Five reasons why wind energy providers should invest in transformer monitoring

In the last 20 years, the contribution of wind power to the UK's energy needs has grown from 320MW in 2001 to more than 24GW in 2021. Nearly 20GW of that has come on stream in the last 10 years. As the renewable energy market continues to grow, so does the need to understand asset availability and optimise operation and maintenance strategies.

With this increased pressure, onshore and offshore wind farm owners and operators are now facing a new challenge of identifying and investing in technologies that will give them critical insights into the health of their assets to maximise performance.

A key asset within an offshore and onshore wind farm is the power transformer which connects the wind energy to the electricity grid. Power transformers have a design life that nominally is at least the typical 25-year life of the wind farm. However, transformers can develop faults well before the end of their life expectancy, leading to failure and ultimately downtime for the wind farm.

Transformer monitoring can provide immediate insight into the health of these assets and risk to availability. By continuously monitoring each transformer, developing faults are immediately identified in real-time, enabling interventions to be taken to minimise the potential risk of downtime for the wind farm’s facilities.

Here, we outline five reasons why wind farm owners and operators should invest and implement transformer monitoring to protect their investments and optimise their operations.

1. Maximise availability and reduce risks

Uptime is a top priority for any onshore and offshore wind farm owner or operator. Many consider the power transformer as the single point of failure for any plant. If a transformer suffers a critical failure, this will lead to a potential loss of not only the entire generation capacity of a wind farm but also revenues. It is therefore vital to have solutions in place to monitor crucial assets like power transformers and implement condition-based and preventative maintenance programmes to reduce the risk of unscheduled downtime.

Outages not only mean loss of revenues, but also the reduction in power supply from wind generation and, in some cases, potentially the need to back up with fossil generation. This can have a huge impact on the operator’s targets for energy generated. Due to the UK’s net-zero targets and the high prices of fossil fuels and the risks associated with oil, gas and coal supplies in the current geopolitical scenario, the power output from domestic renewable sources is becoming increasingly important for energy security.

Finally, insurance premiums are a significant cost, especially for offshore installations. With insurers increasingly demanding that best practices in asset management are implemented, monitoring transformers, which are considered single points of failure in the wind farm, can help wind farms manage their insurance costs. Implementing a monitoring solution provides better information on the health of the asset being insured. It enables preventative maintenance to be undertaken before faults develop to a point of catastrophic failure, therefore reducing the risk to insurers.

2. Increased visibility of asset condition and reduced maintenance costs

Without visibility of assets and their performance, onshore and offshore farm owners and operators can only be reactive to issues as they arise, causing expensive operational costs and interrupted service delivery. By installing a powerful transformer monitoring system, a real-time view and a pre-emptive approach to maintenance and repairs can be achieved. For maximum results, the monitoring solution implemented should be holistic. This will allow the asset manager to have a complete view of the conditions of each component of the power transformer, thus covering most of the possible failure modes through dedicated sensors, advanced analytics, and diagnostic tools.

With many onshore and offshore sites often in remote and unmanned locations, visiting an offshore or onshore wind farm for maintenance or data gathering can be costly and time-consuming. Online transformer monitoring solutions will have advanced communication and alarm capabilities which alert Operations Managers of any potential faults before they become serious. This helps them to prioritise, and plan interventions and maintenance, reducing the need for unplanned site visits and the associated costs that come with that.

3. Asset digitalisation and the importance of data-driven decision making

With the complexity of onshore and offshore wind farms becoming greater, it’s not always possible to have a subject matter expert for each individual component within the organisation. Transformer experts, in particular, are becoming very scarce, therefore, exploiting real-time data from sensors deployed in the field and other available data such as the asset’s age, location, off-line tests etc. is of the utmost importance. Transformer condition monitoring solutions can produce an overwhelming amount of data, making an Asset Manager’s job even more challenging. That’s why any transformer condition monitoring solution should be accompanied by advanced data solutions and digital expert services, which provide Operations Managers with data-driven insights and support which can help them make more informed decisions. Advanced analytics, software tools and dedicated digital consultancy services can help wind farm operators to manage their transformer fleet more effectively. This can also be supported with insights and prescriptive actions which offer a more realistic view of each asset’s health, plan maintenance activities and determine the impact it has on safety, reliability, and risk to the company’s revenue.

4. Reducing the risk of downtime and plant failure

Although power transformers are static machines, with a relatively simple working principle, they are complex assets, as they are made up of several materials, such as copper, iron, solid and liquid insulating materials like paper, wood, porcelain, resin, and oil. Such materials are prone to different failure modes that can affect the main tank, bushings, tap changer, oil conservator, cooling system, etc. Combining these elements and ensuring they last for their entire design life is not an easy task. As power transformers are subject to multiple and combined types of stress: electrical, thermal, mechanical, environmental, and even chemical, the risk of failure with these elements can be high. Furthermore, by its nature wind generation is intermittent, which places additional stress on transformers. Therefore, only well-operated, and managed transformers can reach the end of their expected lifespan without major issues.

5. Avoiding the chance of a transformer replacement and associated loss of revenues

If a power transformer fails and needs to be replaced, the costs are not only those of the asset but also the loss of revenues and possible collateral damages that a major catastrophic fault of a high voltage asset may cause. With the global demand for power transformers only rising and the current supply chain challenges, acquiring a power transformer may be easier said than done. The specification, purchase, delivery, and installation of a new transformer to replace a failed one involves several people and entities both internally and externally and could take several months, during which time power is not being generated. Even in cases where a spare transformer is held in stock, the remote location of many renewable installations means it could take up to several weeks and could imply oversize load cranes, and specialists to carry out the replacement.

With critical assets experiencing more variable load patterns due to an increased output of wind energy, it is vital for owners and operators of these wind farms to gain a better understanding of their key assets.

Power transformers are one the most critical and complex components on an onshore/offshore wind farm; they are prone to different kinds of faults and technical issues and with a lack of in-house expertise on specific critical assets such as power transformers, it can be challenging to optimise the performance of these key assets and extend their lifespan.

By investing in an end-to-end transformer monitoring solution, Asset Managers can gain increased visibility and insight into the health, risk, and performance of these assets. With this, the wind farm owner can also gain a better understanding of the potential risks to availability and consequently risks to revenue. Faults can be identified in real-time, enabling interventions to be taken to minimise the potential risk of downtime and proactive maintenance strategies can be put in place. By being better equipped with the more appropriate data and insights on their critical assets, wind farm owners and operators can make more informed decisions.

Get in touch with Kelvatek today to find out more about how we can partner with you to safeguard your supply of wind power to the electricity grid.