Schatz Fellow joins panel on inclusivity at American Solar Energy Society conference

This August, Schatz Energy Fellow Thalia Quinn presented for a panel discussion on Broadening Access to Solar: Jobs, Careers, and Futures, at the American Solar Energy Society’s 47th annual conference in Boulder, Colorado. Panelists discussed paths for the solar energy field to increase inclusivity and the economic opportunities of underrepresented communities. Thalia shared her recent journey from undergraduate work in chemical engineering into the field of renewable energy. Moderated by Annie Lappé, the panel also included representatives from Grid Alternatives, the American Association for Blacks in Energy, Power52, SolarWorld, and Sandia Labs.

Conference talks included the estimated locational value of solar, progress in electric vehicle costs compared to combustion engines, solar resource and solar cost/benefit webtools, and current events in solar policy. The conference closed with a discussion of policies designed to increase the deployment and ease of procuring solar energy in the Interior West region. Jessica Scott described achievements and lessons learned from Vote Solar campaigns: recently, Nevada legislature submitted a ballot initiative pushing for a higher renewable portfolio standard (RPS), which would increase the state’s RPS from 25 percent by 2025, to 40 percent by 2040.

A meadow leads to evergreens, peaked mountains, and white clouds in a blue sky

Conference participants took a Sunday hike through Chautauqua Park (photo by Thalia Quinn)

New publication: measuring residence time distributions in screw conveyor reactors

Charles Chamberlin, David Carter, and Arne Jacobson recently authored an article on measuring residence time distributions of wood chips in a screw conveyor reactor. A screw conveyor or auger makes use of a rotating helical blade inside of a tube or trough to move wood chips, sawdust, flour, or other granular materials through a reactor — such as a dryer, heater, cooler, gasifier, or torrefier. How much change in the materials takes place in such reactors depends on the average residence time and how variable that residence time is.

Internal view of a screw conveyor.

The screw conveyor in this Norris Thermal Technologies torrefier moves the woods chips from the inlet (on the left) to the outlet (on the right). The rate of rotation controls the residence time within the reactor. The reactor cover has been removed to show the screw.

This paper compares three alternative methods for measuring the residence time distribution of wood chips in a screw conveyor reactor using experimental results from a pilot scale torrefier:

  • addition of material to an empty reactor (step-up),
  • halting addition of material to a reactor under steady flow, (step-down), and
  • addition of a pulse of labelled material (i.e., a tracer) to a reactor under steady flow.

We found that all three methods yield residence time distributions that are approximately symmetrical and bell-shaped, but the distribution estimated from the pulse input of tracer exhibited a long trailing tail that was not detectable in either the step-up or step-down results. Second, we demonstrated that a normal probability plot provided a useful way to display and analyze the distributions obtained in the tracer experiments. Finally, we observed that all three methods yielded mean residence times that consistently differed from the nominal values, with the step-up method averaging 8% shorter, the pulse addition of tracer averaging 7% longer, and the step-down averaging 60% longer.

The article appeared in the August 2018 issue of Fuel Processing Technology and is available to download here in pdf.

October 18 lecture: Local water innovation through community-university partnerships

Headshot of Lonny Grafman

This talk will share inspiring solutions for water collection, storage, treatment, and conservation that have been created by community engagement.

Lonny Grafman has worked on and led teams for hundreds of domestic and international projects across a broad spectrum of sustainable design and entrepreneurship — from solar energy to improved cookstoves, micro-hydro power to rainwater catchment, and from earthen construction to plastic bottle schoolrooms. Throughout all these technology implementations, he has found the most vital component to be community. His first book shares stories and strategies for communities coming together To Catch the Rain.

Grafman is an engineering instructor at HSU; the founder of the Practivistas summer abroad, full immersion, resilient community technology program; the project manager of the epi-apocalyptic city art project Swale; the Chief Product Officer of Nexi; Managing Director of the BlueTechValley North Coast Hub; and the President of the Appropedia Foundation, sharing knowledge to build rich, sustainable lives.

Download the event flyer

The Sustainable Futures Speaker Series at Humboldt State creates interdisciplinary discussion, debate, and collaboration around issues related to energy, the environment, and society. Fall 2018 lectures are held on Thursdays from 5:30-7 pm in HSU Siemens Hall 108 (with the exception of Catherine Sandoval’s talk on November 1, which will be held in the Native American Forum / BSS 162). For details on upcoming events or to request accessibility accommodations, visit our series events page or call (707) 826-4345.

