Sustainable Energy Technologies Department

Energy Conversion Group

The Energy Conversion Group offers advanced technical solutions to achieve reduced fossil fuel use in geothermal power and building energy applications. Focus is on advanced materials, biofuel end use, combustion and system concepts. We seek to continuously improve the capabilities of relevant research tools being applied in collaborative initiatives to achieving these goals.    

Capabilities

The group conducts research in a number of energy-related areas.  These include advanced materials for geothermal energy, applications of biofuels and alternative fuels, efficiency in heating/cooling equipment, advanced oil burner development and particulate emissions for wood boilers.

Advanced Materials for Geothermal Energy

Supercritical carbon dioxide has properties midway between a gas and a liquid and forms at temperatures and pressures above carbon dioxide’s critical point. Group contributors study the interaction of supercritical CO₂ with rock structures, important for future enhanced geothermal systems. Enhanced geothermal systems are a new technology that extracts hydrothermal energy at any location worldwide having underground temperature greater than 200C. Supercritical CO₂ is being proposed as a working fluid for enhanced geothermal systems because of its thermodynamic and physical properties. In addition, the behavior of supercritical CO₂ is crucial for the underground sequestration of post-combustion carbon. How CO₂ will interact with rocks underground and various structural materials is important to the success of carbon sequestration and some enhanced geothermal technologies. The group also studies advanced cements and coatings for reducing the cost of geothermal energy systems, an area where Brookhaven Lab has a long history of accomplishment.

Biofuels and Alternative Fuels

Group members study the applications of biofuels and alternative fuels -- how we use them and the limitations of their use including material compatibility, combustion characteristics, storage stability, and corrosion, all issues associated with a wide range of fuels including biodiesel from soy, canola, palm, jatropha and algae; pyrolysis oils; hydrolysis product fuels; and levulinates.  They also work with coal to liquid (CTL) and gas to liquid (GTL) fuels.

Equipment Efficiency and Next-Generation Systems

The group has long been focused on how to increase the efficiency of oil-fired and gas-fired heating systems, and particularly the issue of idle loss- the energy these systems use when they are inactive. They have developed performance maps for many different systems and matched them with building energy-use profiles for different cities to look at the effect of steady-state efficiency and the effect of idle loss, among other things, on annual fuel use. The group has created a web tool people can use to estimate the potential savings for their buildings.

Group members have been involved with advanced oil burner development, and will be studying the next generation of HVAC equipment with efficiency levels far higher than those achieved in current systems. The goal is to understand the real performance of the current generation of equipment and the next, including micro CHP systems (heating systems that also make electricity ) and a wide variety of heat pumps. They are currently studying fuel-fired heat pumps - absorption heat pumps which offer the potential to go to efficiency levels in the range of 160 percent.

Particulate Emissions of Wood Combustion Systems

The group studies wood boilers and air-pollutant emissions from advanced wood combustion. Wood is becoming an increasingly critical issue in the northeast and is becoming a dominant source of particulates for the region.  Work on particulate emissions aims to ensure that the growth of direct use of wood and solid biomass fuel occurs in as environmentally positive a manner as possible.  With NYSERDA and the U.S. EPA, group members have been working on efficiency test methods for wood boilers.