Using Electrification and Automation to Create More Efficient and Sustainable Power Grids – Part Two of Two

Replacing traditional power grid energy sources with sustainable, green ones is called electrification. In Part 1 of this series, some of the challenges associated with electrification were discussed along with how automation can aid in its efficiency and sustainability. This article, Part 2 of 2, will discuss leadership in energy and environmental design (LEED) and zero energy building (ZEB) certifications and how they can reduce carbon emissions and improve sustainability.

Leadership in energy and environmental design (LEED) and zero energy building (ZEB) certifications represent significant efforts supporting society’s desire to reduce carbon emissions and improve sustainability. Achieving LEED and ZEB certifications requires a holistic approach that combines electrification that replaces fossil fuels-based energy systems with green alternatives like photovoltaics (PV) and electric vehicles (EVs) with advanced automation and control systems.

The LEED program from the U.S. Green Building Council (USGBC) includes decarbonizing existing buildings and new construction. ZEB efforts are coordinated by the Energy Efficiency and Renewable Energy (EERE) office of the US Department of Energy. Achievement of LEED and ZEB certifications requires architects and contractors to take new approaches to how buildings are designed, built, and operated. Compared with ZEB, which focuses solely on energy consumption, LEED is a more expansive concept that addresses carbon, energy, water, waste, transportation, materials, health, and indoor environmental quality.

This second of a two-article series on electrification and sustainability begins by looking at the LEED and ZEB certification levels and what it takes to get those certifications for commercial and industrial buildings, including a comparison of several definitions of a ZEB. It then details an example of how Phoenix Contact used automation and on-site PV electricity generation to achieve LEED Silver and ZEB certification for a 70,000-square-foot addition on its main campus, including how some of the company’s own products contributed to the success of the project (Figure 1). It closes with a glance at how LEED buildings can contribute to the United Nations’ Sustainable Development Goals.

Figure 1: Rooftop PV generation was a key factor enabling this Phoenix Contact facility to achieve LEED Silver and ZEB certifications. (Image source: Phoenix Contact)

LEED is holistic

LEED is a comprehensive system that factors in all elements needed to create high-performance buildings. LEED certifications are based on credits or points awarded to a project using detailed performance criteria. The performance categories and their relative importance (from most- to least important) are¹:

• Reduce contribution to global climate change.
• Enhance individual human health.
• Protect and restore water resources.
• Protect and enhance biodiversity and ecosystem services.
• Promote sustainable and regenerative material cycles.
• Enhance community quality of life.

The most essential criteria, reducing contribution to global climate change, accounts for 35% of all points. The levels of LEED certifications include Certified (40-49 points), Silver (50-59 points), Gold (60-79 points), and Platinum (80+ points).

In the newest version of LEED, v4.1, most points are related to operational and embodied carbon. Operational carbon is the carbon dioxide (CO₂) emissions generated by heating, ventilation and air conditioning (HVAC), lighting, and other energy-consuming building systems. Embodied carbon are emissions associated with the production of building materials and building construction processes throughout the whole lifecycle of a building.

LEED certification is important for the creation of a greener society. Buildings account for 39% of global CO₂ emissions, with 28% from building operations and 11% from embodied emissions (Figure 2). Since the buildings sector is the most significant contributor to global CO₂ emissions, special programs have also been developed to encourage the development of zero energy buildings.

Figure 2: Building operations plus materials and construction are major contributors to global CO₂ production. (Image source: new buildings institute)

Defining zero

Zero energy seems like a straightforward concept, but it has several definitions. The three most cited are the LEED Zero Energy program, International Living Future Institute (ILFI) Zero Energy, and the Zero Code Renewable Energy Procurement Framework (Zero Code) — an initiative of the Architecture 2030 organization that has been adopted as a California building energy standard. There are significant differences in how “zero” is defined.

To achieve LEED Zero Energy certification, a building must have an energy balance of zero for 12 months, including on-site generation and externally generated (sourced) energy. On-site fossil fuel combustion is not prohibited. The total energy consumption must consist of on-site or externally generated renewable energy or carbon offsets.

ILFI Zero Energy Certification is the most restrictive standard. It requires on-site renewable sources to supply 100% of the building’s energy needs. No combustion is allowed, and certification is based on actual performance; modeling is not allowed.

Zero Code specifically targets new commercial, institutional, and mid-to high-rise residential buildings. It defines a zero-carbon building as one that uses no on-site fossil fuels and produces on-site or procures enough of carbon-free renewable energy or carbon credits to meet building operational energy needs. Zero Code also requires that buildings meet the ASHRAE Standard 90.1-2019 for building efficiency. Zero Code allows the substitution of other energy efficiency standards if they result in equal or greater energy efficiency.

LEEDing by example

Phoenix Contact recently installed a 961-kilowatt (kW) PV system on the roof of the logistics center on the company’s main US campus. The system generates enough power to satisfy about 30% of the facility’s energy needs, or the equivalent energy consumption of about 160 homes per year. The building earned LEED Silver and Zero Energy certifications.

The on-site, natural gas-fired 1 MW microturbine cogeneration system was integrated with the PV system. The central energy control system monitors the PV plant’s output and the building’s energy consumption in real time. The microturbine generator is used when overall energy demand exceeds the PV system’s output. There are times when the PV system and the microturbine are used together to provide electricity to the grid through net metering, generating income for the company.

