Slideshow shadow

Clean Cities Question of the Month: What is Renewable Natural Gas?

November 23, 2015 in Alternative Fuels, Compressed Natural Gas (CNG), Question of the Month

Question of the Month: What is renewable natural gas (RNG) and can it be used to fuel vehicles?

Answer: RNG is pipeline-quality natural gas made by collecting and purifying biogas, the methane produced from decomposing organic matter. Biogas can be collected from sources such as landfills, livestock operations, wastewater treatment plants, food manufacturing and wholesalers, supermarkets, restaurants, and hospitals. Once purified to remove contaminants and increase its heat content, the gas is called RNG and is a “drop-in” fuel that can be transported with conventional natural gas in pipelines, dispensed at the same fueling stations, stored in the same storage tanks, and used in natural gas vehicles without any engine modifications.

Despite its advantages, there are only 60 operational RNG production facilities in the United States. Many more use the biogas to generate electricity. This is due to federal and state programs, such as the federal Investment Tax Credit and state renewable portfolio standards, which incentivize the use of biogas for power generation rather than for vehicle fuel.


The purification process for biogas is called conditioning or upgrading, and it involves removing water, carbon dioxide, hydrogen sulfide, and various contaminants and trace elements. From there, RNG can be compressed to make renewable compressed natural gas (R-CNG) or super-cooled to make renewable liquefied natural gas (R-LNG).

RNG is produced from feedstocks that come from a wide range of industrial sectors, many of which already collect and process biomass as part of their daily operations:

  • Landfills: Landfill gas (LFG) is collected from decomposing waste in landfills. According to the U.S. Environmental Protection Agency (EPA), landfills are the third largest source of human-related methane emissions in the United States. Landfills account for 70% of the operational RNG projects in the United States. One of the largest LFG-to-vehicle fuel projects is Waste Management’s Altamont Landfill near Livermore, California. This project produces up to 13,000 gallons of R-LNG each day to fuel 300 refuse trucks.
  • Livestock Operations: Animal manure can be collected and taken to an anaerobic digester for RNG production. A few farms across the country have started to use biogas to produce RNG vehicle fuel, including Hilarides Dairy in California and Fair Oaks Dairy in Indiana.
  • Wastewater Treatment Plants: Approximately 9% of the more than 16,000 wastewater treatment plants in the United States use anaerobic digestion to produce biogas. The Janesville Wastewater Treatment Plant in Wisconsin is an example of a plant that uses biogas to produce RNG for use in vehicles.
  • Other Biomass Sources: RNG can also be produced from lignocellulosic material, such as crop residues and dedicated energy crops, through thermochemical conversion, co-digestion, and dry fermentation. These technologies are being used in Europe, but have limited applications in the United States. RNG also can be produced from food waste, either alone or in conjunction with biosolids from livestock operations or wastewater treatment plants. CleanWorld Partners’ Sacramento BioDigester and quasar’s Central Ohio BioEnergy project convert food waste to RNG for vehicle fueling.

RFS2 Compliance

RNG qualifies as a cellulosic biofuel under the EPA’s Renewable Fuel Standard (RFS2) program. In fact, RNG accounted for more than 50 million renewable identification numbers (RINs) in 2014 – 98% of all cellulosic biofuel RINs.  According to organizations that track biofuels market data, cellulosic biofuel RINs were valued at $0.70– 0.85 per diesel gallon equivalent in 2014; this value is expected to increase in the future.

Other Benefits

Like conventional natural gas, RNG can be produced domestically and can displace the petroleum currently being imported for transportation use. However, RNG offers some additional benefits. RNG has practically a net zero carbon impact. On a lifecycle basis, RNG accounts for fewer greenhouse gas (GHG) emissions than most currently available motor fuels. RNG can reduce GHG emissions by 95% compared to conventional gasoline and diesel fuel. This is partially because capturing biogas from landfills and livestock operations can reduce GHG emissions by preventing methane releases that were occurring into the atmosphere. Additionally, RNG produced through anaerobic digestion eliminates odors and results in nutrient-rich liquid fertilizer as a by-product. Also, biogas feedstocks are plentiful, so RNG could make use of the 450 million pounds of municipal solid waste dumped in landfills, 160 billion pounds of food waste generated, or the 500 million tons of animal waste produced each year.


