Networks Europe March/April 2019 - Page 45

GOING GREEN Solar power is one of the most promising sources of renewable energy due to its many advantages, such as sustainability, long lifetime and low maintenance operation. The initial cost of photovoltaic (PV) cells, however, is still a significant barrier to the widespread adoption of this technology. So, in order to compete with other forms of power generation, a combination of reduced fabrication costs and high solar cell efficiencies are required. This barrier is even bigger for the data centre industry. A large installation of solar panels is required to produce only a fraction of the energy needed for any data centre. For example, in the UK a 10kWp PV system consisting of 40 modules of monocrystalline silicon would need an area of approximately 65m 2 plus batteries, if any. Extrapolating, to produce 1MW about 4000 modules would be needed, taking an area of 6500m2. It is widely thought that solar power is too expensive for application at data centres, and the current technology isn’t efficient enough to fulfil the power consumption requirements of a data centre. The investment required to install photovoltaic solar panels is huge and it takes several years to recover investments. On the other hand, while other carbon-based power sources will continue to rise in price, solar power is becoming more affordable in terms of initial cost and payback time. How solar energy is currently used in data centres Some data centres around the world, for example Microsoft in Singapore and Google in the Netherlands, buy renewable energy from nearby solar farms. This not only reduces the data centre’s carbon footprint but also supports the investment made by the solar farm. There are still relatively few solar farms that generate significant quantities of electricity, so sometimes this may not even be an option. Some facilities use on-site PV to supply a portion of the site’s energy needs. The amount of land available for solar panels is normally limited to the building’s roof area, therefore the solar system can only generate a small percentage of the total energy required by the data centre. To produce enough energy for the whole site’s demand would require a large area of panels and is unlikely to be cost effective. 45