Optimizing Residential Ventilation with RIVEC

Tighter housing envelopes help homeowners maintain thermal comfort but also require continuous mechanical ventilation to maintain healthy indoor air quality. While that tighter envelope can reduce homeowners’ heating and cooling energy use and costs, the required mechanical ventilation and the need to condition air brought in from outside cuts into those savings.

Three maxims are key to designing a superior mechanical residential ventilation strategy: use minimal energy, avoid peak electricity costs, and minimize infiltration of outdoor pollutants. To ensure an economical ventilation system that provides healthy indoor air quality and occupant comfort under the residential ventilation rates recommended by the widely used ASHRAE 62.2 standard, all of these factors must be addressed. Energy recovery ventilators can help, but they can be expensive and installation can be complicated.

For years, Lawrence Berkeley National Laboratory (Berkeley Lab) researchers Iain Walker, Darryl Dickerhoff, and Max Sherman have focused their attention on the problem, to simplify the solutions and reduce costs. The result is the Residential Integrated Ventilation Controller (RIVEC)—a control algorithm that is incorporated into heating, ventilation, and air conditioning (HVAC) controls to optimize fan energy use, costs, and indoor air quality. This work has been funded by the U.S. Department of Energy (DOE) and the California Energy Commission’s Public Interest Energy Research Program (PIER).

Reducing Fan Use by Looking at the Whole Picture

The control algorithm considers floor area, volume, number of bedrooms, infiltration, target ventilation rate, peak demand hours, and airflow capacities to provide the same annual exposure as a continuously operating whole-house mechanical ventilation system (as required by ASHRAE 62.2). By dynamically accounting for these various considerations, it reduces the ventilation system’s energy demand and conditioning losses and mitigates pollutant exposure.

The amount of energy needed for ventilation can change substantially, depending on the time of day when outdoor air is brought into the system. By minimizing the need to heat or cool the outside air to match the desired indoor temperature, less energy is expended. Ventilating with mid-afternoon summer air in Phoenix or nighttime winter air in Detroit both result in a huge energy penalty. To mitigate that penalty, air can be brought in at different times of the day; but it must be done in a way that still maintains healthy indoor air quality. RIVEC avoids ventilating at times of high energy use, and also can help ensure that ventilation occurs at times when outdoor pollutants such as ozone are lower or absent. It avoids over-ventilation by sensing when other systems that move air in and out of the house are operating and turning off the whole-house fan when it is not needed.

“As RIVEC controls the whole-house fan,” Walker explains, “it considers the operation of the other fans in the house and their contribution to the overall ventilation. By doing so, it reduces the need for the whole-house fan to run as much. Also, despite all the efforts to tighten building envelopes, houses still do leak some air, so we’ve incorporated that into RIVEC as well. You can take a credit for leakage under the ASHRAE 62.2 standard, and we took advantage of that. The system senses the outdoor temperature and wind speed and estimates infiltration rates, and if the infiltration rate is providing sufficient ventilation, RIVEC turns off the mechanical fan.”


RIVEC Accounts for Secondary Ventilation Activity

RIVEC works on the principle of “equivalent ventilation”— that is, the ventilation achieves the same results as it would if the fan were running all the time. It varies the ventilation rate by evaluating the ventilation options and operating the whole-house fan when the cost and outdoor pollutants are lowest. To decide when the whole-house fan should be turned on, RIVEC uses calculations of dose and exposure that examine how changing the ventilation rates affect pollutant levels indoors. It then compares those results to the pollutant concentrations that would be found if a continuous ventilation rate were used. If the ventilation is off for an extended time, RIVEC calculates how much additional time it needs to run once it starts again, to make up for the time it was idle.

Field Tests and Simulations Help Confirm Benefits

Field Tests

RIVEC has been field tested in homes to show that it can help homeowners achieve the energy savings predicted by simulations. The tests have monitored home heating and cooling energy use, measured air exchange rates, and looked at other aspects of RIVEC operation. Currently, the Berkeley Lab team is working with a University of Illinois team led by Paul Francisco in a field test collaboration with DOE’s Building America program to evaluate the feasibility of using an outdoor temperature measurement to help control fans. Additional efforts in this project are investigating the potential benefits of using RIVEC in a two-speed fan instead of a one-speed fan; potentially, more energy could be saved by the fan having a medium mode in which to operate.


However, simulations are able to provide more information about RIVEC’s efficacy than field tests.

