Zero-carbon buildings are possible following these four steps
Written by Clay Nesler, Vice-President, Global Sustainability and Regulatory Affairs, Johnson Controls
With increasing numbers of countries, states, cities and organisations committing to carbon neutrality by mid-century, zero carbon buildings are finally getting the attention they deserve as a critical climate solution. Buildings are responsible for nearly 40% of global greenhouse gas emissions. The good news is that both interest and investment in zero carbon buildings are growing along with the launch of public commitments and global initiatives.
In the 2018 Johnson Controls Energy Efficiency Indicator Study, 50% of 1,900 global organizations in 20 countries plan to have at least one zero carbon (or net zero energy) building over the next 10 years. Additionally, 59% of organizations plan to increase investment in energy efficiency, renewable energy and smart building technology next year. These investments are key to decarbonizing both new and existing buildings.
The design of zero carbon buildings and communities is being driven by four major trends: decarbonisation of the electric power grid; electrification of building space and water heating; efficiency improvements to reduce energy demand; and digitalisation to provide needed flexibility in meeting the needs of building occupants and the energy grid. Efficiency, particularly when enabled by digitalisation at a systems-level (i.e. active efficiency), is critical for dynamic peak demand reduction and affordability. Every dollar spent on energy efficiency returns $3 over time and saves $2 in energy supply investment. Combined, these four good “DEEDs”, decarbonisation, electrification, efficiency and digitalisation, provide a comprehensive pathway for buildings and communities to contribute to a low carbon future.
While zero carbon buildings and communities may seem complex and rare, they are quickly becoming mainstream with the support of global organizations such as Architecture 2030, Global Alliance for Buildings and Construction and the World Green Building Council. While less than 1% of new buildings are constructed to be zero carbon or zero carbon ready today, a number of cities, companies and real estate organizations have already committed to be 100% zero carbon across their portfolio by 2030. Furthermore, zero carbon buildings can be found in every climate zone of the world, as shown in the following examples.
In order to help meet California’s ambitious climate goals, the University of California committed to a goal of 100% renewable energy by 2025. Stanford University, although not part of the state university system, also committed to the goal and proceeded to make investments in energy efficiency in campus buildings, saving up to 50% and an average 24% through whole building retrofits. In order to meet renewable energy targets, the campus added 5 MW rooftop solar and 68 MW at an off-site central solar plant. It then de-commissioned a gas combined heat and power plant and converted the steam heating system to hot water so that 90% of campus heating could be provided by heat recovery chillers in a new central energy facility. An advanced model predictive controller optimizes the use of large chilled and hot water storage tanks using seven day forecasts of thermal load and real-time energy prices. The projected impact is a 68% greenhouse gas reduction, 15% water reduction and $420M in cost savings over 35 years.https://www.youtube.com/embed/h0K3zTIxG2c?enablejsapi=1&wmode=transparent
Similar to California, the University of Hawaii System committed to achieve 100% renewable energy by 2035, 10 years ahead of a 2045 state-wide renewables commitment. Maui College focused on energy efficiency first, resulting in a 45% reduced demand for electricity through new building controls, HVAC (heating, ventilation, and air conditioning) equipment retrofits, cool window films and LED lighting upgrades. The college then installed 2.8 MW solar PV and 13.2 MWh of energy storage, making it the first campus powered by 100% on-site renewable energy in the country. The building energy management system is digitally integrated with the lighting, EV charging, solar PV and battery storage systems and a micro-grid controller provides load shifting and grid stabilization services to the utility. The project, which includes five campuses, will provide $79M savings over 20 years and was financed through an energy savings performance contract, eliminating the need for taxpayer or ratepayer investment.
Moving from a tropical to an extremely hot and dry climate, the new Bee’ah Headquarters under construction in Sharjah, United Arab Emirates has the goal of being the smartest and most sustainable building in the Middle East. The 7,450m2 building, designed by the world-renowned Zaha Hadid Architects, will be 100% powered by 3.23 GWh of on-site solar PV. It is designed to LEED Platinum standards and includes many active and passive energy efficiency measures including dynamic window control, daylight controls, insulated glazing and high efficiency HVAC systems. Data from all building systems are stored in a digital data vault to enable advanced data analytics and machine learning to continuously reduce environmental impact and improve occupant productivity.
One of the most impressive of all current zero carbon buildings is at 63 degrees north latitude in Trondheim, Norway designed by the Powerhouse alliance. The Powerhouse Brattorkaia is energy positive across the entire building life cycle including embodied energy in construction materials and end-of-life deconstruction. It is an eight-story office building with 3,000 m2 of solar PV producing 85,000 kWh annually, which is enough excess electricity to charge 200 EVs. A seawater-source natural refrigerant heat pump provides all cooling and heating for the office as well as some neighbouring buildings through a district energy system.
The building is highly efficient, achieving BREEAM Outstanding green building standard, with air-side heat recovery, a super-insulated envelope, control of thermal mass for heating and cooling and occupant adaptive lighting and ventilation systems. A digitalization strategy called “Smart by Powerhouse” defines five levels of intelligence including Automated; Smart Ready; Smart Standard; Smart Predictive; and Smart Cognitive. All building technical systems (14 total) are connected using a common digital infrastructure which facilitates remote monitoring to optimize energy use and operations across all 25 Powerhouse sites.
These diverse projects from around the world demonstrate that focusing on decarbonisation, electrification, efficiency and digitalisation can deliver zero carbon buildings and communities that are smart, safe, sustainable and affordable.