Technology

Fossils + Renewables, a viable option?

 By Amanda Saint

In a bid to meet growing energy demands alongside climate change mitigation needs, the latest energy research is thinking differently and bringing together the innovations developed in both the fossil fuel and renewable energy sectors to develop new technologies…

Researchers at the National Energy Technology Laboratory (NETL) are looking at ways that fossil fuel energy systems can be integrated with renewable energy technologies to advance environmental performance while still delivering the amount of power needed. The research is being carried out as part of an NETL initiative called Synergistic Fossil Integrations with Renewable Energy (SFIRE), and seeks ways to effectively combine renewable energy resources with fossil energy fuels.

Geothermal resources

To date, the research team’s main focus has been on the use of geothermal energy for electricity generation and a number of sites have been investigated for their potential. One of these, Camp Dawson in West Virginia, which is a state-owned National Guard training facility, is considered a very viable option. Camp Dawson is based in a geothermal energy site that can potentially deliver 14–18 GW of electricity generation capacity from deep geothermal resources. Another potential site is the Southpointe Business Park in Washington County, Pennsylvania.

https://www.theet.com/prestoncountynews/news/netl-looks-at-heating-camp-dawson-with-geothermal-energy-process/article_3554d81d-5e1c-5d5b-b35a-a492acdf0805.html
Camp Dawson in West Virginia (theet.com)

SFIRE’s lead researcher, Dan Oryshchyn, said: “There is a range of potential geothermal opportunities at Camp Dawson, but additional research is needed to reduce the uncertainties of project costs and resource assessment. At Southpointe Business Park the geothermal resource and regional thermal energy loads align well so as to possibly offer lower levelized cost of heat comparable to current residential costs using natural gas furnaces.” The team was quick to point out, when presenting their findings at the West Virginia Governor’s Energy Summit in October 2016, that the financial viability of both sites is going to be dependent on the costs of drilling for access to deep geothermal energy resources decreasing considerably.

Aside from these locations, there is a significant number of potential geothermal sites across the US, particularly in the west and midwest states. The National Renewable Energy Laboratory (NREL) has produced a map based on its research, which shows the locations of both identified hydrothermal sites and potential deep enhanced geothermal systems (EGS). Hydrothermal sites are those that have naturally-occurring geothermal resources that are already being used by conventional geothermal power projects. Deep EGS refers to the harder to access geothermal heat. This is the geothermal resource available at Camp Dawson and it requires the technologies that are currently being developed by projects such as SFIRE for recovery and use in combination with fossil fuels.
“Based on our research to date, combining fossil energy with geothermal energy for on-site power generation can offer risk reductions for power generation, as well as a long-term energy resource.” Oryshchyn added.

http://www.washcochamber.com/
Southpointe Business Park in Pennsylvania (washcochamber.com)

Technology hybrids

Identifying the sites where geothermal could be used in combination with fossil fuel technology innovations is just one step in the team’s work. The hybrid technology that is being explored by SFIRE researchers uses combustion/geofluid cycles for energy-producing turbines. This hybrid solution is known as geoHART, which translates as geothermal humidified air recuperated turbine. It works through a humidified cycle that uses low-temperature geofluid water, which is usually only used for heating, to generate power more efficiently than typical geothermal cycles. The environmental benefits are twofold as the hybrid technology uses less natural gas per unit of electricity produced than conventional combustion turbines, and less water than water-cooled combustion-based power cycles.

Future research focus

There is considerable potential for future energy systems to be developed using this integrated approach. The SFIRE team’s goal is to find ways to effectively use a whole range of renewable energy resources, including biomass feedstock, solid waste gasification, wind, solar and geothermal, in combination with fossil energy fuels, such as coal and natural gas. The researchers plan to improve the efficiency and environmental performance of these processes though the use of non-typical cycles like the ones they have already developed in geoHART. When you consider the knowledge and advances that have been made in both the fossil fuel and renewable energy sectors in recent years, combining the two for the best results seems like a completely viable option. And one that can deliver many benefits while the move to completely phase out of fossil fuels, without impacting energy supplies, continues.

SEE MORE: How natural gas can help solar power shine by Robin Wylie

about the author
Amanda Saint
Journalist and content writer, specialised in engineering and technology with a focus on environmental sustainability, urbanisation and biotechnology.