Like conventional natural gas, the main barriers to RNG are lack of vehicle availability and fueling infrastructure, though efforts are underway to address both of these obstacles. However, RNG production costs exceed those for conventional natural gas, especially for small-scale operations. Small-scale RNG production can cost around $5.50–$9 per million British thermal units compared to $4.50 for conventional natural gas. Additional financing and incentive opportunities, as well as state renewable portfolio standards that encourage the investment in biogas for vehicle fuel production, may spur additional production.

More Information

For more information on RNG, please see the following additional resources:

o   Landfill Methane Outreach Program:

o   AgSTAR Program:

Share with Friends!

Propane Landscaping Equipment Workshop

November 18, 2015 in Alternative Fuels, Calendar of Events, Events, Propane


The San Diego Regional Clean Cities is hosting a free workshop on the benefits of propane-fueled lawn-care and landscaping equipment. Propane is an easily deployable alternative fuel with significant savings in greenhouse gas emissions and fuel costs. Discussions will include the basics of propane fueling, various equipment options, and the financial benefits of replacing old landscaping equipment with more efficient propane-fueled equipment.

The workshop will feature local propane fuel providers, equipment manufacturers, and industry experts to assist landscaping companies in going green. There will also be opportunities to see equipment and interact with vendors in a Q&A discussion, networking lunch, and equipment showcase.

The program and provided lunch are FREE, but space is limited so register today!

register online

Share with Friends!

IKEA and TransPower Complete Evaluation of a Zero-Emission Tractor

October 30, 2015 in Uncategorized

IKEA has announced its plans to adopt a zero-emission electric tractor into its fleet for permanent use. This news comes after a full year of testing on an advanced electric yard tractor at IKEA’s Tejon, CA distribution center. This is the first long-term trial of an electric fleet vehicle at an IKEA facility. TransPower manufactured the tractor for IKEA in cooperation with the EPA and San Joaquin Valley Air Pollution Control District. The tractor features electric propulsion technology that significantly decreases CO2 emissions.

Since deployment in September of 2014, IKEA has noted the tractor’s reliability and low operating cost compared to equivalent diesel tractors. The company typically uses the electric tractor for three shifts per day, accumulating over 13,000 miles in operation in the last year. At this rate of use, the tractor reduces CO2 emissions by 50 tons per year. TransPower has since converted four additional tractors for IKEA’s California operations.

The energy cost of the tractor’s operation is less than 3 cents per mile, largely due to the facility’s 1.8 megawatt solar roof installation. This solar array provides 90% of the energy needed to charge the tractor’s 120 lithium-ion batteries. In comparison, the same operation of a diesel tractor costs about 75 cents per mile.

TransPower, located in Poway, develops clean vehicles and energy storage technologies. The company has developed the proprietary ElecTruck, an electric drive system for large tractors, trucks, and buses and the Grid-Saver energy storage system. TransPower is currently developing products with hybrid-electric and fuel cell hybrid propulsion technology.

Share with Friends!

World’s First LNG-Powered Containership

October 28, 2015 in Alternative Fuel Vehicles, Alternative Fuels, Clean Air, Feature, Uncategorized


San Diego’s General Dynamics NASSCO has built the first LNG powered containership. The 764-foot long Isla Bella was delivered earlier this month to TOTE Maritime, two months ahead of its scheduled delivery. The containership is part of a two-ship contract with TOTE that was signed in December of 2012. The second ship, Perla del Caribe, was launched in August and is expected to enter service at the beginning of next year.

The Marlin class containership is currently the largest dry cargo ship powered by LNG, making it the cleanest ship in the world. In the switch to natural gas, the ship will reduce NOx emissions by 98%, SOx by 97%, carbon dioxide by 72% and particulate matter by 60% compared to TOTE’s vessels currently in service.

In January of 2013, TOTE and NASSCO also signed a contract to convert two of TOTE’s existing diesel-electric trailerships to LNG propulsion. The 839-foot Orca class ships were originally constructed by NASSCO in 2003.

The construction of these ships marks a successful partnership between TOTE, NASSCO, the American Bureau of Shipping, and the U.S. Coast Guard, who issued the final inspection of the LNG powered ship. The four collaborated on the design, construction and final commissioning of the ships.

