ARPA-E announced a flexible, simplified, ongoing funding opportunity in 2019 (formerly known as ‘Solicitations on Topics Informing New Program Areas’), used as needed for smaller efforts that do not fit our typical focused program model. This flexible opportunity is used to fund exploratory and disruptive R&D seedlings, to provide resource teams that support focused programs, and to investigate topic areas in which a full focused program may later be developed. This ability to respond to needs in a quick and agile manner enables ARPA-E to better support focused programs while constantly pursuing innovation in new areas.

Funding Opportunity Announcements (FOAs)

These projects are developed through two distinct funding opportunities listed below – one geared toward applicants of all types across the entire energy innovation ecosystem, and the other dedicated specifically to small businesses - and organized into groups we call Exploratory Topics.

Generic ARPA-E Program Graphic Solicitations on Topics Informing New Program Areas


This Funding Opportunity Announcement (FOA) is purposely broad in scope, and will cover a wide range of topics to encourage the submission of the most innovative and unconventional ideas in energy technology. This FOA is open to U.S. universities, national laboratories, industry, and individuals.

Generic ARPA-E Program Graphic SBIR STTR Solicitations on Topics Informing New Program Areas (SBIR/STTR)


Eligibility for this Funding Opportunity Announcement (FOA) is limited to "Small Business Concerns" as defined by the Small Business Administration (SBA). For more information on what constitutes a Small Business Concern, please consult the SBA guidelines for SBIR/STTR eligibility.

Learn More About Each ARPA-E Exploratory Topic

Below is a list of all ARPA-E Exploratory Topics developed through the FOAs listed above and a brief description of the specific technology areas addressed. For more information on a particular Exploratory Topic, including descriptions of the specific energy technology projects selected within them, click any of the links below. Exploratory Topics will continue to be added to this list on an on-going basis. Stay tuned to ARPA-E's eXCHANGE platform for up-to-date information on all of the Exploratory Topics, as well as all other ARPA-E FOAs, as they develop.





Exploratory Topic M

Supporting the development of innovative approaches for hydrogen gas detection and quantification across the hydrogen supply chain.


Exploratory Topic L

Investigating the feasibility of cost-competitive and low-carbon footprint extraction of nickel in soil by terrestrial plants.

NEXTCAR Field Evaluations

Exploratory Topic I

Testing and validation of energy-saving technologies that utilize connectivity and autonomous vehicle technologies.

Geologic Hydrogen

Exploratory Topics G & H

Developing and demonstrating technologies that can lead to the lowest cost and lowest environmental impact production of hydrogen fuel from the subsurface.

Superconducting Tape

Exploratory Topic F

Widely available low-cost high-temperature superconducting (HTS) tapes for nuclear fusion, the electric grid, electric aviation, and superconductor-based electric generators/motors.

Algal Mining

Exploratory Topic E

Extracting critical minerals, specifically Rare Earth Elements (REEs) critical for the production of electric motors and generators, and high-value Platinum Group Metals (PGMs), from macroalgae.

Aviation Contrails

Exploratory Topic D

This new system could foster the development of a) avoidance strategies – allowing re-direction of airplanes by ground control to more favorable (non-AIC) flight trajectories – and/or b) on-board mitigation technologies.


Exploratory Topic C

Awards under this program will support research projects that establish potential new areas of technology development and provide ARPA-E with information that could lead to new focused funding programs.

Intermodal Freight Transportation System

Exploratory Topic B

Deployment of energy infrastructure and logistics for moving goods across maritime, rail, and road transportation in the United States.

Low-Energy Nuclear Reactions

Exploratory Topic A

Low-energy nuclear reactions (LENR) could be the basis for a potentially transformative carbon-free energy source.



Life Cycle Assessment for Carbon Negative Buildings

Exploratory Topic V

Life cycle assessment tools and frameworks associated with transforming buildings into net carbon storage structures

Sulfur Hexafluoride (SF6)-Free Routes for Electrical Equipment

Exploratory Topic U

Technologies aimed at reducing sulfur hexafluoride (SF6) emissions from the electric transmission and distribution sector.