A pipe sliced in half to catch rain

A sliced PVC pipe is ready to catch rain at the Pedregal Permaculture Demonstration Center in San Andres Huayapam, Mexico

Student research developments: summer 2018

This summer, thirteen students contributed to Schatz Center research projects in smart grids, bioenergy, wind, and off-grid energy access.

SMART GRIDS

Craig Mitchell provided construction observation at the Solar+ installation, tracking the canopy weight in real-time and serving as an onsite liaison between contractors and the Schatz microgrid team. As part of his observation, Craig recorded the installation’s actual daily labor and equipment requirements, to better define the needs for similar projects in the future. He is currently developing a hardware design toolkit that documents lessons learned in the Solar+ installation.

Solar+ students standing outside the Schatz Center

Solar+ student team: (l to r) Craig Mitchell, Thalia Quinn, Ellen Thompson and Rene DeWees

Thalia Quinn, Ellen Thompson and René DeWees have been developing a model to assess the current and future costs of building microgrids that integrate solar, battery storage, and fast EV charging. This model will help define which sites are good candidates for investment, and identify future research and development opportunities. This summer, the team conducted a detailed literature review to assess current and forecasted cost data: Thalia focused on battery storage, Ellen on electric vehicle charging infrastructure, and René on solar PV. They are now refining their cost model and generating a convenience store survey, to understand how current site owners view microgrids and to better assess installation opportunities.

Smart grid design is also evolving to take advantage of demand response technologies. As part of a collaboration with GE & Southern California Edison, Anh Bui developed an algorithm using Python code for estimating the tension between shifting a customer load to benefit the grid versus shifting a load to reduce their bill. Anh also helped with the installation of our new Schatz Solar Array in September.

Anh Bui tightens a solar module on the Schatz Center roof

Anh Bui installs a module for the new Schatz Solar Array

BIOENERGY

This summer, Sabrinna Rios Romero quantified decay rates for the post-harvest residues of seven agricultural crops: corn, wheat, rice, cotton, almond, walnut and grape. These decay rates will allow us to better assess the greenhouse gas (GHG) emission implications of leaving residues in field versus converting them into electricity. This fall, Sabrinna is surveying state foresters to clarify the fate of forest residues — i.e. whether they are piled, burned, or scattered in the field — information which will allow us to more accurately assess emissions following forest harvest. She has also been analyzing biomass samples using a bomb calorimeter and a thermogravimetric analyzer, to measure the performance of a gasifier system.

Cassidy Barrientos conducted a literature review that characterized GHG emissions from wood chip storage (e.g. chip piles at a power plant). Decomposition during storage — and the resulting emissions — are an area that have not been well-quantified, and may represent an important source of greenhouse gases. In September, Cassidy and Schatz Faculty Research Associate Sintana Vergara presented a poster, “Characterizing greenhouse gas emissions from wood chip storage,” and gave an oral presentation “Waste not: Improving the efficiency of using forestry residues as an energy resource” at the ARI Principal Investigator’s Meeting in Sacramento.

Cassidy Barrientos in front of her poster at the ARI conference

Cassidy Barrientos at the ARI Principal Investigator’s Meeting

Max Blasdel continued his ongoing work for the California Biopower Impacts Project. Max is characterizing the field decomposition of woody biomass residues left behind by forestry operations. His efforts comprise a key component of the business-as-usual case used to evaluate the net climate impacts of biomass removal for electricity generation. Max’s project research will form the basis for his master’s thesis in the Natural Resources program here at Humboldt State.

WIND ENERGY

Karsten Hayes developed an initial cost model (using Python and R) for north coast California offshore wind energy. The model includes associated storage needs, and integrates high-resolution offshore wind resource data from the National Renewable Energy Laboratory with load data for Humboldt County and California, drawn from Pacific Gas & Electric and the California Independent System Operator (CAISO).

OFF-GRID ENERGY ACCESS

Eli Wallach and Chih-Wei Hsu developed a method to estimate the number of fossil fuel generators used in low- and middle-income countries, how much electricity they generate, and how much fuel they consume. Their work supports a larger effort to estimate the economic, environmental and health impacts of fossil fuel generator systems used as a primary or backup source of electricity. To inform their assumptions and approach, they drew from multiple sources of data, including dozens of nationally representative household and business surveys. These data helped them understand the intensity of generator use at the country level, and in which sectors they are being utilized (i.e. commercial, residential). Eli and Chih-Wei’s fuel consumption estimates for over 130 countries are currently being utilized to update a widely used air quality and climate impacts model maintained by project collaborators at the International Institute of Applied Systems Analysis.

