Learning From Experience

Ask anyone who designs, owns, or manages an office building if they want the occupants of their building to feel comfortable, healthy, and productive, and the answer would of course be ‘yes’.   But ask again if they know what the occupants actually feel about the space, and the answer will be quite different.

Photo_Carnegie_rainbowThe facility manager is most likely to have a sense, but often it’s only anecdotal. The building owner might eventually have an inkling about occupant sentiment if they see a financial effect because an environment is inadequate. Yet, sadly, very few architects or other members of the design team are likely to know how well their building is working after it is completed and occupied, the fees have been paid, and they are on to another project. Without learning from experience in an objective way, building industry professionals are less likely to make design or economic decisions that will truly enhance the performance and experiential quality of their buildings.

And while this information would be valuable for any project, it is particularly essential if one is claiming to have designed or built a green building, where the quality of the indoor environment is a critical dimension of sustainable design. The only way to back up those claims is to evaluate a building’s actual performance, in terms of energy consumption or indoor environmental quality, and compare the performance to design intent.

Without question, it is absolutely crucial to reduce energy consumption in buildings and help avoid the potentially devastating impacts of climate change. But in terms of the building owner’s pocketbook, energy costs are still relatively small compared to worker salaries, which represent over 90% of the total operating costs of a commercial building. In addition, the cost of worker recruitment and retention is significant. Thus, from the building or company owner’s point of view, perhaps the most persuasive argument for sustainable design is one that makes the connection between a higher quality indoor environment, and increased comfort, health and productivity of the workers.

So, how does one learn about the quality of the indoor environment? While there are many physical measurements one can take, they need to be interpreted in terms of the impact on occupants. Occupants themselves are a rich yet underutilized source of direct information about how well a building is working, but the challenge is how to collect both the positive and negative feedback in a systematic way. This has been at the core of research underway at UC Berkeley.

 Center for the Built Environment

The Center for the Built Environment (CBE) is a collaborative research organization that links faculty, researcher, and students with a consortium of firms and organizations that share a commitment to improving the performance of commercial buildings. The Center has two broad purposes, represented in a wide range of research projects of relevance to the building industry. First, we develop ways to “take the pulse” of occupied buildings, looking at how people use space, what they like and don’t like, and we link those responses back to physical measurements of indoor environmental quality. Secondly, we study technologies that have the potential to make buildings more environmentally friendly, more healthy and productive to work in, and more economical to operate. These range from envelope and HVAC systems, to controls and information technology. Our industry partners represent architects, engineers, contractors, manufacturers, utilities, building owners, and government organizations. Our current CBE Industry Partners are Armstrong World Industries, Arup, CA Dept. of General Services, CA Energy Commission, Charles M. Salter Associates, CTG Energetics, Flack + Kurtz, Guttmann & Blaevoet, HOK, PG&E Pacific Energy Center, Price Industries, RTKL Associates, SOM, Southland Industries, Swinerton Buildings, Stantec, Steelcase, Syska Hennessy Group, Tate Access Floors, Taylor Engineering, Trane, US Dept. of Energy, US General Services Administration, Webcor Buildings, and York International.

Survey Page_acoustics The CBE Survey

CBE has developed a web-based indoor environmental quality survey to help designers, building owners and operators, and tenants evaluate how well their office buildings are working from the occupants’ perspective. Advantages of the web-based format are: 1) it is quick and inexpensive to use; 2) it facilitates more focused and detailed feedback (particularly, when the occupant indicates dissatisfaction with a certain area); and 3) survey results can be accessed using an automated, advanced reporting tool that allows users to filter, aggregate, compare, or benchmark their data. The core CBE survey measures occupant satisfaction and self-reported productivity related to nine environmental categories: office layout, office furnishings, thermal comfort, air quality, lighting, acoustics, cleanliness and maintenance, overall satisfaction with the building, and with the workspace. Additional, custom survey modules can be added, which would enable you to gather data about additional topics, depending on available building features or the client’s particular issues. Examples of existing modules include accessibility, safety and security, daylighting, and operable windows.

To date, the CBE Survey has been implemented in nearly 300 buildings, with over 41,000 individual responses, making it the largest database of its kind. The survey can be used as a diagnostic tool for individual buildings, to enable designers or building owners to evaluate specific aspects of their building design features and operating strategies, identify problem areas, and help prioritize investments for improvements. Users can do both before and after surveys to evaluate the effectiveness of changes in the design or operational improvements, or before and after a move. The database is also useful for evaluating trends across many buildings. By using a standardized instrument to collect data from a wide variety of office buildings, we are able to mine the data to look for trends or comparative analysis in the performance of particular design strategies or technologies. By utilizing the full database, clients can also evaluate how their building is doing in comparison to groups of buildings in the same or different categories.

The CBE Survey is being used in a wide variety of contexts, for both private and institutional clients. In some cases, we are contacted directly by architecture and engineering firms to study their buildings (recent examples include Arup, Chong Partners, EHDD, ELS, Enermodal Engineering, Glumac, HKT, HOK, Keen Engineering, Moseley Architects).

The U.S. General Services Administration (GSA) is using the CBE Survey to evaluate tenant satisfaction in up to 100 buildings each summer as part of their facility management assessment program, replacing their previous paper-based survey administered by Gallup. We are also developing and administering new surveys as part of GSA’s Workplace 20/20 initiative, which focuses on the interrelationships between people, space, technology, knowledge, work process, and organizational effectiveness.

