PHILADELPHIA — Penn State University, in collaboration with the Philadelphia Industrial Development Corporation and other technology providers and with funding from the Pennsylvania Department of Environmental Protection (DEP), is demonstrating a cost-effective technology path to increase the use of renewable-energy power generation in Pennsylvania. Pennsylvania Marcellus shale gas will be used to fuel a gas-fired turbine power generator in combination with solar cell and battery energy storage systems.
This project will continuously monitor the solar photovoltaic panel arrays, battery storage systems, gas turbine electric power and useful heat output and how the outputs are being used by the buildings that the hybrid system serves. That data will be transferred to The Navy Yard network operating for analysis and visualization. This will form the basis of a hybrid system design process for the sizing and operation of resilient, low-carbon footprint microgrids.
The alpha prototype system is being implemented on a 600-kilowatt nano-loop of The Navy Yard microgrid. The nano-loop currently powers 8 occupied office buildings, a sewage pump station, and Penn State’s GridSTAR house and Solar Energy Training Center facilities. Most of these buildings also use natural gas for space heating and domestic hot water production. A hotel is also planned for the loop in the near future.
James Freihaut, technical director of The Navy Yard and professor of architectural engineering, said the hybrid system also includes thermal energy generation, from the gas-fired and thermal energy storage, but operates to act as a single total energy providing system.
“A natural gas-fired gas turbine system is used to generate electricity in coordination with a solar photovoltaic generating system. Excess electrical energy is stored in an associated battery system, to be utilized when on-site demand is temporarily larger than the system generating capacity, or it can be sold back to the connected utility grid on high demand days,” Freihaut said.
Thermal heat produced by the gas turbine is captured and used on-site for heating and cooling various facilities. By capturing and using the heat on-site, there is little waste of primary energy.
The goal of the project is to provide the data and system operation experience for a transferable design guide to develop potential hybrid microgrid sites across the state, using an Extension Center outreach model similar to that used by the Penn State Extension program in the College of Agricultural Sciences.
“Hybrid energy systems enable the best features of solar, energy storage, and natural gas turbines to be combined,” said David Riley, associate professor of architectural engineering. “This project will provide us with a highly unique platform to experiment with the operations and controls of hybrid systems, and also provide hands-on teaching and learning experiences for a variety of audiences.”
Penn State researchers at the University Park campus and at The Navy Yard have been working for the last several years with municipal planning organizations across the state — in Pittsburgh, Reading and Philadelphia — as well as the U.S. Department of Energy’s Energy Efficiency and Renewable Energy Program, to investigate the use of combined heat and power (CHP) turbines and CHP-enabled renewables distributed-energy manufacturing in single facility, existing, and planned industrial park settings.
While a handful of functioning microgrids have been developed at sites owned and operated by single owners — mostly at industrial sites and hospital and college campuses — the proliferation of microgrids and renewable energy resources could accelerate if a replicable method to deploy them at sites with multiple types of tenants can be demonstrated. In the next few years, to align with The Navy Yard’s energy master plan, several community solar-array projects may be installed, along with a 6-megawatt gas-fired turbine to manage peak energy demand and augment the power supplied by PECO, the regional electric utility.
Balancing the power generated by renewables with a microturbine that can be powered up and down over a period of only a few minutes will complement the ability of battery-storage systems to compensate for rapid fluctuations in solar-power generation due to intermittent cloud cover, and will reduce the need for "standby" conventional-base power generation on the overall electric-power grid. A successful deployment has the potential to be scaled up to the entire Navy Yard electric grid and could be replicated across the state and nation.
The deployment of new gas-fired turbines is controversial to some, but while researchers work to improve battery storage technologies and drive prices down to levels that will make them economically feasible at utility scale, they represent a demonstrably low-carbon approach to power generation, complementing the inherently intermittent nature of solar and wind resources. This is because thermal energy normally wasted by a conventional power plant is captured and used, avoiding the need for additional fossil-fuel energy to generate hot water.
CHP technology can realize up to 80 percent in primary energy utilization efficiencies with a 50 percent reduction in a carbon footprint compared to conventional fossil-fuel electric production. CHP-Enabled Renewable Energy Hybrid systems applied to manufacturing promises to realize even higher primary energy efficiencies and carbon-footprint reductions, while simultaneously providing a plausible, economically rational path to zero-net carbon-footprint manufacturing.
The Commonwealth of Pennsylvania could become a regional and national leader in the use of domestic natural gas to foster economic growth and establish a realistic, cost-effective and resilient path to increased use of renewable energy in power generation, said Freihaut.
“Due to the abundance of Marcellus shale gas in Pennsylvania and a desire to lower its carbon footprint while growing the economy, the Pennsylvania Department of Environment Protection seeks to use the data and information gained from this demonstration to establish a methodology accelerating the deployment of hybrid distributed energy system application across the state,” he said.
The DEP funding for the project is provided by the U.S. Department of Energy’s State Energy Program.