“It’s impractical to field-test RIVEC in the multitude of climates, temperatures, humidities, housing styles, and HVAC configurations that represent the entire existing housing stock,” explains Walker. “Simulations enable us to evaluate a far greater number of situations. I expect we’ll continue to conduct simulations for the next two or three years. Now that we’re done simulating the general case, we’re evaluating the potential benefits of using RIVEC in specific cases.”

This year, simulations are focusing on outside temperature control; next year, on optimizing for humidity control in areas of the country where that’s a pressing HVAC concern. Other future evaluations may focus on: the energy-reduction effects of adding occupancy controls, passive stacks that provide constant ventilation, and an occupancy algorithm to allow pollutant exposure ratios to rise slightly when the house is unoccupied.

“With each simulation, we learn more about RIVEC’s potential to address the spectrum of HVAC issues,” says Walker. “As a result, we continue to add new features to it all the time.”

To date, simulations have shown a 40 percent savings of ventilation-related energy—approximately 5 to 10 percent energy savings from the total monthly energy bill. The peak load energy reduction for a typical home would be about 2 kW. Nationally, the potential energy savings could amount to 1.1 quads.

Bringing RIVEC to Market

To help plan RIVEC’s commercialization, the team worked with the Cleantech-to-Market program at the University of California’s Haas School of Business. Walker was impressed with the program, which teams business students with researchers to evaluate the commercial potential of products and to develop marketing analyses and materials.

“The background work they did was very good, and they put together an excellent marketing package for us,” says Walker. “It was quite valuable to get the marketing perspective.”

RIVEC is slated to become commercially available in the United States later in 2014, and Berkeley Lab is coordinating efforts with several potential manufacturers.

More information

Iain Walker, ISWalker@lbl.gov, 510-486-4692

RIVEC website

Researchers Will Advance Hybrid Energy Modeling in New Department of Energy-Funded Project 

The U.S. Department of Energy is funding research aimed at improving the accuracy of building energy simulation through an approach known as hybrid modeling.

“Traditional physics-based energy modeling for existing buildings relies on user inputs among which some are unknown or difficult to measure, such as air infiltration rate and interior thermal mass that can vary significantly by time and by buildings,” says Tianzhen Hong, a Computational Research Scientist in the Environmental Energy Technologies Division of Lawrence Berkeley National Laboratory (Berkeley Lab).

The inaccuracy of these inputs is a major reason for the uncertainty in building simulation models of energy use. In the newly funded research, Hong and team members will develop a new hybrid approach to energy modeling that will avoid using difficult-to-measure parameters. Instead, they will use the measured data of space temperature as new inputs, and reformulate the EnergyPlus model’s space heat balance equations to improve the accuracy of simulation results.

EnergyPlus is DOE’s flagship whole-building energy simulation engine. It takes a physical description of a building’s geometry, construction materials, HVAC systems, operations and control schemes, occupancy schedules, and prevailing weather conditions and calculates the energy and water used to maintain occupant thermal and visual comfort. The model is widely used by architects and engineers to design comfortable, energy-efficient buildings, and demonstrate buildings’ compliance with codes and standards. The research team will incorporate the new modeling algorithm into EnergyPlus by 2017.

Download EnergyPlus for free at:




New research assesses energy balance of large-scale photoelectrochemical hydrogen production

In the search for clean energy solutions to displace greenhouse gas emitting fossil fuels, few technological options are as alluring as directly producing hydrogen from sunlight. If hydrogen, the most abundant element in the universe, could be produced on earth economically and with a minimum overall environmental impact, it could provide energy to both stationary and transportation applications with very low overall carbon footprint and climate impact. For example, hydrogen could be the fuel input in fuel cells to generate electricity, or feedstock for producing liquid transportation fuels.

Today however, the most economical way to make hydrogen is by reforming fossil fuels such as natural gas—with the nearly same negative impact to the climate as direct combustion. Hydrogen production via electrolysis—splitting water into hydrogen and oxygen using electricity—can in principle use renewable electricity, but it is currently much more expensive.

Scientists are pursuing a promising pathway to generating large-scale amounts of hydrogen for clean energy production directly by splitting water using sunlight, a process called photoelectrochemical (PEC) production. Instead of splitting off the hydrogen from hydrocarbons and being left with carbon, which is typically oxidized and emitted into the atmosphere as carbon dioxide, photoelectrochemical production splits off hydrogen from water, leaving clean oxygen gas.  Researchers have accomplished PEC on a small scale in laboratories, but scaling up the process into hydrogen generating plants capable of supplying enough to meet the needs of industrial societies requires considerably more research and technology development.