With UC San Francisco, we have developed a new module to evaluate laboratories. We completed several baseline surveys of UCSF facilities, and we will continue to evaluate many of their new lab facilities.

As a one-year promotion, we offered the CBE Survey free for LEED-certified buildings, to improve our understanding of how green buildings were performing in the field. We have also been contacted independently by architects or building owners who can use the CBE Survey to achieve a LEED-NCv2.2 credit for thermal monitoring.

Internationally, we have collaborated with Indoorium, a Finland-based consulting firm specializing in indoor air quality, lighting, and acoustics, to evaluate 20 buildings and develop multi-lingual capabilities for the survey.

And here on the UC Berkeley campus, in Cris Benton’s Arch 249: Secret Life of Buildings, students surveyed 13 campus buildings and discovered that the deferred maintenance of recent years is keenly felt!

We are currently embarking on new projects to use the CBE Survey to evaluate some of the recent AIA-COTE Top Ten Green Projects, and to survey occupants of the new San Francisco Federal Buildings, both in their current spaces and then after they move later this year.

And finally, we utilize the CBE Survey extensively in our own research projects investigating technologies such as underfloor air distribution, operable windows, demand response technologies, and high performance facades — often combining the survey with detailed indoor physical measurements.

Survey Results_Avg ScoresLessons Learned

Looking at the entire database, of all the environmental attributes evaluated in the CBE Survey, acoustics consistently receives the lowest ratings, followed by thermal comfort and air quality. The most common sources of dissatisfaction with acoustics relate to sound privacy (people overhearing others’ private conversations) and distractions from hearing people’s conversations while talking on the phone or to others in neighboring areas. Much less frequent were complaints about excessively loud sounds, noise from the HVAC system or office equipment, or outdoor noises (even in buildings with operable windows). Not surprisingly, people with private offices are significantly more satisfied with acoustics that those in open plan spaces. However, when we looked at the influence of open plan design, we were surprised to find that the absence of partitions provided higher satisfaction scores than having partitions, yetpartition height itself had no discernible effect. This suggests that visual privacy may lead to unrealistic expectations of acoustic privacy. When people have a full view of their co-workers, they are either more courteous at keeping their voices lower, or change their expectations and are therefore not disturbed by the lack of privacy.

ASHRAE publishes standards for both thermal comfort and acceptable air quality in buildings (ASHRAE Standard 55-2004, and 62.1-2004, respectively), both recommending conditions in which 80% of the occupants are satisfied. But when we look at satisfaction scores from our database, we find that buildings are falling far short of these standards. It was disturbing to find that only 11% of the buildings met the intent of the thermal comfort standard, with an overall average of only 59% of the occupants expressing satisfaction with the thermal environment. Thermal dissatisfaction was most commonly related to people feeling that they did not have enough control over their environment, in addition to complaints about air movement being too low. This is particularly interesting given that thermal comfort standards are geared towards limiting air movement, mistakenly believing that drafts are a more common problem.

Responses to air quality were only slightly better, with only 26% of the buildings meeting the intent of the standard, and on average 69% of occupants are satisfied with the air quality. The most common complaints were that the air was stuffy or stale, or smelled badly, with the most frequently identified sources being food, carpet or furniture, or other people.

Not surprisingly, we found that satisfaction with both thermal comfort and air quality increases significantly in buildings that provide people with some means of personal control over their environment, such as thermostats or operable windows. The opposite was true for people with portable heaters and fans, indicating that the presence of these devices may have been a result of inadequate performance of the centralized HVAC system. Given the relative energy intensity of these portable devices, it is clear that providing for personal control should be a thoughtful and integrated part of the overall building design, rather than an afterthought.

We also did a comparative analysis of 21 green buildings, 15 of which were LEED-rated. In comparison to the rest of the database, occupants in these buildings expressed higher rates of satisfaction with thermal comfort and air quality, and with the building overall. Contributing reasons for this include improved ventilation, green materials with reduced off-gassing, solar gain control, operable windows, task-conditioning, and other means of personal control. In contrast, we didn’t see any significant improvement in lighting and acoustic quality in the green buildings. With regard to lighting, occupants consistently enjoyed and valued higher levels of daylight and access to views, but there were often problems with glare (particularly on computer screens), and inadequate electric task lighting or provision of controls over the lighting. High levels of dissatisfaction with acoustics in the green buildings were often attributed to problems with sound privacy and noise distractions, often exacerbated by the high ceilings and open plan layouts that are beneficial for daylighting and natural ventilation. Additional factors influencing the acoustics in these buildings were often harder surfaces associated with minimal use of textiles as a way of avoiding the off-gassing.

Conclusion

Providing workers with a quality indoor environment should be a goal of any building design, but is particularly important for green buildings that claim to be more responsive to supporting occupant comfort, health and productivity. Improving the quality of our buildings critically depends on accountability and learning from experience – what works, what doesn’t, and what choices about building design or operation can make the biggest difference. The voices of the occupants are an invaluable component of that assessment. As we move towards embracing high-performance, green buildings as the industry standard (as we must), we must also insist that post-occupancy evaluations be a natural part of that process. In the end, everyone benefits from learning how a building performs in practice.

Acknowledgements

I’d like to acknowledge the members of CBE who have contributed to this work, including Charlie Huizenga, Leah Zagreus, Sahar Abbaszadeh, David Lehrer, and CBE Director, Ed Arens. We also acknowledge the numerous students from Architecture and other departments on campus who have contributed to and received financial support from the Survey project.

