Building automation generally has been the automatic centralised control of a building’s heating, ventilation, air conditioning, and lighting systems. While this offers improved convenience and comfort, reduced O&M costs, and decreased energy consumption, it is a limited approach.
As solar energy is reaching greater grid penetration and the cost of batteries decreases, smart energy management and storage are more heavily contributing to advancing building automation.
When integrating smart energy management and storage into a building’s automation process, the level of energy independence increases dramatically. To achieve this, it is important to understand the necessary components and how they interact.
To combine energy sources in an insightful and intelligent manner for storage and building automation purposes, power electronics are needed for two important management functions.
The first is to convert energy from different sources, for instance, from solar panels, battery, and grid, and then allocate the energy according to different uses and needs (consumption, storage, grid feed-in).
The second important function is to provide full visibility into production, consumption, and storage status and their individual requirements in order to properly allocate energy in real time. As the brain of the solar energy system, the inverter is the only component that has all of this information and already contains most of the required electronic hardware.
In terms of the battery, high-voltage DC batteries are seen as the most efficient and cost-effective way to integrate batteries into a PV system.While the quality of the actual battery is important, it is the inverter that is responsible for its functionality.
For instance, you can buy a top-of-the-line guitar, but if you don’t have a knowledgeable musician to play it, then it simply becomes decoration. In a PV plus storage system, the inverter controls when the PV is utilised, stored in a battery, or transferred to the grid, and controls when the battery is charged, idle, or discharged.
To properly function with batteries, inverters need to know how to read and control batteries. This includes having the capability to charge and discharge the battery according to the set profile and monitor its system status. Inverters that offer backup also need to have the capability to operate without the grid.
For example, SolarEdge’s StorEdge solution is programmed to discharge the battery in an optimal manner to meet its programmed goal, such as electric bill reduction, TOU gain, or maximising backup. The inverter is also responsible for increasing system efficiency, simplicity of design and installation, and safety.
There are a number key factors in the relationship between the PV system, inverter, and battery that are important. For instance, the relationship that minimises energy losses is key.
First of all, if one inverter can manage and monitor PV production, consumption, and storage, then this not only reduces CAPEX costs, but it also improves energy efficiency. A DC coupled battery system means that there is no additional conversion from AC to DC and back to AC, and therefore there are no unnecessary energy losses in the conversion process.
Another key relationship between the battery and the inverter, is the ability to provide insight into the battery status. The inverter is the gateway for all communications, such as managing and monitoring PV production, reading the meter, and analysing house consumption habits.
For example, system owners should be able to receive full visibility into battery status, PV production, and self-consumption data through a single monitoring platform. Another advantage is that the monitoring platform can also allow O&M providers to perform remote maintenance.
Once a PV plus storage system is installed to improve building automation, it is possible to take energy management another step forward. With the inverter already in place, more smart energy management can be easily integrated in the building automation strategy.
For instance, the inverter can divert excess PV power to different devices to increase solar energy usage and further decrease electricity bills, improve energy independence, and provide automatic on-the-go device control.
Device control can apply to hot water controllers, different electrical appliances, and heat pumps. For the commercial and industrial space, this smart energy can be applied to cold-storage in warehousing. The inverter can divert excess energy during times of high PV generation for the freezer to reach minimum temperatures, while during low PV generation, it will allow the maximum temperature to be reached.
There are many opportunities to add smart energy management and storage into building automation. As the technology advances, we will continue to see more opportunities to further integrate this into our lives; for example, weather and irradiance forecasting integrated into energy management systems can help ensure more efficient planning of building heating, or personalised profiles and thermostat controls that can help increase comfort without additional resources, as well as many more possibilities.
The key to implementing energy systems into building management is to ensure that the systems are future-ready and can continue to evolve as the technology advances. This will ensure that buildings can continually integrate new forms of automation.
Lior Handelsman is VP of Marketing & Product Strategy and Founder of SolarEdge