Schatz fellow Anamika Singh worked this summer with a team led by Dr. Amol Phadke at Lawrence Berkeley National Laboratory. Her research, which included collaboration with Dr. Phadke and Dr. Nikit Abhyankar, focused on identifying the parity price at which renewable energy technologies become feasible for heavy industries in India. Read more in our Fall 2018 From the Fellows report…

Chih-Wei and Anamika also helped with our Schatz Solar Array installation in September.

Tanya Garcia worked in the Schatz Center’s off-grid solar lab this summer, conducting solar product tests — including durability (drop and ingress), safety, and truth in advertising (light output, max power, full battery run time, etc.). She developed communications templates for the test lab network and edited specifications sheets to clarify product test policies. Tanya also helped test an open source electricity monitor, the EmonPi, and provided energy outreach activities for university and K-12 groups. Tanya is continuing her work in the off-grid solar lab this fall.

Tanya Garcia unpacks a solar module in the Schatz courtyard

Tanya Garcia prepares to test a solar module

Fuel Cell Vehicle Readiness: Project Update

Over the last three years, the Schatz Center has been a technical lead for the North Coast and Upstate Fuel Cell Vehicle Readiness Project, in partnership with the Redwood Coast Energy Authority and six local government agencies across eight counties in Northern California. Funded by the California Energy Commission (PON-14-607), this project seeks to support the successful introduction of fuel cell electric vehicles (FCEVs), reduce barriers to the effective deployment of hydrogen fueling infrastructure, and help catalyze a robust regional market for FCEVs. This project is catalyzed by aggressive California targets to transition the on-road vehicle fleet to zero emission vehicles (ZEVs).

Map of Redding area with priority fueling zones

Map of recommended early market hydrogen fueling zones for the City of Redding, from the Micrositing Summary Report (Image courtesy of Redwood Coast Energy Authority)

This year, the Center has led the completion of two key project deliverables. The first is a Site Readiness Report that provides recommendations for public fueling infrastructure, focusing on the cities of Eureka and Redding. Led by Greg Chapman P.E. with support from Jerome Carman, this report provides an overview of:

  • state of the art of hydrogen fueling station design,
  • current code and safety requirements,
  • station design recommendations, and
  • a list of recommended locations for the installation of hydrogen fueling infrastructure.

The second is a Micrositing Summary Report which documents past efforts and recommends next steps regarding potential station development locations and stakeholder engagement. Going forward, this report will be used to continue engagement with key stakeholders and catalyze momentum towards the development of fueling stations in the North State.

Currently the project team is engaging with state government fleet managers to leverage aggressive mandates (DGS Memo 16-07, SAM 4121, SAM 4126, EO-18-12) as a way to catalyze FCEV adoption in rural areas.

RELATED EVENTS…

On Thursday, October 11, the Sustainable Futures Speaker Series will host a panel discussion on zero-emission vehicles. For this special event, we’re bringing together experts in local planning, state regulation, mass transit, and advanced fuel infrastructure development, to share strategies for achieving a ZEV rollout on the north coast. The talk will be held from 5:30-7 pm on the HSU campus, in Siemens Hall 108.

Biochar Quality Assessment Project

Biochar has the potential to provide environmental and economic benefits to California’s agricultural sector through improved water retention [1], carbon sequestration [2], and reduced nutrient leaching [3], but realization of this potential is currently impeded by an information market failure [4]. In August, the Schatz Center was awarded a new project from the Agricultural Research Institute (ARI) to study the biochar market and evaluate how physical characteristics of different biochars relate to their market price. The outcomes from this project will help biochar producers understand how to price their product based on its characteristics, and it will help consumers identify the quality of different biochars using informed knowledge and price signals.

Two cupped hands hold (a) woody biomass and (b) biochar.

Woody biomass before and after biochar conversion

The current market size for biochar is estimated around 400,000 tons per year for gardening and landscaping — but it is poised to quickly grow into much larger agricultural sector opportunities where biochar could gain an estimated 2% of the soil amendment market [5]. To achieve this growth, improved information about available biochar products is needed. Currently, many sellers may not receive the full value for their product, and consumers do not know the characteristics of the biochar they are considering for purchase because quality assessment protocols have not been widely adopted. This project aims to understand this market failure and help close the information gap between producers, distributors, and buyers by measuring the characteristics of a dozen biochar products and interviewing stakeholders about desirable properties. By improving the maturity of the biochar market, this project will help California farmers save water and improve crop yield by appropriate, context-specific biochar applications.

