If electricity was the cheapest way to heat buildings, we wouldn’t need to ban gas and force people to go all-electric.They will do so willingly.But schools, churches, large office buildings, concert halls, libraries, sports fields, hospitals, laboratories and similar buildings always use natural gas (if available).
Before passing a ban, we should consider the extent to which it may hinder the development of quality commercial and institutional buildings.
For clues, see Eugene’s 2017 Facility Greenhouse Emissions Reduction Analysis prepared by SOLARC Energy Group.Section 3.5 recommends adding air-to-water heat pumps as the primary heat source for the airport terminal, downtown library, Hult Center, atrium, fire station 1 and police/fire training building.Table 16 shows that the estimated cost of library renovations alone in 2017 was $1,479,400.This suggests that electrification of heating systems in large buildings increases construction costs.
The second point is that SOLARC proposes to add heat pumps rather than replace existing natural gas boilers.Here’s a direct quote from the report: “The existing natural gas boiler will remain and act as a backup heat source.”
In the proposed scenario, the buildings would be powered by a hybrid heating system instead of 100% electricity.
The problem with 100% electric buildings is the nature of the air source heat pump, which draws heat from the outside air.In mild weather, they generate heat very efficiently.But as the outside temperature drops and the building needs more heat, the heat pump provides less heat.Therefore, some type of auxiliary heat is required.If the building is 100% electric, then the auxiliary heat is resistive heat, which is notoriously inefficient.It is the same efficiency as electric ceiling heating or baseboard heating.
If we insist on 100% electric heat for large buildings, it will greatly increase the peak demand for cold weather.This is significant for Eugene Hydro, as it will have to buy more electricity in the wholesale electricity market, which has a much higher percentage of fossil fuel generation.It also increases costs and the likelihood of power outages, such as the one in Texas in 2021.
Hybrid (dual fuel) buildings will be able to take advantage of the high efficiency of heat pumps in mild weather, but they will run gas boilers in cold weather.This will provide EWEB with an important demand-side management tool and allow the use of smaller, “right-sized” heat pumps, reducing the cost of the heating system.
Hybrid buildings will immediately reduce carbon emissions and eventually approach zero, as NW Natural works to provide more and more renewable natural gas in the pipeline.This is a more promising path than increasing our reliance on resistive heating.
Hybrid heat pump/gas buildings could meet our climate recovery goals without significantly increasing peak electricity demand, but they won’t be allowed if the city council passes a gas ban.Instead of banning natural gas, we need EWEB, NW Natural, and the city to develop financial incentives to encourage dual-fuel buildings.
Jim Ball, retired, spent 30 years with consulting engineering firms designing HVAC and plumbing systems for large buildings.He lives in Eugene.