For more information:

To see a demo of the CBE Survey and reporting tool, or to find out how to use the CBE Survey in your building, see:

http://www.cbe.berkeley.edu/research/briefs-survey.htm

Or send us an e-mail at:

cbe-survey@berkeley.edu

For more detailed discussions of this subject see:

Abbaszadeh, S., L. Zagreus, D. Lehrer and C. Huizenga. Occupant Satisfaction with Indoor Environmental Quality in Green Buidlings. Indoor Air 2004; 14 (suppl 8) December 2004. 65-74.

Huizenga, C., S. Abbaszadeh, L. Zagreus and E. Arens. Air Quality and Thermal Comfort in Office Buildings: Results of a Large Indoor Environmental Quality Survey. Proceedings of Healthy Buildings 2006, Lisbon, Vol. III, 393-397.

Zagreus, L., C. Huzenga, E. Arens, and D. Lehrer. Listening to the Occupants: A Web-based Indoor Environmental Quality Survey.   Indoor Air 2004; 14 (suppl 8) December 2004. 65-74.

Gail Brager is Professor of Building Science in the Department of Architecture, and Associate Director of the Center for the Built Environment.

 

CAR-SHARING | Moving into the mainstream

For decades the American Dream was synonymous with car ownership. The number of vehicles surpassed the number of households in the United States in the 1920s, and currently, around 92% of households own at least one automobile. Even so, many people remain car-free or car-limited.

Thousands of young urban students and professionals chose homes to be close to work, school or transit, and commute, shop, and play mostly by transit, bicycling or walking. Additionally, there are thousands of households which, due to issues of affordability, have fewer vehicles than workers, or have no vehicles at all. On the other hand, there are also many households with extra vehicles which are hardly used. For all of these situations, “car-sharing” – the idea of having access to a car and paying for it only when you need it – provides a suitable option. For young professionals, it can improve mobility on those occasions when a car is needed, when in the past a car would have been rented or borrowed. Similarly, for low income households, it can add mobility at important times when other options are too time-consuming or inconvenient. For households with extra vehicles, selling the vehicle and car-sharing instead can eliminate the costs of ownership for the little-used vehicle.

For all of these reasons and more, car-sharing has taken off in many major U.S. cities. By now, residents in major metropolitan areas probably took notice of the strangely painted shared-car vehicles zipping around. As of 2005, there were 28 car-share systems in 36 cities in North America, with a total membership of over 75,000, and a total shared fleet of over 1100 vehicles. [1] Commercial car-sharing began in Europe in the 1980s and came to the U.S. around 1994. [1]

They all work along similar lines: the car-share operator owns and maintains a fleet of cars, the scheduling system, website, etc. The cars are placed in special, reserved parking spots in various locations in the city. Anyone can become a car-share member (with certain restrictions for those under 21). Members can use any car in the system, as long as it is available. They can check availability of any car by phone or internet and reserve the car at the location for the time frame they desire. Members have a universal key which opens and activates any car in the system. During their reservation period, they can use the car as much as they please. They can extend their reservation during use by phone or internet, as long as the car hasn’t been reserved immediately afterwards by another member. At the end of the month, the member is billed for their use, plus small monthly membership fees, if any. There are certain restrictions that help things run more smoothly; the hefty penalty for a late return helps ensure that users plan realistic reservation times and don’t leave the next user waiting.

Each system has a different system of rates. One local Bay Area operator charges 44 cents per mile and four dollars per hour during the day, or two dollars per hour at night. Another operator charges 8 dollars per hour with no charge for mileage. Some operators offer various types of vehicles and might charge different rates for each vehicle. A number of operators offer car-sharing and compete head-to-head in the different cities, placing competing vehicles right next to each other in a parking lot.

Because car-sharing has the potential to reduce automobile ownership for some, meanwhile increasing access to automobiles for others, the impact of car-sharing on urban travel and the environment is difficult to unravel. Professor Robert Cervero and a team of researchers and students have been working to understand these relationships for the past five years, supported by a Value Pricing Demonstration Grant from the U.S. Department of Transportation. Planning for the opening of City CarShare, a non-profit car-share operator in San Francisco, the team took a longitudinal approach. They tracked a group of car-share members and “non-members” over four years, beginning before the opening of the program, in order to reveal the impacts of car-sharing on travel consumption and vehicle ownership and make strong statements about the impacts of car-sharing.

Those who signed up to immediately join the program formed the “member” group, while those signing up to one day become active members functioned as the “non-member” control group. These non-members were ideal controls because they displayed comparable levels of motivation and interest, having taken the time to sign up for the program, but had not formally joined due to factors like there not being shared vehicles in their neighborhood. The first set of surveys was conducted several weeks before City CarShare’s March, 2001 inauguration. Similar surveys were then conducted of both groups three months, nine months, and two years into the program. The fifth and final set of surveys was conducted in May of 2005. As a result, the research team reached some main conclusions of the work and important implications for urban transportation policy, beginning with trends in car-share usage among members, followed by comparisons between members and non-members.

From the initial March 2001 opening in San Francisco in early to mid-2005, City CarShare grew tremendously. The number of points-of-departure (PODs) grew from 6 to 43, and the number of shared vehicles grew from 12 to 87. Part of this expansion resulted from the introduction of the program to Berkeley and Oakland in 2003. Active membership in City CarShare has trended upwards from over 1800 in September 2002 to 3800 in May 2005. The monthly average number of reservations grew from less than a thousand during the first year to well over 5000 by mid-2005. Members logged 106,000 miles in CarShare vehicles in the month of May, 2005.

