Key considerations for designing energy efficient products
Written by Chris Paine, sales & application engineer, Morgan Technical Ceramics
The first requirements for electric motors due to the European Energy Using Products (EuP) directive came into effect on 16th June 2011 and many manufacturers are now reviewing ways to make their products more efficient.
The aim of the directive is to reduce the environmental impact of energy using products and puts new restrictions in place for energy efficiency. It is relevant for all motors in the power range 0.75kW to 375kW and introduces a new mandatory scale for their efficiency. All motors must now meet the IE2 high efficiency standard and any motors not achieving this standard will be prohibited. The motor efficiency ratings are based on the efficiency classes defined in the IEC 60034-30 standard published by the International Electrotechnical Commission (IEC).
The requirements are being introduced in three stages. Tougher regulations for achieving higher energy efficiencies will be implemented in a second phase in 2015 and a final phase in 2017, whereby all 0.75 – 375 kW motors must be able to meet the IE3 standard, or meet the IE2 standard and be equipped with a variable frequency drive.
Approximately 70 per cent of industrial energy demand comes from electric motors and the directive is expected to result in a dramatic reduction in CO2 emissions. In addition, it is estimated that changes made to energy using products will cut EU annual electricity consumption by five per cent, resulting in energy savings worth around 12 billion Euros.
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Increasing energy efficiencies through motor design is just one consideration and further efficiencies can be achieved by looking at all aspects of product design, the manufacturing process and involving trusted suppliers at the initial design stages.
For example, choice of materials can have a significant impact on efficiencies and many manufacturers are turning to ceramic components to help. Morgan Technical Ceramics works with leading manufacturers, such as Grundfos, who fully realise the benefits of ceramic and proactively design the material into their products.
The company’s ceramic pump components are being used in circulator pumps. The requirements of circulator pumps, according to the EuP directive, will lead to a reduction in electricity consumption of 23 TWh a year by 2020 in the EU. This savings potential corresponds to the electricity consumption of 14 million people.
Ceramic’s mechanical properties lead to long product life
Stainless steel and other material components (such as shafts and bearings) continue to remain common in pump design. However, the material combination does not always offer the best abrasive wear resistance to limescale and black iron oxide particles found in heating systems. The gradual wearing of these components increases noise levels, reduces efficiency and can lead to pump failure.
Technical ceramic materials can be engineered to feature hardness, physical stability, extreme heat resistance and chemical inertness – important characteristics to increase pump life and the efficiency of the whole system. The life cycle cost of the pump is significantly reduced by using ceramic shafts and bearings.
Ceramic is well known for being extremely hard (Rockwell Hardness of 75-86 R45N), second only to diamond. As such, it is incredibly hard wearing and hence ceramic components used in pumps have a long lifetime despite high speeds of more than 3000 rpm. Ceramic also has exceptional corrosion resistance in aqueous based pumping applications and is not affected by corrosion inhibitors or aggressive environments.
Shaft / bearing clearances can be manufactured within 10µm to ensure minimal pump running noise and provide optimum hydrodynamic lubrication. With the negligible wear of ceramic components over many years (unlike steel) the tolerance fit is maintained, which results in less vibration and less drain on the motor. As a result it delivers optimum efficiency.
Ceramic can also be machined to micron precision tolerances using state of the art diamond processing and grinding wheel technology. For example, on a rod 0.5mm in diameter and 200mm in length, tolerances of 0.5µm roundness, 2µm straightness and 5µm can be achieved. In addition, the components can be produced in high volume.
Next generation manufacturing
While the mechanical properties of ceramic make it the ideal material choice, next generation manufacturing techniques are enabling the design of more complex ceramic components to further increase efficiencies.
For example, for components requiring high precision and medium to high volumes, Morgan Technical Ceramics offers ceramic injection moulding (CIM). CIM is an innovative forming technique used to manufacture a range of components, including those with high geometric complexities, and provides excellent batch-to-batch repeatability. CIM offers a solution when component complexity goes beyond the boundaries of more basic forming technologies such as dry pressing and is an alternative to CNC machining of ceramics when higher volumes are not viable.
