Vytau K. Virskus – Principal – Millenium Energy Company
I would like to thank the Association of Energy Engineers for this award on behalf of the project team: the City of Dearborn, Millenium Energy Company, Larkin engineering, along with, CSM mechanical and Energy solutions.
This very important project places the city in the forefront of energy efficiency and sustainability for years to come. It has saved the city over 4 million kilowatt hours, $500,000 a year in annual energy cost (50%), and over 1 million annually in cost savings that includes maintenance and staffing.
In addition to retrofitting buildings with LED lighting, the chillers at the Central Cooling Plant were replaced with electromagnetic bearing, frictionless chillers which require no oil for lubrication. These super high efficiency, variable capacity chillers operate at three times the efficiency of typical freon DX compressor technology that operates at 1.4 KW per ton.
The project eliminated virtually all of the old DX, R-22 freon-cooled systems on the campus and converted them to high efficiency cooling from the Central Cooling Plant. This, together with the variable volume pumping saved over 0.6 megawatts of electric demand.
Virtually all of the HVAC infrastructure was replaced throughout the half-million square foot campus of six buildings. However, the heart of the energy and sustainability portion of the project related to converting all of the constant volume pumping and cooling systems to respond directly to building energy demand. This was done through the new distributed building automation system (dBAS). For the hydronic systems we used differential energy control, or E-flow to satisfy building heating and cooling energy demands.
E~flow is a patented control technology based on an algorithm that responds to both building occupancy and weather-related energy demand to deliver hydronic energy on a just-in-time basis.
The E~flow algorithm continuously calculates the building energy demand using the relationships of fluid temperature, and the flow rate. E~flow manages the speed of thermal hydronic pumping systems, and temperature of the water, to deliver only the energy required to satisfy heating or cooling demand.
Our newly patented mass flow and hydronic energy meter will measure the thermal energy that is actually being consumed by any hydronically supplied thermal system. The mass flow meter (MFM) is designed to be inexpensive, accurate, has a low pressure drop, and it is easily and quickly installed.
The E~flow control system and the MFM combined are an effective and cost-efficient system for updating the millions of older buildings in the US, saving significant amounts of precious energy and millions of dollars of energy and labor costs.
It is important to note that the Dearborn Project resulted in reducing the electric demand for the campus by approximately 1.3 megawatts. This is 1.3 megawatts of “virtual” electric generating capacity that will be utilized by the local utility, DTE, to serve other customers in their service territory. This is “new” generating capacity that does not have to be permitted and constructed costing millions of dollars. This new capacity produces no new greenhouse gas emissions. It is essentially a free electrical energy source – provided at no additional cost, or allocations of new capital.
This new capacity was created, or more accurately liberated, without the installation of even one photovoltaic (PV) cell, nor the construction of one additional windmill. It is essential to explore and incentivize new applications of technology such as E~flow, and more efficient methods of thermal energy distribution. There should also be an effort to convert the older, and larger existing buildings that use hydronic heating and cooling to more efficient variable capacity hydronic systems.
There are over 6 million commercial buildings in the US as of 2012. Over one half of the commercial building floor space is in excess of 50,000, with approximately 50% being constructed prior to 1984 (US EIA). When taking into consideration the many thousands of the older hydronically heated and cooled commercial buildings, over 6,000,000 MWh of electrical energy could be saved using these new heating/cooling and hydronic distribution technologies, the cost savings collectively approaching a $1 Billion annually.
Most of the summer season peak electric demand is due primarily to air conditioning. If electric demand due to the A/C load can be cut in half at the City of Dearborn campus of nearly 0.5 million square feet of commercial-style buildings, it would be eminently achievable for reducing peak A/C loads significantly in commercial buildings across the country. Incentives are needed to convert existing HVAC systems to high efficiency cooling technologies, and to variable cooling capacity based more specifically on instantaneous cooling demand. We already have the technology to accomplish this.
This can be done by aggressively incentivizing the replacement of HVAC systems with more efficient technologies. The City of Dearborn Project, along with many others, serve as examples of the levels of energy savings that are achievable.
One final observation: There has been a growing trend to create more “net zero”, operating buildings, or buildings that do not take any energy from the electric grid, or any source of fossil fuel. This is very difficult for older buildings, and even newer buildings find it difficult to attain that zero status without a much higher cost of construction. Yet the City of Dearborn has achieved a sufficient amount of peak electric demand reduction that it is now in a position to contemplate achieving a net zero electric demand during the summer cooling season with the installation of a much smaller photovoltaic generation and battery storage system – literally less than half the size and half the cost.
The lesson here is that to achieve any level of reduced dependence on electric grid or fossil fuels, it is necessary to reduce the use of energy, and instantaneous energy demand in the building by utilizing the newest technologies for thermal generation and distribution. It is also important to look at the recycling of energy. Energy that was considered waste heat in the past can now be recycled through the use of heat wheels and other thermal regeneration and storage devices. When retrofitting older buildings and systems, it is important to look at the energy being saved by the outlay of capital as a monetized cost avoidance to offset lifecycle costs of a retrofit project.
Thank you again to the Association of Energy Engineers for recognizing this groundbreaking project with this prestigious Project of the Year Award.