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Design professionals have, perhaps, the most difficult task when trying to adapt to new industry goals. When the standard has been combustion furnaces, boilers and combined heat and power systems, the request to switch new (and retrofit) buildings to all-electric heat pumps can seem daunting.
Modular chillers and heat recover equipment can bring a whole new set of obstacles in the design process. The fact is, it’s the new normal, so the sooner we’re all on board with beneficial electrification, the better.
The topic of beneficial electrification has been a difficult topic since I started writing back in 2009. One of my first articles, written for National Geographic, simply talked about heat pump efficiency. Using the Coefficient of Performance (COP) measurement, I went on to explain that a geothermal heat pump has an efficiency of 500 percent, meaning it delivered five units of heat for every unit of electricity used by the heat pump.
The comments resulting from the article were abrasive. The most typical comment was similar to this: “How can something even be 100-percent efficient? It’s impossible. Nothing can be more than 100-percent efficient.”
It simply is not intuitive to state that something is more than 100-percent efficient. It’s better to explain that a heat pump is a device pumping energy from one location to another. Sometimes it can pump heat from the outside or ambient air into a home; other times, it can pump heat from the earth into a building. It just depends on how the heat pump is designed.
Beneficial electrification is used to describe the need and the benefit to our society to electrify all our buildings. The primary purpose for doing this is to reduce the emissions coming from combustion heating of those homes and businesses.
There are more emissions from the heating of homes and commercial buildings than there are emissions from internal combustion engines involved in transportation. This is typical of cities and areas with cold winters and high populations.
Many people are concerned about emissions from transportation. However, we cannot reduce emissions to achieve our goals without the elimination of combustion heating for homes and buildings. Some of the figures we see indicate that 40 to 45 percent of the CO2emissions are coming from heating buildings and power generation, while only 28 percent is coming from transportation.
So, to reduce emissions 80 percent by 2030 and 100 percent by 2040, buildings must switch from furnaces and boilers to electric heat pumps. There is a lot of education still to be done to accomplish this.
Hurdles to Adoption
First, let’s talk about public perception. Some people wish to have nothing to do with anything that involves the reduction of fossil-fuel combustion. They simply do not believe it is part of the problem. However, most of this sector of the population is quite good with electrification if it can be proven to them that a heat pump will reduce their overall energy bill.
The benefit is there, but it’s still an educational process, and we are in the midst of it right now.
Second, we need to educate consumers on how heat pumps work. The Carnot refrigeration cycle is simply not intuitive. Too often, we wish to help consumers understand how it is that a compressor, an expansion valve, a condenser and an evaporator can manipulate the movement of heat from one space to another.
Probably the best analogy is to just point to the typical kitchen refrigerator. It is a heat pump electrically powered and takes heat out of the refrigerator box and into the kitchen. Similarly, a heat pump can pump heat out of the cold outdoors and into the building to be heated.
The third hurdle to overcome has to do with explaining that CO2 emissions come from combustion. That combustion source can be coal, oil, natural gas, propane or any other combustible source used for heating. Science tells us that combustion heating adds to CO2emissions, and does not help us in our goal toward emissions reductions.
The average American may think of the thousands of years of human beings warmed by the fireplace on cold winter days, while reading bedtime stories to their children, or enjoying idle chit-chat. This is a picture difficult to overcome for those of us in the green heating industry. These people will have serious reservations about anyone turning off the gas to their homes.
I’ve dealt with it many times in high-rise apartments and office buildings. The primary question asked is, “What do I do if the heat breaks down?” Fortunately, there is an easy answer. With an electrically powered heat pump, emergency and backup resistance heat strips are a “standard” option. It usually satisfies most people.
Another fact few people have been able to wrap their heads around is that natural gas, or methane, is a more potent greenhouse gas than we could have ever imagined. It has 84 times the impact of CO2. It means that as far as greenhouse gas emissions go, unburnt natural gas is far more damaging by a factor of 84 then combusted natural gas. Go figure!
(subhead) Heat Pump Conversion
With about 45 percent of greenhouse gas emissions coming from the burning of fossil fuels to make energy, including heat and electricity, having a fully electric society is the direction we want to go. Air-source geothermal heat pumps are absolutely necessary to help us attain the goal of zero on-site admissions. They provide a terrific amount of site-sourced energy from the ambient air and the earth beneath our buildings.
Just because we state that we want an all-electric society doesn’t make it easy to do. I’ve used the analogy of a family who genuinely believes it’s doing the right thing for the environment when it purchases an electric car and installs photovoltaic panels on the home. Most people think it is all that is needed to be as environmentally conscious and active as possible.
