Harnessing renewable energy to power our office

On a daily average, this means the solar power system could potentially cover up to 25% our energy needs during a working day and up to 57.04% on a day off.

In tropical climates like Indonesia, sunlight is a constant and abundant resource. Harnessing this abundant solar energy into fueling our life is a really compelling idea, especially for those of us who experience bright and hot days regularly. However, solar technology adoption is still limited due to accessibility and affordability issues. 

PV panels on our office roof.

We believe that the very first step to understand what it takes to have renewable energy powering our daily life is to walk the talk. We aim to understand how this small step impacts our energy consumption and reduces our carbon footprint. Through this article, we hope to spark a broader conversation about the potential of solar energy, how convenient it is, and the challenges we have faced during our first 100 days of harnessing solar energy to run our office.

Each PV panel was being carried one by one to the roof due to limited workspace.

Our experience started on February 28th, 2024 when the equipment was installed on the roof of our office building, which has a slight slope to maximize sunlight exposure throughout the day. The installation took around a week to complete. After a few adjustments, we started recording the solar power data on March 25th, aiming to complete the first 100-day monitoring period by July 2nd.

Over the first 100 days, the installed 28 PV (photovoltaic) panels have produced a total of 4,399.50 kWh1. On average, the panels have generated 43.995 kWh per day. In comparison, our office's average daily power consumption during working days is 183.07 kWh1, and 72.45 kWh1 during the weekends and public holidays (day offs). 

Due to varying weather and sun exposure conditions, the solar power production meets between 17-32% of our office power needs on working days and 43-70% during a day off (ranging from rainy, cloudy days, and bright sunny days). On a daily average, this means the solar power system could potentially cover up to 25% our energy needs during a working day and up to 57.04% on a day off. 

PV panels installation on the roof.

However, it is important to note that our solar power system does not include a battery. Why? Because the ones that are available in the market are still considerably expensive and have a short lifespan. As a result, any surplus power is sold back to the grid (PLN)2. In this context, surplus means when the solar energy production exceeds the power consumed during that particular time during the day. We do not store the extra solar power for later use. Therefore, the percentage of solar power production compared to daily power consumption does not fully reflect the actual solar power covering the office’s power needs. 

The final and foremost question of this effort would be how much will it impact our electricity bills. Based on daily average power production of 43.995 kWh and the highest PLN tariff of Rp1,699.53/kWh, the generated solar power is equivalent to approximately Rp74,771 per day. Over a month (30 days), it’s equivalent to approximately Rp2,243,125 or $137 USD in savings. While the amount in monthly savings might not seem significant yet, considering the inve

Real-time power consumption: 16.7 kW total, with 10.9 kW from solar panels and 

5.8 kW from the grid.

While the amount in monthly savings might not seem significant yet, considering the investment cost (even without the battery) and limited space to install the more PV panels. But, does it actually reduce our electricity bill? To accurately determine this, we need to measure the power usage from the grid, which forms the basis of our bill, to understand how much solar power was used and how much was sold back to the grid. Obtaining this information might need extra time to request the detailed breakdown of the monthly bill. To understand better how much independent solar energy use impacts the overall electricity bill, we need to review the power use at least in one year ahead. 

Overall, for those considering installing solar panel systems at your home or building, it’s crucial to understand the options available in the market, as this will influence the equipment needed. Generally, make sure to have sufficient space for the PV panels, power meters, battery (if you decide for it), and other needed equipment. Please double-check these requirements with your preferred provider. Second, verify that the structure can support the weight of the equipment. 

Additionally, PV panels need to be located on a relatively flat surface to maximize sun exposure throughout the day. Make sure this space is not obstructed by trees or nearby building shadows.

Our journey with solar power is just beginning. While immediate savings might be modest, the long-term benefits include reduced carbon footprints and a move towards sustainable energy practices. By sharing our experience, we hope to inspire others to explore solar energy and contribute to a greener future.

Footnotes:

1 Data obtained from the solar power system meter.

2 PLN (Perusahaan Listrik Negara) is a grid power provider run by the government in Indonesia.

(PDW/PSY)