Updated: Jul 29, 2019
Author: Wei-Tai Kwok, Past President, Sustainable Lafayette
In February 2019, my wife Violet and I attended an East Bay Electrification Expo in Berkeley, CA. We wanted to learn about the benefits and feasibility of renovating our home to remove natural gas and go all-electric. Why? Many who know me know that for the past decade I’ve been trying to explore the ways that I can be part of the solution to the climate crisis, and not part of the problem. Mankind needs to stop burning fossil fuels which are the #1 source of climate disruption and instead keep them in the ground for good.
Thankfully, in September 2018 at his Global Climate Summit in San Francisco, California’s Governor Jerry Brown signed landmark legislation which mandated that all electricity must come from carbon-free sources by 2045. Hooray for being just the second state in the nation to do so (after Hawaii). So California is on a path to all-clean electricity, but what about the other fossil fuels we use in our lives, like natural gas to heat my home and my water, and to cook my food? And the gasoline for my car? How are we going to keep those in the ground?
In the last year I heard the phrase “Building Decarbonization” for the first time, and more and more people in the climate change solutions community have been talking about it. What does that mean? I wanted to learn if it was economically possible to “fully get rid of fossil fuels” in my home without it costing a fortune. I started reading research papers and attending seminars and workshops.
I discovered there are indeed many electric alternatives to natural gas equipment, and the cost has been dropping and the quality has been rising. Specifically, air-source heat pump technology is now one of the most cost and energy efficient ways to heat and cool our homes.
I had looked into a ground-source heat pump system when we built our home in 2004, but my contractor was unfamiliar with the technology and it may not have been cost effective at the time. Frankly, I didn’t even understand what “heat pump” meant or how it even worked at the time, simply that it was a cool technology that was highly energy efficient. I didn’t have time to figure it out then. Fast forward 15 years later, and today heat pump technology is king (at least in Asia it is). I’m finally forced to figure out what a heat pump actually does and I’ll share with you what I learned.
While we Americans may be less familiar with heat pumps, in Asia I realized how popular it is for AC and heating. Over the past decade when I’ve traveled through China, Taiwan, Hong Kong, Philippines, Singapore, Malaysia, it’s a common sight that every bedroom has its own heat pump heating and cooling remote control and minisplit (more on this later), though I didn’t really think much about it at the time.
WHAT IS A HEAT PUMP? HOW DOES IT WORK?
A heat pump *moves* heat, it doesn’t create it. Hmmm… I had to do a double-take on that one. Think about a refrigerator, which is the most common US appliance using heat pumps. The heat pump *moves* heat from inside the fridge to outside, leaving the inside *cooler* and the outside *warmer*. If you’re barefooted standing in front of your fridge, that’s the warm air you feel on your toes being taken out of the fridge. A heat pump can easily switch into reverse mode and move heat from outside a fridge, into the fridge to make it warmer, though of course we don’t do that. But think of your house as the fridge, and the ability of a heat pump to move hot air out of your house in the summer (it’s an AC) and then the ability to move warm air from outside in during the winter (believe it or not there is *warm* air present outside even when its 15-degrees F).
Since the heat pump is “collecting” existing (free) warm air, that’s a whole lot cheaper than having to create the warm air through combustion. Specifically, my “high efficiency” gas furnace which I removed was 90% efficient (converted 90% of gas to heat, and wasted 10% through inefficiencies and losses in the combustion process) whereas the Fujitsu heat pump I replaced it with is 200-300% efficient because the input energy is used to *move* and not *create* warm air. (Heat pump efficiency depends upon the outside temperature…the warmer the weather, the more ‘free’ warm air and thus the more efficient. Note even at 15F, which is never the case in Lafayette, CA, the efficiency would drop from 300% down to 100%, still better than burning natural gas.)
In addition to using heat pumps to replace our AC and gas furnace, it is also cost effective to use heat pump technology to replace my gas water heater (which at 15 years old is coming due for replacement). I'll cover that very interesting topic in a later post.
So back to the residential decarbonization workshop we attended in Berkeley back in February, which featured exhibit booths from several heat pump equipment distributors and installers, and a few speakers including the guru Sean Armstrong from Redwood Energy who was an excellent resource in understanding the state of the art and demystifying how to go all electric with heating, cooling, hot water and even induction cooktops and electric fireplaces as well (watch video or download his presentation).
Violet and I were definitely intrigued and concluded that going electric for our home was completely feasible. The main question then was “How much is this going to cost us for our house?” We needed to get quotes and figure out the health and comfort benefits as well as what would be the return on our investment.
Read my next Blog Post on what happened next: Finding Rebates, Incentives and Contractors.
NOTES: Of the many reports I reviewed, the following two were very well written and influenced my resolve to proceed NOW not LATER:
“Decarbonization of Heating Energy Use in California Buildings” by Synapse Energy Economics, October 2018. A fantastic report summarizing the viability, costs and technology issues around heat pump deployment in California. My net takeaway is that going all-electric with heat pump systems in new home construction makes sense and almost always has a positive Return on Investment. Residential retrofits (like mine) could have positive or negative ROI, depending on a lot of factors.
“The Economics of Electrifying Buildings” by the Rocky Mountain Institute (RMI), 2018. Cost comparisons of going electric in four test cities: Oakland, Houston, Providence and Chicago.