Case Study: Which solar assets need attention?

Understanding solar performance across nine council sites and identifying where further investigation can help facilities teams make better-informed energy decisions.

Understanding how solar supports each facility

The City of Casey operates solar systems across multiple council facilities. Each site has its own energy demand, solar generation and reliance on grid electricity.

For the team responsible for these facilities, knowing how much electricity the solar systems produce is only part of the picture. They also need to understand how much solar energy is used on-site, how much is exported and when facilities continue drawing electricity from the grid.

Minnovation reviewed 30 days of AlphaX operational data across nine sites and 18 physical devices. The objective was practical: bring the available energy information together, identify patterns across the portfolio and help the City of Casey understand which facilities may need closer attention.

PROBLEM

Solar generation does not tell the whole story

A solar system can produce substantial electricity while the facility continues importing energy from the grid. A site may export electricity during the day but still record significant grid demand at other times. Looking at generation totals alone does not explain how effectively each facility uses its available solar energy.

For the City of Casey, the challenge was understanding these differences across multiple sites. Three questions guided the review:

1. How much of each facility’s calculated electricity consumption was supplied by solar?
2. How much generated solar electricity was used on-site rather than exported?
3. When were facilities importing electricity from the grid, including outside their stated operating hours?

Answering these questions would give the facilities team a clearer starting point for reviewing solar utilisation, energy demand and operating schedules.

APPROACH

Bringing energy information together

Minnovation used AlphaX operational data to examine available five-minute electrical readings alongside recorded Grid Import and Grid Export. The analysis focused on producing a consistent, evidence-based view of energy use across the portfolio.

Calculating solar production

Calculated Solar Production was derived from valid three-phase voltage and solar-current readings. To maintain the integrity of the analysis, missing readings were not filled in or scaled up. Negative currents and isolated outliers were excluded.

Understanding on-site solar use

For eight sites, calculated Solar Used On-Site was determined by subtracting recorded Grid Export from calculated Solar Production. Total Site Consumption was then calculated by adding recorded Grid Import to Solar Used On-Site. These calculations helped establish how much of each site’s electricity consumption was supplied by solar and what proportion of generated solar energy was used within the facility.

Reviewing demand outside operating hours

For seven facilities with stated weekday operating hours of 08:00–17:00, the review also examined recorded Grid Import between 17:00 and 07:59 on weekdays and throughout weekends. This provided a way to identify sites where electricity demand outside stated hours warranted further investigation.

Importantly, electricity consumed outside those hours was not automatically classified as waste. Facilities may have legitimate after-hours requirements, including essential equipment, bookings or other operating needs. The analysis identified where the team could review these patterns in more detail.

BY THE NUMBERS

What the energy data showed

Metric	Result
Portfolio reviewed	9 sites / 18 physical devices
Calculated Total Site Consumption	32,529.8 kWh
Calculated solar contribution	24.00%
Calculated Solar Production	15,185.1 kWh
Calculated Solar Used On-Site	7,796.5 kWh
Calculated solar self-consumption	51.30%
Observed Grid Import outside stated hours	13,611.9 kWh
Outside-hours share of observed Grid Import	67.20%

Scope note: Total Site Consumption, solar contribution and solar self-consumption refer to the eight-site on-site-use analysis. Solar Production covers the reviewed portfolio. Outside-hours figures refer to the seven-site operating-hours comparison.

PROOF

Identifying where attention is needed

The review revealed differences in solar contribution, on-site energy use and grid dependence across the facilities.

Solar supplied 24.0% of calculated site consumption

Across the eight sites included in the on-site-use analysis, calculated Total Site Consumption was 32,529.8 kWh. Of this, 7,796.5 kWh was supplied by solar used on-site, while recorded Grid Import accounted for 24,733.3 kWh. This established a clearer view of the contribution solar was making to the facilities’ electricity requirements.

Just over half of calculated solar production was used on-site

Across the portfolio, calculated Solar Production totalled 15,185.1 kWh, while recorded Grid Export totalled 7,388.6 kWh. For the eight-site on-site-use analysis, 51.3% of calculated solar production was used within the facilities. This gives the team a basis for examining differences in solar utilisation between sites.

Bridgewater recorded a strong solar contribution

Bridgewater recorded 3,057.9 kWh of calculated Solar Production. Among sites with at least 95% solar-data coverage, it recorded the highest solar contribution to calculated site consumption at 44.2%. This provides a useful reference when comparing solar contribution across facilities with sufficient data coverage.

Littlecroft was identified for closer review

Littlecroft recorded a 35.4% solar contribution. It also recorded the highest proportion of observed Grid Import outside stated weekday hours among the seven facilities reviewed, at 86.0%. This does not mean that 86.0% of its electricity was wasted. It means the site warrants closer examination of its baseload, bookings, equipment schedules and operating controls to understand the demand.

Outside-hours electricity demand provided another investigation priority

Across the seven facilities included in the operating-hours comparison, 13,611.9 kWh of observed Grid Import occurred outside stated weekday hours. This represented 67.2% of their combined observed Grid Import. For the facilities team, this identifies where reviewing operating patterns may help explain energy demand and determine whether any adjustments are appropriate.

Understanding the limits of the data

Arbourlea and Ramlegh had partial solar data. Autumn Place recorded very low calculated Solar Production during the available period. At Manna Gum, the hybrid inverter and battery flows were not measured separately. As a result, an on-site solar-use percentage could not be established for that facility. Solar sample coverage describes the availability of readings, not their measurement accuracy. These limitations help the team distinguish reliable comparisons from findings that require further investigation before decisions are made.

OUTCOME

A clearer view of what to review next

The City of Casey gained a portfolio-level evidence base for understanding solar utilisation, grid dependence and electricity demand across its facilities. Rather than relying on generation totals alone, the review brought together information that helps identify practical investigation priorities.

The findings highlighted facilities with substantial grid demand outside stated operating hours, differences in how generated solar electricity was used on-site, and locations where incomplete or unusual readings required validation. For the people responsible for these facilities, the value is knowing where to look and what to investigate before making changes. This is the kind of operational clarity AlphaX is designed to support: bringing connected asset information together so the people responsible can understand the findings, prioritise investigation and determine the appropriate next step.

The review did not establish realised energy or cost savings. No post-intervention savings were measured or claimed. Its demonstrated outcome was a clearer, evidence-based starting point for engineering investigation and better-informed energy decisions.

Better asset decisions begin with knowing what needs attention.

NEXT STEP

Know where your energy needs attention

Managing solar systems across multiple facilities? Talk to Minnovation about using AlphaX operational data to understand your energy assets, review the findings that matter and identify where your team should look next.

Discuss your energy monitoring requirements.