Many unanswered questions lie not just in the technology, but in the area of life-cycle impact—in particular, its net energy balance. An energy production facility such as one based on PEC technology, should generate more energy over its lifetime than is used to manufacture and operate it. Scientists and funding agencies would like to understand what research directions they need to follow in order to make large-scale PEC-based hydrogen production a reality.

A new study from scientists at the Joint Center for Artificial Photosynthesis (JCAP) created a life-cycle assessment (LCA) model to provide some estimates that might help guide research directions to faster marketplace success. They constructed a model simulation of a large-scale PEC-based hydrogen production facility, using what is known currently about the technology as well as projections of future performance. JCAP scientists affiliated with the Materials, Physical Biosciences, Chemical Sciences and Environmental Energy Technologies (EETD) Divisions of Lawrence Berkeley National Laboratory (Berkeley Lab) participated in the study.

“The modeling of this solar-to-hydrogen technology provides insights into its potential competitiveness,” says the study’s lead author, Roger Sathre of the Environmental Energy Technologies D. “It will help identify the key challenges and opportunities for improvement.”

EETD researchers have had considerable experience performing life cycle assessments of technologies still in the laboratory, such as new infrared-blocking electrochromic window coatings, carbon sequestration technologies, as well as advanced biofuels. Their results are intended to help guide lab R&D to market success.

Thorough description and many inputs

The development of the hydrogen production model required many components, and considerable input from the researchers developing the technology. The research team modeled a facility capable of producing the hydrogen equivalent of 1 GW of continuous output, or 610 tons of hydrogen per day. All U.S. light-duty vehicles could be powered by about 160 such plants.

“This study is the first to look at a large hydrogen generation system, and to make a thorough assessment of its balance of system [BOS] requirements—its energy and materials inputs and outputs,” says Jeffery Greenblatt of EETD, one of the study’s authors. A couple of prior studies have evaluated smaller scale systems, about one-thousandth the size, focusing on their economics.

The Berkeley researchers prepared a preliminary engineering design of the plant, and generated a model describing the system-wide energy flows associated with producing, using, and decommissioning the facility. This allowed them to calculate the facility’s three primary energy metrics.

One is the life-cycle primary energy balance, or how much net energy the facility would provide over its lifetime. The second is the energy return on energy investment (EROEI), which describes how much usable energy the facility generates divided by its energy inputs—it must be greater than one by as much as possible for the technology to be viable. Finally, the energy payback time measures how long the facility must operate to deliver the hydrogen equivalent of the energy required for its manufacturing, construction and decommissioning.

Creating the model required building the facility up from its components. The team modeled a large, two square meter photoelectrochemical cell, assembled in a truck-transportable structure called a panel containing 14 cells. Panels were arranged in fields consisting of 1,000 panels each, and the overall facility was made up of 1,510 fields. (See Figure 1.)

The model required estimates of energy use to make all these components, plus the rest of the plant such as pipes for water and gas, storage tanks, compressors, sensors, roads, and the like. Construction, operation and decommissioning required estimates of the energy inputs, material inputs such as water and process gases, and transportation to bring in materials and cart out wastes. The plant was assumed to have a service life of 40 years.


Positive energy benefits require meeting system-level goals

Under the model’s base case conditions, the plant’s payback time is 8.1 years. The energy return on energy invested, at 1.7, is positive. The life-cycle primary energy balance over the plant’s 40-year life is more than 500 petajoules. “One petajoule is the energy required to power 50,000 hydrogen fuel-cell cars for a year,” Greenblatt points out.

“Our results show that hydrogen production based on photoelectrochemical technology has the potential to deliver significant amounts of energy,” says Sathre. “There are a number of variables that influence how much energy, and these are variables that R&D in the field needs to focus on.“

The most important factor is the overall efficiency of conversion from solar energy to hydrogen, termed the solar-to-hydrogen (STH) efficiency ratio. The higher the STH efficiency, the better the energy return (the base case assumed 10 percent conversion efficiency). The lifespan of the PEC cell, the energy used to manufacture the PEC cell, and the lifespan of the rest of the facility are the other most important factors. The report addresses a number of research directions that could lead to more efficient PEC cells.

The researchers estimate that if PEC cells have an STH efficiency of 20 percent (which they believe is possible eventually), and a cell life span of 20 years, the plant can have an energy payback time of just three years, and an EROEI of more than 3, almost double that of the base case.

