Case Study: Sunly Installs Solar Power System on Boswall's Doctor's Office Roof

System Lifetime Savings: $218,800 Simple Payback Period: 7.1 years

Introduction

In 2021 the owners of the doctor’s office located at 18 MacLeod Cres awarded Sunly with the turnkey installation of a solar power system on their roof to offset approximately 100% of their previous 12 months of energy usage. This was under the provincial Net Energy Metering (NEM) program.

The site is a newly constructed doctors office completed in late 2020 that operates typical business hours and has approximately 35MWh of annual consumption. The utility rate class for the account is General Service 1 which has a 2 tier billing structure.

Tier 1 @ $0.1871/kWh (circa. 2022) for the first 5,000kWh/billing cycle

Tier 2 @ $12.01/kWh (circa 2022) for the remaining

Given that the majority of the power used by the facility falls within the Tier 1 rate, this improves the offset economics.

The system was proposed to have a payback of approximately 7 years and an estimated 30 year lifetime savings of about $218,800 after paying the capital expenditure off. In our analysis, we included a 2.1% annual increase to the cost of power and a 0.5% annual degradation to the output of the system.

Solar Project Summary

Size:                 29.37kWp

No. Panels:       66

Panel:               Canadian Solar CS3W 445 Monocrystalline

Inverters:          SolarEdge SE14.4KUS & SE9KUS 120/208VAC 3-Phase

Optimizers:       SolarEdge P950 Dual Module Optimizers

Roof:                Standard Metal Exposed Fastener Roofing

Irradiance:        1,208kWh/kW/yr.

Est. Prod:          35,482kWh/yr.

Est. Savings:      $6,400 (Apr 2022 to Mar 2023)

Commissioned Date:     23 December 2021

The process time line:

Apr 2021 First Meeting

Jul 2021 Contract Signed

Oct 2021 Engineering, Permitting and Procurement Completed

Nov 2021 Panels Installed

Dec 2021 System Connected and Activated

NB: Due to the pandemic, the project experienced supply chain issues and delays.

System Performance:

Performance analysis was conducted with a partial year’s data from 23 December 2021 to 30 November 2022.

Based on the data, the total usage for 2022 will be very similar to the 2021 usage, however, they imported fewer kWh’s than the previous year by about 33%. This was supplied directly from the solar system, known as self consumption, that doesn’t flow through either the generation or consumption meter. Total Usage is a combination of the power imported from the utility and supplied directly by the system(self consumption).

Because the system was commissioned in late December, there was not enough sunlight to generate significant credits until April of the following year. As the client enters into their first full year of production, they have accumulated over 15MWh of credits which will be used to offset the cost of importing power from the utility. Based on the estimated previous usage, this should be sufficient to cover their usage until April or May of 2023 after which they will be generating surplus power and credits.

The following table is intended to illustrate the systems real world performance against the estimated production used in the proposal. The actual system output data was obtained from the inverters monitoring system. The estimated production was determined using Aurora. This is an industry approved modelling software that has proven to be reliable and accurate.

Based on this data, we are able to conclude that the system has performed within expectations.

There is only a 1% over production to date for the system. It is important to remember that the actual system production is affected by a number of environmental factors and will vary year to year. These variations are typically small, but can be large.

At the end of Sept 2022, PEI was hit by Post Tropical Storm Fiona. As a result, the building was without power from Sept 24 to Oct 5. The system was off and unable to produce power for those 11 days. This would explain the shortfall in September, but October still produced slightly more than expected. The system however was undamaged by the record-breaking storm and the building did not experience any leaks.

Conclusion

Sunly is confident that this solar power system will meet the client's needs and provide the promised benefits throughout its lifetime, both financially and physically. Contact us at Sunly.ca to learn more.