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Off-Grid Solar Smart Energy Storage

Analysing data from energy audits and IoT sensors to identify the best locations for solar panels on community buildings

Interpretation of the SEMM model

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This pilot demonstrates the efficiency and necessity of utilising solar energy as a renewable energy source in Community buildings. It shows how the impact of Solar Panels can be best utilised when the sites chosen are based on how the site currently consumes energy.

The main objectives are:

  • Demonstrate that solar panels are a viable renewable energy alternative to using fossil fuels in community buildings 
  • Demonstrate that a data-driven approach is best when choosing sites to install solar panels
Target Groups

Target Groups

Technologies Used

Techologies Used

Sensors: Solar Panels:32 Pcs LONGI SOLAR LR4-60HPH. 375-watt black Monocrystalline PV modules with a efficiency of 19.05% Network: Inverter: 1 Pcs Solis 10KRHI-3P10K-HVES-5G. 3 phase hybrid inverters with a efficiency of 98.4%, dual MMPT. Built in color 7-inch LCD display to show power being generated today. Batteries: Pylontech high voltage storage batteries with a capacity of 5 KWh Data: Power generation data plus average daily usage, average nightly usage, average winter monthly, average summer monthly and annual consumption. Mapping: Display built-in to inverter shows power being generated today plus monitoring system shows average daily, nightly, winter monthly, summer monthly usage and annual consumption. Engagement: Solis online monitoring system supplied so that the data from the inverter can be displayed on a PC or smart phone.

Pilot Story

Several community buildings were identified, which are all different models in terms of age and energy profile. They are the County Library, County Museum, Regional Cultural Centre, An Grianan theatre and Letterkenny Public Services Centre. The common element is that the main sources of energy are fossil-based. The energy consumption in these buildings is now measured in real-time, which is the result of our Smart Energy Pilot. We analysed the following data in respect of the sites:

  • Energy being consumed on daily/annual basis
  • Recommendations contained in Digital Energy Certificates
  • Physical Suitability of Building for installation of Panels
  • Estimated amount of energy that could be generated in each site based on DC System Size(kW), Module type, Array Type, System losses, tilt angle and ground coverage ratio
  • Pattern of energy usage in each site e.g. main demand in Theatre is evening time, main demand in Museum is daytime. What are the implications.

Based on outputs, we chose three buildings which were the most suitable for solar panel installation

Tenders were sought for implementation of an appropriately sized farm at each site and a company was chosen. The County Museum is a heritage building so their solar farm was placed on the ground rather than the roof. In the other two sites i.e. the Regional Cultural Centre and An Grianan Theatre, the solar farms were placed on the roofs. Energy usage in both the Regional Cultural Centre and An Grianan Theatre is mostly in the evening time so batteries were installed in both locations, to enable the storage of energy during the day to be used at evening performances.

Pilot Results

Pilot Results

Solar panels were implemented at three locations, based on analysis of their suitability, their location, usage, etc. Below are the actual generated energy vs. average consumed and the estimated energy generated annually at each solar installation.


Average Daily Usage

Avg. Nightly Usage

Avg. Winter Monthly

Avg. Summer Monthly

Annual Amount Consumption

An Grianan



















Peak Output

Generates annually


An Grianan



10kwh capacity




10kwh capacity





Lessons Learned

Lessons Learned & Recommendations

Due to the Covid-19 pandemic, installation of the solar panels occurred later in the project than planned, so there has not been sufficient usage time to generate good quality data. However, early analysis of the buildings and locations allowed for the adjustment of installing the County Museum solar panels on the ground within the project timelines. When conducting a project of this nature, it is recommended to have a qualified person onsite to ensure the work is done to the expected standard.