Design, Procure, and Install the Energy System

Facility owners who want to hire professionals to design and construct energy systems should know how to create a bid document and avoid common design and procurement problems.

The design, procurement, and installation of a new energy system for a health-care facility builds on the work conducted in the previous three steps: energy demand analysis, accounting for change, and electrification options. An energy system designer uses that information to create a custom energy system design for the health-care facility. If the energy system is large, the designer will not be able to install it, and the donor, project manager, or facility manager will need to initiate a procurement process to identify engineering, procurement, and construction companies (EPCs) that will construct the energy system according to the designer’s and facility owner’s specifications. Once an EPC is selected, the system can be installed and commissioned for operation.

Design

Proper system design is the first step required for sustainable on-site health facility energy systems. Off-grid energy system design is quite complex and should typically be done by a trained professional. The professional should have specific expertise designing systems using the Electrification Option that best suits the health-care facility. The expert’s design should include input collected from several stakeholders during the Energy Demand Analysis and Accounting for Change steps. The energy audit template is a good tool for collecting information the system designer needs. If the health-care facility owner is unable to conduct the energy audit, the energy system designer will need to complete this process. The energy system design should use an optimization tool, like the HOMER Powering Health Tool, or an energy system modeling tool to properly size energy system components.

Design Key Lessons Learned

• System design should always take into account local meteorological conditions and loads; rules of thumb or a one-size-fits-all design usually result in an energy system that fails to completely meet the facility’s load.
• Anti-theft measures should be considered in all design plans.
• “Maintenance-free” batteries are a good option for health facilities.
• Energy systems do not need to serve the entire health-care facility. Dedicated systems designed for specific loads (e.g., computer, vaccine refrigerator) have high success rates.
• When sizing solar arrays or wind turbines, designers should consider the need to recharge fully discharged batteries after a windless or cloudy day.
• Diesel/PV hybrid systems (as opposed to solar-only systems) are recommended for all but the smallest health centers in order to reduce solar array and battery bank size and cost.

Procurement

A “bid package” is prepared to ensure that the group procuring energy equipment and services and the suppliers are clear about what is needed and the manner in which it is to be provided.

The bid package is a source of information for tendering companies and should contain the following pieces of information:

• General Terms of Reference (or Scope of Work)
• Expected number of work hours, quantity of goods, or budget ceiling
• Expected period of performance
• List of any required skills or equipment to perform the work
• List of required materials, technology, or standards compliance
• Specific deliverables or reports to be submitted

The system design should be included in the bid package’s Terms of Reference.

The bid package will provide applicants with a complete set of information on the system design and expected system performance. The more complete the bid package, the more likely that suppliers will provide equipment and services that meet the needs of the job.

The level of detail used in technical specifications for the procurement of power equipment and services will differ based on the needs and expected outcomes for a particular facility. Providing a high level of detail in technical specifications will help to ensure that contractors provide quality equipment and workmanship. However, too much detail may limit a bidder’s ability to offer low-cost options or alternative proposals.

Generally, bidders should be allowed some flexibility in offering equipment or services. For example, unless a specific brand of equipment is needed, it is best not to specify equipment brands or excessive technical requirements. Citing established standards, like those listed on this page, is a good way to ensure the quality of products and services while allowing bidders to determine the best value they can offer. Below are some additional tips to keep in mind when specifying particular types of power equipment.

Guidance for Specifying System Components in the Specification and Bid Documents

• Clearly indicate the system voltage.
• Provide clear instructions with regard to the array size and type of solar modules required.
• Include relevant site details. Mounting structures will vary depending on the location, roofing materials, and specific circumstances of the site (shade, security, etc.). Clearly state the type and size of batteries required. Battery technology changes rapidly, and there are many different types of batteries on the market.
• Clearly indicate the type of battery enclosure (or rack) required for each PV or backup system.
• Specify the required ratings of charge regulators (charge controllers) to be used in systems.
• Describe the features required of the inverter.
• Specify the size, type, and proposed installation location of generators, if any, to be supplied for use in systems.
• Identify the size and type of lighting equipment to be supplied in the system.

Procurement Lessons Learned

• Evaluation of energy system cost based only upon initial cost discourages the choice of renewable energy (RE) sources. Life-cycle costs should be used and can be calculated using the optimization tool.
• Inverters that easily allow users to override low voltage cutoff are not recommended. Low voltage cutoff settings should often be increased from factory set default values to prolong battery life in developing country settings.
• Access to locally available spare parts should be a consideration in initial equipment procurement.
• Designers and bid preparers should pay attention to the wiring, panel boxes, and other supporting components that safely carry power from the equipment center to the actual loads.

Installation

After winning the construction outlined in the bid package created by the facility owner, the EPC contractor should submit any proposed design changes, a project timeline, and a description of construction methods. The donor, project manager, or facility manager should also work with the construction company to develop a commissioning process. The commissioning process will be a period of energy system performance testing to confirm that the system is performing to the specifications outlined in the bid document. During the installation and commissioning of the system, it is common for the facility owner to retain the original system designer or hire a separate owner’s engineer to oversee the construction process. This ensures that the construction consultant installs the system according to the agreed-upon design and critical standards.

Links to two Terms of Reference examples for different types of energy systems are included below. A link to applicable technical standards is also included below.

Additional Resources

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  Terms of Reference

  Stand-Alone Solar PV Systems: Guyana Hinterlands

  The full Terms of Reference used to procure solar systems for remote health clinics in Guyana includes all relevant technical specifications, standards, and bid and procurement procedures. Read the terms

• USAID

  Terms of Reference

  Inverter and Battery Systems: Haiti Health Facilities

  The full Terms of Reference used to procure backup power systems for use in Haitian hospitals includes all relevant technical specifications, standards, and bid and procurement procedures. Read the terms

• Sandia National Laboratory

  Resources

  Technical Standards

  Proper specifications using international standards allow each energy system to be tailored to meet the needs of the facility while ensuring that design best practices and installation protocols are followed. Learn more