Will Decarbonization Work Without Energy Efficiency?
Efficiency First California
California is going through a policy paradigm shift concerning energy efficiency, the goal of saving energy overall taking a back seat to reducing emissions. Assembly Bill 3232 directs the state to reduce greenhouse gas emissions to 40 percent below 1990 levels by 2030.
The direct combustion of fossil fuels in buildings (primarily for space and water heating), accounts for 10 percent of the state’s greenhouse gas emissions, while buildings in general responsible for 25 percent of the total. This means that reducing emissions generated by buildings will be a significant contributor to meeting the state’s greenhouse gas reduction goals.
One obvious move to reduce these emissions is to use the cleanest fuel available, which today is electricity. Increased supply and reduced costs of emissions-free renewables, such as wind and utility-scale solar, are making the electricity supply grid cleaner every day. The percentage of renewable energy on the electric grid is now occasionally surpassing 50 percent, which is far above initial projections and was unthinkable as little as ten years ago.
It stands to reason that as the grid gets greener, we need to shift to electricity as a primary fuel whenever possible. This shift is already happening in the residential energy sector, with statewide incentive programs encouraging the use of heat pump technology for space heating and water heating applications. Induction cooktops are getting a lot of attention too, as they are 60 percent more efficient than electric resistance cooktops and don’t produce harmful combustion byproducts like gas units. Today, many top chefs are embracing and advocating for induction cooking as a preferred choice, regardless of other considerations.
With all of these changes, it’s easy to discount the value of energy efficiency and shift all attention toward the shiny new object of electrification. But while a shift in focus toward emissions reduction and electrification will impact the role energy efficiency plays, the goal of using less is still essential. As we move away from burning fossil fuels in buildings, the impacts on the grid will be significant. If we abandon efficiency and move full bore into electrification, we will need to make substantial upgrades to the electric grid to support the new load. In my opinion, the move towards an all-electric future will actually increase the importance of energy efficiency, as we will depend on targeted savings to offset the new loads that we will be adding to the existing infrastructure.
Just think about what will happen to a neighborhood if overnight all the homes go all-electric and add electric vehicles (EV) as well. Unless you cover all the roofs with solar panels and add storage, the grid impacts and cost will be huge.
The utility will likely need to replace a bunch of feeder wires to the homes, as they will be too small to carry the new loads. Utilities will also need to replace transformers, as they won’t be correctly sized for loads and will likely overheat. Homeowners will need to upgrade service panels, sometimes due to capacity and frequently due to physical limitations in size (not enough room to add more breakers).
Another consideration is the load requirements of EVs. A utility employee told me that the load requirements for a single EV are roughly the same as for an entire home. So now our new electric appliances and EVs in our new all-electric neighborhood have doubled the load on the electrical infrastructure. As long as these increases are met by renewable energy and/or storage the emissions reductions will be significant, but at what cost?
Now let’s revisit the above scenario and add energy efficiency into the equation. First, we start with air sealing and insulation to reduce heating and cooling loads, which allows us to install a smaller system and still provide comfort. Next, we either design a new duct system that is adequately sized to reduce airflow restriction (static pressure) and deep bury the ducts in insulation to prevent conductive losses, or we use a ductless system to eliminate those losses entirely. Then, we step up to variable capacity heating and cooling systems so that we are only providing as much heat or cooling as is needed. We update lighting to LED and perhaps consider a whole house fan to supplement the air conditioning loads. A whole house fan allows you to pre-cool the home by pulling in cool air during the early part of the day. We could also consider window shades or properly planted trees to reduce cooling needs.
Now that we significantly reduced our loads, adding an EV will likely put us right back to where we were before we went all-electric. The existing infrastructure is capable of supplying the energy demands, and to the utility, our home looks the same. Now we can consider adding PV to reduce our impact further.
In other words, if emissions reduction is the goal, I can’t imagine how we are going to get there without addressing waste, which is what energy efficiency does.
Consumer satisfaction is an additional reason we need to be cautious about how we approach electrification. California promoted heat pump space heating in the 1970s, and it was a failure. The technology worked, but contractors were not well educated and just replaced one kind of box with another. In most cases, they did not address the size of the existing ductwork, seal the leaks or change the sizing to improve flow and distribution. This approach was a huge mistake, as heat pumps don’t have loads of extra capacity and therefore need correct sizing and higher quality installation to perform well. The result was poorly performing systems, uncomfortable homeowners, and lots of callbacks. Gas furnaces are pretty easy to install and will work reasonably well even if they are not sized right or installed correctly. Heat pumps require a higher skill level and careful consideration to perform as intended. When installed properly and in conjunction with additional efficiency measures, they are great. If they are hastily thrown in as a replacement, the results are poor. The poor performance of these systems is not a fault of the technology but a result of poor installation.
California has a long history of promoting energy efficiency, and it has served us well. In the late 70s, we added energy to building codes via Title 24. Over the last 40 years, our population has increased significantly, and yet our per capita energy consumption has remained relatively flat. The demand curve for energy is proof that energy efficiency works and energy codes are successful. Some estimates have concluded that adding energy efficiency to building codes in 1978 has curtailed the production of 17-20 power plants in the state. Talk about emissions reductions!
In this new emissions reduction environment, it’s easy to think that converting to electric appliances is the whole solution. It is true that if we want to reduce emissions, using electricity as an energy source makes a ton of sense, but we need to remember that electrification alone will not solve the problem. We need to encourage electrification, promote contractor education to improve the quality of installations, and include efficiency in the equation. I would go so far as to say we need to address efficiency first and then electrification. Efficiency first has a nice ring to it! Maybe we’re on to something.