A 2009 evaluation of geoengineering techniques by the Royal Society concluded that stratospheric aerosols could be highly effective and affordable, although there are questions over adverse effects. From: Geoengineering the Climate (2009) Click to enlarge.

The UK’s Engineering and Physical Sciences Research Council (EPSRC) has awarded £1.609 million (US$2.4 million) in funding to the project SPICE (Stratospheric Particle Injection for Climate Engineering).

A variety of geoengineering options have been proposed in response to anthropogenic global warming, including solar radiation management (SRM) which involves offsetting the effects of GHG increases by causing the Earth to absorb less radiation from the Sun. Reducing incoming solar radiation by injecting sulfate aerosol into the stratosphere was considered the most rapidly deployable, affordable and effective option by the recent Royal Society report on Geoengineering the Climate. (Earlier post.)

The report did note, however, that there are some serious questions over adverse effects with this method, particularly depletion of stratospheric ozone.

Volcanic eruptions provide evidence that sulfate particle injection leads to reductions in globally-averaged surface temperatures. However, there are concerns that there will be substantial regional impacts, on temperatures, rainfall and other aspects of climate. There are also uncertainties concerning timescales e.g. how rapidly injection might act, how quickly it could be turned off and whether the climate responds differently to continued injection of aerosols compared with the episodic nature of volcanic eruptions.

In terms of geo-engineering, the natural volcanic analogue of sulfate particle injection may not be optimum in terms of radiation management, and there may be better candidate particles for injection. Related to this, there are significant issues of cost and feasibility of injecting candidate particles into the stratosphere and the sustainability of particular injection technologies that require much further investigation.

The SPICE project will investigate the effectiveness of stratospheric particle injection. It will address the three main challenges in solar radiation management:

1. How much, of what, needs to be injected where into the atmosphere to effectively and safely manage the climate system?
2. How do we deliver it there?
3. What are the likely impacts?

SPICE addresses these questions through three coordinated and inter-linked work packages:

1. WP1. Evaluating candidate particles. What is the “perfect” particle that maximizes solar radiation scattering, minimizes the greenhouse effect and the impact on the stratospheric ozone layer and has minimal impact on climate, weather, ecosystems and human health?

   Critical in this project is the understanding of the interaction of radiation (of various wavelengths) with aerosol particles, and likely chemical effects on the stratosphere of injection of significant additional surface area as a potential catalyst for multiphase chemistry. Researchers will develop metrics of the suitability of various particle compositions, sizes and surface properties for stratospheric aerosol geoengineering (including scattering efficiency, greenhouse effect, chemical reactivity, lifetime, cost of fabrication, health impact, capability to serve as ice nuclei, etc) and perform an assessment of candidate aerosol particles (sulphuric acid, sea-salt, other salts, minerals, and metal oxides) from the available literature and simple modelling of the key reactions, surface properties, agglomeration and sedimentation rates, and light scattering theory.

2. WP2. Delivery Systems. What are the various options for delivery of particles? ( A range of delivery systems have at various times been proposed including batch delivery by aircraft, balloons or ballistics and steady-state delivery by thermal plumes, or from a fixed tower or pipe supported by a balloon.) What is the feasibility of using a tethered-balloon pipe to inject particles and/or gases into the stratosphere in a more cost-effective and sustainable way than alternative methods?

   Particles are to be injected into the stratosphere at heights upwards of 10km (mid-latitude) and 18km (equatorial). The rate required for global climate modification is upward of 1Mte p.a. and at this rate the delivery costs for batch methods are estimated to be well above £1 billion (US$1.5 billion) p.a. but an order of magnitude less than 1/10 of this for the pipe delivery method.

   If current thinking is validated, the WP will proceed with a more detailed design of a tethered balloon approach which will involve the design of a pipe and associated pumping and deployment systems. The WP will begin with a preliminary technical evaluation of the pipe-balloon system and the associated fluid/structural mechanics. The pipe will be up to 25 km long, subject to high tensile and bursting pressures. It will be a sealed unit, abrasion resistant, insulated to prevent freezing and made of a braided or filament wound fibre composite.