The most common purpose for car-sharing was shopping, followed by social-recreational travel and personal business, with work trips constituting only around 10% of car-share trips. Around two-thirds of CarShare trips were made by the driver alone, with no passengers. The highest vehicle occupancies were for trips to school (nearly 2 persons), and the least discretionary trips were made mainly by solo-drivers. CarShare users were asked what modes they would have otherwise taken had car-sharing not been available. Interestingly, respondents claimed that 30% of trips would likely not have been made. For trips that would have been made, car-sharing draws more trips from public transit than any other modal option. To access shared cars, most walked (78%), took transit (14%), or biked (6%).

Looking at overall travel patterns, car-sharing made up 4.8% of members’ total daily trips, up from 2.2% three months into the program but down from 8.1% at the nine-month mark. Adjusting for trip length, car-sharing made up 5.4% of total vehicle miles travelled (VMT) by members. The overall most popular form of conveyance by members – representing 47.6% of all trips – was “non-motorized” (i.e., walking or cycling). Non-members were twice as likely to use a private car, and significantly less likely to take transit, compared to members. Members generally took “green modes” to work or school: nearly 90% of their journeys to work or school were by public transit, foot, or bicycle – a far higher share than for non-members. Members and non-members also differed in how they made shopping, social, and personal business trips, with members more likely to take transit or non-motorized modes. Most members and non-members have a transit pass, own a bicycle and many clearly have options for private car travel. Non-members were slightly more likely than members to have off-street parking (56% versus 41%).

City CarShare’s first wave of members were found to be fairly unrepresentative of the Bay Area’s and even San Francisco’s population, drawn disproportionately from professional-class residents who did not own cars and who lived either alone or in non-traditional households. This pattern generally held four years after City CarShare’s inception. In 2005, whites made up 82.8% of surveyed members (considerably above the 49.6% and 48.8% share for San Francisco and Alameda County, respectively). Members’ median annual personal income of $58,150 was above the census averages for San Francisco as well as the East Bay. Car-share membership also ran in the family: 32.6% of surveyed members’ reported another City CarShare member in the household.

In 2005, 62.8% of members were from zero-vehicle households and 28.7% were from one-vehicle households. Thus, 91.5% were from 0-1 vehicle households – above the 83.3% share during the program’s first year and well above the average of 70.6% for all San Francisco households. Members were half as likely as non-members to have acquired a vehicle, and about as likely to have reduced car ownership since 2001. Consequently, for every 100 member households, about 7 net vehicles were shed, while for every 100 non-member households, about 3 net vehicles were added during the period.

Compared to the first survey (“pre-car-share” — February 2001) and the fourth survey (“second anniversary” – March 2003), mean daily travel distances of City CarShare members fell slightly by the 2005 survey. For non-members, they rose over the long-term but largely stabilized over the 2003-2005 period. None of these changes, however, were statistically significant. Mean travel times steadily fell for both groups over the three survey periods, although more rapidly for non-members. Average travel speeds rose markedly among members, in part from the substitution of City CarShare trips for travel formerly by foot, bicycle and transit. In effect, car-sharing has enhanced mobility, allowing members to conveniently reach more destinations in and around San Francisco.

During City CarShare’s first two years, average daily travel (VMT) fell slightly for members yet increased for non-members. In order to understand differences in the mix of modes and occupancy of the vehicles by members and non-members, we adjusted the mileage to make a Mode-adjusted-VMT (MVMT). For example, a mile by transit or carpool was discounted compared to a mile as a solo driver because of the differences in environmental impacts. For members, MVMT fell by 67% over the long term (2001 to 2005) and by 38% over the intermediate term (2003 to 2005). Such declines were a combination of not only shifts to “green modes” and shorter travel, but also relatively high occupancy levels for private car trips, including those in City CarShare vehicles. MVMT for non-members rose in the first two years but like with members, appear to have fallen some since 2003.

Accounting for the differences in fuel economies among personal cars used by members and non-members, as well as the shared cars (which include mostly small cars and hybrids), members’ average daily fuel consumption fell steadily during the program’s first four years. This likely reflected a combination of members reducing private car ownership, switching to more fuel-efficient City CarShare vehicles, and carrying passengers for many car-share trips. By comparison, mean fuel consumption rose among non-members during the first two survey periods and fell during the 2003-2005 period.

Before and after comparisons from the first four years of the City CarShare program reveal declines in travel consumption among members compared to non-members. While most of these declines attributable to car-sharing accrued during the first several years in recent years levels of travel suppression appear to have stabilized or perhaps slightly reversed themselves. This makes sense – a typical member can only reduce travel so much. Though averages level off, as membership grows, the total impact of car-sharing continues to grow accordingly.

A statistical model of car ownership shows that membership in City CarShare and living near a POD significantly increases the likelihood that an individual lives in a car-free household. In a model of changes in car ownership, member status significantly predicts a reduction in car ownership during the period from 2001 to 2005. Similarly, having a transit pass and having at least one POD near one’s residence were both associated with net declines in household cars. Overall, members were half as likely as non-members to have acquired a vehicle during the 2001 to 2005 period and about equally as likely to have reduced car ownership since 2001. In essence, for every 100 member households, about 7 vehicles were shed, while for every 100 non-member households about 3 vehicles were added during the period. A statistical model of the choice of using car-sharing or otherwise for a trip revealed that members were less likely to choose car-sharing for work trips and that car-sharing decreased with increasing numbers of vehicles owned per household member. In this light, car-sharing is seen to be self-reinforcing: it facilitates the reduction in the number of private vehicles in the household, which in turn induces more car-share use.