“Our result validates the need for high efficiency PEC cells, something the research community already understands,” says Frances Houle, Department Head for Science-Based Scale-Up at JCAP and another of the study’s authors. “It also drives home the need for cell longevity—on the scale of years—well beyond what is currently measured in the lab, which is the scale of hours. Also, we found that the energy investment in the balance of system is smaller than that required to fabricate the PEC cells, so methods to make the cells with less energy will be impactful.”

Greenblatt adds that “research is on the right track, because the analysis suggests that a plant built with PEC technology will be energy-positive, but future R&D should ensure that the variables most affecting net energy balance—efficiency, longevity, initial energy investment—are well-understood and optimized.”

—Allan Chen

Roger Sathre, Corinne D. Scown, William R. Morrow III, John C. Stevens, Ian D. Sharp, Joel W. Ager III, Karl Walczak, Frances A. Houle, and Jeffery B. Greenblatt. “Life-cycle net energy assessment of large-scale hydrogen production via photochemical water splitting,” Energy & Environmental Sciences, DOI: 10.1039/c4ee01019a.


This research was supported by JCAP, a DOE Energy Innovation Hub, supported through the Office of Science of the US Department of Energy. Information about JCAP is available online at http://solarfuelshub.org/.



EETD Microgrids Researchers to Collaborate with MIT and IIT-Comillas University

Lawrence Berkeley National Laboratory (Berkeley Lab) announces the signature of a collaboration license with the Massachusetts Institute of Technology and IIT-Comillas University (Madrid) for the Utility of the Future Program. DER-CAM, software developed in the Microgrids Group at the Environmental Energy Technologies Division (EETD), will play a key-role in this project, which is part of the MIT Energy Initiative.

Greater utilization of local energy resources, increasing use of natural gas (NG), and integration of renewables (solar photovoltaic and wind) into electricity supply are prominent in contemporary discussions of energy policy both in the European Union and the U.S. The deployment of distributed generation (DG) and renewable energy sources is expected to grow in coming years, and significant impacts on the operation and planning of distribution grids and, more generally, the sustainability of energy systems, are expected.

DER-CAM, the Distributed Energy Resources Customer Adoption Model, has been developed and improved for more than 10 years at Berkeley Lab. The main feature of DER-CAM is its ability to determine the cost-optimal design inside one or more buildings. It chooses which DG technologies a customer should adopt and how these technologies should be operated based on specific site load, technology characteristics and price information. This makes DER-CAM the ideal software for such a project.

The Utility of the Future project will provide a neutral framework within which to evaluate the economic, regulatory, and technological impacts of the ongoing evolution of the power sector worldwide.

The study brings together an interdisciplinary MIT Energy Initiative consortium in partnership with IIT-Comillas University. The research partners will develop scenarios of distributed energy resources (DER) technologies, business models, and regulatory environment to understand how the electricity system will change over the coming decade.

Improvements in the cost and performance of a range of distributed energy generation (DG) technologies, and the potential for breakthroughs in distributed energy storage (DS) are creating new options for on-site power generation and storage, driving increasing adoption and impacting utility distribution system operations. In addition, changing uses and use patterns for electricity–from plug-in electric vehicles (EVs) to demand response (DR)–are altering demands on the electric power system.

To this end, the research partners will use DER-CAM to simulate technical capabilities and economic and environmental benefits associated with the provision of energy services based on distributed energy resources—including distributed generation, distributed energy storage, electric vehicles and demand response—that will allow the creation and proliferation of new business models.

DER-CAM will also help assess NG-fuelled distributed generation technologies from an economic point of view, identify the most attractive areas of application and understand the opportunities to increased natural gas utilization in distributed generation applications. Indeed, the developments observed in the electric power sector offer both opportunities and challenges for natural gas utilization in DG applications like co-generation, which will provide a bound between gas and electricity systems.

The Microgrids group at Berkeley Lab is looking forward to this partnership, which will start the week of July 14 with the arrival of students from both universities in Berkeley to be trained on DER-CAM by EETD staff.

The duration of the project is expected to be two years. Some of the researchers include Professor José Ignacio Pérez-Arriaga (co-PI, MIT), Stephen Connors (Senior Research Scientist, MIT) and Pablo Frías (Professor, IIT-Comillas University) among others.

