I believe that the Reforming the Energy Vision (REV) call for microgrids will result in the unintended consequence of encouraging the development of natural gas fired combined heat and power units. The most compelling reason is because that approach does not need to include storage in order to provide 24-7 power and any storage component will make that option much more expensive. However that reality does not comport with the dreams of those who believe a no-fossil future is necessary. This brings us to an ideal situation to see how this will be reconciled in New York State.
The ideal candidate for conversion to a combined heat and power unit is an office complex that has a power plant for steam heat and uses grid electricity. The Empire State Plaza in Albany NY is just such a complex. The New York Power Authority (NYPA) has proposed the Empire State Plaza Microgrid and Combined Heat and Power Plant to replace the existing system. However, their rationale ran aground against the idealism of local community members and environmentalists from across the state who assailed NYPA’s plan to replace aging steam turbines in the low-income, predominantly African-American Sheridan Hollow community with two new combined heat and power turbines to provide electricity and steam.
On February 5, 2018 NYPA caved to this pressure and announced that they will do additional studies of the proposed Empire State Plaza Microgrid and Combined Heat and Power Plant project in Albany in order to better evaluate renewable energy options for the project. The press release claimed that:
“This will allow a more comprehensive review of possible alternative energy sources that may be feasible to explore as part of the Sheridan Avenue project to improve reliability, resiliency and energy efficiency at the plaza. The project partners, the New York State Office of General Services and NYPA, will take this time to enlist ongoing engagement and input from members of the public, including local community members, energy experts and advocacy organizations and will incorporate community benefits into the project’s go-forward plan.”
According to slide 8 in the NYPA presentation on the Empire State Plaza CHP and Microgrid Project Overview the Plaza consumes 111,000,000 kWh per year and uses 1,003,084 klbs of steam per year. NYPA proposed two Taurus 70 combustion turbines that will produce more than enough electricity and steam heat to fulfill those needs. The key to the greater efficiency of a combined heat and power facility is that you use the waste heat, in this case to produce steam for heating. The proposed application is ideal because the CHP output can use the existing electrical and steam infrastructure thus saving costs.
According to slide 5 in the NYPA presentation Project Overview Slide 5, NYPA considered and rejected:
- Solar Photovoltaic
- Solar Thermal
- Wind Power
Let’s review the feasibility of these alternative energy sources. As noted above my main rationale for using natural gas CHP is that you eliminate the need for storage. In their project overview this issue was not addressed because they noted fatal flaws without it. The more comprehensive review proposed in the press release must address that issue or be compromised.
NYPA noted that there is not enough roof space or appropriate acreage in Albany and that the option does not provide heat for solar photovoltaic as issues. At the simplest level if we assume 0.75 kWH per day per square yard of solar photovoltaic, then you would need 84 acres of space for enough PV cells so I have to agree with the NYPA space argument. Furthermore that is the minimum level needed because PV output varies over the year. In order to do the calculation correctly you would need to match the PV output with the actual daily and seasonal load curves. In any event you would still need to provide energy for heating and that requirement is exacerbated by the fact that the fact that when you need the heat the most the solar energy is lowest.
With regards to solar thermal, NYPA noted that the technology cannot generate steam, space is an issue and it does not provide electricity. If your only requirement is hot water then solar thermal may have value but in this case I agree with NYPA. To use solar thermal for heating you would have to replace the existing heating system, you need the solar thermal collectors contiguous to the facility so space is an even bigger constraint, and the peak need for energy is in winter when the solar energy available is lowest. The final nail in the coffin is that this option does not provide electricity.
Geothermal has two flaws. In the first place it cannot generate steam heat so that means that the existing heating system cannot be used. Secondly, it does not produce electricity.
NYPA noted that wind power is hard to site in urban areas, has safety issues in urban areas, and noted that the area does not have enough wind potential for the project. In addition they could have noted that wind does not produce steam so the heating system would have to be changed.
The press release course of action notes:
NYPA will engage community stakeholders, energy experts, and community advocacy organizations to examine renewable options including large scale net metering for solar and wind inputs. The Authority will further assess the feasibility of incorporating any renewable energy options as part of a proposed locally-sourced mini-power grid. The grid will be connected to the statewide grid, and also be able to operate independently, to power the Governor Nelson A. Rockefeller Empire State Plaza in Albany. The goal for the proposed project is to be able to supply 90 percent of the power for the 98-acre downtown Albany complex and be able to save the Plaza an estimated $2.7 million in annual energy costs.
In my opinion, this will be difficult to justify and meet the criteria listed. The ultimate problem is that renewable energy is intermittent and diffuse. Any meaningful renewable energy component to this project will have to include storage to address intermittency or it is simply a virtue signaling symbolic gesture. As noted by NYPA and confirmed in my simple estimates, renewable energy’s Achilles Heel of diffusivity means that in order to include any substantive wind or solar it will have to be collected beyond the Empire State Plaza boundary. When that happens the goal of being able to operate independently is contradicted because the existing grid will be used to transmit the power.
Judith Enck, the former EPA regional administrator for the Obama administration claims “If the state of New York is serious about climate change, it has to stop investing in fossil fuels.” While for this particular project I concede that it is technologically feasible to use renewable energy I don’t see how it could be implemented without substantially higher costs to address intermittency with storage and without contradicting the basic tenet that it will be able to operate independently. NYPA is a New York agency controlled by the Governor. It will be interesting to see how the short-comings of renewable energy are reconciled with the reality of the electrical and heating needs of the Empire State Plaza.