Statistical models showed that City CarShare membership was associated with a reduction in daily VMT after controlling for respondents’ socio-economic characteristics. All else being equal, City CarShare membership predicted lowered daily travel by 7 vehicle miles (equal to about 1/3 gallon of gas per day per member). Additionally, the model showed that residing in San Francisco (compared to the East Bay) predicted a reduction in travel by 3 miles, owning a bicycle cut travel an additional 4 miles, while on the other hand, every additional car owned per household member raised daily VMT by 13 miles. The combination of being a City CarShare member, owning a bicycle, and reducing car ownership all serve to shrink a household’s ecological footprint in the San Francisco Bay Area. Increasing the net impact of car-sharing can only be achieved by adding more members.

Based on the five surveys of City CarShare members and non-members, there is clear evidence of sustained net reductions in car-share members’ VMT and fuel consumption some four years into the City CarShare program, due mainly to shorter, higher occupancy, and reduced private car travel during the first several years of the program. In relative terms, the biggest long-term environmental benefits of car-sharing in the San Francisco Bay Area came from reduced gasoline consumption, followed by VMT reductions, and reduced travel distances. Car-share members’ propensities to walk, bike, take public transit, and when they drive, to have other occupants in the vehicle, largely account for these sustained benefits. Reduced travel was matched by increased accessibility afforded to those who joined City CarShare. Rising personal benefits matched by declining social costs (declining VMT, fuel consumption, vehicle ownership) suggests car-sharing is a “win-win” proposition – benefiting users and non-users alike.

The circularity between car-share membership and car-shedding is not unlike that of car ownership and induced travel. Membership was associated with reduced car ownership, and reduced car ownership was associated with more car-share travel. It was not just average VMT that fell among members relative to non-members. Because car-share vehicles tend to be small, fuel-efficient, and carry several people, per capita levels of gasoline consumption and accordingly greenhouse gas emissions have also trended downwards. Mindful of the cumulative costs of driving, car-share members, we believe, have also become more judicious and selective when deciding whether to use a car, take public transit, walk, bike, or even forgo a trip.

These results point to important implications for larger urban planning issues. Car-sharing could become an important component to improving mobility for low-income families, without the heavy burden of vehicle ownership costs. It could also delay or reduce the acquisition of vehicles by young urban residents who may have growing mobility needs as incomes rise. There are also important synergies with urban development to consider. While infill and transit oriented developments are growing in importance in most metropolitan areas in the country, pressures remain on developers to supply parking at traditionally high rates, reducing the cost effectiveness and profitability of potential projects. Car-sharing has been shown to reduce vehicle ownership rates among members, and may become an important element to infill proposals with lower parking to unit ratios. Indeed, at least one large housing project in San Francisco house City CarShare vehicles in exchange for lower parking requirements. Furthermore, project proposals involving car-sharing may strengthen their case for approval because it can be shown that car-share users tend to travel more judiciously and reduce their negative traffic impacts.

For all of these reasons and more, car-sharing is growing beyond just a niche and becoming a common site across the country. And with further urban infill development, rising gas prices, and growing environmental concerns, the market potential is likely to grow. And with that growth comes lower parking pressures, traffic, fuel use and improved travel options for households with a wide range of travel needs.

1. Shaheen, S. and A. Cohen (2005) CARSHARING IN NORTH AMERICA:MARKET GROWTH, CURRENT DEVELOPMENTS, AND FUTURE POTENTIAL. TRB, Washington D.C..

This research was supported by a Value Pricing Demonstration Grant from the U.S. Department of Transportation. We thank the staff of City CarShare, Billy Charlton of the San Francisco Transportation Authority, Mike Mauch of Institute for Transportation Studies at UC Berkeley, and Mike Duncan and Chris Amado from UC Berkeley’s Institute of Urban and Regional Development for their help with this research.

Solar Power Shines

Alameda County is reducing CO2 emissions by 1,000+ tons per year. It is one of the nation’s earliest proving grounds for the U.S.’s fastest growing renewable energy technology.

No other county in the U.S. better exemplifies the thoughtful and ambitious deployment of solar power than Alameda County.

Alameda County has been at the forefront when it comes to using solar power — and demonstrates continued leadership in this arena. At the county level, Alameda is the nation’s largest deployer of solar power, with a total of 3.0 MW of solar photovoltaics (PV) commissioned at nine County-owned facilities.

Alameda County was keen to deploy smart energy strategies — integrating solar generation and energy efficiency measures into county-owned and operated facilities. For years, the County has been a leader in smart energy investments; this is a direct result of the vision and leadership of the County’s Board of Supervisors and General Services Agency to reduce the County’s annual overall energy usage and costs.

A number of cost-effective energy efficiency programs were launched in 1993, when the County’s General Services Agency hired its Energy Program Manager, Matt Muniz, P.E. One of Muniz’s first projects was to retrofit over 12,000 fluorescent light fixtures with energy efficient T-8 lamps and electronic ballasts and install innovative lighting controls throughout the County’s Santa Rita County Jail in Dublin, CA. Later Mr. Muniz’s energy team replaced over 550 inefficient fractional horsepower exhaust fan motors with premium efficiency motors at a payback of less than one year. Both of these projects are part of Pacific Gas & Electric’s (PG&E) “PowerSaving Partners” demand-side management program. As a PowerSaving Partner, the County has received over $3.2 million in direct incentive payments and ultimately reduced electricity costs at its Santa Rita Jail by one-third.

