Wind farms are now one of the most popular sources of green energy, and look set to grow in prominence significantly over the next few decades. Many countries have set ambitious decarbonisation targets for 2050, and a switch to renewable energy sources is a key component of strategies that have been put in place to achieve this.
The relative efficiency and availability of wind power mean that it already provides a significant proportion of renewable energies to the UK’s energy grid, along with hydroelectric and solar power. The total capacity of the country’s onshore wind farms reached 14,000 megawatts (Mw) in 2020, while offshore wind power now accounts for an additional 10,000Mw and is expected to almost double in capacity by 2025.
While this will be an exciting time for investment in renewables, wind farms will need to function as efficiently as possible to actually reach this level of capacity. The figures above are referred to as nameplate capacity, which describes the theoretical output of a facility or power unit operating at its maximum capacity. It is used as a means of classifying these units, but may not tell the whole story of a unit’s performance and efficiency.
Instead, efficiency of units may be measured by their net capacity factor, which compares their output to their theoretical nameplate capacity. Lubricants play an extremely important part in helping wind turbines to operate efficiently compared to their nameplate capacity.
Lubricants can increase uptime, reduce the need for maintenance and help with durability in many differing industrial applications, and are vital for wind turbines because of how expensive downtime or repairs can be.
A combination of different lubricants will often be the most suitable solution to ensure wind turbines can operate as close to their nameplate capacity as possible. Below, the experts at Broughton Lubricants detail how oils and greases are applied to wind turbines, discuss the applications of these products in other renewable energy sectors, and how to ensure that lubricants are used sustainably to complement the push towards eco-friendly renewable energy.
What are lubricants used for in the wind energy sector?
As explained above, lubricants are used in a wide range of industries to help machines operate more efficiently. There are many parts of a wind turbine to which lubricants need to be applied, and these can make a big difference in how effectively the unit operates and prevent expensive downtime.
Areas that are important to consider include:
● The gear box
● The rotor hub shaft
● The pitch, yaw and generator bearings
● Hydraulics systems
Of these applications, the gearbox is a particular area of concern. The torque-related stresses that gearbox components face, compounded by the weather and other factors, can cause significant downtime without careful consideration to the application of lubricant.
In fact, the Wind Operations and Maintenance Report produced by the New Energy Update in 2016 showed that almost 40% of unscheduled downtime days are caused by gearbox failures. This downtime not only affects energy production and reduces capacity - the cost of each event is estimated at almost £150,000, and so preventing gearbox problems is a key priority for most wind farm operators.
A lubricating oil will often be the best product for a gearbox, while grease will typically be applied to the bearings. This is because grease is ideally suited for parts that are hard to access regularly, as it stays effective for longer than oil. However, it is usually only suitable in cases where the lubricant does not need to be resistant to high temperatures.
How do lubricants affect sustainability?
Lubricant products themselves are undergoing significant development to ensure that they can contribute to the efficient generation of green energy without negatively impacting the environment themselves. For example, Castrol developed the world’s first carbon neutral gear oil for wind turbines, and other manufacturers have contributed their own efforts to decarbonise the lifespan of lubricants.
Most turbines use nearly 100 gallons of oil at a time and it needs to be replaced once a year. The average size of a wind farm varies, but on average many farms are using thousands of gallons of lubricant per year. This is why using products that can be recycled, reused or biodegraded is an important way that wind farm operators can further ensure the environmental friendliness of their operations.
Another factor to consider is the lifespan of the lubricant product you are using. Most oils need to be changed around once per year, and the turbine will not be in operation during this process, so it is also important to consider how this will affect the unit’s capacity. Some products will have longer change intervals than others, so this must be factored into overall calculations about sustainability.
What other renewable energy sources use lubricants?
Almost every method of renewable power generation that uses turbines will rely on lubricants to operate as efficiently as possible. For example, as well as wind turbines, hydroelectric turbines make use of oils and greases to lubricate bearings, decrease internal resistance and maximise energy generation. This means that a variety of lubricant products are common in both pumped hydroelectric energy storage and run-of-river hydroelectricity plants.
There are lubricant products that are specially designed for this type of application, which provide low foaming tendency, efficiency and operability at a wide temperature range, and longer oil change intervals. These qualities are all vital for improving efficiency in hydroelectric power generation.
As this demonstrates, each type of unit and each application will have different lubricant requirements that you should consider before choosing a product. While manufacturers’ recommendations are typically a useful place to start in terms of identifying the appropriate product, there are often reasons why you should consult other sources in addition. For example, the market for oils, greases and other lubricant products changes very quickly, while the units themselves will usually last a long time, especially if the right lubricant is chosen. This means that lubricants recommended in a user’s manual for a piece of machinery may have been discontinued, or that more advanced products have reached the market that can outperform the lubricant you have been encouraged to use.
In such cases, it is important to consult an expert about the lubricant you are using for your specific use case. At Broughton Lubricants, we can recommend the most suitable product that is currently available and even test your machinery and the lubricants you are using to determine whether or not you could make improvements.
To find out more about choosing the right lubricant to maintain wind turbines or other industrial machinery, or for advice on the sustainability and eco-friendly application of different products, call Broughton Lubricants today on 03300 555 655.
