Smart Decarbonization

Decarbonization is Happening

The rush to a carbon-free future is in full swing. The effort has slowly been gaining traction, and funding from the Biden administration’s Inflation Reduction Act (IRA) will significantly advance the pace.

Energy use in buildings currently relies heavily on fossil fuels, primarily for space heating and making hot water. The good news is that the technology to provide heating and cooling from carbon-free electricity exists today and is often superior to fossil fuel options. Many all-electric buildings exist today. Changes to building codes are requiring new construction projects to be all-electric too. Retrofitting existing structures to be all-electric will be a more complicated challenge but an achievable one. All-electric buildings are the future.

But as we rush toward electrification, it’s critical that we not forget the multiple factors that make a building efficient. Focusing on only electrification without taking other basic but essential steps will make the transition more expensive, less comfortable, and less sustainable than it could be.

Converting a Building to All-Electric is Not Hard 

Most of the energy consumption in buildings is related to thermal loads. The most significant thermal loads are space heating and cooling and making hot water. For decades we have relied on gas furnaces or boilers and natural gas water heaters for thermal loads. The good news is there are electric alternatives, and they are available today.

Electric heat pump space heating has been around for decades, and computer controls have vastly improved the performance and efficiency of the technology. Previous concerns with noise, energy use, and poor cold weather performance are not an issue today. Variable capacity units offer improved comfort and reliably provide heat in cold climates without heat strips. A new breed of low-temperature heat pumps is now available to address the challenge of colder temperatures. These new “cold climate” models use advanced refrigerants and compressor designs, allowing them to produce heat reliably down to -20 F. I think it’s safe to say that the shortcomings of early-generation heat pumps have been addressed with modern technology.

Heat pump water heaters are a comparatively new technology, but they are already the most efficient way to heat water. They, too, are electric and rely on refrigeration to move heat rather than producing heat with flames. Like heat pumps for space heating, heat pump water heaters are safer, as they don’t have open flames or produce toxic emissions.

Electrification Without Performance is Only Half a Solution

While all of this is great, that doesn’t mean electrification is the be-all-end-all solution. This is especially true for existing buildings where improving performance is as vital as what fuel you use.

Let’s compare buildings to automobiles. Fifty years ago, cars were used to take people from one place to another, just like today. Cars today are much better than the ones from the 1960s and 1970s because the automotive industry has focused on improving them over time. Today’s entry-level rental car will outperform many of the legendary muscle cars of the 1960s. Modern vehicles are faster, more comfortable, safer, and get much better fuel economy. As much as I enjoy and appreciate classic cars, I want modern conveniences like power windows, air conditioning, airbags, and decent fuel mileage. I think most people agree.

Buildings still serve the same purpose as in the past, but actual building performance has barely changed compared to cars. Many of us live in homes that don’t perform much better than they did in the 1970s. Houses and buildings built before 1978, when energy codes were added to the building code, are energy hogs, just like the cars of the same era. The difference is that the vehicles have worn out and been replaced by newer, more efficient models.

People buy older homes, spend a ton of money making them pretty, and pay absolutely zero attention to how they perform. Simply electrifying these homes without improving their performance is a missed opportunity. To be truly effective, we must address performance as part of the push for all-electric buildings.

I believe the right solution is to combine efficiency and electrification. It might even make sense to promote “efficiency first” as part of the decarbonization effort.

Fix the Shell First and Everything Benefits

If I were upgrading an older building, I would first concentrate on the building envelope or shell. Improving the building envelope has multiple benefits. The list is extensive: less energy consumption, improved indoor air quality, reduced dust and insects, improved comfort, less temperature differential, and improved resilience. Building envelope improvements bring your building into the modern era. The first step is to find a contractor who provides air sealing and insulation services. Make these upgrades first, and the rest is easy.

Efficient Buildings Can Use Smaller Heating and Cooling Systems

Envelope improvements reduce heating and cooling loads, which means you can provide comfort with smaller heating and cooling systems. Reducing heating and cooling loads before you convert to a heat pump space heater is a great idea, and it’s not incredibly expensive. Insulation and air sealing are not nearly as sexy as a fancy new heat pump or solar panels. If you convert your house to all-electric before you address the building envelope, you are making an expensive mistake.

The first thing a quality contractor will do before installing a new heating and cooling system is size it based on the needs of the building. They do this by performing a “load calculation.” If you size the equipment based on your old leaky building with no insulation and later upgrade your insulation and do some air sealing, the new heating and cooling system will be oversized. That means not only did you pay more than you needed to up front, but your long-term operational costs will be higher than they need to be. Oversized systems can lead to comfort and other issues as well.

Another suggestion would be to consider replacing your older kitchen appliances with new, more efficient models. When it comes to replacing kitchen appliances, change your refrigerator first. Old refrigerators are energy hogs. Inverter technology makes new fridges much more efficient and significantly reduces their noise levels.

An excellent suggestion to anyone starting down the path to decarbonization is to begin with an Energy Audit. Having measured data allows you to address the low-hanging fruit first, maximizing your impact. An energy audit can identify what makes the most sense for your building and are worth every dollar invested.

Once You Are All-Electric, Consider Solar Panels

Once you electrify your home, you might consider adding solar panels. Here again, you’ll benefit from having improved building performance first. A quality solar installer will access your loads to size the solar array. The solar industry makes money by installing larger systems, which is an incentive to install large systems. If you’ve already reduced your load and installed appropriately-sized heating and cooling systems, you won’t need as many solar panels, reducing the cost of your project.

So ideally, you should start with an energy audit. Use the information from the audit to decide which efficiency measures make sense, typically some basic shell improvements. Next, address the most significant loads, heating, and hot water. Then convert to high-efficiency all-electric appliances. Your total electric loads will be less, allowing you to meet your needs with a smaller solar system. Less solar panels equal less cost. Perhaps you can apply the savings from the properly sized solar system to offset the cost of a battery to store the excess solar production.

Efficiency Needs to Be a Part of the Electrification Effort

Efficient buildings with correctly sized heating and cooling systems are more comfortable and have much lower operational costs. An efficient building can use smaller mechanical and solar systems to meet its electrical energy demands. Efficient buildings are more comfortable, more resilient, and safer.

Improving efficiency can also eliminate other costly measures, such as upgrading your electrical service panel. An efficient approach to electrification also provides benefits to the electrical distribution grid. As we electrify buildings, we must consider secondary impacts such as grid infrastructure and adding loads to the grid. High-performance all-electric buildings will place less strain on the electric grid and help reduce peak loads.

We need to be smart about electrification and decarbonization. Work on fundamental improvements to reduce energy needs first, then convert the building to all-electric appliances. If funding allows, produce your energy on-site with solar panels and storage.

At Efficiency First California, we support building electrification and decarbonization. We also believe that you need to consider the building and the multiple interactions of its various systems. Assess the building, as a whole, before making it all-electric. Decarbonization and electric buildings are the future. Let’s be smart about electrification and get it right the first time.

This article originally appeared on the EFCA blog and is reprinted with permission.