Charged with the task of achieving even greater energy savings at other Alameda County facilities, Mr. Muniz and his energy program colleagues implemented a number of other energy efficiency measures that presently total over $4 million in annual cost avoidance savings. These measures included lighting retrofits in 95% of County owned-buildings, the installation of state-of-the-art building automation systems in 25 facilities, replacement of most chillers with energy efficient and CFC-friendly equipment, and installation of Variable Frequency Drives to the HVAC systems in County facilities.

In early 2000, the City of Oakland was evaluating ‘green’ electricity purchase options and met with executives of PowerLight Corporation, a subsidiary of SunPower Corporation. PowerLight’s protective insulating solar electric rooftop technology gave them a new demand reduction challenge: How could he and his colleagues continue to reduce energy costs at the Santa Rita Jail by generating electricity from an onsite solar power plant?

“I thought that we had completed all the cost-effective energy saving measures that were possible at the jail,” said Matt Muniz, P.E., Alameda County’s Energy Program Manager. “But with over a half-million square feet of unused flat roof space at the jail and the recent drop in prices for solar cells I immediately concluded that solar electricity was the perfect solution for further demand reduction.”

How could Alameda County achieve its vision of becoming a leader in solar energy? Could the economics of large-scale solar PV pencil out? How would such a large capital purchase be financed?

The answers to these questions began with the abundant solar electric incentive programs available in California — the predecessors to today’s statewide California Solar Initiative program — that made the solar electric system affordable in its own right. However, an even more affordable idea was devised: to combine on-site solar electric generation with reductions in the jail’s overall energy use by implementing energy efficiency and sophisticated energy management measures.

Soon thereafter PowerLight Corporation contracted with its strategic partner, CMS Viron Energy Services (which was acquired in 2003 by Chevron Energy Solutions), to showcase the synergy between the latest advancements in solar PV and state-of-the-art energy efficiency technology.

Alameda County, PowerLight, and Viron then crafted an integrated solar electric generation and energy efficiency plan with the goal of exceeding the County’s 10% internal rate of return threshold for energy projects. It would soon serve as a model for other local governments and large commercial customers concerned about rising electricity rates, reliability, and the nation’s increasing reliance upon polluting sources to supply electricity.

The Santa Rita Jail offers proof that solar and energy efficiency are a synergistic blend of technological innovations well suited to respond to today’s stressed power grid in California. By linking the largest rooftop solar PV system in the U.S. explicitly with energy efficiency upgrades and state-of-the-art energy management software, Alameda County is able to reduce its peak power consumption, without any expenditure from its general fund. Some of the innovations that make the Santa Rita Jail project noteworthy include:

Solar Power Installation Provides Multiple Benefits:
PowerGuard® tiles incorporate state-of-the-art solar cells backed with insulating polystyrene foam, turning the sun’s free energy into usable power while increasing building thermal insulation and extending roof life. A key innovation of these roof tiles is that they can be installed on flat rooftops without penetrating the roof membrane.

Applying a “Cool Roof” Membrane with High Solar Reflectivity:
By applying a “Cool Roof” reflective coating on the jail’s existing roof, the roof area not covered by solar tiles now reflects 65% of the solar energy. This effectively reduces the roof’s temperature during the hot summer months by 50 degrees Fahrenheit. Peak electrical demand reductions result from the reduced air conditioning requirement in the occupied spaces below.

Replacing Inefficient Equipment Generates Large Electricity Savings:
Large electricity savings are garnered by replacing an old inefficient chiller with a new 850-ton high efficiency chiller that does not use CFCs that contribute to the degradation of the ozone layer. New variable speed drives attached to the new chiller, chilled water pumps, and cooling towers will respond directly to the precise real-time cooling requirements needed to deliver chilled water instead of operating at 100% speed all of the time.

Smart Energy Management Optimizes Overall System:
Implementation of Utility Vision™, a computerized energy management system developed by CMS Viron automatically reduces peak power consumption during dips in solar power generation. These dips may be caused by normal weather conditions such as cloud cover. For example, if clouds block the sun for five minutes on a summer afternoon, Utility Vision automatically reduces power consumption proportionately so that no additional purchases of expensive peak priced electricity are necessary.

Following the installation of the solar system at the Santa Rita Jail Alameda County was so pleased that it decided to add an additional 1.8 MW of clean solar power into its energy mix. Several more solar arrays were installed at the following County venues between 2003 and 2007 — the Office of Emergency Services, the Environmental Health Services, the Winton Avenue Government Building, the Wiley W. Manuel Courthouse, Hayward Public Works, Fremont Hall of Justice, and the new Juvenile Justice Center.

Alameda County’s deployment of solar power has played an enormous role in bringing down utility costs. By integrating solar power generation with energy efficiency measures, Alameda County has demonstrated enormous leadership in defining both clean and cost-efficient energy solutions. The County’s cumulative 3.0 MW of solar power systems generate 4 million kilowatt-hours of electricity annually, much of it produced during peak demand times, when the utility grid is the most strained and electricity is most expensive.

Overall, Alameda County’s solar energy investments are enabling the County to meet eight percent of its electrical needs at its facilities with clean, renewable solar power. Its grid-connected solar systems help reduce the County’s electrical demand; consequently, it saves over $500,000 annually in avoided electricity purchases. These savings add to the $3.5 million annual savings associated with its energy efficiency measures.

