Navigant Research Blog

Green Roofs Sprouting Up Globally

— September 18, 2014

Many cities have mandated increased energy efficiency in buildings and, in some cases, net zero energy use by buildings.  A variety of solutions is needed to meet these goals; some are cutting-edge digital technologies, while others have been around for thousands of years.  Green roofs, one of the oldest energy-saving technologies, are becoming increasingly popular and having an impact on sustainability efforts.

Modern green roofs employ advanced design and materials to provide residents with rooftop oases while saving energy.  There are two primary types of green roofs: extensive green roofs, which generally have 2 to 12 cm of planting medium and are designed to be virtually self-sustaining; and intensive green roofs, which are far more complex and act as rooftop parks and gardens.  Intensive green roofs have soil depths of more than 12 cm and can include shrubs, small trees, and conventional lawns.  Given the amount of materials and the additional weight required for intensive designs, they are not suitable for all roofs.  Companies such as Illinois-based TectaGreen have been installing various types of green roofs on buildings across the United States for many years.

Cool Under Cover

Green roofs have been used for centuries to provide insulation and protect roofing materials, and they provide many benefits to building owners, occupants, and the general public.  Rooftop vegetation offers several public benefits; it improves urban air quality, manages stormwater runoff, and helps moderate the urban heat-island effect.  But it’s the private benefits for building owners that are primarily driving the market for green roofs.

The most direct benefit is reducing the amount of energy required to heat and cool buildings.  Several studies have shown that installing a green roof reduces summer cooling needs and winter heat loss by as much as 26%.  Green roofing can also extend the lifespan of a roof by protecting the waterproofing membrane from ultraviolet radiation and physical damage.  Other benefits include noise reduction, the reduction of electromagnetic radiation, and compliance with building codes such as Leadership in Energy and Environmental Design (LEED).

Small but Growing

While costs for green roofs have dropped in recent years, there is an ongoing debate over their cost-effectiveness and payback period.  Installed costs of green roof systems can vary dramatically; extensive roofs (shallower) generally cost from $10 to $23 per square foot to install.  Intensive roofs can cost anywhere from $25 to $220 per square foot and may require regular maintenance.  Some argue that at those prices, green roofs cannot pay back their installation costs.  But it can also be argued that the most important benefits are those which are not easily quantified.  What’s more, compared to other, more intrusive energy efficiency measures, green roofs are relatively inexpensive.

Despite the cost, green roofs continue to be installed around the world.  Navigant Research’s recent Zero Energy Buildings report discusses the efforts underway to lower building energy consumption; green roofs represent a small but growing part of that effort.  In addition to energy efficiency, green roofs are part of a growing movement to improve the sustainability of urban environments and reconnect residents with the natural environment that their cities have largely erased.  They are sure to grow in popularity over the coming years.

 

Smoggy Skies Drive City Innovation

— September 16, 2014

The air pollution caused by rising vehicle numbers and coal-fired power plants in Chinese cities has been well documented.  But these issues are not limited to cities of the developing world.  In March, smog levels in Paris reached levels that forced the city government to limit vehicle access to the city and make public transport free.  Subsequent analysis suggests that this drastic measure had a notable impact on air quality, if only temporarily.

Paris is not alone among European cities in suffering from deteriorating air quality.  London and other U.K. cities, for example, have been under the spotlight for failing to meet European Union (EU) standards on air quality.  A report in July suggested that Oxford Street in London was one of the most polluted roads in the word with regard to nitrogen dioxide (largely produced by diesel buses and cars), with levels 3 times the EU-recommended amount – and higher than Beijing.  London and some other U.K. cities are not expected to meet EU targets for air pollution reduction until 2030.

Fewer Vehicles, Cleaner Air

The World Health Organization estimates that outdoor air pollution causes 3.7 million premature deaths worldwide each year; this mortality is due to exposure to small particulate matter of 10 microns or less in diameter, which cause cardiovascular and respiratory diseases and cancers.  Of particular concern in cities are fine particulate matter below 2.5 microns, referred to as PM2.5, which can lodge deep within the lungs.  This life-threatening type of smog is created by burning vehicle fuel as well as other fuels such as coal and wood.

The need to address air pollution is becoming a significant driver for the adoption of electric vehicles in cities, restrictions on the worst polluting vehicles, and the introduction of technologies that can monitor and improve air quality.  Madrid, for example, is using parking fees to target the worst polluting vehicles, while also introducing an electric bike rental scheme.  Boston is piloting high-tech city benches that can collect information on air quality and provide solar-powered charging for electronic devices.  Other high-tech attempts to improve air quality have been less than successful: a project supported by the Mayor of London that used a form of glue to collect contaminants proved to be largely ineffective in capturing vehicle pollution.  More recently, the Mayor has suggested that diesel vehicles, responsible for much of London’s damaging air pollution, may face additional charges for driving in the capital under the city’s congestion charging scheme.

Looking East

In the future, western cities may look to China as a leader in air quality improvement.  In 2013, the Chinese government launched its Airborne Pollution Prevention and Control Action Plan, which will see it invest $277 billion in an attempt to reduce air pollution by up to 25% in selected provinces and cities (including the municipality of Beijing) by 2017 compared to 2012 levels.  Beijing alone is expected to invest around $160 billion.  Beijing is also working with IBM on a 10-year project called Green Horizon that will employ sensor technologies, big data analytics, weather modelling, and other advanced techniques to help the city monitor and address air pollution.  The project will also integrate renewable energy forecasting and industrial energy management.