As the first step in this project, Mark Severy attended the U.S. Biochar Initiative 2018 Conference in Wilmington, Delaware to deliver a presentation and connect with key stakeholders. The presentation, Biochar Quality and Market Assessment: Comparing Physical Properties to Market Value, provided an overview of the current state of the biochar market and demonstrated how price is not always reflective of quantitative, measured physical characteristics. Mark connected with many biochar producers who are willing to participate in interviews and contribute samples for testing and analysis.

This work will continue by collecting samples of biochar and conducting measurements to quantify their chemical, physical, and agricultural properties. Before and after the tests, interviews with biochar suppliers and end users will be used to understand how they evaluate the use value of biochar in each context. Results will be disseminated through a webinar and technical report when the project concludes in early 2020.

  1. Abel, Stefan, Andre Peters, Steffen Trinks, Horst Schonsky, Michael Facklam, and Gerd Wessolek. “Impact of biochar and hydrochar addition on water retention and water repellency of sandy soil.” Geoderma 202 (2013): 183-191. doi: 10.1016/j.geoderma.2013.03.003
  2. Brassard, Patrick, Stephane Godbout, and Vijaya Raghavan. “Soil biochar amendment as a climate change mitigation tool: Key parameters and mechanisms involved.” Journal of environmental management 181 (2016): 484-497. doi: 10.1016/j.jenvman.2016.06.063
  3. Laird, David, Pierce Fleming, Baiqun Wang, Robert Horton, and Douglas Karlen. “Biochar impact on nutrient leaching from a Midwestern agricultural soil.” Geoderma 158, no. 3 (2010): 436-442. doi: 10.1016/j.geoderma.2010.05.012
  4. Groot, Harry, Jeff Howe, Jim Bowyer, Ed Pepke, Richard, A. Levins, and Kathryn Fernholz. “Biochar as an innovative wood product: A look at barriers to realization of its full potential.” Dovetails Partners, Inc. (2017) Accessed August 27 2018
  5. Sasatani, Daisuke and Ivan Eastin. “Demand curve estimation of locally produced woody biomass products.” Applied Engineering in Agriculture 34, no. 1 (2018): 145-155. doi: 10.13031/aea.12392

Achieving 5 million zero-emission vehicles in California by 2030: the local perspective

On October 11, the Sustainable Futures Speaker Series will host a panel discussion on zero-emission vehicles. For this special event, we’re bringing together experts in local planning, state regulation, mass transit, and advanced fuel infrastructure development, to share strategies for achieving a ZEV rollout on the north coast.

Panelists include:
Closeup photo of a charging car

Download the event flyer

The Sustainable Futures Speaker Series at Humboldt State creates interdisciplinary discussion, debate, and collaboration around issues related to energy, the environment, and society. Fall 2018 lectures are held on Thursdays from 5:30-7 pm in HSU Siemens Hall 108. For details on upcoming events or to request accessibility accommodations, visit our series events page or call (707) 826-4345.

The Schatz Center roof goes solar

On the last weekend of September, HSU and Schatz Center alumnus Nate Coleman returned to Humboldt State with a team of solar professionals to lead the installation of a photovoltaic array on the roof of the Schatz Energy Research Center. Dodging between downpours, and assisted by Center staff, students, and HSU Facilities Management personnel, the team heroically completed the installation in two days.

The system is now complete except for the final electrical connections and an inspection, and should be live near the end of October. The 20 kilowatt (DC) array will produce an average of 57 kilowatt-hours per day, enough to completely power the Center’s new West Wing, with 25 kWh left over to power the main building.

The eighty modules of the solar array and the proprietary mounting hardware and connectors were donated to Humboldt State from Zep Solar through the efforts of Coleman and Jack West — a member of the Center’s Advisory Board and also an alumnus of the university.

Ahn and Greg insert a module into its place

Anh Bui and Greg Ball leverage a module into position

Later this year, an array display will be installed outside the Center. Visitors will be able to see a live report of energy generated by the array, plus rooftop weather data that directly impacts array efficiency: solar radiation, air temperature and relative humidity, wind speed and direction, and the temperature of the modules. The monitor will also feature project news from the Schatz Center and data from the onsite EV charging station. The interpretive display has been funded by HEIF, the student-run Humboldt Energy Independence Fund, and NorthCAT, the Northern California Center for Alternative Transportation Fuels and Advanced Vehicle Technologies. HEIF also provided the instrumentation for the data acquisition system.