A certain degree of consumer education is needed to explain these concepts. Not only do furnaces need to be converted to heat pumps, but also stoves and cooktops, as well as domestic hot water tanks.
Folks who are used to cooking with gas have quite an aversion to electric cooking. The group Mothers out Front (www.mothersoutfront.org) has been extraordinarily helpful in educating the public on the virtues of induction cooking. I don’t have time to talk about it too much here, but if you go to the site, you can see a little bit about what they’re doing.
Another essential part of the education process is reminding people that the natural gas infrastructure in the United States is becoming very aged. So much so that in many city centers throughout the country, double-digit billions of dollars are needed to upgrade the old natural gas piping infrastructure.
This is an opportunity for beneficial electrification. The opportunity comes as we educate consumers, regulators and utilities that while the natural gas pipelines must be upgraded, they can be upgraded to geothermal micro districts, which will provide the ground-coupling service to geothermal heat pumps as quickly as new natural gas pipelines could be put in. This is a perfect example of installing infrastructure that will not become a stranded asset.
Stranded asset is a term used to describe the installation of a system that will be obsolete or illegal at some point before the end of its usable life span. Indeed, many state laws have outlawed combustion heating in buildings after the year 2050. Putting in a natural gas pipeline now, with a lifespan estimated at 60 years, is a waste of money, or a stranded asset.
Putting in a geothermal micro-district now — which takes about the same footprint, about the same or less in construction costs, and will be a permanent asset for homes and businesses and upcoming generations — is the answer toward electrification. There have been several studies done on this electrification effort and the conversion of a natural gas pipe grid over to geothermal in many districts, the most recent being in Massachusetts.
For more information, read this Plumbing Engineer column, titled “The $9 Billion Question: Stranded Assets or GeoMicroDistricts?” (http://bit.ly/37ZjkFh). It has quite a bit of information that can make a believer out of just about anyone.
Air-source heat pumps and geothermal heat pumps work very well when installed correctly. Like anything, it takes training and due attention to the manufacturer’s instructions and operational settings to ensure an excellent system install. I recognized this as a young contractor 35 years ago when I started installing geothermal heat pumps in homes. I was being interviewed on a network in Tampa, Fla., and they asked me where I thought the geothermal heat pump market was going.
It’s important to note here that geothermal heat pumps work very effectively for cooling, and there are quite literally hundreds of thousands of them installed in hot, tropical climates.
I replied that much like utilities supplied electricity, drinking water and wastewater drains to buildings, I believed geothermal exchange means would be installed in neighborhoods and cities, making installation of geothermal heat pumps as simple as hooking up a dishwasher or washing machine.
My point is that consumers are using BTUs, which are quite similar to a utility charging for electricity or anything else of that nature. Why would a utility not want to sell BTUs to consumers? Why would a consumer not wish to purchase BTUs from a utility whose responsibility it is to make sure the energy is always there?
If you think about the logic in this, it’s simpler for a consumer to hook to a geothermal district main than it is to hire a well driller and have him drill a 500-foot borehole in his yard. That would be as silly as having all customers dig their own water well when there is a water main running right through the property.
Building electrification is not a new idea. Ronald Reagan was a paid spokesman for the National Electrical Manufacturers Association (NEMA), the group pushing for building all-electric homes. The point is that it is safer and easier to provide only one source of energy to a home.
I think this effort will gain traction again nationally and internationally, and we might even have a medallion for new homes similar to the total electric award medallion you see in the image. It would be similar to a LEED rating.
As far as building electrification goes, the big picture is that electric utilities have to watch the load profile of the grid. Currently, in heating-dominant areas, most utilities provide electricity and natural gas or another combustible fuel for heating. So as a result, we see a peak in electrical consumption in the middle of the summer for air conditioning, while electrical consumption drops in the winter and you see a spike for natural gas consumption.
This situation, in and of itself, has become a problem in many places where they’ve had to enact natural gas moratoriums because consumption is outpacing the deliverables.
When heat pumps are introduced into this same community or city, the summertime peak would generally stay about the same. But the winter time, which is normally low on electrical demand, would become better balanced. The potential problem is that the winter peak usage could far outweigh the summer peak.
With most electric utilities built to the design capacity of the summertime peak, a much-increased wintertime peak as a result of building electrification would result in overwhelming expenditures of new power-generating facilities. It is central to the strategy of demand-side management focusing on geothermal heat pumps to level the load profile.