Topology Optimization and Additive Manufacturing for Performance Enhancement of High Temperature and High Pressure Heat Exchangers

Exploratory Topic S

Design and manufacture of high-temperature, high-pressure, and compact heat exchangers.

Lowering CO2: Models to Optimize Train Infrastructure, Vehicles, and Energy Storage

Exploratory Topic R

Planning tools for identification, evaluation, and prioritization of energy storage-related technology developments whose deployment would significantly reduce GHG emissions from the rail freight sector.

Connecting Aviation By Lighter Electric Systems

Exploratory Topic Q

Medium-voltage (>10 kV) power distribution cables, connectors, and circuit breakers for fully electric aviation applications.

Direct Removal of Carbon Dioxide from Ambient Air

Exploratory Topic P

Robust, energy efficient, and low-cost strategies for direct removal of carbon dioxide from ambient air.

Direct Removal of Carbon Dioxide from Oceanwater

Exploratory Topic O

Direct removal of carbon dioxide from oceanwater and other natural waters by addressing challenges and opportunities specifically found in operation in an oceanic environment.

Waste into X

Exploratory Topic N

Improvement of the physical or chemical properties of Municipal Solid Waste Incineration (MWSI) ash into valuable products.

Mining Incinerated Disposal Ash Streams

Exploratory Topic M

Recovery and reclamation of critical materials (CMs) and other valuable elements from Municipal Solid Waste Incineration (MSWI) ashes.

Insulating Nanofluids and Solids to Upgrade our Large Aging Transformer Equipment

Exploratory Topic L

Vital insulating elements in large power transformers (LPTs) to increase their durability, reliability, and resilience.

Recycle Underutilized Solids to Energy

Exploratory Topic K

Processes to convert plastics, rubber, composites,  and paper to create a high-energy content liquid that can be easily shipped to and stored at points of aggregation.

Biotechnologies to Ensure a Robust Supply of Critical Materials for Clean Energy

Exploratory Topic J

Novel approaches in microbiology, synthetic biology and process engineering in support of addressing mining industry challenges to ensure a robust mineral supply chain for clean energy applications.

Electricity System Models for Carbon Capture Resources

Exploratory Topic I

Electricity system models and associated analysis that can inform technology development for new grid resources. 

Establishing Validation Sites for Field-Level Emissions Quantification of Agricultural Bioenergy Feedstock Production

Exploratory Topic H

“Ground truth” solutions to establish measurements and protocols for emissions monitoring at the field level to create publicly available, open-source, high-resolution datasets to support testing and validation of emerging biofuel production monitoring technologies.

Supporting Entrepreneurial Energy Discoveries

Exploratory Topics G, T, & W

An ongoing funding opportunity for a range of the most innovative and unconventional ideas across the energy technology spectrum, exploring high-risk R&D that could lead to the development of disruptive technologies.

High Value Methane Pyrolysis

Exploratory Topic F

High value methane pyrolysis, including approaches that can economically convert natural gas to both fuel cell-grade hydrogen and higher value carbon materials (e.g., carbon fiber) with a low CO2 footprint.

Diagnostic Resource Teams to Support the Validation of Potentially Transformative Fusion-Energy Concepts

Exploratory Topic D

State-of-the-art diagnostic measurements to be made on potentially transformative, ARPA-E-supported fusion-energy concepts in order to validate their performance, uncover problems, and guide research priorities.

Leveraging Innovations Supporting Nuclear Energy

Exploratory Topic C

Advancements in nuclear facility sensors, tools, analytics and controls.

Downhole Tools to Enable Enhanced Geothermal Systems

Exploratory Topic B

Novel, low-cost sensor technologies that can help mitigate risks and lower costs for deep, extremely hot enhanced geothermal systems (EGS) by better characterizing rock formations and fluid enthalpy at depth.

Extremely Durable Concretes and Cementitious Materials

Exploratory Topic A

Extremely durable concretes and cementitious materials to tackle technology challenges in the development of widely applicable concrete and cement.