Share with Friends!

Annual Advancing the Choice Expo

October 19, 2015 in Alternative Fuel Vehicles, Calendar of Events, Education, Events


The Future of Transportation

Thursday, October 29th 2015

The Western Riverside County Clean Cities Coalition will be hosting the 16th Annual Advancing the Choice Expo, featuring this year’s theme of “The Future of Transportation.” This year’s keynote speaker is Jim Madaffer, Chair of the California Transportation Committee and former San Diego City Council Member. The price of admission is $30 and includes opportunities to network, test-drive clean tech vehicles, and learn about future alternative fuel technologies.

This event is FREE for students.

register online

Date: Thursday, October 29 2015
Time: 9:00 am – 1:00 pm
Location: UC Riverside Center for Environmental Research & Technology
1084 Columbia Avenue, Riverside, CA
Share with Friends!

National Hydrogen and Fuel Cell Day

October 8, 2015 in Alternative Fuel Vehicles, Alternative Fuels, Clean Air, Events, Hydrogen, Uncategorized

Hydrogen Day

Today is National Hydrogen and Fuel Cell Day! In recognition of hydrogen’s atomic weight of 1.008, October 8 is the perfect day to celebrate as hydrogen and fuel cell technologies are being deployed nationwide. California’s investments in alternative fuel vehicles, like hydrogen fuel cell electric cars, are fueling the state’s economy and reducing greenhouse gas emissions. These zero-emission vehicles contribute to cleaner air and are hitting the roads now with numbers expecting to increase. National Hydrogen and Fuel Cell Day aims to help raise awareness of this abundant source of fuel that is cleaner and more efficient than petroleum.

Learn more about these vehicles and the commercialization of hydrogen fuel cell vehicles through efforts of the California Fuel Cell Partnership (CaFCP). For additional information on National Hydrogen and Fuel Cell Day, read the details of the California Energy Commission’s News Release.

Visit a list of events and downloadable resources.

Share with Friends!

Goods Movement Emission Reduction Program Accepting Applications

September 22, 2015 in Alternative Fuel Vehicles, Alternative Fuels, Clean Air, Compressed Natural Gas (CNG), Diesel/Biodiesel, Electric Vehicles, Fleets, Funding, Hybrid Vehicles, Uncategorized

SDAPCD Funding Available

The San Diego County Air Pollution Control District is now accepting applications for the Proposition 1B Goods Movement Emission Reduction Program (GMERP) through November 20, 2015 at 5:00 PM. GMERP will offer approximately $12 million in funding to owners of eligible heavy-duty diesel trucks and transportation refrigeration units (TRUs) who upgrade to cleaner technologies. Formed by a partnership between the California Air Resources Board and local agencies, GMERP aims to reduce air pollution and health risk from freight movement along California’s trade corridors.

Qualifying applicants include owners of class 6, 7, or 8 heavy-duty diesel trucks and/or diesel TRUs, truck stops, distribution centers, or other heavy-duty diesel truck congregation centers within defined trade corridors.

Visit or call 916-44-GOODS for a complete list of program requirements.

Visit for online forms and instructions.

Share with Friends!

Reducing our Carbon Bootprint

September 9, 2015 in Alternative Fuel Vehicles, Alternative Fuels, Calendar of Events, Events, Fleets, Infrastructure, Uncategorized


Reducing our Carbon Bootprint

Next Wednesday, September 16

Register now for the San Diego Regional Clean Cities Coalition’s event showcasing the local military’s leadership in alternative fuels and renewable energy. The discussion will focus on challenges and lessons learned which may be valuable to other regional alternative fuel deployments. Speakers will include Len Hering, RADM, USN (ret), Executive Director of the Center for Sustainable Energy and Gary Funk, Fleet Manager for Marine Corps Base Camp Pendleton.

The program and provided lunch are FREE.

For more information, contact

Date: Wednesday, September 16, 2015
Time: 10:45 a.m. — Registration
11:00 a.m. – 1:00 p.m. — Discussion & Networking Lunch
Location:  Center for Sustainable Energy
 9325 Sky Park Court, Suite 100
 San Diego, CA 92123
Share with Friends!