Dr. José Ignacio Pérez-Arriaga
Visiting Professor, Center for Energy and Environmental Policy Research (CEEPR), MIT
Professor and Director of the BP Chair on Energy & Sustainability, Instituto de Investigacion Tecnologica (IIT), Universidad Pontificia Comillas


Stephen Connors
Head, Analysis Group for Regional Energy Alternatives (AGREA); Director, AGS Energy Flagship Program
MIT Energy Initiative


Dr. Pablo Frías
Professor of Electrical Engineering at the Engineering School of Universidad Pontificia Comillas.


Additional information

For more information about the MIT Energy Initiative, go here.

To learn more about DER-CAM, please click here.


Karen Tapia-Ahumada, GTI-MIT Energy Fellow, katapia@mit.edu

Tomás Gómez, Professor at IIT Comillas, tomas.gomez@iit.upcomillas.es

Michael Stadler, Microgrids Group at Berkeley Lab, mstadler@lbl.gov



Department of Energy’s FLEXLAB Opens Test Beds to Drive Dramatic Increase In Building Efficiency

Berkeley, Calif. – July 10, 2014 – The world’s most advanced energy efficiency test bed for buildings is open for business, launched today by U.S. Department of Energy Deputy Secretary Daniel Poneman. DOE’s FLEXLAB at Lawrence Berkeley National Laboratory (Berkeley Lab) is already signing up companies determined to reduce their energy use by testing and deploying the most energy efficient technologies as integrated systems under real-world conditions. The facility includes a rotating test bed to track and test sun exposure impacts, and other high-tech features.

In addition to Deputy Secretary Poneman, University of California President Janet Napolitano, Genentech Vice President Carla Boragno, Webcor CEO Jes Pederson, and PG&E Vice President Laurie Giammona joined event host Berkeley Lab Director Paul Alivisatos to speak about the power and potential of this facility to help California, the nation and the world reduce energy use, curb greenhouse gas emissions and save money.

“In the United States, nearly 40 percent of all energy and over two-thirds of all electricity consumed goes to operate commercial, industrial and residential buildings,” said Deputy Secretary Daniel Poneman. “To power these buildings, Americans spend more than $400 billion every year. By making buildings more energy efficient, we can save money by saving energy and drive the nation to our low-carbon future.”

“So far, Berkeley Lab’s energy efficiency work has saved American families, businesses, and institutions many billions of dollars in energy bills. If all goes as planned, FLEXLAB – the first of its kind test bed designed to enable much more aggressive whole building energy savings – will add to that impressive tab,” said Berkeley Lab Director Paul Alivisatos.

“Berkeley Lab is already a global leader in smart-building innovations that are helping our nation cut greenhouse gas emissions,” said Napolitano, president of the University of California, which manages Berkeley Lab for the U.S. Department of Energy. “FLEXLAB will allow us to cut building emissions even further, and lessons learned here will be instrumental in helping UC reach its carbon neutrality goal by 2025.”

In the first test bed experiment, leading biotech company Genentech is leveraging FLEXLAB to test systems for a new building at their South San Francisco headquarters.

“At Genentech, we are constantly innovating and following the science, so we were excited to apply this approach to energy efficiency and building optimization,” said Carla Boragno, Genentech Vice President for Site Services. “FLEXLAB represents a new type of experiment for us, and presents the opportunity to be first-in-class in another area of innovation. We are proud to be the leading client of FLEXLAB.”

PG&E is next in line to use the facility to test the next generation of technologies – those that focus on whole building systems – for emerging technologies incentive programs.

PG&E is working with an advisory committee to identify system-scale efficiency improvements that make best sense for most businesses. It is testing alternatives in FLEXLAB, starting with innovations in building envelopes, lighting and shading.

“Compared to the usual ‘widget’ approach of offering incentives for single pieces of equipment, utilities are finding the next generation of energy efficiency technology – which includes single or multiple integrated building systems – is an order of magnitude more complex. FLEXLAB will help them get a handle on this,” said FLEXLAB Executive Manager Cindy Regnier. “And that opens the door to new and renovated buildings that are dramatically more energy efficient.”

That’s what Bay Area-based builder Webcor – Genentech’s contractor – hopes to find. In FLEXLAB’s pre-launch private-sector experiment, Webcor is using the rotating test bed to plan a 250,000-square-foot building, which includes a built-out space that mimics Genentech’s interior office space and will test for user comfort and utility.

“We are running tests and gathering data that will allow us to maximize the Genentech building’s energy-efficiency potential,” said Webcor CEO Jes Pederson. “FLEXLAB could revolutionize the way we plan and build energy-efficient buildings.”

