Navigant Research Blog

Feeling Homesick, or Just Sick from Your Home?

— November 4, 2015

Many studies by the U.S. Green Building Council (as well as other groups) show the importance of indoor air quality and the direct impact it has on occupant health. Sick building syndrome (SBS) affects many commercial and residential buildings—according to the World Health Organization, as much as 30% of the global building stock is affected. SBS includes a range of illnesses resulting from time spent in a polluted building. There are a variety of causes of SBS, from pathogens to particulate matter, from allergens to volatile organic compounds like formaldehyde.

With many Americans spending as much as 90% of their day indoors, it seems like a healthy indoor environment should be a greater concern for building managers. Yet for all the research being done on indoor air quality, there is a general lack of interest in rectifying the situation. Just as it is difficult to convince people of the importance of exercise, bad indoor air quality is a chronic health concern that many are loathe to devote energy to. It seems that an automatic system to regulate the indoor environment is needed.

Integrate with the New Environment

Outside of experimental and university studies, few systems exist that combine ventilation, filtration, and monitoring systems to optimize indoor air quality. The onus of combining data from expensive monitors with implemented solutions may not be one that already-overburdened building managers bother to handle. To be fair, there are a number of aspects to indoor air quality that interact in complex and often unexpected ways. The current trend to tighten a building’s envelope leads to less ventilation, ultimately trapping contaminants inside. Urea formaldehyde adhesives are popular in building materials, but the previously leaky buildings of the 1980s prevented the buildup of formaldehyde from becoming hazardous in most cases.

One way to rectify this buildup is to increase the ventilation rates of HVAC systems. However, increasing ventilation rates leads to an increase in energy use, oftentimes cancelling the energy savings gained from tightening the building in the first place. In addition, many commercial buildings experience wide variation in the levels of occupancy and activity of different zones, yet don’t have matching variable ventilation rates. CO2 sensors and other proxies of activity can be used to adjust ventilation to match occupancy, but advanced and integrated systems do not currently exist. It still falls on the building operator to do the bulk of adjusting ventilation.

Newer sensors are coming onto the market, such as the Beagle sensor, which promises data delivered remotely to homeowners at an affordable price. These sensors can deliver diagnostic feedback on light, noise, pressure, humidity, and air quality (primarily CO2). This makes it easy to monitor indoor air quality, but it does not offer a control feature. Many other multi-variable sensor units have entered the marketplace in the past 5 years, such as the Air Quality Egg and CubeSensors. However, none of these products integrate easily with HVAC systems already present in homes and buildings, making controlling indoor air quality a hassle for building owners.

More data is available on the quality of indoor environments than ever before. There is a huge opportunity to integrate this data into control systems and improve the indoor environment. Watch for Navigant Research’s upcoming Indoor Environmental and Air Quality report for further analysis of this market.


National High-Voltage Transmission Interconnect Project Continues to Face Support and Financing Hurdles

— August 7, 2015

The proposed Tres Amigas interconnection has been viewed as a critical development for establishing solid superconducting high-voltage direct current (HVDC) linkages between the three primary transmission networks in the United States. These networks include the Western Electric Coordinating Council (WECC), ERCOT, and the Eastern systems.  The project is thought to be critical to maintaining reliability and connecting the tremendous wind and solar renewable energy resources in the upper Midwest and the Southwest, with the urban population centers in the Central Midwest and the East.  The project has been in planning and early development stages since 2008, and it has struggled to get approximately $1.6 billion in funding for a highly technical project that involves large scale high-voltage alternating current transmission lines (HVAC) to HVDC lines necessary for synchronization of the three systems. It also incorporates re-conversion to HVAC at the interconnect points with the other networks.

In late July, the Federal Energy Regulatory Commission (FERC) announced that it had approved a request from the Southwest Power Pool (SPP) to void an interconnection agreement between Tres Amigas and Southwestern Public Service (SPS), primarily based on Tres Amigas missing multiple payments and a number of performance milestones. While the missed payments are a small portion of the total $1.6 billion dollar project, partnerships with adjacent transmission operators are critical to the completion of the project.

In previous Navigant Research blogs, I have discussed the development of a north-south transmission highway between the northern Midwest wind farms, the utility scale solar in the Southwest, and the population centers in Nebraska, Kansas, and Texas. Interestingly, the SPP transmission plans I saw show that this conceptual idea is beginning to come to fruition as new 345 kV transmissions systems are being built and older systems are upgraded.  Many of these projects have been completed by the transmission owner/entities in the region to address congestion issues in corridors like the Omaha/Kansas City to the Texas Panhandle route.

Anticipating Coal Plant Retirements

However, coal plant retirements across the lower Midwest, East Coast, and southeastern United States will have a serious impact on electric reliability across those regions, according to the North American Electric Reliability Corporation (NERC). Forward-thinking electric transmission companies are anticipating this and are now building new West-to-East transmission to deliver wind power from the High Plains to population centers in the Midwest and Southeast that will be hit hard by the retirements.  The Tres Amigas interconnection may be a critical part of the puzzle that is the modernization of the national versus regional transmission grids.  While Navigant Research expects that it will ultimately be funded by numerous transmission utilities, the full funding for the multi-billion dollar project has yet to fall into place.