The environmental benefits of Alameda County’s deployment of solar power and other energy efficiency improvements are considerable. Over the next 30 years, the environment will be spared from thousands of tons of air emissions such as nitrogen oxides, sulfur dioxide and carbon dioxide. These emissions are to blame for our urban smog, a primary cause of asthma and other respiratory diseases and contribute to global warming. And over that same 30 years, the solar-generated electricity will reduce carbon dioxide emissions by 45,000 tons. These environmental savings are the equivalent to planting over 270 acres of trees or avoiding driving 71 million miles on California’s roadways.

Energy performance data is posted on the internet so that Alameda County, governmental agencies, solar customers and other interested parties can review and analyze the performance of Alameda County’s solar installations and the energy efficiency measures.

Alameda County has shown that large-scale solar systems can indeed be cost effective investments and even more cost effective if the system is integrated with the facility’s energy management infrastructure.

The solutions offered by effective deployment of solar power reflect the future of the energy industry and point the way toward stable power costs and pollution-free, local energy choices. As volatility in energy pricing continues, increasingly the public and private sector will follow Alameda County’s visionary lead.

The Impact of Energy Consumption on the Environment

What is the Biggest Culprit? Concerns about the impact of energy consumption on the environment, especially global climate change, have finally penetrated public consciousness to the point where significant political action is beginning to happen.

USEnergy3 copyAny number of events can be cited as triggering this step change in consciousness. Al Gore’s movie An Inconvenient Truth, numerous cover articles by our leading weekly magazines, a continuous stream of newspaper articles, scientific reports from prestigious committees, appeals to the President by business leaders, politicians, and scientists, etc., have outlined the risks and challenges to the planet in compelling detail. As Governor Arnold Schwarzenegger commented when he introduced Executive Order S305 on greenhouse gas reduction, “I say the debate is over. We know the science. We see the threat. And we know the time for action is now.”

The question is: where should we focus our efforts? We can begin by asking: where are the biggest culprits and what are the most immediate cost effective strategies, but the challenge is more fundamental than the idea of mitigation or conservation, as important as they are. Ultimately, we must rethink and convert our 200-year-old fossil fuel economy to renewable sources. An even more fundamental question is: can we do it in time to avoid catastrophic change and human hardship?

The recent announcement at UC Berkeley of a $500 million grant by oil giant British Petroleum (BP) to develop biofuels is not only by far the largest alliance between industry and the academies, but also the kind of investment and vision necessary to bring renewable energy swiftly to market. BP’s grant will fund hundreds of researchers in 25 teams, 18 at UC Berkeley and Lawrence Berkeley National Laboratory (LBNL) and 7 at University of Illinois Urbana-Champaign, while BP will assign up to 50 of its own researchers to join the teams. The potential of this landmark interdisciplinary effort is planetary. LBNL Director Steve Chu has estimated that if the acreage which American farmers are currently subsidized not to cultivate were planted in “switch grass” and if ethanol from this cellulose source could be brought to market at the efficiencies demonstrated in the lab, it could provide as much as 100% of the country’s transportation fuel needs. UC Berkeley Chancellor Robert Birgeneau has characterized the effort as “our generation’s moon shot.” Charles Zukoski, Vice Chancellor of Research at the University of Illinois Urbana-Champaign, described it as launching “a new age for agriculture, altering the energy economy of the planet.” As essential and groundbreaking as this effort is, how big an impact will it have on the problem?

World Energy Supply Bar GraphAn examination of our energy consumption by broad sectors reveals the following approximate breakdown: 27% transportation, 30% industrial, 22% commercial, 21% residential. Almost all the energy consumed (90%) comes from fossil fuels, with the remainder from nuclear and renewables, including wind and hydro. When each sector is examined in greater detail, some surprising facts are revealed. Within the transportation sector, only 16% is consumed by cars and trucks, the remaining 7% goes to trains and planes. Thus, if all the transportation fuel for cars and trucks (as big a number at that is) were converted to biofuels, it would still only address 16% of the problem. So what is the biggest culprit?

As Ed Mazria has pointed out in his “2030 Challenge” to design and construction professionals, if you add up the residential and commercial sectors with the portion of the industrial sector consumed by buildings, it totals 48% of the total energy consumption! If you look at electric consumption by itself, 75% goes to operate buildings. With the projected increase in electrical demand planned to be met by coal-fired power plants, the impact of buildings is even more important. Quite simply, buildings are both the biggest problem and opportunity.

Mazria also points out that over the next 30+ years, we will build approximately half again as much new square footage as already exists and we will renovate about 50% of the existing square footage. This means that in the year 2035, three quarters of the built environment in the U.S. will be either new or renovated. This gives design and construction professionals the largest responsibility for making a real difference, but as Schwarzenegger has said “the time for action is now.”

We know from over 30 years of research and development since the last oil crisis in the early 1970s, that we can reduce the energy consumption in buildings by 50-70% through intelligent conservation and the application of passive solar heating, natural ventilation and careful daylighting. The question becomes how do we get the rest of the way to zero carbon buildings — i.e., buildings which generate all of their energy needs from renewables. This is the “moon shot” challenge to design and construction professionals.

