With a warming climate, Greg Nahn, Slipstream, stresses that we must decrease the amount of fossil fuel we are burning worldwide. And he also noted that Iowa is on the cutting edge of the transition from fossil fuels to carbon-free renewables.
That is good news for Iowa, where coal use, for example, has dropped from about 85 percent in 1990 to approximately 40 percent in 2020 and with a projection of slightly over 20 percent by 2030. In contrast, wind energy production was at 0 percent in 1990, is a bit over 40 percent today, and is expected to be more than 60 percent of our energy use by 2030.
Greg explains, “This is a win-win-win for Iowa consumers. As Iowa brings more renewable energy resources online, there is potential for better grid management. Iowa has one of the most carbon-free mixes of generation resources in the country.” He goes on to add that all the ground source (geothermal) heat pumps that have been installed in the past few years are “only getting cleaner” as our power generation continues to swing to incorporate more renewable, carbon-free sources.
To provide heating, cooling, and even water heating using this mix of future-based energy sources, geothermal isn’t the only sustainable option. Several types of air source heat pumps and heat pump water heaters are also future-forward and are referred to as “advanced electric heat” systems. Note that electric resistance heating is not in this category.
To make this transition, he argues that the natural replacement is for utilities, including electric cooperatives, to use a variety of electric resources “fueled” by renewables with a natural gas backup if required.
Advanced electric heat
If you haven’t already shifted to an advanced electric source to heat and cool your home, it may become a wise decision as you consider changing HVAC systems. Along with geothermal, newer advanced heat pump options include several types of air source heat pumps (ASHP): ductless, mini-duct, and centrally ducted air source heat pump systems. All of these have an indoor unit and an outdoor unit, too.
Ductless ASHP. These are flexible, allowing you to zone and control each unit individually. They can readily meet small or customized loads, heating and cooling a single room such as a master bedroom or a newly built addition, or the main part of your home, displacing the use of your older less efficient heating or cooling system These are usually mounted on a wall. If your home doesn’t have ductwork, or if you want to heat/cool rooms that aren’t currently connected to your central HVAC system, this is an excellent option to consider.
Mini-duct ASHP. Similar to the ductless version, except the units are connected to ductwork that runs through a portion of your home; heating and cooling several adjacent rooms. ASHP systems can be a great option for bedrooms
Centrally ducted ASHP. This type of unit uses the ductwork already in your home to distribute conditioned air throughout the entire home. It may be necessary to redo some of the ductwork for optimal performance.
Advantages of advanced electric heating systems
Besides offering energy efficiency and using an increasingly more sustainable energy source, there are additional advantages:
No gas lines run to buildings. This avoids the initial cost of running the lines, and there will never be a dangerous gas leak.
Because there is no combustion, there also won’t be any dangerous carbon monoxide produced.
It’s easy and economical to add a heat pump water heater along with the heat pump. As water heating is generally a home’s second largest utility bill (after heating and cooling), this can offer a substantial benefit.
If you start out small with a zoned ductless or mini-ducted component, you may be able to offset the operation of less-efficient heating and reduce your dependence on delivered fuels.
Energy savings can be substantial. Shifting from propane to a ducted air source heat pump can garner a cost savings of up to 48%, using between 35% to 60% less propane.
New cold climate heat pumps (multiple stage or inverter driven) will operate at lower temperatures—with minimal backup—than in the past, down to -5 degrees F, offering security during winter months.
Our cooperative offers rebates on the purchase of heat pumps and for operating a wholly electric home. There are also tax credits for geothermal heat pump installation. Contact us for details.
Source: Greg Nahn, Slipstream, speaker at the Momentum Is Building Conference, February 2020