You can read more about the Tres Amigas project and HVDC transmission systems in my syndicated reports, including High-Voltage Transmission Systems  and High-Voltage Direct Current Transmission Systems.


Submarine Cable Project to Link Canada, New York

— May 26, 2015

The Champlain Hudson Power Express Project is an epic example of the creative solutions that major transmission utilities and third parties are undertaking to interconnect adjacent markets across borders. This hybrid 337-mile project will carry more than 1,000 MW of renewable power from Canada to the New York metropolitan areas. The project includes sections of high-voltage direct current (HVDC) submarine power cables running through Lake Champlain, the Hudson, East, and Harlem Rivers, with other sections using HVDC underground with the existing Delaware & Hudson Railroad and CSX Transportation railroad right of ways.

The $2.2 billion dollar project is expected to be completed and commissioned in 2017, linking the Montreal area to the New York City neighborhood of Astoria, Queens.  The transmission link between Canada and New York is being developed by Transmission Developers Inc. (TDI), a Blackstone Group, L.P, and is designed to transport electricity from hydropower and wind resources in eastern Canada and feed it directly into the New York City electricity market. The Quebec section of the line and high-voltage alternating current (HVAC) to HVDC converter station is being built and will be operated by TransÉnergie, the transmission division of Hydro-Québec, one of the largest Canadian utilities.

The following graphic shows the scope of the project, starting out at the Hertel converter station in Quebec, where HVAC is converted to HVDC.  The HVDC line runs under Lake Champlain for over 100 miles and then through railroad right of ways for 126 miles.  It then runs under the Hudson River to New York City over about 100 miles, with a few underground transitions in New York City.

Champlain Hudson Power Express

Champlain Hudson Power Express

(Source: Transmission Developers, Inc.)

It’s clear that these HVDC submarine and underground systems are complex solutions that have less environmental impact than overhead transmission lines with associated right of way and eminent domain issues.

The majority of HVDC submarine electric transmission projects are being planned and completed in the European market, where tremendous off-shore wind resources in the Nordic countries, Germany, and the United Kingdom are coming online. It’s great to see that creative projects such as the Champlain Hudson Power Express transmission system are also happening in North America. Over the next 5 to 10 years, this type of interconnection/intertie between independent system operator/regional transmission organization (ISO/RTO) regions and countries will be critical to delivering adequate and increasingly renewable power resources. For more information, look for my upcoming report (expected to publish in 2Q 2015) on submarine electric transmission, which will include regional and global forecasts for capacity and revenue through 2024.



Going Ductless, AC Systems Gain Efficiency

— February 17, 2015

If the rest of the world used air conditioning like the United States, we’d be in trouble. Luckily, that is not the case. The presence of ductless split systems (which are ubiquitous almost everywhere else in the world) in U.S. homes is dwarfed by ducted central air conditioning units. Ducted units circulate air within a house to maintain an appropriate temperature, whereas ductless systems circulate refrigerant. Typical efficiencies of ducted central air conditioners run from 13 seasonal energy efficiency ratio (SEER), a measure of the energy consumed by an air conditioner based on its electricity consumption, to 21 SEER. Ductless split systems far more efficient; they’re available up to 33 SEER.

Many factors contribute to the slow adoption in the United States. U.S. houses are designed for and typically supplied with ducted systems. Running ducts through wood-framed American homes is far easier than in concrete, stone, or brick houses, which are more common abroad. But, general resistance to change among consumers, contractors, and distributors is the biggest factor that is holding back greater adoption. Ductless manufacturers have acknowledged this and are working to lower the barriers for switching that each stakeholder faces.

Changes to the Equipment

For contractors and distributors, ductless split system manufacturers reduce the burden of inventory management. Systems can come in a variety of configurations. One outdoor condensing unit can be connected to several indoor units (multi-zone) or just a single indoor unit (single-zone). Previously, these configurations required different units for multi-zone and single-zone configuration, and even units that have the same capacity aren’t interchangeable. But, earlier this year, Haier introduced its FlexFit ductless system, which can use the same indoor units in both single-zone and multi-zone configurations.

Similarly, several manufacturers of ductless split systems have eliminated cooling-only units and provide heat pump capability to all units.  Mechanically, the only difference between the two is a four-way valve. All heat pumps are capable of cooling, so providing a heat pump for a cooling application does not create any functional problems. Indeed, it appears that the logistics improvements associated with reducing the number of models offset the slightly higher cost of materials.

Is It Enough?

To win over reluctant consumers, LG Electronics has long focused on the aesthetics of the system. A traditional ducted system has a discreet register hidden on a wall, ceiling, or floor. Ductless systems entail indoor units in occupied spaces. To some, the units are unsightly. But, LG’s design-oriented Art Cool product line, featuring low profiles and designer color finishes, is an attempt at making indoor units pretty. Additionally, the company’s Art Cool Gallery hides the indoor unit in a picture frame that can be personalized with artwork or photography.

Navigant Research expects ductless systems to expand in North America in the future. But, even at aggressive growth rates, it will take years for ductless systems to reach parity with ducted ones. Cost remains a factor. Depending on the complexity of the system and whether ductwork already exists, installation of a ductless system can be much more expensive than the installation of a ducted system. Even if the United States never sees the same penetration rate as the rest of the world, though, ductless split systems will drive energy efficiency improvements in residential air conditioning.


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