Recognizing that building inefficiency is a critical obstacle to achieving U.S. clean energy and emissions goals, DOE issued a Request for Proposal in 2009 for a new kind of testing facility to address the challenges buildings face in achieving deeper levels of energy savings. Many buildings are designed to be energy efficient, but once they are up and running, can use a lot more energy than planned. To close that achievement gap and accelerate breakthrough technologies, Berkeley Lab competed and won the $15.9 million contract to build FLEXLAB, a testament to the Lab’s long history of energy efficiency innovations.

FLEXLAB is a testing ground for developing new, energy-efficient and low-carbon building technologies. Berkeley Lab and its utility and private sector partners will identify, test and measure technologies of the future that will help California and the world move to a cleaner, more efficient energy future.

Opening day featured a series of panel discussions focused on energy efficiency from a business perspective. Speakers represented companies including Microsoft, Siemens, Oracle, Wells Fargo, Colliers International, and Schneider Electric.

For more information, including photos and videos, go to flexlab.lbl.gov.

# # #


Lignin’s role in reducing life-cycle carbon emissions explored in new research paper

Cellulosic biofuels are the focus of intense research aimed at developing transportation fuels that are significantly lower in carbon intensity than those derived from petroleum. Biofuels have the potential to reduce the impact of the transportation sector on the climate—cellulosic ethanol, by some estimates, may reduce the carbon emissions relative to gasoline by up to 80 percent. While researchers have developed technologies capable of converting many components of wood and other plant material into liquid fuels, lignin, a chemical in plants that gives their cells rigidity, has proven difficult to break down.

Current models of the refining process for biomass-to-transportation fuels assume that the lignin component is burned onsite to meet the plant’s process heat and power needs. Onsite combustion offsets some of the plant’s energy costs, and provides the plant with offset credits for greenhouse gas emissions.

Other options exist, including shipping the lignin to nearby coal-fired power plants. Offsetting some of the coal burned in these plants with lignin from biorefining reduces their carbon footprint. What is the most effective way to use lignin such that the positive impacts of reducing energy demand and emissions can be achieved at the lowest capital cost and water demand? The answer to this question interests parties across the energy industry, from policymakers to utilities and operators of generating plants, to the biofuels research & development community. For the first time, research conducted at the Lawrence Berkeley National Laboratory (Berkeley Lab) addresses this question at a national production scale.

A new study, published in the journal Environmental Science & Technology and led by Corinne Scown, uses life cycle analysis modeling (LCA) to answer this question. Scown is in Berkeley Lab’s Environmental Energy Technologies Division (EETD). Scown and her colleagues conducted a life-cycle assessment of four options for using lignin: (1) onsite combustion for heat and power; (2) onsite combustion plus the use of additional gas-fired power generation; (3) export lignin to coal-fired power plants, use natural gas to meet the biorefinery’s heat requirements and a portion of electricity use; (4) export lignin to coal-fired plants, use natural gas to meet all of the biorefinery’s heat and power needs.

In cases 1 and 2, biogas produced at the refinery and a solids boiler for the lignin produce electricity and process heat used in the manufacturing of the biofuels. Cases 3 and 4 eliminate the need for a solids boiler at the refinery site.

The team evaluated these four cases under a U.S.-based cellulosic biofuel production scenario in which corn stover (leaves, stalks, husks and cobs of corn), wheat straw, and the fast-growing tall grasses of the genus Miscanthus are converted to 160 billion liters of ethanol annually. The results are applicable to any biofuel process that cannot breakdown lignin. “As far as we know, this is the first evaluation of lignin use options at the scale of a national biofuels production scenario,” says Scown. “We also know of no other study that has explored the life-cycle water use tradeoffs of such a scenario.”

Using a computer model of an ethanol biorefinery, the research team calculated that the life-cycle greenhouse gas emissions ranges from 4.7 to 61 grams of carbon dioxide per megajoule (g CO2e/MJ). This compares to 95 g CO2e/MJ for gasoline.

Scown adds, “Overall, we found that exporting lignin to coal-fired power plants can reduce GHG emissions at a magnitude comparable to using lignin onsite to provide power in some cases. Export of lignin can reduce life-cycle water consumption by up to 40 percent, and reduce capital costs by up to 63 percent, in part, by eliminating the need for an onsite solids boiler.”

