Case Studies

Below are several examples of the sophisticated and aggressive approach Energywiz uses to cut energy costs.


Exposing An Overpriced PV PPA

An industrial facility with a large flat roof was approached by a major PV developer proposing to install almost 2 MW of solar panels. PV panel    Through a 15-year power purchasing agreement (PPA), it offered on-site solar electricity at a price 20% lower than the local average rate, with a 3% annual escalator. Energywiz was asked to review the deal.

The developer's benchmark utility price assumed low-tension delivery service and a standard commercial load profile wherein peak demand occurred in the early afternoon (e.g., 1-3 PM on most days). The facility, however, received high-tension power that cost less than the local average. Correcting for that difference cut the proposed savings to less than 15%.

Energywiz then reviewed the facility's 15-minute interval metering demand data to assess when its peak actually occurred. Based on interval output data from smaller local PV systems, Energywiz then projected the supply load profile of the proposed 2 MW system. The two profiles were then combined to simulate a quarter-hourly demand profile for the facility with the PV system installed.

Due to the scheduling of its various processes and deliveries, the facility was found to peak between 8 AM and 11 AM, during which output of the PV system was much lower than when it later peaked. By that later time, the facility's demand had already dropped. The PV system was found to reduce charges only for consumption, not those for peak demand, which were a significant part of the total bill.

The actual value of the PV-generated electricity was found to be about 30% lower than that quoted by the supplier, making the PPA a losing proposition relative to utility power. Even after admitting that its system would indeed not reduce peak demand, the developer refused to drop his price so his project was scuttled. Another PV developer later offered a price reflecting the lack of demand reduction, and that project is now proceeding. Had the first proposal been accepted, the facility would have (over the 15-year PPA term) lost almost $2 million.


Improving A Cogen Design

A medical center was planning to build a new hospital that would receive most of its power and thermal energy from a combined heat and power plant (i.e., cogeneration) to be built by a private developer. When completed, energy from the system would be sold to the hospital at a price based on the amortized cost of the plant plus an operations fee paid to the developer to run it. Energywiz was called in to review the system design and the proposed contract.

While the system design was technically acceptable, its sizing was found to be based on flawed assumptions regarding electric and thermal demands of the new hospital. Despite the fact that the new building would be about the same size and population as the existing hospital, use the same medical equipment, and would have more efficient HVAC and lighting systems, the mathematical model used to develop its loads showed demands and usages 300% higher. The result would have been a very high fixed fee to amortize an oversized plant across a relatively small quantity of energy units, yielding much higher energy pricing than presently paid. The developer, however, stood fast on its claims that the system would instead save money.

To settle the matter, a third party was brought in to simulate hourly loads using an accepted computer program and negotiated methodology. Energywiz found and corrected several errors in the first runs of the model. Once adjusted, the model confirmed oversizing of the plant and a resulting need to change the design to better utilize its waste heat. The revised plant was much smaller, immediately saving several million dollars in projected installation costs. Overall plant efficiency was raised, and significantly lower energy pricing was secured.



Developing New Lighting Efficiency Products

A major university wanted to upgrade its 7 million square feet of lighting to cut energy and maintenance costs, but without spending any money out-of-pocket. To provide such financing, Energywiz brought in an energy service company (ESCo) working under a shared savings contract. At the time (the early 1990s), however, lighting efficiency technology was in its infancy. Prior work on the university's lighting using standard lighting technologies resulted in unacceptably low light levels, dingy appearance, and unhappy occupants. A variety of technical challenges (e.g., asbestos in plenums and walls) and the ESCo's 3-year payback limit were severely crimping the scope of the work.

To overcome these barriers, Energywiz developed a detailed lighting specification calling for state-of-the-art lighting options. Working with equipment manufacturers, we developed performance specs for a variety of new lighting efficiency products and sought bids on them. Among those new options were:

  • the first low-power T8 electronic ballast
  • an electronic timer that replaces a standard switch
  • a series of specular reflectors designed to spread light, allowing wider fixture spacing
  • a semi-recessed fixture that fit into an existing unit, avoiding any need to remove it
  • a specialized reflector for a 28-watt screw-in CFL that boosted and focused output, allowing it to successfully replace 100 and 150-watt incandescent reflector lamps.

To create and purchase these items, Energywiz leveraged commitments to buy the first 1,000 (or more) units – if they performed to specs – and allow the designs to remain property of the developers. Several of the devices were configured around existing utility rebate programs to maximize their financial incentives. In several cases, the rebates covered most of the purchase cost of the units, realizing paybacks of 2 years or less. The utility even gave us an award for securing the most rebates in a single year.



Cutting Chilled Water Costs Several Ways

A college needed to cut its costs for chilled water. As each new building was added over the years, it got its own chiller, resulting in different systems requiring extra maintenance labor and costs, as well as suboptimal efficiencies. To cut those costs, Energywiz proposed and pushed the following steps:

  • Most of the existing plants were interconnected so that a only a few would be needed to handle the campus cooling load most of the time, running them more efficiently, while allowing others to be shut off.
  • A new building was to be erected that would house a new central chiller plant to also serve the chilled water loop. The plant's specs were upgraded to choose state-of-the-art high-efficiency chillers, and utility incentives were obtained to cover the extra cost.

  • An economic development program offering a long-term electric rate cut if new jobs were created in the new building was secured and successfully interpreted to allow it to cover all power used in both the new building and central plant. That plant then supplied chilled water to buildings on the loop having higher electric rates, thus economically displacing their local chillers, even at high loads.

Together, those three efforts had a multiplying effect that significantly cut the cost of chilled water while reducing maintenance and labor costs.



"Headhunting" Energy Efficiency Personnel

While developing energy master plans for several large institutions, Energywiz reviewed why their past efforts had often failed. Key to such problems was a low level of expertise and focus of the facility personnel tasked with overseeing energy efficiency efforts. Too often, they approached such work in a furtive manner as a collection of occasional projects, such as a lighting upgrade or boiler replacement. Little (if any) long-term planning was done. Where it did occur, it was a sideline to the work of otherwise busy facilities personnel tasked with keeping existing systems running properly. To worsen matters, they often lacked professional training in energy efficiency, and depended on vendors for most of their information and guidance. Aside from occasional review of utility bills, no in-house commissioning or savings verification was performed as long as the new equipment didn't create any problems.

Realizing that any new energy plan was also likely to falter, Energywiz recommended addition of an energy manager position tasked with ensuring that energy cost-cutting would become an ongoing proactive effort. To ensure an appropriately qualified and experienced person would be found, Energywiz assisted in writing the job description and then sought and vetted appropriate candidates.

For half a dozen large institutions, we found and placed highly qualified and trained personnel, all of whom went on to save millions of dollars at each facility. Energywiz continued as a supporting resource to each new energy manager to ensure his or her ongoing success.