The latest manufacturing techniques are enabling the design of more complex shafts to high precision, for example, smaller, fluted shafts with multiple grooves. Morgan Technical Ceramics has facilitated the design of a rotor that can be easily attached to the shaft by injection
over-moulding. This enables manufacturers to reduce costs associated with assembly and the carbon footprint from manufacturing, while reducing time to market.
Early supplier involvement
Key to the design process is engaging with a trusted supplier early in the development stages, which enhances design capabilities. Working together, engineers from both companies can review proposals and enhance the vision and aspirations for the project. This increases innovation and creates more open thinking in the preliminary design stages, eliminates waste from the design review cycle and provides better manufacturability and a more predictable product.
Earlier identification of project risks enables more effective management and predictable outcomes, allowing Morgan Technical Ceramics to put contingency plans in place and ensure production readiness to meet critical time to market schedules.
With greater demand to increase efficiencies and the introduction of the EuP motor directive, manufacturers are reviewing every element of product design. By using ceramic components, the latest manufacturing techniques and involving knowledgeable partners early in the design stage, increased product efficiencies and reduced life cycle costs can be achieved.
Morgan Technical Ceramics is a market leader in pump components, extrusions and precision seals, as well as exciting new technologies such as CIM. It specialises in medium to high volume production of technical ceramics components, providing engineered ceramic solutions to customers around the world and enabling them to increase product efficiencies.
The company has recently been selected as one of Grundfos’ Top 5 “Best Performance Suppliers” for 2010. This accolade demonstrates the exceptional operational and commercial performance Morgan Technical Ceramics consistently delivers to its customers.
Major move forward for UK’s nascent marine energy sector
Although the industry is small and the technologies are limited, marine-based energy systems look to be taking off as “the world’s most powerful tidal turbine” begins grid-connected power generation at the European Marine Energy Centre.
At around 74 metres long, the turbine single-handedly holds the potential to supply the annual electricity demand to approximately 2,000 homes within the UK and offset 2,200 tonnes of CO2 per year.
Orbital Marine Power, a privately held Scottish-based company, announced the turbine is set to operate for around 15 years in the waters surrounding Orkney, Scotland, where the 2-megawatt O2 turbine weighing around 680 metric tons will be linked to a local on-land electricity network via a subsea cable.
How optimistic is the outlook for the UK’s turbine bid?
Described as a “major milestone for O2” by CEO of Orbital Marine Power Andrew Scott, the turbine will also supply additional power to generate ‘green hydrogen’ through the use of a land-based electrolyser in the hopes it will demonstrate the “decarbonisation of wider energy requirements.”
“Our vision is that this project is the trigger to the harnessing of tidal stream resources around the world to play a role in tackling climate change whilst creating a new, low-carbon industrial sector,” says Scott in a statement.
The Scottish Government has awarded £3.4 million through the Saltire Tidal Energy Challenge Fund to support the project’s construction, while public lenders also contributed to the financial requirements of the tidal turbine through the ethical investment platform Abundance Investment.
“The deployment of Orbital Marine Power’s O2, the world’s most powerful tidal turbine, is a proud moment for Scotland and a significant milestone in our journey to net zero,” says Michael Matheson, the Cabinet Secretary for Net-Zero, Energy and Transport for the Scottish Government.
“With our abundant natural resources, expertise and ambition, Scotland is ideally placed to harness the enormous global market for marine energy whilst helping deliver a net-zero economy.
“That’s why the Scottish Government has consistently supported the marine energy sector for over 10 years.”
However, Orbital Marine CEO Scott believes there’s potential to commercialise the technology being used in the project with the prospect of working towards more efficient and advanced marine energy projects in the future.
“We believe pioneering our vision in the UK can deliver on a broad spectrum of political initiatives across net-zero, levelling up and building back better at the same time as demonstrating global leadership in the area of low carbon innovation that is essential to creating a more sustainable future for the generations to come.”
The UK’s growing marine energy endeavours
This latest tidal turbine project isn’t a first for marine energy in the UK. The Port of London Authority permitted the River Thames to become a temporary home for trials into tidal energy technology and, more recently, a research project spanning the course of a year is set to focus on the potential tidal, wave, and floating wind technology holds for the future efficiency of renewable energy. The research is due to take place off of the Southwest coast of England on the Isles of Scilly