Alexis Abramson’s First Love is a study of calories – how to use it, protect it and eliminate waste.
“Everyone is connected to heat in some way,” said Abramson, dean of the Columbia University School of Climate. “But heat is the black sheep of the energy family.” We need heat for obvious reasons, but when we use other forms of energy, such as electricity, we usually want to minimize waste — meaning we don’t want it to be converted to heat unnecessarily.
In addition to serving as the dean of the climate school, Abramson is also an energy efficiency expert, specializing in upgrading and transformation. Under the Obama administration, Abramson is the chief scientist in the Office of Building Technology, so he has personally experienced all aspects of research, development, and deployment around energy-efficient buildings.
Prior to coming to Columbia, Abramson was the dean of engineering at Dartmouth College and then led the Institute for Energy before working as a professor of engineering at Case Western Reserve University. In the following Q&A, Abramson discusses how she is about energy efficiency, how heat pumps work, and how homeowners take some simple steps to minimize their carbon footprint and energy bills. (Click here to get an animation for home energy efficiency.)
What inspired your interest in energy efficiency?
I have always loved the clarity and logic of mathematics and science. I decided to study mechanical engineering as an undergraduate and it was related to the concept of heat. We learned the basic science about heat transfer and thermodynamics, two themes I grew up in love. Everyone needs calories, right? We are always adjusting the environment to keep it comfortable, whether it is heating or cooling the house or preparing meals.
This led me to the path of doing research on heat, manipulation of thermal properties and materials and trying to see if we can use waste heat and convert it into electricity, a region called thermoelectricity. After a few years of slow progress, I decided that I wanted to focus on more practical applications, which brought me into buildings and building efficiency – we are still very struggling.
Can you talk about energy and buildings? Why is renovating a building so important?
There are major reasons to make buildings cleaner and greener: Save money and contribute to reducing emissions and resilience. For example, residential solar power directly provides clean electricity to your home. If your power supply goes out, as long as your solar system is properly set up, you can use the power when your neighbors are out of service.
It can also promote electrification of everything in the building, so once the grid is 100% green or close to it, everything we run in the house with electricity is green and clean. If your goal is to minimize carbon, you don’t even need solar panels as you will be able to get 100% green power from the grid.
I think it’s important to think about how to prepare for the future and a greener, cleaner world.
Let’s move to some steps homeowners can take to reduce carbon emissions. Solar energy seems to be on the list.
If I could pay upfront to put solar energy on the roof, solar panels could be invested in almost all parts of the United States, which is free to me, and most homes have a return on investment for less than 12 years. Solar panels usually last between 20 and 25 years, so for eight years or more, electricity is indeed free. The problem is usually that upfront capital costs are considerable, but in many parts of the country, green financing or clean energy programs are available so that more people can access the technology.
Another topic that often comes up when talking about energy efficiency: heat pumps. What are they and how do they work?
Heat pumps are my favorite topic. “Heat pumps” are a general category for heating and cooling, and when it sounds like a heat pump moves heat from one place to another. Your air conditioning system is a heat pump, and so is the refrigerator. Essentially, your refrigerator is taking heat from the inside and pushing the back of the refrigerator into the kitchen. The same goes for air conditioning – that’s why you need an external unit as you need to move the heat from the inside of the house to the outside.
The heat pump runs on the refrigerant. These refrigerants absorb and release heat as they circulate at different pressures and temperatures. For example, if air at 30 degrees Fahrenheit flows through a refrigerant of 10 degrees F, the refrigerant absorbs heat. This is a clever application of thermodynamics.
Can they work in really cold climates?
Absolutely. Even at -10 degrees Celsius, you can design a system with refrigerant below that temperature to extract heat. It’s a bit complicated, but manufacturers are using air conditioning pumps to make major improvements. There are different settings – central piping systems or tubeless mini slices, which are common in Europe. I have a mini split in my own home. They allow for heating and cooling division and are connected to a single outdoor condenser unit.
How about the reverse? If you want to cool your home instead of warming it?
This is the same principle. You can take heat pumps for cooling and run them the other way around and use them for heating. You take it out of the cold outside air and push it into the interior of the house. For example, if your indoor air is 80 degrees F and the refrigerant is 50 degrees F, the refrigerant absorbs heat and drains it out. You’re just reversing the calories.
What about water and electricity? Can it be used by individuals?
Hydropower makes the most sense if you live in rural areas and near a running river. Otherwise, it is usually not cost-effective for a home. But on the utility scale, it plays a big role – considering large projects like Hydro-Québec.
What are the cost-effective improvements that every homeowner should consider?
insulation. Most homes in the United States are poorly insulated. People often upgrade their HVAC systems without realizing that well-insulated homes require less heating and cooling capacity first.
Better isolation of a home can be relatively simple or very complex. But something as simple as going to a hardware store, pulling some pink insulation and pushing it to the loft and crawling space can make a big difference.
The biggest cost of energy in most parts of the country is heating, not cooling, contrary to popular belief. Most of the heat escapes from the roof of your home. Stop heat loss is one way to cut your energy bills.
How much money can you save by implementing these changes?
Some basic changes can really save you money. Research shows that your energy bills average about 30%, although it varies greatly. Some homes may save 10%, while others are as high as 70%. In winter, those who save may be considerable.
But some upgrades are very expensive.
Yes, the upfront cost of installing solar panels, heat pumps or new windows can be expensive. But many states and territories have discount plans or green financing plans. Utilities usually have green financing plans as well. For example, they might pay for the upfront fee of the heat pump and let you pay it over time through your utility bill, just like a car loan.
New York City, for example, offers kickbacks for turning stoves. And solar power purchase agreements (PPAs) allow homeowners to pay any advance payments and lock in lower electricity prices. Then after about 12 years, the homeowner has solar panels and then free electricity.
Then there is the Inflation Reduction Act passed during Biden’s administration. While some elements are retreating, it still offers many discounts and tax credits for energy-efficient home improvements. It is especially suitable for low-income households and helps ensure fair use of clean energy technologies.