In North America and Europe, air pollution is often associated with a previous age of industrialization, but the growing public awareness of the continuing threat to public health is accelerating policy and technology innovation.  Ultimately, air pollution in our cities needs to be addressed through a combination of transportation and energy policies and the general adoption of clean fuel vehicles and other clean technologies.

 

Building Sensors Reach Vanishing Point

— September 9, 2014

Sensors play a critical role in building operations, from safety and security to optimizing building system performance.  Building energy management systems, lighting controls, and heating, ventilation, and air conditioning (HVAC) systems are slowly incorporating more sensors as their prices fall and their values rise.  Navigant Research’s report Advanced Sensors in Smart Buildings delves into the future of the market for sensors that have built-in processors, networking capability, and the capability to sense more than one phenomenon at a time.  Yet, as design elements in rooms and ceilings, most sensors, like the traditional thermostat, are unappealing appendages with little aesthetic value.  The good news is that the ugly boxes and knobs are shrinking and may disappear from view altogether.

Redwood Systems (acquired last year by networking company Commscope) recently released its third-generation light and motion sensor.  Redwood’s approach is to capture fine-grain occupancy and light levels to deliver lighting precisely to those in offices who need it, when they want it, even with shifting levels of sunlight.  Its lighting solution and accompanying open application programming interface (API) were deployed at the San Francisco headquarters of the software management firm GitHub, then promptly customized to enable the employees to tailor light levels as they see fit.  Redwood’s sensor looks like a small lump on the ceiling and can even be embedded in LED lighting systems themselves.

Sense of Control

The next generation of sensors may not look like anything.  New materials and manufacturing techniques will hide sensors from view, either embedding them in equipment or as objects to paste on surfaces as needed.  Imagine living in a house with smooth walls and ceilings.  No light switches or thermostats in view, other than as decorative objects.  Norwegian company Thinfilm has developed a printable temperature sensor that can function as both a temperature sensor and display for a myriad of applications.  Funded by PARC, Xerox’s research arm, Thinfilm has focused its efforts on thin labels for consumer products (like produce) that have tight temperature and lifetime tolerances.  Thinfilm has also developed advanced ID cards for people that can display names and access levels to different locations.  With data storage and near-field communications capability, Thinfilm’s products have the potential to leap from smart temperature labels to flat room temperature sensors with built-in displays and network communication.

The French company ISORG is also developing a technology using printed sensors.  Its flat light sensors are designed not for occupancy or light level applications, but for applications where light level variances can be used to control equipment, like consumer devices.  And it just received $8.7 million in financing,  bringing new attention to the printed sensor space.  This technology may jump into equipment themselves, like HVAC fans and pumps, where minuscule sensors can enable more granular control and system optimization.

 

Hidden Meters Provide Visible Savings

— September 8, 2014

A fundamental challenge in commercial building energy management is in understanding where all the electrons are flowing.  Most buildings have a meter that will tell the facility or energy manager how much power is being consumed, and smart meters have contributed greatly to their insight (in some parts of the world, including the United States, groups of buildings share a meter).  And many, such as apartment buildings, have dedicated meters for each tenant.

But to find out how much power is consumed by tenants or equipment, a finer grain view is needed.  It sounds easy to simply deploy more meters or submeters, watch the data flow in, and manage accordingly.  But the barriers to additional submeters, including the cost of deployment and regulatory issues, are limiting their deployment.

Most large heating, ventilation, and air conditioning (HVAC) and other large equipment vendors now sell embedded energy meters with their equipment, making energy management for large systems possible, albeit more expensive.  Today, an alternative is on the rise, in the form of in-line circuit breaker meters.  These devices snap on to the feeder wires of the breakers, recording the power used inside the cable without interfering with it.  All of these companies are touting the fast and easy installation, along with the value of actionable data for facility managers.  These are compelling arguments, especially considering the vast amount of commercial space and the massive plug loads associated with them.

Thinking Inside the Box

A few companies use these innocuous looking grey boxes as the data source to manage energy, displacing the traditional meter and submeter streams and setting up an interesting set of partnerships along the way.   Pennsylvania-based E-Mon sells a line of circuit breaker submeters that capture power and can then communicate via Ethernet (or TIA-485-A) with an energy management system (EMS).  While E-Mon has its own software package, the company recently announced a partnership with Honeywell to use its Attune Energy Dashboard service.   Similarly, Panoramic Power formed a partnership with Lucid, joining its ConnectNow partner group.  Panoramic Power sells only energy services, not the devices themselves, and uses wireless as opposed to wired solutions.

Enertiv both sells devices and EMSs, using Ethernet to communicate with the EMS.  In late July, the New York City-based company received $750,000 in seed funding, indicating the interest in this space.  This interest is rubbing off on newcomer Bractlet.  The Austin-based company, receiver of venture capital and seed funding from Start-Up Chile, sees circuit-level data as a way to validate the upfront costs needed for building retrofits and a way for building and energy managers to measure the value of retrofits.

It’s a compelling business case.  When it comes to retrofits, the first question asked is, “What will this retrofit cost me?” Followed by, “How long will it take to recoup my investment?”  The last question is the most difficult: “How will I know if those savings are actually achieved?” Bractlet, along with its competitors in this emerging space, may have the right approach to answering those questions.

 

Blog Articles

Most Recent

By Date

Tags

Clean Transportation, Electric Vehicles, Energy Storage, Policy & Regulation, Renewable Energy, Smart Energy Practice, Smart Energy Program, Smart Grid Practice, Smart Transportation Practice, Utility Innovations

By Author


{"userID":"","pageName":"Smart Buildings Program","path":"\/tag\/smart-buildings-program","date":"9\/22\/2014"}