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Energy Design Reviews: Starting out on the Greenest Foot

The energy savings that may be achieved from potential retrofit projects may present challenges such as high capital costs, space constraints and disruption of plant operation. What if it were possible to apply “energy audit” principles to the design phase of a new facility or expansion project? Of course, it is not possible to conduct an energy audit in a facility that is not in operation, but it is possible to conduct an energy design review for that facility’s engineering design.

Intervention during the design stages can significantly reduce long-term energy consumption on a lifecycle cost basis and help projects reach their required energy performance targets. Since the conventional design process may not include preparation of detailed estimates of energy use and costs, the resulting level of operating costs will often come as a surprise to the owners and operators.

There is potential for energy improvements in all stages of the design project—conceptual level, preliminary level and detailed level—but, sometimes, the inclusion of high-efficient equipment at a late stage in the design process is not always successful because, at that point, it could be incompatible with the current design, difficult to change and could result in considerable capital cost increases.

A more effective approach to achieve an energy-efficient and sustainable design is to conduct an Energy Design Review (EDR), which provides holistic views and systematic thinking toward incorporating energy-efficient principles to the design package of new systems or facilities. EDRs are effective at reaching energy performance targets by benchmarking new technologies to ensure they have been applied correctly, using energy-efficient equipment and production process technology, and ensuring instrumentation and building controls are automated.

The owner takes a proactive role in energy efficiency to coordinate the EDR, led by the site’s energy champion or an independent energy management facilitator. Although this concept may seems obvious, energy efficiency is often overlooked since lifecycle operating cost impacts are typically less important in the design stage than capital cost estimates.

Typical elements of an EDR include the following:
• Define the owner’s project requirements, including the development of initial statements of performance goals, targets for a broad range of parameters, and general description of preliminary strategies to achieve these targets.

• Assemble the multidisciplinary design team led by the energy champion. Members of this team may include a specialist in the field of energy engineering and/or energy simulation.

• Conduct an alignment meeting to confirm the project scope, highlight any outstanding data that is required before the EDR workshop and discuss the owner’s expectations of the workshop. Develop two or three schematic options for improved performance and hold an open discussion on the resulting performance, cost and other implications. After the meeting, prepare a list of potential opportunities to review during the opportunity evaluation workshop.

• Perform the EDR opportunity evaluation workshop with the participation of the multidisciplinary team involved in the design project to evaluate potential opportunities on a high level by stepping through each of the large energy consumption areas. Examine the potential of applying renewable energy technologies and the most efficient forms of heating, cooling, ventilation and power supply systems. Review energy use, energy efficiency, technology applied and develop an opportunity matrix.

• Prioritize the opportunities identified to determine the top energy savings opportunities that achieve the required performance targets.

• Conduct the opportunity cost/benefit analysis quantifying the potential energy savings and present the business case for implementation for the top energy savings opportunities derived from the EDR workshop, followed by a final presentation and energy training.

Some of the benefits of carrying out EDRs include reduced long-term energy expenses, decreased long-term energy intensity, improved long-term operational efficiency and reduced long-term operations and maintenance costs.

Case study
Recently, a Canadian oil sands project at the basic engineering design phase underwent a cold-eyes energy design review and significant energy cost savings were identified as compared to the baseline energy spending. The primary objective of the project was to identify opportunities to reduce energy consumption thereby reducing GHG emissions and energy costs. The review examined the extraction plant, cogeneration area and site-wide infrastructure and considered all energy users of heat and electricity. The review also covered other systems not directly associated with the process such as HVAC and heat tracing.

The review took place in a workshop setting and the review team used the following design documents used to drive the discussions: process flow diagrams, process and environmental design criteria and mass and energy balances. The review team identified 24 energy-saving opportunities that were examined in detail for feasibility. The opportunities were then grouped into three categories based on when they needed to be implemented to achieve the estimated energy savings.

The oil sands project was also benchmarked against existing oil sands mining operations to ensure that best practice concepts were applied to the design. The final deliverables from the cold-eyes energy design review included a design review report and presentation containing tools to both implement specific energy-savings opportunities and establish energy management practices in line with the new ISO 50001 Energy Management Systems standard.

If all opportunities identified are implemented, the project’s energy spending could be reduced by 40% compared with the original design. In addition, GHG emission savings (direct and indirect) could potentially reduce the baseline GHG footprint by 37%. The oil sands project is now entering in the detailed engineering design phase.

Juan Orozco, P. Eng, CEM, LEED AP, is a senior energy management consultant with Hatch Ltd., which supplies engineering, project and construction management services, process and business consulting and operational services to the mining, metallurgical, energy and infrastructure industries.