With the loads for heating, cooling and lighting reduced dramatically by the strategies above, the remaining challenge is the electric loads for building equipment, appliances and especially the so-called “plug loads” for computers, televisions, kitchen and office equipment. Conservation in lighting and appliances, especially refrigerators, are the reason why electric consumption in California has been flat for the last 20 years in spite of population growth. This phenomenon has been called the “Art Rosenfeld Effect” because he pioneered the “energy star” rating system for all appliances, especially refrigerators. Natural competition in the market place, as a result, reduced energy consumption by 50%. His colleagues at LBNL pioneered in the development of high efficiency light bulbs with a similar result.kyoto

To achieve the goal of zero carbon buildings, the country will need the next generation in conservation technologies in all areas of electric usage, including lighting, appliances, televisions, computers, etc. Fortunately, many of these technologies are in the development phases and are on the way. As demonstrated in California by the “Rosenfeld Effect”, conservation will remain the single most cost effective first step. Nonetheless, buildings will still require electric power; even with reduced loads, and the challenge is can it be met by renewables?

Through our research at the college on the application of photovoltaics and wind technologies to buildings, we have discovered recent commercially available breakthroughs which are extremely promising. By integrating photovoltaics (PV) directly into building assemblies, like roofs and curtain walls, i.e., substituting existing materials with PV materials, the cost effectiveness of PV is already competitive in some markets, especially when compared with peak power. When the next generation of efficiency achieved in the lab (20%-40%) is brought to market in 3-5 years, the integration of PV into building assemblies should become a matter of course for designers.

The story about the integration of small-scale wind machines into building design is equally promising. A new generation of vertical axis machines, double-helix spiral-like rotors, seems to have solved many of the prior problems. Quiet, non-vibrating, effective at low speeds and multi-directional, their applications on roofs and facades offers multiple design opportunities.

When both of these technologies are combined, we have discovered that they have the potential of providing more than 100% of the total electric loads, on an annual average basis, after careful conservation. Yet, the final challenge is overcoming the intermittent timing of these renewables. What do you do if there is no sun and no wind, and you are unable to capture excess energy (when available) by running the meter backwards, i.e., using the grid as storage?

The final step to zero carbon buildings, for instance providing the backup to wind and solar, comes from a surprising source — the waste streams. In our research work on sustainable neighborhoods in China, we have discovered that food wastes, the sludge from primary sewage treatment and green wastes from the landscape, urban gardening and agriculture together generate a significant energy resource in the form of biomass. New technological breakthroughs in biogas generation use a two-stage anaerobic process to convert as much as 80% of the potential energy in the biomass into biogas — methane and hydrogen. This energy source can be put to many uses, for example: providing gas for cooking, compressed gas for gas-powered vehicles, or powering gas-electric turbines for the base or back-up electric loads.

solarFor this technology to be cost effective, however, it needs a minimum flow of biomass material equal to about 8-10 tons per day, or the waste created by a mixed-use, high density neighborhood of approximately 5,000 units of housing (15,000 people). While the construction of such a neighborhood is the exception in the U.S., 10-15 of these kinds of neighborhoods are completed every day in China. We have discovered that the three renewable energy sources, wind, solar and biomass together can provide all the energy for such a neighborhood. Indeed, the neighborhood can be a significant energy exporter to the grid — especially at peak demand during summer afternoons. The challenge of realizing such an integrated and self-sustaining system of energy supply is that it requires a whole new way of doing business for the design and construction industry. The developer, architect, landscape architect, civil engineer, mechanical engineer, city departments of planning and public works, have to operate under a whole new paradigm of collaboration and integration. But the rewards are planetary; zero carbon neighborhoods could become a reality.

In the end, the goal of achieving a carbon neutral future in the building sector is at least several years off, at the building scale. It will take multiple technology breakthroughs in all areas of energy conservation and renewables before the building will be an appropriate scale for supplying all of its own energy needs. On the other hand, a carbon neutral future is already achievable at the neighborhood scale. The question is: will planning, design and construction professionals seize the opportunity?

At CED we are striving to provide the educational foundation for our students which will prepare them to seize a leadership role in this effort. UC Berkeley tops a short list of institutions with the unique combination of breadth and depth needed to develop innovative design solutions and approaches to public policy. It requires not only the collaboration of multiple faculty in our three disciplines, but also reaching across campus to civil engineering, the energy and resources group and anthropology, listed below. CED is the only school in the country where this new paradigm has a chance of being realized and is exemplified by:

  • Elizabeth Deakin and Robert Cervario’s work in transit-oriented development and the making of walkable and bikeable cities with Michael Southworth
  • Tim Duane and Randy Hester’s work to reconcile competing demands on the ecosystem on the island of Hawaii
  • Judith Stilgenbauer’s work on green infrastrutures — the multi-functional and productive features of landscape
  • Galen Cranz’s examination of the social and cultural bases of a sustainable lifestyle
  • Our building science faculty – Cris Benton, Gail Brager, Ed Arens, and Susan Ubbelohde — work on energy conservation, daylighting, lighting controls, interfloor mechanized systems, dual mode buildings and user response to environmental quality
  • Our collaboration with The Berkeley Institute of the Environment (BIE) and Energy Resources Group (ERG) faculty – Inez Fung, Dan Kammen, et.al — on renewable energy systems, solar, wind, and biomass
  • Anthropology Ph.D. student Shannon May’s work on the post occupancy evaluation of China’s fact eco-village

The greatest challenge is developing the institutional structure and pedagogy to create an effective framework for this interdisciplinary collaboration to flourish. The impact that the built environment has on our planet’s future has never been more critical to our survival and presents us with our greatest opportunity for change.