Solar Jack PG&E Assessment

This report presents the findings of technical assessment to evaluate energy efficiency potential of the Solar Jack Energy Management System (also referred as “Solar Jack”). PG&E’s Emerging Technologies (ET) Group within the Customer Energy Solutions (CES) organization has funded this assessment. Lincus, Inc. an energy efficiency consulting firm was commissioned to perform this assessment.

Project Goals

The goals of this assessment are to:

  • Research existing information about the Solar Jack technology from published materials, field experts and manufacturers.
  • Develop Measurement and Verification (M&V) procedures for determining Solar Jack energy savings potential, perform M&V, analyze data, and calculate the DEER peak kW and annual kWh energy savings potential over the existing/industry standard baseline.
  • Determine the energy savings contribution from each of the (3) three components in the Solar Jack system which includes regenerative component, Variable Frequency Drive (VFD), and Solar Photovoltaic (PV) panel.
  • Discuss PG&E Customized Incentive Program eligibility and utilization of the findings for future projects.

Project Description

Solar Jack is installed on a rod beam pump as add-on equipment. Solar Jack is a combination of the following (3) energy saving sub-components:

  • VFD is controlled by the customer’s existing monitoring system to match motor RPM with well output.
  • Regeneration Component –Solar Jack has a capacitor bank to store regenerative power during down-stroke and reuse it without exporting to the grid. Without this component, the regenerative power is either wasted as heat or exported to the grid as poor quality (low Power Factor) power.
  • Solar PV – A solar PV system is installed to provide auxiliary power to the rod beam pump. A properly sized Solar PV system in combination with the above components may allow the pumping system to operate off-grid.

To assess the energy savings potential of Solar Jack, it was installed on three wells with rod beam pumping system at three different customer sites, designated as Host Site #1, Host Site #2 and Host Site #3. During the course of the assessment, Host Site #3 dropped out of the study for reasons explained later in the report. Host Site #2 and Host Site #1 rod beam pumps are driven by a 15HP and 30HP motor, respectively, with continuous operation and no controls. The installed Solar Jack system at each site had appropriately-sized VFD, regen capacitor bank, and Solar PV rated for 2.12 kW DC output. The performance of each pumping system was measured before and after the installation of the Solar Jack system.

Project Results

Table 1 summarizes the total annual energy savings and DEER peak demand reduction at each test site, and Table 2 provides component level savings values. It is important to note that at Host Site #2 there were two post installation monitoring periods, once when the pump was running at full speed and the other when the VFD on the pump’s motor was modulated to a reduced speed.

Table 1: Total Energy Savings and Peak Demand Reduction


Table 2: Savings Contributed by Each Component


While the study concludes that each component of the Solar Jack system has the potential to save energy, it is observed that savings magnitude is dependent on several factors such as well characteristics, well stimulation technique, well balancing, motor/pump sizing, etc. Solar Jack resulted in about 16.7% reduction in annual energy consumption at the Host Site #1, 22% reduction at Host Site #2 at 100% VFD speed, and 51.7% reduction at reduced a VFD speed. As can be seen, savings vary significantly between each test site and operational characteristics; hence, project team is of the opinion that PG&E’s Customized Incentive Program which evaluates each project independently is the most appropriate program for incentivizing this technology/measure.