San Diego Regional ZEV Incentives

September 1, 2015 in Alternative Fuel Vehicles, Clean Air, Electric Vehicles, Funding, Infrastructure

California state and regional incentives have proven effective to help increase alternative fuel vehicle adoption and decrease GHG emissions. Since transportation accounts for about 45% of GHG emissions in both San Diego County and California, and 30% nationwide, transportation policies are central to meeting state and federal emission reduction goals. Present zero emission vehicle (ZEV) incentives in San Diego County and future regionally tailored policies will be especially useful for achieving GHG scenarios outlined in the San Diego Association of Governments (SANDAG)’s newest regional plan, San Diego Forward: The Regional Plan.

The San Diego County Air Pollution Control District (SDCAPCD) participates in a number of statewide vehicle incentive programs. Although they don’t target ZEVs, these incentives can facilitate their adoption for trucks and heavy duty vehicles. The Carl Moyer Memorial Air Quality Standards Attainment Program, in its 17th year, provides up to $3 million annually for the replacement of heavy-duty diesel engines with lower emitting vehicles. The On-Road Heavy-Duty Voucher Incentive Program helps to replace qualifying trucks with lower-emission vehicles, or to install Verified Diesel Emission Control Strategies. It offers $5,000 to $45,000 for trucks with an engine model year 2006 or older. Both programs are run by the San Diego Air Pollution Control District (SDAPCD). About half of San Diego County’s transportation greenhouse gas emissions are from medium- and heavy-duty vehicles, so the current incentives are successful in targeting substantial GHG emitters. However, as discussed previously, air districts have adopted a range of ZEV incentives to complement state and federal policies to spur light-duty ZEV adoption. At present, the SDAPCD offers few vouchers or tax credits for light-duty ZEVs. It did recently offer incentives to upgrade older airport taxis to hybrid electric and alternative fuel vehicles. However, the San Diego region could greatly benefit from an incentive program for light-duty passenger vehicles.

San Diego County is a national leader in electric vehicle adoption, but its regional plan highlights a need to continue to increase adoption at an ambitious level to meet statewide GHG emission reduction targets. If the state intends to have 1.5 million ZEVs on the road by 2025, San Diego County’s share would be 141,000 vehicles. With 17,000 vehicles presently –including about twice the number of BEVs as PHEVs, 400 car2go car-share ZEVs, and a small number of other alternative fuel vehicles –that is an increase of 124,000 ZEVs. According to estimated statewide ZEV sales, the San Diego region population of PEVs is expected to increase to 50,000 in 2020; 300,000 in 2035; and nearly 400,000 in 2050 (SANDAG). As the San Diego Regional PEV Readiness Plan notes, “mandates and incentives will prove to be essential to encourage PEV growth” and “in order to foster the market’s rapid growth, a robust EVSE [electric vehicle supply equipment] network needs to be built.” The region presently has 908 public charging stations at 330 locations and 60 DC fast chargers at 34 locations (SDG&E, 2015). Between April 2011 and May 2013, 114 business and fleet stations at 39 sites were installed (Appendix U.12: PEV Readiness Plan). This is an appreciable growth, and should hope to be an ongoing trend.


Source: San Diego Association of Governments, 2015.

Fortunately, SANDAG is planning to increase EVSE infrastructure as part of its Transportation System and Demand Management Programs. In 2020, it will implement Transit Infrastructure Electrification and Regional Charger Programs. Through 2050, it has allocated $10 million to infrastructure electrification of bus fleets, installing wireless recharging at transit stations (San Diego Forward: The Regional Plan, Appendix E). It has allocated $30 million to expand the network of Level 1 and 2 charging stations through regional planning and installation incentives. Three-quarters of stations will be Level 1, with an installation incentive of $250, and one-quarter will be Level 2, with an installation incentive of $2,100 (similar to Metropolitan Transportation Commission incentive levels). The program should result in 36,000 charging stations by 2035 and 43,000 by 2050 (Appendix E). Following estimates of the Electric Power Research Institute, SANDAG assumes that one charging station would support five PHEVs, and increase electric miles traveled of PHEVs from 30% to 41% (Appendix E). The additional electric miles of PHEVs should allow for a net reduction of carbon dioxide emissions of 390,000lbs by 2035 and 455,000lbs by 2050 (SANDAG, 2015).

