens. Over the course of a year, these panels are expected to generate half of the heat required for all of the flats’ hot water needs. These panels lead to a much-reduced dependence on gas heating, saving around ten tonnes of carbon dioxide emissions annually.

With its commitment to renewably sourcing as much energy as it can, the University is smart to utilize solar panels where it is able. Cost-effective and very green, these panels demonstrate the value the University has chosen to place on responsible and sustainable consumption.

Wave and tidal

Wave and tidal power have the potential to harness a vast source of energy in a manner that is both practical and comparatively safe for the environment. The United Kingdom has already installed more wave and tidal stream devices than the rest of the world combined, and the Carbon Trust estimates that fully developed wave and tidal power resources could ultimately account for up to 20 per cent of the UK’s energy needs. Wave generators float over the sea’s undulations, pivoting hydraulic joints between their buoyant pistons to generate electricity. By contrast, tidal stream generators stand upright in straits and channels, allowing the predictable tidal forces of the moon and sun to funnel water across a spinning turbine that looks similar in design to a windmill.

The aesthetic problems often associated with windmills are unnoticeable with wave and tidal power generators. The former can be placed inconspicuously on the open sea, while the latter can often be found in docks or under bridges, depending on the model. Noise pollution from wave generators must be monitored carefully, and the rotating blades of tidal stream devices may kill some fish and deter them from swimming in the area. Nevertheless, energy generated from waves and tides results in virtually no carbon emissions and, on balance, poses few hazards to marine environments. Scotland recently approved Europe’s largest tidal energy project. The £13 million project will place with six demonstration turbines in the fast-moving Pentland Firth channel to power 42,000 homes, or 40% of all homes in the Highlands. Once fully implemented, this tidal stream array may deploy as many as 400 turbines to yield 398 megawatts.

Wave and tidal power have a substantial advantage over other renewable resources for local energy production, especially on the coastline. In 2011 Fife approved a £4 million contract to place 800 wave energy devices off the cost of Methil. For local communities, these generators have the potential to harvest energy from natural resources without being an eyesore or a detriment to local environments. But wave generators could make marine navigation more difficult and may disrupt traditional fishing spots. Last month the top prize in the UK round of James Dyson’s 2013 engineering awards went to a kite surfer from the Lake District who has developed a renewable wave power generator that soaks up energy from the sea. Sam Etherington’s generator is composed of a series of linked pistons that collect energy as waves peak and trough around them. The design solves a major flaw in previous wave power technologies, which could only generate energy efficiently when water travelled in one direction. This new generator faces some scrutiny over its potentially high cost of energy production.

Wave and tidal power lack the name recognition and abundant research funding of other alternative energy options, but further expansion could feasibly bring these technologies to large-scale production without disproportionately harming the environment. Wave power generators and tidal stream devices should be part of any country’s diverse energy strategy, although further scientific development may be needed to make this nascent alternative commercially viable.

LEAVE A REPLY

Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.