PCB + ASSEMBLY Assisting
PCB + ASSEMBLY Assisting with protection compounds The power of renewable sources of energy Renewable energy is energy collected from renewable resources that are naturally replenished on a human timescale and are projected to account for more than 50 % of global electricity production by 2035. Put another way, this is energy harnessed from the earth’s infinite or non-exhaustible natural resources rather than our traditional reliance upon finite resources of fossil fuels. According to Allied Market Research, the renewable energy market is predicted to grow exponentially by 2025 with biomass representing the leading form of energy within this market. From looking into the applications in more detail, a much wider potential use for all forms of renewable energy sources can be demonstrated. Jade Bridges, Technical Manager, Electrolube The discussion commences with a traditional source of renewable energy, water. Water-based power sources, hydropower, tidal power and wave power all rely on hydrokinetic potential; that is, the energy carried by bodies of water. Water-based power is sustainable and has a low carbon footprint. The energy generated by falling or fast-moving water is typically known as hydropower and has been used for centuries for a variety of mechanical applications. In the late 19th century, hydropower was first used for the generation of electricity and has since continued to develop as an important source of renewable power. Water based renewable energy Hydroelectricity is produced by passing the flowing water through turbine generators which consist of a number of electronic parts; simply identified as alternators, inverters, control panels and power switches or breakers. This type of power is incredibly versatile, and examples of its application can be seen around the world, one of the most famous being the Hoover Dam in USA. Run-in-river applications can also be utilised to harness the power from flowing water, rather than falling water as seen in a reservoir-dam facility. Whilst the emissions from these plants may be low, they are not totally emission free and their effect on the environment also has to Source: Electrolube With the future development of energy generation and harvesting technologies, thermal management materials, conformal coatings and encapsulation resins will continue to have a vital part to play. 28 EPP EUROPE November 2020
PCB + ASSEMBLY Electrolube products assist with protection compounds that aid the efficient and prolonged application of electronics in challenging environmental conditions. Source: Electrolube be considered; protection of fish from turbines, appropriate use of the land and evaluation of surrounding wildlife, are just some criteria that must be addressed when developing new sites. The two remaining water based renewable energy sources sound similar but in fact are very different. Tidal pattern is continuous therefore the energy generation from this is predictable. Tidal generators are placed on suitable shorelines in order to harness the power of this source. Wave power, however, is generated at sea, is unpredictable and currently plays a very minor role in the global mix of energy sources. Consideration in both cases, needs to be placed on the effects of any machinery or movement on the surrounding ecosystem. It is in these demanding electronic applications where Electrolube products assist with protection compounds, such as encapsulation resins and conformal coatings, that aid the efficient and prolonged application of these electronics in challenging environmental conditions. Devices such as sensors and data loggers are important for gathering information both in and out of the plant, providing details such as water depth and wave acceleration to adjust systems and achieve maximum capability. Water protection for these devices is just one example of where an encapsulation resin may make these measurements possible, greatly reducing maintenance requirements and human interaction in data collection. Solar based renewable energy Moving on, solar energy has to be one of the most iconic forms of renewable energy, particularly prevalent in the domestic electricity market. Solar cells produce direct current electricity from sunlight via the technology known as photovoltaics (PV), and it is these solar cells that are seen in many different applications globally. However, the technology doesn’t stop at the solar cell alone. Inverters are used to convert the direct current into alternating current electricity so that it can be fed from the solar panel into a home/building to operate standard appliances. In addition, capacitors are used to temporarily store electricity where required, or in off-grid applications batteries may be required to store power for more widespread use. In such cases, these electronic devices will require protection from the elements but will also be required to operate at higher temperatures and offer some form of thermal dissipation, due to the heat emitted during operation. Depending on the design, thermal management products may be used to help dissipate heat away from devices, this could be in the form of thermal gap fillers (Electrolube GF400) for example. However, to offer both protection from the environment and thermal dissipation, specialist encapsulation resins such as the ER2221 may be required. In addition to capturing and converting the energy, the requirement for measuring the performance or having some control over the solar panel may be required. Measurements such as solar panel temperature, can help to manage solar farms and ensure the most efficient use of the technology is attained. Unfortunately, some of these system electronics can be relatively small and possibly fragile, yet conversely, the average piece of solar equipment must be able to withstand some pretty extreme weather conditions, including direct exposure to the sun, heat and other environmental elements. Electrolube has worked directly with organisations harnessing solar power. In one particular instance, a small device displaying information on the performance and connectivity of the solar panels in an array required protection from the external environment. Some issues had arisen with resins tested, where the hardness and Tg of the material resulted in pressure on the LCD screen, leading to failures in operation. Initially silicone options were tested due to this low stress requirement, but these did not perform to the high level achieved by the company’s UR5044, which showed great stability and low hardness over a wide temperature range. Adhesion of this polyurethane resin was greatly improved compared to the previous silicone resins tested and thus an improved protection from the external conditions was realised. Devices separate from the solar farm are also very important. Measurements of solar radiation, incoming UV and infrared light spectrums will give data to help correctly position and manage these solar plants. Such data is required to be transmitted, often by GPRS or maybe Bluetooth, and any protection compound used must not interfere with these signals. Encapsulation resins with a low dielectric constant are most suited, such as the UR5118, which also offers excellent water resistance. However, if the unit is well sealed by the outer casing and has a high IP rating, it may also be possible to use a conformal coating (Electrolube AFA) to prevent the effects of condensation on the electronics and also minimise the weight of the device in comparison to a potted unit. EPP EUROPE November 2020 29