As you look at the ASHRAE building image in Figure 11, the blue lines indicate the geothermal heat pumps’ load profile, and it actually comes in under the summertime peak by a good margin. This clearly illustrates that the geothermal heat pumps can increase the productivity of the grid while reducing demand in the summertime, which will give a greater capacity overall for heating and cooling.
In fact, full penetration of heat pumps into the market with prescribed numbers of geothermal heat pumps could realistically provide a reduction in overall demand that could offset the need for new electrical power-generation facilities well into the future. This equates to a very good use of resources.
Beyond the financial benefits realized by building electrification, some of the other benefits include reduced reliance on fossil fuels, which is obvious, but reduced-price risk is another remarkable benefit. Those of us with any experience with natural gas cost fluctuations know that the cost for this fuel can vary dramatically. Just 10 years ago, natural gas cost three times what it costs today.
Electricity, on the other hand, has always been fairly stable. That is because electricity can be generated from a number of different sources including hydroelectric, photovoltaic, wind power, nuclear and even natural gas-fired power plants. By the way, the use of natural gas to generate electricity is its most effective use. It creates more benefit with fewer emissions in the process of making electricity than in any other way. You could say that the COP is higher.
Thermal Load Diversification
Another benefit of a hydronically based geothermal micro district is something called load diversification. This has been proven out in applications throughout the world. The study done by Stanford in theory and then in practice is a remarkable illustration, one that can be understood by anyone.
Before upgrading the campus, Stanford officials had electrically driven chillers that provided all the cooling for the campus; combustion boilers provided all the heating cooling and heating systems. When the campus converted to heat recovery chillers at the central energy plant, all the waste heat that normally went out the cooling towers was then pumped over to be used in heat recovery operations for the heating system.
By the same token, heat recovery chillers strip the heat out of the fluid in the hydronic pipelines, providing essentially free cooling while in the process of heating other systems. This is called thermal load diversification. This also is true in geothermal districts for towns and communities. The BuroHappold study completed in Massachusetts shows many examples of thermal diversification that can be applied.
Recently, the New York State Electric Research and Development Authority created an insightful poster highlighting the benefits of building electrification: more comfortable homes, less maintenance, safer and emissions-free, and much lower operating costs.
Back in 2010, Oak Ridge National Laboratories performed a study on a geothermal heating and cooling neighborhood and was able to report that full building electrification using geothermal heat pumps would reduce carbon emissions in the United States by 45 percent and reduce summer peak electrical demand by 56 percent.
Of course, this translates into remarkable energy savings for consumers, but did you catch that 56 percent reduction in summer electrical peak? It means electrical generation facilities will not need to be upgraded for quite some time to come; another great point for strategic building electrification.
It has been my experience that the largest natural gas distribution companies in North America are keenly aware of the benefits of geothermal districts. Both distribution systems require pipelines (Figure 14); however, natural gas distribution pipelines need source energy, meaning they need a constant supply of natural gas. And they do not deliver a product capable of cooling the building.
Similar infrastructure for geothermal micro districts provides a renewable energy source, one that needs no source energy because it’s exchanging heat with the earth and other utilities. Its deliverables are space heating and cooling, as well as domestic hot water.
As we move toward building electrification and develop the technology for full integration, the workforce is going to shift its talents a bit. It’s helpful to our workforce and economy to know that the pipelines that need to be replaced for natural gas systems will simply be replaced with a material similar to what natural gas distribution lines are made of currently — high-density polyethylene.
Heat pumps installed in buildings will be put in by cross-trained plumbers and heating contractors. In principle, geothermal heat pumps are an appliance as simple as a window air conditioner. The difference is that they need to be installed in cooperation with a competent duct distribution system, electrical services and controls for monitoring the temperature of the space.
Most utilities have begun to recognize energy in the form of BTUs rather than kilowatt-hours and therms. Whatever measure you use, Figure 15 represents the result of transportation and building electrification. You can see that the peach and pink represent the number of gas furnaces and boilers, and the blue represents the number of electric heat pumps.
Overall electric consumption increases annually, while peak demand is reduced, resulting in an overall energy reduction of nearly 50 percent in total energy consumption. This is due to the fact that heat pumps use one unit of electricity to create three to five units of heating or cooling. This is the image that reflects building electrification and deep decarbonization. This is it. This works. This is where we’re going.
Special thanks to HEET, Mothers Out Front and BuroHappold. #EPRI #Electrification #GeothermalHeatPumps #Geo MicroDistrict #HeatPumps #StrandedAssets