The system was designed to reduce natural gas consumption during daylight hours and run the microturbine generator mostly at night, maximizing overall energy efficiency and minimizing overall CO₂ generation. On some days, it’s possible to reduce natural gas consumption to almost zero. Some statistics of the PV system include:

• 2,185 solar panels
• 1,214,235 kWh generated annually
• 1,939,279 pounds of CO₂ footprint reduction

Continuous monitoring and control of individual PV system segments in large installations like this one is necessary to achieve maximum efficiency and availability of power production.

Automation needs actionable information

Effective automation and control for electrification systems like PV installations requires extensive and actionable information. Real-time monitoring of each string of PV panels maximizes production and supports preventative maintenance. If a string goes down unexpectedly, it could lose thousands of kW of power with corresponding monetary losses.

The 961 kW PV system at Phoenix Contact’s main US campus includes twelve inverters with six strings of PV panels feeding each inverter, and it incorporates several of the company’s products, starting with second-generation EMpro energy meters like the panel mount 2908286. These meters are designed to measure and transmit key energy parameters to cloud-based platforms that support remote monitoring of all the system elements. EMpro energy meters are available for various power system designs, including one-, two- and three-phase installations and configurations. The system monitors numerous system elements and operational conditions in real-time, including:

• Inverters are individually monitored for DC input power, AC output power, active and reactive power, faults, and operational status.
• Each PV string is monitored for current and voltage output. That data is evaluated to determine string health and possible maintenance needs.
• Panel temperatures are monitored with numerous sensors spread throughout the installation.
• Weather conditions like wind speed and direction, temperature, relative humidity, and air pressure are collected.
• Solar irradiance is measured with two pyranometers, one at a 10-degree angle matching the installed angle of the panels and one installed horizontally.
• Soiling sensors measure the light loss caused by dust and dirt on the surface of the PV panels.
• Cameras provide security monitoring of the system.

The system also needs data loggers and interfaces. For example, the company’s Radioline wireless modules, like the model 2901541, communicate wirelessly with PV module temperature and soiling sensors using the RS-485 protocol without cables. In other cases, power over Ethernet (PoE) is used to transmit power and data at the same time. Intrusion protection can be provided by FL mGuard 1000 Series Security Routers, like the model 1153079, that provide firewall security and user management.

Tying it all together takes a controller like the DIN-rail mount model 1069208 from Phoenix Contact based on the company’s PLCnext Technology (Figure 3). When paired with an input/output (I/O) module like the model 2702783, the controller aggregates data from the sensor network and transmits it to a cloud service provider. In addition, an industrial PC runs Phoenix Contact’s Solarworx software. The included software tools and libraries support communication protocols and standards the solar industry adopts. The system enables customized automation and visualization of PV system operation, and it’s compatible with third-party software packages that can analyze historical and real-time data for performance optimization. The libraries include functional blocks that meet the requirements of IEC 61131 standard for programmable controllers.

Figure 3: DIN-rail mount controller suitable for large-scale PV generation systems.  (Image source: Phoenix Contact)

Feed-in control is the final piece of the electrification puzzle for integrating distributed energy resources (DERs) like PV arrays with the power grid. PGS controllers from Phoenix Contact can monitor the voltage and reactive power levels at grid connection points and determine the required control values for the inverters to support feed-in management of power into medium- and high-voltage grids.

LEED and sustainable development

The United Nations (UN) has identified 17 Sustainable Development Goals² (SDGs) intended to end global poverty by 2030. According to the USGBC, the electrification and automation inherent in LEED buildings can contribute toward meeting 11 of the 17 SDGs, including:

Goal 3: Good health and well-being

Goal 6: Clean water and sanitation

Goal 7: Affordable and clean energy

Goal 8: Promote sustained, inclusive, and sustainable economic growth, full and productive employment, and decent work for all

Goal 9: Build resilient infrastructure, promote inclusive and sustainable industrialization, and foster innovation

Goal 10: Reduce inequality within and among countries

Goal 11: Sustainable cities and communities

Goal 12: Responsible consumption and production

Goal 13: Climate action

Goal 15: Protect, restore, and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation andbiodiversity loss

Goal 17: Strengthen the means of implementation and revitalize the Global Partnership for Sustainable Development

Corporate strategies can also contribute to a more sustainable society. For example, Phoenix Contact’s gaining LEED Silver and Zero Energy certifications for its logistics center for the Americas was one part of the company’s initial goal to achieve carbon neutrality at all of its worldwide locations. The company’s next target is to create an entirely climate-neutral value-added chain before 2030.

Conclusion

The building sector is the most significant contributor to global CO₂ production. LEED and ZEB certifications are important tools for measuring the success of using electrification and automation to create more efficient and sustainable buildings. As shown, large-scale PV generation installations integrated with on-site cogeneration capacity can contribute to a greener society. LEED-certified buildings also support achievement of the UN’s seventeen SDGs and the goal of eliminating global poverty by 2030.

References:

1. LEED rating system, Green Building Council
2. Sustainable Development Goals, United Nations