The study also found that nearly half of U.S. coal-fired power plant capacity is expected to be retired by 2050, which will limit the capacity for co-firing with lignin, and double the transportation distances between biorefineries and coal power plants.

The article “The role of lignin in reducing life-cycle carbon emissions, water use, and cost for U.S. cellulosic biofuels,” was authored by Corinne D. Scown, Amit A. Gokhale, Paul A. Willems, Arpad Horvath, and Thomas E. McKone. The research was funded by the Energy Biosciences Institute.

Read the full report at: http://pubs.acs.org/doi/abs/10.1021/es5012753



2014 ITRI-Rosenfeld Fellowship Winners Announced

Zhenhua Liu and Chinmayee Subban were recently announced as the winners of the 2014 ITRI-Rosenfeld Postdoctoral Fellowship. The fellowship honors the contributions of Arthur H. Rosenfeld, of Lawrence Berkeley National Laboratory’s Environmental Energy Technologies Division (EETD), for his work toward the advancement of energy efficiency on a global scale. The selection process includes scrutiny of the applications by a selection committee, presentations by the finalists, and panel interviews. The award enables the applicants to engage in innovative research that leads to new energy-efficiency technologies or policies, as well as the reduction of adverse energy-related environmental impacts. It is made possible through a gift from the Industrial Technology Research Institute of Taiwan (ITRI) and with EETD support.

Zhenhua Liu earned his PhD in Computer Science at California Institute of Technology (Caltech). His research focuses on the efficient integration of renewable energy into IT and the power grid. His proposal topic for the fellowship was Demand Response: Coordinating IT and the Smart Grid Towards a More Sustainable Future, and his mentor for this work is EETD’s Mary Ann Piette. For this project Liu plans to develop new demand management algorithms, develop new demand-response programs, and investigate other opportunities that would help guide the management of data centers, buildings, and other systems. He has already begun working on his project at the Lab.

Chinmayee Subban earned her PhD from Cornell University’s Department of Chemistry and Chemical Biology. Her graduate and postdoctoral research has been focused on the design and characterization of electrode materials for fuels cells and lithium-ion batteries. Her proposed topic of research for the fellowship was Technology Invention: New Electrode Materials for Water Treatment with Capacitive Deionization (CDI), and her mentor for the work is EETD’s Ashok Gadgil. Her goal for this project is to develop more efficient, affordable electrode materials for CDI, bringing costs down and thus enabling the widespread use of the technology in treating brackish water for poor and rural communities around the world. She will begin at the Lab in September.

The award ceremony will take place in October 2014, at Berkeley Lab.

The application period for the 2015 ITRI-Rosenfeld Postdoctoral Fellowship will open in August 2014.

More Information

ITRI-Rosenfeld Postdoctoral Fellowship website


EETD Scientist Participates in Energy Efficiency Standardization Roadmap

The following press release is from the American National Standards Institute (ANSI) Energy Efficiency Standardization Coordination Collaborative (EESCC), a group chaired by the U.S. Department of Energy and the private sector. William Miller of the Environmental Energy Technologies Division, and, formerly, a longtime energy efficiency manager at Pacific Gas & Electric, participated in the development of this document.

For information on downloading the Roadmap document, see the links below.

New Energy Efficiency Standardization Roadmap Establishes National Framework for ActionRoadmap Details 125 Recommendations to Advance Energy Efficiency Standardization in the Built Environment

With the release today of the Standardization Roadmap: Energy Efficiency in the Built Environment, U.S. industry, government, standards developing organizations (SDOs) and other energy efficiency stakeholders now have a national framework for action and coordination on future energy efficiency standardization. Developed by the American National Standards Institute (ANSI)Energy Efficiency Standardization Coordination Collaborative (EESCC) – a cross-sector group chaired by representatives of the U.S. Department of Energy (DOE) and Schneider Electric – the roadmap charts 125 recommendations to advance energy efficiency within the built environment.

