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Did You Know Your House Has A Tailpipe Too?

Photo by Charley Cormany in Paris, France that inspired this blog post.

Recently, there has been a noticeable shift in California energy efficiency policy. For years the focus has been on the overall reduction in energy use. Today, the goals are much more complicated, with aggressive state mandates specifically targeting greenhouse gas emissions. As a result, when energy savings occur has become a factor, often superseding total consumption. The utilities have responded with time-of-use rates and incentives.

In California, the transportation sector is by far the most significant source of emissions. There is no question that to meet our mandated targets, we need to electrify the transportation sector, and we need to do it soon. Many people have taken this same approach to buildings and other sectors of the economy. If electric cars are great, electric homes and offices can’t be too far behind. While in general, I support the idea of electrifying buildings, I also have some reservations.

Buildings account for 35 to 45 percent of total energy consumption in California, depending on who’s numbers you use. Residential energy use is significant and presents an excellent opportunity to save energy via energy efficiency incentives. However, this doesn’t mean that electrification should be a one-size-fits-all solution.

First off, there are some specific sectors of the economy that currently rely on natural gas and other fossil fuels that will take decades or longer to electrify. It will be difficult, for example, for many chemical, industrial, or maritime industries to go all-electric, at least in the short term. The second concern is cost.

That said, there is absolutely a good case to be made for electrifying as much as possible, especially as the grid gets cleaner. A few decades ago producing electricity was a dirty business. Power plants often relied on coal or fossil fuels to produce steam, which in turn spun generators that made electricity. There were some cleaner options, such as nuclear and hydro, but the bulk of power generated was from dirty sources.

Electricity generation today benefits from a variety of clean alternative energy options, including wind, geothermal, solar thermal, rooftop and utility-scale solar photovoltaic, biogas, and others. The cost of wind turbines has decreased significantly, and the price of rooftop solar continues to decline, encouraging consumers to add more to their homes. It now makes economic sense for utilities to build large scale solar farms and invest in wind generation.

The net result is that the grid today is much cleaner than it was even ten years ago. These days, the amount of emissions-free electricity on the grid can reach fifty percent on certain days and times of year. If our new mandate is to reduce emissions, shifting as much load as possible to electricity makes a lot of sense.

There are other reasons to consider switching our homes and building to all-electric solutions. You might not think about it, but our houses have tailpipes too, just like cars. Some are obvious– look at an older building and count the number of chimneys. When we heated with wood, fireplace chimneys were the tailpipe.

Today it’s not as obvious, but I guarantee you the majority of us live in buildings that are spewing emissions all day long.

Vent stacks on our roofs now replace chimneys. These vent stacks are typically attached to an appliance that is burning something to make heat. Look at a cold roof on a winter day and you’ll see large round pipes that have no frost on them. These are exhaust vents and they don’t have frost because they are hot, as heat is a by-product of incomplete combustion. The majority of residential emissions come from thermal loads, specifically the heating of the space itself and heat to produce hot water.

Burning things to heat water or our homes means houses dump all kinds of combustion byproducts into the air every day. The problem is most of these byproducts you can’t see, and very few of us take the time to consider their impact.

Efficiency definitively helps. Gas furnaces can achieve up to 98 percent efficiency that’s pretty good. But in addition to taking advantage of much cleaner sources of power, most electrical appliances are more efficient than conventional natural gas counterparts. Electric heat pumps can do the same task and offer efficiency ratings of 300 percent or more. Gas water heaters are typically 65 to 80 percent efficient. Electric heat pump water heaters are in the range of 300 to 500 percent efficient.

Moving to electric appliances has significant safety benefits too. With no flame, heat pumps produce no combustion by-products or toxic fumes. I believe we would all be better off if we were to remove all combustion appliances from residential applications. If we removed combustion from our homes, there would be no deaths from carbon monoxide poisoning and no adverse health effects from ingesting combustion by-products in homes. Electric-only residential options are safer, more efficient, and use energy from a cleaner source. That is something I can stand behind and support, so as regards to residential energy consumption, I would encourage you to electrify as much as you can.

So why do I hesitate on the general goal of electrifying everything immediately? I think we need to be realistic and recognize that there are several situations where it will be difficult if not impossible to replace the properties provided by an open flame.

To meet the state’s goals and ensure a future for our children, instead of adopting a blanket “electrify everything” approach, we need a “make everything more efficient and electrify when you can” strategy. Prioritize residential electrification, especially for new construction, where you can save huge infrastructure costs by not laying gas lines, to begin with. Move toward electrifying older buildings whenever it’s feasible and affordable. When it’s not, focus on performance upgrades to make the buildings as efficient as possible. The task at hand is daunting, and we need to address it from all perspectives, including more efficient use of natural gas and other less desirable options.

Fortunately, in residential applications, there are a wide variety of electric solutions that make sense, both from a societal and financial perspective. The critical thing to remember is next time you use hot water or turn your heat on is your house has a tailpipe. GHG emissions are a by-product of combustion when you burn something. Perhaps it’s time to consider making your home or building all-electric and take advantage of this clean, safe, reduced emissions option.

Charles Cormany
Executive Director
Efficiency First California