What are the most interesting areas of research in the wind energy industry at the moment?
There are exciting developments happening at every stage of the life of a wind turbine. From its manufacture and its use in a wind farm through to the end of its lifespan. Wind turbines are the largest ever rotating machines to be built by man and are designed to have a 20 year lifespan. The biggest turbines sweep an area equal to two football fields. This places huge demands on materials scientists, aerodynamicists and structural engineers. Researchers are constantly improving designs including the use of condition monitoring sensors, such as fibreoptic sensors, in the turbines.
Old generator technology is also being updated with permanent magnet generators, and designs based on high-temperature superconductors are being explored.
A turbine pays back its energy debt in the first six to eight months of its 20 year operational life and wind energy is an extremely clean way of producing electricity. The environmental footprint of a turbine can still be improved. Most of a turbine can be successfully recycled but we need to look at new ways of disposing of turbine blades at the end of their lifespan. Researchers have investigated using thermoplastics instead of today’s more traditional composite materials, as this would enable the materials to be recycled, but current thermoplastics are just not appropriate for the job.
There is plenty to be done to design and optimise real offshore turbines. At the moment, we are putting into the sea an adaptation of what we would put on land. This is not necessarily the most efficienct design and perhaps off-shore wind farms need to look entirely different. There is plenty of scope for improving access and reducing construction cost. Eventually people may live in offshore turbines just as they did in lighthouses. Such an approach is radical but would greatly improve the estimated availability of the machines.
A very exciting area of research in wind farm engineering is the use of statistics and weather forecasting to make short-term (one hour to two hours a day) forecasts of the wind farm’s power production. This is strategically important as many people argue against wind energy because they claim wind is unpredictable. But clever mathematical engineering has shown this is not true. We can now accurately predict the output of a portfolio of wind farms at least one day ahead. Wind is not random and intermittent. Conventional power stations are intermittent; wind farms are variable but predictable.
What do you feel are the most important issues facing the industry today?
One of the most important issues is grid availability. The traditional model of central generation and radial distribution does not apply to wind energy. In fact with wind energy it is the other way around. The windiest places are, by their very nature, remote so we need to build a grid that can collect electricity from these remote places. But even in areas that have invested heavily in wind energy, grid availability is a problem. For example, in Texas there is not enough grid and in Scotland there is little grid capacity left.
If we want wind energy to succeed, we need high-level infrastructure, whether we build new or reinforce the old. And if it were an intelligent grid we could get more out of our wind power. If you can't deliver the energy to where it is needed, all you end up with is a map with lots of dots on it for high wind speed and location of wind farms, with no lines joining those dots and bringing the electricity to where it is needed. However, in a democracy this is a major undertaking and it takes a long time to get such a project moving. In countries such as China a new grid can be built in 18 months, but in the UK such a project would take many years. The grid is key, but unfortunately wherever there is substantial penetration of wind energy into the generation mix this is a major issue.
Politics slows down the building of more grid, and political procedures such as planning applications slow down the building of new wind farms. Policies, surveys, reports and enquiries are all well and good but what we really need now is some action. Progression of this industry is as much down to politics as it is down to engineering. In the UK, we have no department of energy and the average time in office of a minister for energy is less than one year. To get planning permission for a wind farm in the UK takes many years because the British system is a confrontational one. Each application is fought on its own merits. But in other European countries, such as Germany and France for example, they take a positive approach. There a certain proportion of land is allocated for wind energy and it is not a case of whether a wind farm can be build but when and by whom.
On a good site wind energy is now one of the cheapest forms of electricity generation and, as oil becomes more and more expensive, the cost advantage of wind energy grows. Wind energy increases security of energy supply (it is our wind not Russia’s, not Saudi Arabia’s), reduces cost uncertainty (there is no unknown fuel cost) and it is clean – what a great combination! It needs a strong grid and strong political support.