According to the DOE, our nation’s buildings account for more than 70 percent of total U.S. electricity use and 40 percent of the nation’s total energy bill, at a cost of $400 billion dollars per year. With 20 percent or more of this energy wasted, comparable reductions in energy have the potential to save an estimated $80 billion annually. Standards, codes, and conformity assessment programs offer significant opportunities for energy and cost savings and improved energy efficiency capabilities for the nation’s buildings. The roadmap identifies many such opportunities, detailing recommendations and timelines for action across five interrelated areas of focus:

  • Chapter One: Building Energy and Water Assessment and Performance Standards outlines 46 recommendations to address identified standardization gaps in these areas
  • Chapter Two: System Integration and Systems Communications details 9 gaps and recommendations examining how building subsystems could be integrated in order to manage the energy use of a building or campus of buildings for maximum efficiency
  • Chapter Three: Building Energy Rating, Labeling, and Simulation outlines 22 recommendations to address identified standardization gaps
  • Chapter Four: Evaluation, Measurement, and Verification (EM&V) details 32 gaps and recommendations to advance the field of EM&V
  • Chapter Five: Workforce Credentialing puts forth 16 overarching recommendations to advance workforce credentialing for the energy efficiency field



Lev Ruzer, EETD Affiliate and Editor of the Aerosol Handbook, Passes Away at Age 92

Dr. Lev Ruzer, who worked as an affiliate with the Environmental Energy Technologies Division’s Indoor Environment Group for 24 years, has passed away. During his tenure at Lawrence Berkeley National Laboratory (Berkeley Lab), Ruzer, worked without financial support; purely for the love of science.

Ruzer was born in the Soviet Union, where he studied nuclear physics at Moscow University but was unable to work as a scientist upon graduation for political reasons. Once the political tides turned, he worked as a researcher, assessing dosages to animals exposed to radon and its decay products—work that would earn him an equivalent to a PhD in 1961. He founded and chaired the Aerosol Laboratory at the Institute of Physico-Technical and Radiotechnical Measurements in Moscow from 1961 to 1979, and in 1968 published a book on radioactive aerosols. In 1970 he became a doctor of technical sciences, and in 1977, became a professor. However, in 1979, with another political shift, he was discharged, and was unable to work for eight years.

In 1987, he emigrated to the United States, and he began to work as an affiliate at Berkeley Lab in 1989. He published papers in the emerging field of dosimetry of nanoparticles, as well as a book on radioactive aerosols; all in all, he authored more than 130 publications and was granted three patents. He also served as editor of Aerosol Handbook: Measurement, Dosimetry, and Health Effects. The expanded and updated 2nd edition was published in 2012, when Ruzer was 92 years old.

Lev was always friendly, with a great sense of humor. He enjoyed telling stories of his life in the Soviet Union, and when asked how he was doing, would often say, “Not as good as yesterday…but better than tomorrow!”—an example, he said, of Russian optimism. His commitment to science was unwavering, and watching him taught one the value of persistence; even in his nineties, when typing became a challenge, he produced long, detailed papers.

Berkeley Lab was fortunate to have hosted Lev and his research for more than two decades. “We will miss Lev,” says William Fisk, Head of the Indoor Environment Group. “I am happy that we could serve as his host for these many years.”

Mark Wilson

Selling an Energy-Efficient Loan Portfolio—New Policy Brief

Can financing deliver significant private capital and rapid growth in home energy efficiency improvements? A key element may be attracting secondary-market investors to buy the efficiency loans and thereby replenish funds for a new round of lending. A new policy brief from Lawrence Berkeley National Laboratory’s Energy Markets and Policy Group, led by efficiency financing expert Peter Thompson, details how two creative financing entities crafted a ground-breaking deal with several novel features that may offer valuable lessons for future efficiency financing transactions.

The policy brief, Selling an Energy Efficiency Loan Portfolio in Oregon: Resale of the Craft3 Loan Portfolio to Self-Help Credit Union, provides insight into the recent transaction of an on-bill energy efficiency loan portfolio between two mission-oriented lenders, Craft3 in Oregon and Self Help in North Carolina. Craft3 works with local utilities and Clean Energy Works (CEW) program to provide consumer energy efficiency loans for home energy upgrades in Oregon and Washington. The transaction is notable for the many innovative design elements of the Craft3 loans, including: long loan terms (up to 20 years), on-bill collection, and novel underwriting approaches. The case study illustrates how certain design decisions can sometimes both facilitate the objectives of efficiency financing programs and possibly present challenges for the sale of a portfolio of energy efficiency loans.

The policy brief explores:

  • The motivations for the sale and how the transaction benefited both parties;
  • The process that the two parties went through to finalize the transaction;
  • How the design of the CEW/Craft3 program impacted the terms of this transaction and how the deal was structured; and
  • Lessons that efficiency program administrators can take from the transaction.

This case study is the latest in the LBNL Clean Energy Financing Policy Brief series. These working papers highlight emerging financing models, important issues that financing programs face, and how these issues are being addressed.