3. WP3. Climate and environmental modelling. What are the most effective locations for injection? How can we best use past volcanic analogues? What are the climate and environmental impacts of stratospheric particles?

   In this work package essential groundwork will be carried out to assess and optimize the accuracy of the model and an extensive list of metrics and diagnostics will be developed to assess the impact of particle injection in the atmosphere.

Principal investigator on SPICE is Dr. Matthew Watson from the University of Bristol, who also is heading work on WP1. Dr. Hugh Hunt from the University of Cambridge is in charge of WP2 and Prof.Lesleyy Gray from the University of Reading is in charge of WP3.

The Department of Energy has issued a Funding Opportunity Announcement (DE-DOA-000380) soliciting applications in the two topic areas: Liquid Carrier Technology for Hydrogen Storage or Delivery; and Biodiesel Fuels from Low-Impact Crops. DOE anticipates selecting one project of two years duration in each area; the maximum award is $500,000 for each project.

The FOA was issued in compliance with Section 506 of the Energy and Water Development and Related Agencies Appropriations Act, 2010 (Public Law 111-85, October 28, 2009). This provides that projects contained in the report of the Committee on Appropriations of the House of Representatives accompanying the Act (H. Rept. 111-203) that are considered congressional earmarks for purposes of clause 9 of rule XXI of the Rules of the House of Representatives, when intended to be awarded to a for-profit entity, shall be awarded under a full and open competition.

Liquid Carrier Technology for Hydrogen Storage or Delivery.

The Office of Energy Efficiency and Renewable Energy’s (EERE) Fuel Cell Technologies Program (FCT) is seeking applications for projects that employ liquid carrier technology as a means of storing or delivering hydrogen.

Only liquid carriers of hydrogen are eligible for this topic. Other fuels or carriers, liquid or otherwise, are not eligible. The liquid carrier must be a liquid at or near ambient temperature and pressure through all stages of hydrogenation/dehydrogenation and must be regenerable. The use of solvating or slurry agents to maintain the liquid state is acceptable but must be included in all material property characterizations. Slurries of solid phase hydrogen storage materials, such as metal hydrides, are out of scope for this topic.

For applications employing a liquid carrier material that has already been developed, the application must include detailed description and characterization of the material itself. Examples of data requested are temperature, pressure and rate (kinetics) of hydrogen release for a given quantity of stored hydrogen, and thermodynamics, kinetics, temperature, and pressure required for material regeneration or hydrogenation. Data demonstrating cycling (e.g., dehydrogenation/hydrogenation cycles) and conditions (temperature and pressure, etc.) under which the carrier stays as a liquid are also requested.

The target market for the liquid carrier technology may include, but is not limited to, the following: storage for light-duty vehicles, buses, distributed electricity generation, back-up power, and material handling equipment; and as a delivery media for these applications. The application must include a description of the target market studied and the accompanying application performance requirements (e.g., hydrogen delivery rates, temperature/pressure, cost, overall efficiency).

If the target market identified is for light-duty passenger vehicles, the applicant must show that their liquid carrier material, when incorporated into a system, has potential to meet DOE performance targets for on-board hydrogen storage systems. For other target markets, the applicant must describe the required operating parameters and challenges that would have to be met in order for the liquid carrier technology to successfully compete with the leading incumbent and emerging technologies.

Biodiesel Fuels from Low Impact Crops. The Office of Energy Efficiency and Renewable Energy’s (EERE) Office of the Biomass Program is seeking applications for projects that employ low-impact feedstocks for producing biodiesel. Applications for projects undertaking applied research, development, or demonstration, or any combination of these, are eligible. The work scope may include research and development (R&D), scale-up demonstration, or any combination of these, provided that the proposed work scope is commensurate with the available DOE funding and required non-Federal cost sharing.

For the purpose of this FOA, the following definitions apply:

“Biodiesel” is defined as an advanced biofuel produced from fatty acids derived from plant or animal feedstocks using transesterification as the conversion technology.

“Low impact crops” are defined as agronomic crops that can be sustainably produced over an extensive geographic area of the US at a cost that is competitive with other lipid producing crops. Such crops would require a minimum of water, fertilizer, pesticides, energy, and land area and be useful for producing high quality biodiesel fuel. Low impact crops would not be edible by humans and the production of such crops would not cause excessive soil erosion, loss of wildlife habitat, decrease in productivity in other rotational crops produced on the same land, or cause other environmental pollution or health hazards.

