The focus of Session VIII of the AIA+2030 Educational Series was alternative energy sources. Taking place on February 20th, the session – Site Power: Renewable Energy Opportunities – was jam-packed with industry experts in geothermal heating & cooling, biomass, wind, and solar. Each presentation not only described, in detail, how each system works, it also addressed the potential applicability to projects in Southwestern PA.
The evening’s first presentation was provided by Marc Portnoff of Thar Geothermal. Marc started off the presentation by comparing and contrasting ground source geothermal against traditional energy sources such as natural gas, coal-fired electricity, and nuclear energy. According to the US EPA, “ground source geothermal is the most energy-efficient, environmentally clean and cost effective space conditioning system available today.” Starting with that statement, Portnoff transitioned into an explanation of what the ground source geothermal heat pump (GHP) components are, how the system operates in both heating and cooling modes, and when different heat pump designs are relevant. The most recent advances in GHP include radial geo-loops and the environmentally exceptional refrigerant R744 used in the loop. Radial geo-loops (as opposed to vertical loops) reduce the amount of site disturbance while R744 allows the use of significantly smaller sized loops. Both advances increase the feasibility of GHP being incorporated in more project sizes and types. Portnoff concluded by emphasizing that geothermal systems are versatile and can be integrated with numerous standard HVAC systems. This report provides further education on GHP systems.
Michael Palko of the Pennsylvania Department of Conservation and Natural Resources (DCNR) spoke next. Palko spoke about DCNR’s wood energy initiative. The program recognizes that the 17 million woody acres of privately owned land in Pennsylvania could easily be a renewable energy source with sustainable management. These sustainably-managed woody crops (biomass) can then be burned in high-combustion furnaces to produce energy. Currently, there are twelve school districts in northern PA that are using wood chips to heat their schools and campus. Palko explained the components of the biomass heating system. He emphasized that there is no such thing as wood waste. Every part of the woody crop can be commoditized. The heating system is equipped with a cyclone precipitator that compacts the fly ash into a low grade fertilizer. Downdraft gasifiers and a refractory line secondary chamber burn the carbon out of the smoke. The resulting exhaust is actually steam instead of smoke. There are downsides to biomass heating systems. You need a lot of space for the wood storage, the boiler, and the residue processor. For small commercial or residential applications, smaller furnaces can be cascaded together. This type of biomass is an excellent energy source in rural areas around Pennsylvania where there is no access to natural gas.
Next up in the alternative energy showcase was wind. Michael Sell from Saint Francis University’s Renewable Energy Center explained the types of windmills, their components, and design considerations for optimizing wind energy. Site assessment is a critical first step in designing with wind energy. The REC has launched a tool to aid in the site analysis. Wind Explorer provides free access to wind resource maps for Pennsylvania. The maps, in conjunction with actual measurements at the site, will quickly help determine whether wind is a viable energy resource on a particular site.
Sell’s discussion focused on wind turbines with a horizontal axis. These are the type of windmills typically seen in wind farms. His research shows that vertical and helical turbines are not yet efficient enough to be worthwhile investments compared to other renewable energy sources. Furthermore, he used the wind speed maps to demonstrate that Southwestern Pennsylvania has weak wind systems. Wind turbines in SW PA may make good demonstration projects, but they are poor energy producers. The good news is there are numerous locations in the rest of PA where wind is an excellent energy source. Designers can quickly discover those locations by using Wind Explorer.
During his presentation, Sell referred to an article written for Pittsburgh Engineer magazine by one of his colleagues. The article, featured in the magazine’s Fall 2013 issue, by Allison Boehm was entitled Wind Farming in Pennsylvania. The reference to that issue was particularly pertinent to Session VIII’s theme because that issue included informative articles about several renewable energy sources. Anyone interested in learning more about different kinds of alternative energy sources should read that issue.
Ian Smith of Energy Independent Solutions (EIS) was the last speaker of the evening. Smith led a thorough presentation on solar power in Western Pennsylvania, photovoltaic design, and industry trends. While photovoltaics have been in use for several decades, it is a rapidly evolving industry that is growing more applicable and accessible. Through a series of illustrations including city climate comparisons and country solar adoption maps found on NREL’s PVWatts website, Smith demonstrated that solar is a feasible energy source in Pittsburgh. He emphasized that Germany – not a country known for sunshine – is the most prevalent adopter of solar energy. Explanations of grid-tied solar, net metering, and decentralized collection were all part of the discussion. Smith also reviewed the categories of PV technology from crystalline silicone to copper indium gallium selenide (CIGS). The session concluded with a discussion of the latest innovations in thin film PV.
Session IX of the AIA+2030 educational series will be held on March 20th. We’ll be taking our classroom on the road by meeting at Botany Hall on the Phipps Conservatory campus. The Hand-Off + Staying in Shape: Operations, Maintenance, + Education will include a backstage tour of the energy management and measurement tools being utilized at Phipps.