A 3-star hotel consulted us Inspecro when they faced large electricity costs. Meanwhile, they could not reduce electricity usage any further:
- Sacrificing cooling units would make guests uncomfortable by heat.
- Reducing water heating would shock guests in cold evening showers.
- Darkening lighting would destroy the hotel appearance in the eyes of the guests.
- Hotel has no control over guests using fridge and TV in the guest rooms.
The hotel concluded that to maintain guests comfort would require the same electricity consumption. Then, how could the hotel save electricity costs? Hence, we proposed electricity cost savings with solar energy (or Pembangkit Listrik Tenaga Surya / PLTS).
Here, the manager asked us these 3 questions:
- How much are PLTS’s monthly cost savings?
- What is PLTS’s lifetime profit?
- Is PLTS reliable for 25 years?
A. Monthly Cost Savings
The 64.6 kWp PLTS saves Rp 8.8 millions per month on average. (See Exhibit 1.)
How did we get these numbers?
The solar panels or “panel surya” produces 8.5 MWh of electricity per month on average, after losses such as soiling, clouds / nighttime, and wiring loss. (See Exhibit 2.)
Next, using 2018 PLN tariff (IDR 1035 per kWh for golongan B3), we can calculate our cost savings: Net Energy x 2018 PLN tariff.
For example, in September:
Cost savings (September) = 9830 kWh x IDR 1035 per kWh
Cost savings (September) = IDR 10.2 millions
Over the year, the hotel saves IDR 106 millions of electricity cost. However, is this saving profitable compared to the initial investment?
B. Lifetime Profit
With cost savings of IDR 106 millions per year, the PLTS generates lifetime profit of IDR 2.6 billions to IDR 7.5 billions. (See Exhibit 3.)
To determine whether PLTS is the most profitable investment, the hotel’s finance team asked about the ROI. (See Exhibit 4.)
But the analysis above assumes 25 years of operation. The manager asked, “How can we be sure that the PLTS would not break down in just 10 years?”. Great question.
The system is 100% reliable, due to globally known brands, certifications, installation standards, 24/7 online monitoring, and warranty.
Globally known brands. Local brands are not yet proven. Therefore, we use Canadian Solar panels and SMA inverters for this project. (See Exhibit 5.)
Certifications. Both of the solar panels and inverters are certified:
- Solar panels: ISO9001, ISO14001, IEC 61215: VDE / CE / MCS, UL 1703 / IEC 61215 performance: CEC listed (US) / FSEC (US Florida), UNI 9177 Reaction to Fire: Class 1 / IEC 60068-2-68: SGS.
- Inverters: UL 508, UL 60950-1, CSA C22.2 No. 60950-1-07, EN 60950-1, EN 55022 Class A, EN 61000-3-2 Class D, EN 61000-3-3, EN 61000-6-4, EN 55024, FCC Part 15, Sub-part B Class A.
Installation standards. Inspecro follows Australian / New Zealand Standards (AS/NZS) for absolute safety procedures of the hotel’s solar energy system.
After-sales services. Unlike other installers cleaning their hands after you pay them, Inspecro commits to 24/7 online monitoring and warranty:
- 24/7 online monitoring. Inspecro and the hotel may observe the system 24/7 via an internet connection. Therefore, if there is any issue, it shall be solved immediately.
- Warranty. The solar panels have 25 years linear power output warranty. This means the manufacturer guarantees that the panels will still produce above 80% of its initial power in the 25th year. (This degradation of 0.7% per year is already included in our financial study.)
What were the hotel’s conclusions?
The hotel concluded that:
- They must not sacrifice electricity usage, otherwise guests will become uncomfortable by feeling hot, showering in cold water, or seeing a gloomy lighted hotel lobby.
- PLTS solves their electricity costs by saving Rp 8.8 millions per month on average.
- As an investment, PLTS generates profit of Rp 2.6 billions to Rp 7.5 billions over the long-term, with ROI of 15% – 22% per year, depending on PLN tariff growth rate.
- PLTS is risk-free with lifetime of 25 years or more. Meanwhile, the system break evens at 6 years. Therefore, solar energy is free for 19 years or more.
If you are a hotel manager facing the same problem, consult with us for free: