Aging buildings presents an interesting challenge from a decarbonization perspective. While new construction can include efficiency as a key target within the design phase, it’s expensive to entirely retrofit existing buildings to modern efficiency standards through structural changes. Yet, electrification strategies are far less effective for cost savings benefits without a highly efficient building as a backdrop.
Instead of starting with the building, energy managers in existing building infrastructure may want to start by addressing how they use a building rather than what equipment they use. Operational energy efficiency strategies can lower carbon emissions immediately for buildings in use at a far lower cost. All of these changes must be viewed in relation to the sources of energy used within buildings.
Renewables are on the rise: can older buildings benefit?
Increases in renewable energy across the U.S. are bringing cleaner power to building owners. In 2023, 21% of all electricity generated came from renewable sources. Utilities have invested more in utility-scale renewables and battery storage, taking advantage of available incentives and improving access to clean power.
This is great news, but accessing this clean energy and decarbonizing a building requires electrification. One of the most popular approaches is swapping out gas or coal-powered heating sources with heat pumps. For older buildings in use, that’s easier said than done.
An average heat pump only achieves cost savings in buildings with a good, if not excellent, level of insulation. Unfortunately, many older buildings weren’t designed with efficiency in mind. A study of energy costs in single-family homes after heat pump upgrades showed that minimum-efficiency equipment actually increased heating costs in 39% of homes. This number lowered to 19% if insulation was included in the project and 5% when using high-efficiency equipment.
Insulation retrofits can be expensive, though the cost range is significant depending on the style of upgrade. Weatherization by filling air leaks and sealing doorways and windows, for instance, costs much less than a full envelope upgrade.
Another issue in older buildings with radiators is their pipes require high supply temperatures, while heat pumps require low supply temperatures. Adjusting systems to accommodate this change can lead to additional structural adjustments to the size of pipes in use and even removing radiators altogether. In other words, heat pump installation can require significant structural changes and construction in older buildings.
Finally, projects to upgrade HVAC equipment can be disruptive to buildings that are in-use. For buildings like multi-family buildings filled with tenants or other busy commercial spaces, pausing usage for an upgrade simultaneously pauses a building’s ability to generate income.
What other options are there?
It’s essential to consider different options for decarbonizing older buildings. Some strategies may not deliver net zero emissions in the long-term, but they can still lower emissions today at a lower cost, allowing older building owners to get started.
Optimizing behavior-driven emissions, for instance, is a low-cost strategy that combines data analytics and automation to lower emissions. Whereas other approaches focus on emissions-lowering swaps, this approach gamifies your building systems to use as little energy as possible to achieve the same goals.
Data collection can reveal interesting patterns that you may not have realized are driving up energy use and costs. For instance, leaving open windows and doorways produces air leaks that could be minimized. Equipment may produce usable excess heat that can be ventilated to other spaces. Recirculating heat with automated ceiling fans can drive heat back toward occupants who benefit from it. Timing intensive energy load requirements to minimize overloading grids during peak times can lower overall energy costs in areas with peak pricing schemes.
These are just a few ways to look at energy from a more analytical perspective, combining the goals of use with realistic decarbonization targets available today.
How to get started using data collection
Energy-based data management requires a platform where you can store all of your energy-related information. Rather than making this an added energy cost, you can choose a cloud-based platform that can be accessed from any location such as Atrius Energy.
After this, the next step is to conduct an energy audit. When it comes to in-use building emissions and inefficiencies, an energy audit helps to identify how and why energy is consumed in your building. This includes an inventory of all of your energy-consuming equipment and fixtures (lighting, water heating, HVAC, appliances, machinery, and systems). Next, you’ll identify where all of your energy meters are and decide whether the coverage is detailed enough for your energy analysis or if you’d benefit from installing sub-meters to gain more granular detail of area-to-area consumption. You’ll analyze spaces according to when, how, and why they are used. A final step can further analyze how air leaks and temperature loss occur in the building to identify structural weaknesses. This assessment can guide your understanding of where and when the most energy is spent (or lost) and for what purpose.
Once you have completed an energy audit, baselining energy use annually is the next improvement step. A baseline of your emissions provides an internal benchmark against which you can track progress and set targets. In addition, your baseline can help you understand how your building’s emissions compare with others of a comparable size or operations. Then, you can develop a plan to incrementally lower emissions in line with your strategy and goals.
Data analysis is key to both an energy audit and baselining energy use, so storing your data in a centralized platform where you can easily access and assess changes helps to strengthen an energy efficiency strategy for in-use buildings.
Strategies to automate your building and lower carbon emissions
IoT & connected sensors, meters, and appliances provide building data that can inform a responsive strategy. When all of the systems are connected in a central building energy management hub, building managers can adjust settings, trigger automatic shut-offs with motion sensors, sense occupancy to trigger temperature control changes, and schedule the coordinated use of systems and equipment in a way that optimizes their energy.
With all of the data collected from two-way connected devices, predictive analytics using AI and machine learning in a central building management system estimate energy demand and shave off unnecessary energy usage based on occupancy.
Quick energy efficiency wins are available today
Shifting towards a digital approach to building energy management is a lower-cost approach to decarbonization, offering quick wins, especially in older buildings where extensive retrofits are more costly. The International Energy Agency (IEA) calls energy efficiency the “first fuel” in clean energy transitions because of its quick, cost-effective emissions reduction opportunities. It also lowers energy bills and strengthens energy security by avoiding unnecessary energy demand.
Digitization is an essential feature of a clean power future
In addition, digitization, which facilitates energy efficiency, is an important stepping stone to prepare for future energy systems and power grids. As more and more buildings and companies prioritize the electrification of their operations, balancing the grid becomes a more complex challenge for utilities.
As a result, new energy systems that combine battery storage, on-site renewable energy generation and two-way, decentralized energy transmission lines have resulted in the need for detailed coordination for all of the moving parts. This is where digitization can play a key role, to provide demand response and balance supply and demand. Boston Consulting Group suggests that as we move towards this clean energy future, CEOs should start to think more like energy traders to “minimize costs and maximize utilization.”
Setting up digital resources to control and manage your building’s energy today gives you the data intelligence to build out more decarbonization strategies over time.
Decarbonization strategies don’t happen overnight
While deep energy transformations are driven by policy and the urgent need to address the climate crisis, it’s essential to keep a long-term view towards the future. Putting the building blocks in place now, and making quick win reductions makes sense for certain building asset types. This doesn’t mean the choice to focus on energy efficiency is mutually exclusive from other strategies in the future. Equipment upgrades, adding renewable energy resources or other decarbonization strategies may all become part of your strategy when they’re feasible.
A building owner can always apply multiple strategies in tandem to achieve the highest cost and energy savings over time. The important part is to have the data infrastructure in place to track and manage your energy data and derive energy insights, including CO2 emissions measurements, in a user-friendly way.
