Ask the Experts with RMI’s Brett Bridgeland: Resource Efficient Electrification

Published 05/05/2022
By Christian Weeks
enVerid Ask the Experts with Brett Bridgeland of RMI

enVerid Ask the Experts with Brett Bridgeland of RMI

The “Ask the Experts” blog series features conversations with mechanical engineers, architects, IAQ authorities and other built environment thought leaders about their first-hand insights into how to deliver better indoor air quality (IAQ) more energy efficiently and cost effectively. 

In this installment, I catch up with Brett Bridgeland, Manager at RMI, an independent nonprofit organization of experts across disciplines working to accelerate the clean energy transition and improve lives. The mission of RMI (formerly known as Rocky Mountain Institute) is to transform the global energy system to secure a clean, prosperous, zero-carbon future for all.  

In today’s conversation we discuss New York State’s Empire Building Challenge and Resource Efficient Electrification (REE). On Earth Day New York Governor Kathy Hochul unveiled The Empire Building Playbook: An Owner’s Guide to Low Carbon Retrofits – a free online resource to support building owners advancing carbon neutrality in high rise buildings. The Playbook was crafted in partnership with NYSERDA and four leading real estate firms, and REE is featured prominently as a key resource. We thought it would be helpful to learn more from Brett, as the architect of the REE framework.
In addition to our discussion, Brett’s blog post – Decarbonizing Tall Buildings with a New York State of Mind – offers additional context.

CW: You have been working with NYSERDA on their Empire Building Challenge and on a framework to help electrify tall buildings. What is NYSERDA seeking to accomplish with these initiatives?  

BB: New York’s Climate Leadership and Community Protection Act (Climate Act) mandates 100% zero-emissions electricity by 2040 and economy-wide carbon neutrality by 2050. That means that billions of square feet of New York buildings have 28 years to wean off the fossil fuel combustion and fossil-fueled steam that heat the majority of the building stock today and move to 100% building electrification. For many buildings, that translates to roughly one asset replacement cycle, and buildings that simply replace today’s fossil fuel equipment with newer versions of the same will not be in compliance with Climate Act mandates before the equipment reaches the end of its lifetime.  

Against this background, the goal of the Empire Building Challenge (EBC) is to “spur economic growth and renewal in New York by attracting best-in-class manufacturers, solution providers, and entrepreneurs from around the world to help transform our existing building stock into the buildings of the future.” Through demonstration projects, NYSERDA and its EBC partners will reveal what is feasible – both economically and technically – with respect to the decarbonization of tall buildings, with a particular interest in retrofit projects that support decarbonization of heating loads, increase flexibility of a building’s energy demand, and reduce tenant-driven consumption. 

The purpose of the Resource Efficient Electrification (REE) framework is to develop an approach based on lessons learned from over a year of collaboration between EBC real estate partners, their industry-leading consultants, and a NYSERDA team including RMI that can be applied to a wide range of building types, vintages, and systems in New York. Importantly, the REE framework also incorporates the dimension of time, both in the arc of a project – a deep retrofit over time in the age of decarbonization – and in system design, returning to Factor Ten Engineering (10XE) first principles like “meet minimized peak demand; optimize over integrated demand” and “optimize over time and space.” 

CW: Before we get into the REE framework in more detail please share some of the key challenges and lessons learned from your work on the EBC over the past year.  

BB: Decarbonizing tall buildings presents many unique challenges. Even if building owners wanted to simply rip out boilers or disconnect district steam pipes and replace them with the same capacity of air-source heat pumps, it is often not physically or economically feasible to do so. As anyone who has searched for a New York City apartment knows, space is a severely limited resource, and the same goes for spare roof space for additional heating equipment. And even if a building has ample roof space, the heating distribution systems inside the building – whether for steam, air, or high-temperature hot water – may need to be converted to something compatible with the output temperatures from today’s heat pumps. A simple swap to low-efficiency electric resistance heating, meanwhile, would be a step backward in terms of energy affordability and at scale would increase grid loads substantially. 

As I’ve written previously, given the challenges of decarbonizing tall buildings in densely packed cities, it has become clear that traditional approaches – such as building performance audits that aim to tweak but not transform – will likely be insufficient. The solution must involve more than a reactionary mindset or a swap-out of a single component or system. Fortunately, we can do better.  

CW: So how do we do better? Tell us about the Resource Efficient Electrification framework.  

BB: REE addresses many of the challenges I just described by focusing on enabling steps that can be grouped into five categories: Review, Reduce & Reconfigure, Recover & Store, Replace, and Renew/Remove. These categories, and how they can be applied to a wide range of building types, vintages, and systems over time, are illustrated in the following chart.   

The RMI REE Framework for Building Decarbonization

As the chart shows, REE places a big focus on helping buildings transition to electric heat pumps because they are such a big part of the carbon footprint for tall buildings in New York. But it will take a combination of many different technologies and building management practices to implement REE. For example, by switching from economizer cycles that release unwanted heat to the outdoors, we can use heat recovery and redistribute the heat to where it is wanted or store the heat for evenings or mornings warm-ups. This will allow commercial buildings to drastically reduce heating loads, downsize equipment, and even heat themselves for much of the year, which is a key enabler to allow asset managers to replace fossil heat generation with rightsized heat pumps that can economically meet a majority of loads today.  

CW: enVerid has developed Sorbent Ventilation Technology™ to do many of the things you just described including reducing heating and cooling loads and downsizing equipment by cleaning indoor air so that we can maintain good indoor air quality while conditioning less hot/humid and cold outside air. How do you see SVT™ fitting into the REE framework?  

BB: enVerid’s Sorbent Ventilation Technology is another great example of an enabling technology to achieve REE because SVT addresses both the Reduce and Recover steps in the framework by enabling the recovery of conditioned air through air cleaning. This in turn reduces heating and cooling loads and equipment size requirements, which is key to facilitating the transition to electric heat pump systems and other renewable energy systems that become easier to site and less expensive to install and operate when heating and cooling peak demands are reduced.   

To help explain the REE framework, we have created a whole-system, thermal network visual to show how to produce clean heat in cold-climate tall buildings. Sorbent air cleaning is highlighted as a technology that can help with the Reduce and Recover steps. 

How to produce clean heat in cold-climate tall buildingsCW: So REE is the approach to decarbonize tall buildings. Where do we start with what often feels like an overwhelming challenge?  

BB: The good news is that the steps toward REE don’t have to occur concurrently or even sequentially. Sequencing may be dictated by other factors like tenant turnover, investment cycles, repositioning, violations of building performance standards, facade maintenance or other safety considerations, or proactive strategic pilot programming. But the action item for portfolio managers everywhere, with urgency, is to map out an asset investment decision tree of decarbonization pathways to avoid. This is the way to prevent reactionary scrambles and regressive investments. With planning and strategic execution, in 28 years we can find our building stock at its decarbonized destination. 

Click here to learn more about how Sorbent Ventilation Technology can help reduce heating and cooling loads to enable a transition to low carbon building technologies. 

Christian Weeks

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