Generating renewable energy more efficiently

26. května 2020 Cost pressure and stricter environmental requirements are presenting power plant operators with the challenge of finding new options for further increasing the efficiency of hydroelectric power plants. Here, the topic of energy efficiency is becoming ever more important. Specialty lubricants are often underestimated, despite the fact that they can help power plant operators to boost the efficiency of their plants. Together with a leading manufacturer of electro-mechanical systems for hydroelectric power plants, Klüber Lubrication has developed a solution aimed at increasing the efficiency of generators and turbines. By using Klüberoil EE 1-46, efficiency losses in generator bearings can be reduced by 5% on average. This enables power plant operators to generate more power from the same volume of water, without the need for expensive modifications.

Challenges for operators

Hydroelectric power is the most widely utilised source of renewable energy globally. With annual production estimated at 4.2 TWh[1], it accounted for around 16% of global power generation in 2018[2]. When it comes to sustainability, hydroelectric power performs especially well – not only in comparison to non-renewable energies, but also when pitted against solar and wind energy[3].

However, operators are increasingly needing to account for market factors which are having a negative effect on the profitability of hydroelectric power plants.

Prolonged excess capacities, the prioritisation of wind and solar energy feed-in and subsidised feed-in tariffs are reducing the price of power. Cheap nuclear power and the continued production of energy from fossil fuels are, depending on the region, also contributing to the lower profitability of hydroelectric power. Then, add to this growing environmental regulations and still inexpensive CO₂ certificates.

This is why one of the goals of hydroelectric power plant operators is to boost the efficiency of their plants. While this can be accomplished with expensive modifications and capacity expansions, often-underestimated measures such as high-performance lubricants can also contribute to greater energy efficiency, thus increasing profitability while improving a plant’s ecological footprint.

Identifying losses in efficiency

It’s generators in hydroelectric power plants in particular which show great potential for optimisation through the use of custom-made specialty lubricants, as the plain bearings of generators and turbines are lubricated with a large volume of oil. In cooperation with a leading machine manufacturer of electro-mechanical systems for hydroelectric power plants, Klüber Lubrication analysed a large number of current projects, looking at the effect of lubricants on the energy efficiency of hydroelectric power plants. The results show that generators are already running at a high level of efficiency today, but there are still significant efficiency losses at the generator bearings.

Powerful and highly efficient – Klüberoil EE 1-46

The industry standard DIN ISO 51515-2 defines specific parameters within which turbine and generator oils must lie, in order to ensure proper functionality of the application. Klüber Lubrication not only successfully managed to optimise its Klüberoil EE 1-46 lubricant in line with this standard and all the technical properties of a generator bearing, but also managed to exceed the criteria altogether.

Klüberoil EE 1-46 limits internal friction to a greater extent than that specified in DIN 51515-2, thus reducing internal friction loss considerably. Thanks to a viscosity temperature behaviour (VI) specially matched to the application, this product exhibits high system and energy efficiency across a large temperature range. Klüberoil EE 1-46 is characterised by an especially good air shedding capacity, good compatibility with plain bearing materials and good oxidation stability. As the requirements on increased wear protection defined in DIN 51515-2 have also been exceeded, this product contributes to reducing losses in plain bearing efficiency.

Klüberoil EE 1-46 reduces internal friction loss in turbine and generator bearings.

Improved energy efficiency in generators with Klüberoil EE 1-46 – a simple calculation

Calculations from a machine manufacturer show that a reduction in the loss of plain bearing efficiency by 5% on average is possible by changing from standard turbine oil to Klüberoil EE 1-46.

If we take a hydroelectric power plant with an installed capacity of 50 MW, annual production capacity of 264 GWh (operating period of 220 days) and a calculated maximum bearing loss of 350 kW, the use of Klüberoil EE 1-46 can achieve a 5% reduction in efficiency losses – or 17.5 kW – on average. This would enable the power plant to produce up to 92,000 kWh more power annually.

That makes the Klüberoil EE 1-46 lubricant a very good alternative to expensive modifications for increasing the efficiency and profitability of hydroelectric power plants over the long term.

Looking for partners in development

Innovative lubricants from Klüber Lubrication contribute to an increase in the efficiency and sustainability of plants in many different industries. This includes hydroelectric power plants, for which Klüber Lubrication offers a portfolio of high-quality products. In cooperation with manufacturers and operators, this portfolio will be expanded over the coming years. Of particular interest are, for example, applications involving direct contact with water, where other sustainability and environmentally relevant aspects are more important than energy efficiency optimisation.

Tailored solutions are more worthwhile when the lubricant is developed in a specific, application-oriented way. That’s why Klüber Lubrication is on the lookout for additional industry cooperation partners; we want to develop tailored solutions for specific areas of application.

Are you looking for a lubricant precisely suited to your application? Are you interested in finding out how much the efficiency of your specific plant could be increased? We look forward to helping you – simply discuss your project with our specialists!

Contact person: florian.held@at.klueber.com

[1] International Hydropower Association Limited. Hydropower status report 2019. 2018. P. 6
[2] International Hydropower Association Limited. Hydropower status report 2019. 2018. P. 15
[3] Luc Gagnon International Electrotechnical Commission, Electricity Generation Options: Energy Payback Ratio, http://tc4.iec.ch/FactSheetPayback.pdf