Tuesday, March 7, 2023

Home Heating in the U.S. – Electrification Has Limitations and Hydrocarbons Have Some Advantages

 

     This post is in commentary to a recent Washington Post article – America’s great home heating divide, visualized. The article shows home heating sources in detail on a map of the U.S. and how they vary by region. There are several reasons for these variations. The sources of home heating are natural gas, electricity, propane (or more accurately LP gas), home heating oil, and wood. I have used all these sources for home heating at one time or another with the exception of home heating oil, although when I moved into one house there was an oil furnace there. However, we decided not to use it and sold it, using a second wood burner instead. After a year of heating with wood and one chimney fire, we installed LP gas piping and unvented heaters and later only occasionally supplemented with wood in the fall and spring. The LP gas under this setup works great and is entirely immune to power outages, which are more common out here in the “boonies.” In the next place I heat with an air-source heat pump. The cost savings are significant and great but when the power is out there is no heat and when it gets very cold, below 10-15 deg F, it does not perform adequately and must be supplemented with another electric heater and/or a small propane heater. The air conditioning costs are very low and quite satisfactory.

     The graph below is perhaps a bit misleading since it suggests that electric heat may be more widespread. However, the second graph below shows that natural gas is the dominant heating source by far. If one adds all the hydrocarbons together: natural gas, propane, and heating oil, then hydrocarbons, or fossil fuels, make up 56% of U.S. home heating vs. 40% for electricity. If one then considers that natural gas, coal, and oil make up about 61% of U.S. electricity grid power, then one might say that fossil fuels are really responsible for about 80.4% of home heating, with natural gas alone making up about 62.2%. I mention this since the Washington Post article talks about shifting away from fossil fuels, presumably to electricity, which is currently 61% fossil fuels.   




Prevailing Home Heating Sources: Red = home heating oil. Purple = natural gas. Light blue = propane. Gold = electricity. Brown = wood. (The map is interactive in the article and can be zoomed to see different areas in more detail). Source: America’s great home heating divide, visualized. John Muyskens, Shannon Osaka, and Naema Ahmed. Washington Post. March 6, 2023. How Americans heat their homes, from electric heat pump to natural gas - Washington Post





Energy sources of U.S. Home Heating. Source: 2017-2021 American Community Survey.

 

     Electrification makes sense in some areas and situations, less in others. In the U.S. Southeast where winter temperatures are generally mild, electric heat has long been favored. Cold snaps do happen, but typically electric heat is enough to take care of them. However, even there during the cold snap of late December 2022 the grid was stressed and rolling outages had to be implemented in the territories of Duke Energy and Tennessee Valley Authority. That suggests that even there where winter demand is generally lowest, the current grid is not adequately prepared to handle extreme cold snaps. In Texas, with the cold snap of 2020 one might argue that the natural gas system was ill-prepared, and while that is true, if that increased demand had to be met with electricity alone the situation would have been magnitudes worse. The problem there is that the natural gas system is not adequately weatherized. Electrification does make sense economically in the U.S. Northeast where expensive, polluting, and high carbon emissions home heating oil is a major source of home heating. However, it can be too cold for heat pumps so some of the cost advantage is lost by needing a backup heat source in cold events. In some areas heat pumps may be a good choice for replacing propane heat which is a little bit more expensive than natural gas.

     With ambitious pledges and mandates for lowering carbon emissions the push to electrify home heating, building heating, and transportation could result in significant increases in electricity demand. The U.S. Northeast in New England currently powers 46% of the grid with natural gas and 11% with renewables. According to decarbonization plans they want to change that by 2040 to 12% natural gas and 56% renewables. That is a very tall order. In addition to this switch, it is expected that some nuclear, coal, oil, and hydro plants will be retired. Also, in addition will be the increased demand from electrified heating and transport. Thus far, offshore wind, the main hope for the switch, is behind schedule. In New England as of the end of 2021, about 39% of home heating was from natural gas, about 33% from heating oil, about 16% from electricity, about 8% from propane, and about 3% from wood. ISO-New England predicts that by 2031, a little less than 8 years from now, the shift to heat pumps will increase demand from 68MW currently to 1899MW. The predicted demand increase from EVs is from 38MW to 1535MW. In total from those two sources the change is expected to go from 106MW to 3434MW, or 3328MW in new demand. The New England grid is already stressed. Winter reliability has been achieved for several years now by burning oil in power plants (often triggering air quality alerts), by importing expensive LNG (often on the spot market from foreign sources due to nonsensical Jones Act requirements), and by paying a lot more for the natural gas that does come by pipeline. The result is very high electricity costs, especially in the winter. If cold snaps would come that are colder and longer the grid may not be able to handle them. This is a problem in other areas as well, but accelerating electrification will no doubt exacerbate the problem. With an increase of intermittent sources on the grid the reliability will be stressed even further. Just to integrate the planned increases the grid will need to be upgraded significantly, which is a slow and cumbersome process. The reality is that those natural gas plants will likely remain operational as the renewables are increased, just less utilized. That will make the natural gas generation necessarily less efficient, more carbon intense, and more expensive to operate and maintain.   

     The WaPo article also mentions the irony of the states that have high natural gas home heating being the ones advocating for natural gas bans in new homes and buildings. The non-profit advocacy group Rewiring America is advocating for natural gas bans and for heat pumps to replace fuel oil and propane, although I have read recently that their leaders have started quite a few well-funded for-profit companies to be aided by those pushes and by the IRA. The IRA does have tax credit provisions to help with heat pump installation. I will note, however, that I saved a few thousand dollars, by using a contractor that was qualified with heat pumps but not certified under the federal program available at the time in 2018. My installation was significantly cheaper than it would have been with the other installers even with the rebates at that time. I am not sure if this is still the case but even with tax credits the upfront costs can price many would-be switchers out of the market. Another issue of some concern is the lifetime of an air source heat pump (I was told 12-15 years and I’m hoping longer) vs. the lifetime of another type of electric furnace, a natural gas, or a propane furnace, which can exceed 30 years in some cases. I do like its low operating cost compared to the previous electric furnace, especially the low-cost A/C, as well as its lower noise.    

 

References

America’s great home heating divide, visualized. John Muyskens, Shannon Osaka, and Naema Ahmed. Washington Post. March 6, 2023. How Americans heat their homes, from electric heat pump to natural gas - Washington Post

The Heat Is On - Is New England Headed For An Electricity Supply Crisis? Housely Carr. March 6, 2023. RBN Energy.  The Heat Is On - Is New England Headed for an Electricity Supply Crisis? | RBN Energy

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