It is expected that the successfully completed project under this FOA ultimately will lead to commercialization soon after the project is completed. Regardless of the planned stage or scale for the project, each application must demonstrate a well-defined path to commercialization.

The application must specify the low impact crop that will be used during the project, and include a discussion as to why the crop qualifies as being a low impact crop.

Each application must show how the planned use of the proposed low impact crop and scope of the project fits into the overall, integrated process for commercial production of biodiesel.

The application description must also include an evaluation of the potential replicability of the commercialized process. Applications must include a detailed discussion of the risks and barriers associated with the development of the proposed process and the path to commercialization at other locations. This discussion must include the required operating parameters and challenges that would have to be met in order for the biodiesel produced from a low impact crop to successfully compete with the leading conventional and emerging fuels.

Researchers at the University of Colorado, Boulder and the National Renewable Energy Laboratory (NREL) modeled the emissions impact had plug-in hybrid electric vehicles

(PHEVs) replaced light duty gasoline vehicles in the Denver, Colorado area in summer 2006.

Denver represents an interesting case

study for exploring potential PHEV impacts because it violates

the federal air quality standard for ozone and because several

large EGUs [electricity generating units] are located in or near the urbanized area.

—Brinkman et al.

This study models a single urban area with a finer grid resolution (4 km) than has been considered in previous PHEV studies, and also incorporates

plume-in-grid treatment for improved tracking of plume

dispersion. The ozone response to PHEV penetration was modeled under a wide

range of meteorological conditions, as experienced during

July 2006.

In their study, published online 15 June in the ACS journal Environmental Science & Technology, they found that with 100% PHEV penetration, nitrogen oxide (NO_x) emissions would have been reduced by 27 tons per day (tpd) from a fleet of 1.7 million vehicles and would have increased by 3 tpd from power plants. VOC emissions would have been reduced by 57 tpd.

A unit commitment and dispatch model was used to estimate

the charging patterns of PHEVs and dispatch power plants

to meet electricity demand. Emission changes were estimated

based on gasoline displacement and the emission characteristics

of the power plants providing additional electricity.

These emission changes reduced modeled peak 8-h average

ozone concentrations by approximately 2-3 ppb on most days.

Ozone concentration increases were modeled for small

areas near central Denver.

The Comprehensive Air Quality Model with extensions (CAMx)

was used to simulate the effects of these emissions changes

on ozone concentrations. Natural gas units provided most

of the electricity used for charging PHEVs in the scenarios

considered.

This study for Denver focused on impacts on ozone

concentrations, due to Denver’s nonattainment status and

interest in the potentially nonlinear responses this pollutant

can exhibit. For other areas, where PM2.5 concentrations

are higher than in Denver and where coal-fired power plants

may contribute more of the marginal electricity supply,

modeling effects of PHEV use on PM2.5 may also be

warranted, especially if emissions caps are not in place to

mitigate this impact.

In future work, additional research is needed to refine

estimates of PHEV emissions, including understanding the

importance of cold-start conditions. Further research is also

needed to forecast the timing of PHEV penetration and better

anticipate the characteristics of the power plant and vehicle

fleets that might be in place when significant PHEV use might

occur. Such projections will have high uncertainty, because

without having PHEVs in mass production it is difficult to

estimate their emission characteristics and added upfront

costs, including the cost of battery production. Over the long-term,

it is possible that significant PHEV penetration could

affect how the generation fleet develops, possibly by leading

to more base load coal capacity. Finally, future studies should

pursue dispatch modeling that extends beyond the service

territory of a single electric power utility to examine the effects

of more widespread introduction of PHEVs.

—Brinkman et al.

Resources

• Gregory L. Brinkman, Paul Denholm, Michael P. Hannigan and Jana B. Milford (2010) Effects of Plug-In Hybrid Electric Vehicles on Ozone Concentrations in Colorado. Environ. Sci. Technol., Article ASAP

  doi: 10.1021/es101076c