Through green integration, is it possible that building automation and control systems (BACS) could help reduce emissions and subsequently, help save the planet? Raul Simonetti, HVAC/R corporate business manager at Carel, tells us more.
However dramatic the title may sound, there are good reasons to believe that BACS may play a prominent role in reducing the energy used by buildings and their related greenhouse gas (GHG) emissions.
Buildings in the EU consume around 50% of final energy usage and are responsible for approximately 36% of all CO2 emissions in the Union, as stated by the EU’s EPBD (Energy Performance of Buildings Directive), with similar values in other parts of the world.
Given that the EU aims to decarbonise its building stock by 2050, an extensive range of green solutions will need to be deployed in order to reduce buildings’ direct and indirect GHG emissions to zero.
The F-gas phase-downs being implemented worldwide following the Kigali Agreement are focused on reducing direct GHG emissions by minimising the consumption of F-gases in various sectors, notably the HVAC/R sector, in which refrigerants are emitted due to leaks from the systems where they are used (end-of-life venting is also a problem, but life-long leakages are much more significant).
Policies such as the EU’s Ecodesign acts are designed to place products on the market with high energy efficiency, so as to perform the tasks they have been designed for, while minimising energy input.
The target for these policies is the reduction of energy consumed, meaning both the electricity generated by power plants and the primary sources directly consumed by the appliances. The consequence is a reduction in indirect GHG emissions, which in fact have a greater impact than direct F-gas emissions, as much as 80% to 2% (the 18% difference is due to direct emissions of N2O, CH4, PFCs, SF6, NF3).
Is this enough to decarbonise? Unfortunately not.
Fossil fuels will have to give way to renewable energy sources (photovoltaic, wind, hydro, others) and energy storage systems (batteries, compressed air, e-hydrogen, e-methane, thermal storage, others).
Renewables are already well-known and can be further used worldwide. The main advantage of renewables, the fact that they do not generate GHGs at the point of use, is unfortunately offset by their inherent instability.
For instance, PV electricity is not generated during the night, wind power is absent when there is no wind, and so on. Therefore, there is a strong need to develop and run energy storage solutions alongside renewable-based power generation systems, as part of the renewable energy produced when available will need to be stored for later use.
All of these green energy generation and storage systems will interact with buildings, vehicles and products, in general, to provide the required services and execute tasks. The interactions will not be free of constraints; on the contrary, they will very likely be controlled by controllers and supervisory IoT systems with different levels of hierarchy, in order to exploit the availability of green energy resources to the greatest possible extent.
Focusing on buildings, BACS will play a crucial role because, based on statistical estimates, they could reduce the energy consumed by 20% to 50% by properly controlling and modulating all of the connected devices (the range is quite wide due to the various types of buildings and world climates).
Please see the image below, which can help better explain the importance of a BACS in saving energy. If we had two identical AHUs serving the same space, the first one (blue) with a control system, part of a larger BACS, capable of simple on/off control of the devices (coils, dampers, etc.), and the second one (red) with a fully modulating controller, the ‘red’ AHU would save around 37% of total primary input energy compared to the ‘blue’ one, simply because the ‘red’ control system could fully exploit the modulation capabilities of the ‘red’ devices:
This shows the importance of BACS for buildings and, by inference, of control and IoT monitoring systems to take full advantage of the integration of diversified resources (renewables, energy storage, buildings, devices of any type) to reach the goals of providing liveable conditions or process set points while minimising (zeroing) GHG-related emissions.
BACS and IoT monitoring systems, however, can do much more. In addition to reducing the energy input of systems and buildings while accomplishing the required goals (a fundamental task per se, of course), they can also inform users of anomalies, or of preventative maintenance ahead of disruptive downtimes, or simply dispatch information and suggestions on how to better use the buildings and their services.
Green integration will mean, in brief, full integration of green energy sources with buildings, vehicles, devices and equipment, in order to do more than we do today while minimising, if not eliminating, GHG emissions.