In compliance with SB 375, SANDAG has developed its second Sustainable Communities Strategy. Prepared as part of San Diego Forward: The Regional Plan, it expects an 18% per capita reduction in greenhouse gas emissions from passenger vehicles by 2020 and a 24% reduction by 2035 from a 2005 baseline (Appendix C). This significantly surpasses the California Air Resources Board’s targets for the San Diego region of 7% by 2020 and 13% by 2035.

The Value of Tailored ZEV Incentives for San Diego County

The San Diego region has several unique opportunities and challenges to meet regional ZEV adoption targets and progress toward GHG emission reduction goals for 2050. As mentioned previously, the region could fill gaps of state and federal ZEV incentive programs by placing particular emphasis on higher need locations, such as multi-unit dwellings, busy transit corridors, low-income communities, and workplaces.

One of the first incentives the San Diego region could consider adding to its ZEV portfolio is a purchase program for light-duty vehicles to complement those currently in place for medium- and heavy-duty vehicles. Both the BAAQMD and the SJVAPCD have light-duty vehicle purchase incentives that can be stacked onto state and federal incentives. This would offer additional motivation that may be necessary for a customer’s first ZEV purchase. The region could also consider funding design. The California incentive program has recently been modified to include an income cap and progressive funding based on income to stimulate greater ZEV purchasing among lower income groups. San Diego may wish to mirror this design to spread ZEV adoption across income groups. Lastly, funding should vary based on vehicle type—BEV, PHEV, NEV or motorcycle—as these offer different air quality benefits.

Multi-unit dwellings (MUDs) are a particularly important charging site to spur ZEV adoption. The EV Project found that almost three-quarters of PEV charging occurs at a vehicle owner’s residence, and 19% occurs at public charging stations (Appendix U.12). Due to new California housing laws that call for increasing the mix of housing types and increasing infill development, there will be a significant increase in multifamily housing in both 2020 and 2050 (San Diego Forward: The Regional Plan, Appendix L). In fact, 84% of future residential growth will be multifamily housing through 2050 (Appendix L). In addition, the National Household Travel Survey indicates that Level 1 charging stations can satisfy plug-in hybrid electric vehicle (PHEV) drivers, but for battery electric vehicle (BEV) drivers, Level 2 charging is “critical.” Level 2 charging stations presently may not be accessible to those living in multi-unit dwellings (MUDs), partly because many MUD owners have little financial interest in installing stations. Greater incentives for MUD owners are especially necessary to increase resident’s charging opportunities and willingness to purchase a PEV.

An initial step to spurring ZEV adoption at MUDs has been the voluntary CALGreen Code of the California Building Standards. The 2012 Supplement called for “at least 3% of the total parking spaces, but not less than 1%, in low-rise multi-family dwellings be prepared to support electric vehicle charging infrastructure (EVSE) in the future” (Appendix U.12). The proposed 2015 update would require that at least 4% of spaces be prepared to support EVSE. These are important steps to encourage the growth of electric vehicle charging at MUDs, but financial incentives would likely have a greater impact.

Increasing incentives for residents living in low-income housing will also be important for the San Diego region. Over a quarter of Traffic Analysis Zones– a geographic unit used throughout the San Diego regional plan that is about the size of a census block– presently count at least 41% of the population below the regional poverty level (Appendix H, Figure H.6). From 2010 to 2020, abiding by state laws such as SB 375 for increasing the housing mix, 40% of new construction is planned to be for low- to very low-income residents (Appendix L). Providing for the charging needs of these residents will be crucial for ZEV adoption to increase across income levels and have a chance of meeting statewide ZEV adoption goals.

Businesses are another charging site highlighted in most ZEV readiness plans as central to encouraging ZEV adoption. According to the San Diego Regional PEV Readiness Plan, “it is vital to place EVSE at locations in which BEV drivers will stay for long periods: workplaces and other public places such as schools, retail centers, gyms and medical locations” (Appendix U.12). Charging at businesses can decrease “range anxiety” for BEV owners who have long commutes, need to perform extra errands or non-commute trips. The Center for Sustainable Energy offers a fact sheet for businesses considering installing charging stations for employees and a fact sheet for public agencies involved in permitting and building codes.