The Schatz Solar Array installation team included:

  • Solar professionals: Brian Atchley, Greg Ball, Nate Coleman, Marcelo Macedo, and Ryan Woodward
  • HSU Facilities: Charles Day, Travis Fleming, Ray Robinson, and Brian Toroni
  • Students: Anh Bui, Carisse Geronimo, Chih-Wei Hsu, Craig Mitchell, and Anamika Singh
  • Schatz staff: Charles Chamberlin, Nick Lam, Peter Lehman, Marc Marshall, Kyle Palmer, Rich Williams, and Jim Zoellick
Nate and Marcelo on the roof

Nate Coleman and Marcelo Macedo prepare the Schatz roof for module installation

Jim and Carisse set a thermocouple on the white backside of a module

Jim Zoellick shows Carisse Geronimo where to place a thermocouple on the back of a solar panel

Jim, Charles and Ray consult the module layout plan

Jim Zoellick, Charles Chamberlin, and Ray Robinson review the module layout plan

Chih-Wei and Ray remove a panel from the stack on the lift, while Charles holds the remainder

Charles Day delivers solar panels via hydraulic lift to Chih-Wei Hsu and Ray Robinson

Craig twists a module mount near the edge of the roof

Craig Mitchell tightens mounting hardware on the Schatz roof

Charles Chamberlin holds the specialized mounting hardware

“The mounting hardware works like a charm.” – Peter Lehman

Marcelo bends close to the roof to view a connection

Marcelo Macedo inspects hardware connections

Anh works at the base of a rain-covered module

Anh Bui attaches modules to the roof

Travis and Ray transport panels in a hydraulic lift with redwoods behind

Travis Fleming and Ray Robinson lift solar panels from the courtyard to the Schatz roof

Nate, Peter and Craig crimp roof bars

Craig Mitchell, Peter Lehman, and Nate Coleman (l to r) prepare the roof for mounting hardware

The installation team stands on the roof next to the assembled array

The module installation is complete!

Solar+ project continues in Blue Lake

The Solar+ project at the Blue Lake Rancheria (BLR) hit high gear this summer, with activity across our research and design areas — from engineering to market assessment. Our project is at the halfway point, with construction underway and plans afoot for experiments to run once we are operational next year. It has been rewarding to see progress towards a standardized package for microgrids at the building scale.

Over the summer, our engineering designs came into form as the PV array was installed at the Rancheria’s “Playstation 777” fueling station and convenience store. Our partners at BLR have been working closely with us to coordinate the construction and installation of a 60 kW array of high efficiency SunPower modules on the fueling area canopy. Later this year we will install control devices, switchgear, and other microgrid components.

Overhead shot shows solar modules on the canopy of the fueling station

Drone photo of the PV array under construction, September 2018 (courtesy of the BLR)

In parallel to our work designing and installing the microgrid hardware, project partners at Lawrence Berkeley National Lab have been developing the control software that will eventually manage the microgrid. Building off the open source XBOS (“Extensible Building Operating System”) framework, the LBNL team has been adding model-predictive control and communications features needed to optimize the operation of our energy systems. We are in the testing phase for this software now, and look forward to its installation and operation in 2019.

Along with our progress on the prototype installation for our Solar+ microgrid design, we have been synthesizing our overall experience in microgrid design and development. Our cross-site analysis is helping us to model the current costs and benefits of microgrids based on the characteristics of a site — and we are looking ahead to future prices for PV, storage, and integration technology to understand possible deployment pathways for microgrids at scale.

We made a lot of progress this summer, thanks in great part to a crew of excellent summer research assistants. René DeWees and Ellen Thompson joined our market and data analysis team, and helped model the costs of microgrids (along with big contributions from Jo Caminiti and Thalia Quinn). Craig Mitchell joined the hardware design and construction team, and provided important on-site research observation and engineering support as we worked on building the PV array.

Woody biomass poster & presentation given at the annual ARI meeting

In September, Sintana Vergara and Cassidy Barrientos presented on bioenergy and biomass emissions at the annual CSU Agricultural Research Institute (ARI) meeting in Sacramento.

Sintana presented ongoing research on the environmental implications of using residual woody biomass — a timber industry byproduct — as an energy resource, specifically within California. Ongoing work to develop a Life Cycle Assessment (LCA) for evaluating the climate change implications of mobilizing woody biomass for electricity production has uncovered a potentially significant source of greenhouse gas emissions: storage of woody biomass. Current work, funded by ARI, is now focused on characterizing these emissions.

Cassidy assisted with Sintana’s talk, and also presented a poster synthesizing what we know about greenhouse gas emissions from woody biomass. This poster presented a literature review of published studies that directly measured carbon dioxide (CO2) and methane (CH4) emissions from woody biomass stockpiles.

A jpeg of the linked pdf poster