A fourth target location for electric vehicle chargers is along high-traffic transit corridors. The San Diego Regional PEV Readiness Plan acknowledges the need for DC fast chargers “throughout countywide highway corridors [to]… suit the long-range driving needs of PEV owners.” San Diego Forward: The Regional Plan indicates that through 2050, new housing will be “concentrated in urban areas adjacent to transit” in accordance with Sustainable Community Strategies and California’s SB 375 (Appendix L), so charging sites along transit corridors will be especially useful. The Regional Plan states that “the San Diego region will add nearly one million people, 330,000 homes, and 500,000 jobs by 2050” (Appendix H) and that “the number of homes located within one half-mile of high frequency public transit services will increase from 35% in 2012 to 62% in 2050” (Appendix C). DC fast chargers could also be used for long-distance travelers requiring a quick recharge, as well as local residents with regular commutes. In fact, a UC Irvine survey found that “a network of 290 strategically located fast chargers throughout California would enable 98% of drivers to adopt BEVs based on average daily vehicle miles traveled” (Appendix U.12). Currently, the region has 60 DC fast chargers. Planners acknowledge that “organizing future housing and jobs around transit is a critical strategy in preparing for such dramatic change.” Therefore, the Regional Plan projects transportation and housing growth “in an iterative process” to maximum overlap (Appendices H & L).

With additional ZEV and EVSE incentives tailored to the San Diego region’s unique needs, the County has a much higher likelihood of spurring voluntary electric vehicle adoption at a level adequate to meet state and federal GHG targets. Vehicle incentives should be tailored according to present demographics and regional growth expectations. They might be designed similarly to those adopted in other California regions, like the Regional Charger Program based on BAAQMD practices. Vehicle incentives should also complement transportation system and demand management strategies, other alternative fuel strategies, and VMT reduction measures. Meeting the 2050 GHG emission reduction scenarios evaluated in the Regional Plan is an acknowledged challenge. Given the success of incentive programs in other regions, San Diego has a valuable opportunity to reduce long-term emissions through its own light-duty ZEV and EVSE incentives.

Share with Friends!

Biomimicry Seminars

August 31, 2015 in Uncategorized

Biomimicry is about applying nature’s design, patterns, and strategies to developing products, policies, and processes. By applying nature’s underlying design principles to innovations, it is possible to solve many problems and design more efficient processes.

Biomimicry San Diego is offering two free educational seminars on biomimicry at the SDG&E Energy Innovation Center on September 8th and September 16th. Both seminars are all-day, offering not only educational background on biomimicry, but hands-on learning activities as well (and, as an added bonus, breakfast and lunch are both provided). Further, both seminars are led by San Diego Regional Clean Cities Coalition board member Jacques Chirazi (, Certified Biomimicry Professional and Founder of Biomimicry San Diego.

Details for each event is below. Visit the EIC website to register.

Introduction to Biomimicry – Tuesday September 8th Integrating Biology into Design – Wednesday September 16th

Register Now – Space is limited!

8:00 am
– Morning Session: Biomimicry Core Values and relevant biomimicry case studies

What you will learn in this session:

  • Introduction to the field of biomimicry
  • Defining the meme
  • Understanding biomimicry and its core values
  • The Seeds of Biomimicry
  • Deeper exploration of case studies and inspiring organisms

12:30 pm – Afternoon Session: Life’s Principles – How products and processes can learn from nature

What you will learn and do in this session:

  • Introduction to Life’s Principle’s
  • Hands-on exploration of the methodology of using Nature as Mentor, Model and Measure
  • Bringing biology into the scoping, discovery, evaluation stage of design
  • Integrating Biology into Design methodology
Register Now – Space is limited!

8:00 am – Morning Session: Biomimicry methodology and procedures, consulting organisms and ecosystems

What you will learn in this session:

  • Leverage Life’s Principles as a gateway to world of biology and ecology
  • Biomimicry Thinking
  • Learn from the local champions adapters
  • Scoping the challenge

12:30 pm
– Afternoon session: Nature’s Strategies -Practicing the steps of integrating biology into design

What you will learn in this session:

  • Case studies
  • Functional Biology
  • Hand-on learning activities
  • Detailed case study of successful strategies
  • Application Integrating Biology into Design methodology

Download informational flyers here and here.

Share with Friends!