written by Greg Shaw, Solar Energy Consultant and Managing Director, Hua Hin Solar Co., Ltd.
Question: How many years will it take for my 5KW or 10KW system pay itself off?
Answer: Explained in an honest manner in a recent email response to one of our customers.
Dear [valued customer],
Thank you for asking about two scenarios: best case and pessimistic case payback periods for your solar system. We will do our very best to give you a proper answer. To let you know at the start the larger the system you install the faster it will pay itself off and the more money you will make long-term. Also the higher the electricity rate for your home the faster it will pay itself off and the more energy savings you will make long-term.
As you know the 2 answers are estimates only and based on weather patterns so do not accept the answer as hard fact. Only the God’s know what the weather patterns will be in the coming years. But within reason I would say that you are in good hands, because we spent a very long time carefully researching even using Masters of Solar Engineering (Sweden) course material to make our the solar payback calculator that I provided the link to. And the results for a south facing 5KW solar array are decent. Link here:
Our calculator is based on the assumption that the Hua Hin-Pranburi-Cha am area receives 5.2 peak sun hours each day on average, throughout any given year.
Pls. read my blog to better understand where 5.2 hrs came from and the definition of a peak sun hour. Link here:
I also used 5 Baht/watt for your average electricity bill for the next 5-7 years-this is likely conservative as your development owners charge close to this now and they will likely have to raise electricity rates over the years as the electric authority does so – the PEA is already raising it’s electricity rates.
I put the data in our solar payback calculator for a 5KW system (yours is 5.1KW) and the estimated output came out to less than 5 years. So we have an optimal hypothesis: Let’s not be greedy and take this payback of 5.2 years as the optimal.
You should know that it is possible but not guaranteed that the weather could even be sunnier in the coming years, especially with global warming, provide on average of over 5.2 sun hours, and or, if electricity rates go up, this estimate will come down. So that’s good news.
It’s a turkey shoot what to choose for pessimistic weather patterns. So let’s say that there are 7 years straight of crumby weather. V. low chance it will happen but … Lets choose a realistic scenario where the peak sun hours per day based on yearly averages goes from 5.2 hrs to 4 hrs. We think that’s a reasonable scenario. Your estimated payback increases to less than 6 years. Still decent. And again, unlikely to happen. Less than 5 year pay back for a 5KW system is the most likely scenario.
Here is the best news. For 10KW solar system the payback period for Solar Shop Hua Hin systems reduces to about 4 years. If I choose a community electricity rate of, say, 6 Baht/unit the payback is an amazing 3 years! And then if I choose a higher electricity rate often charged to condo owners. Well, I think you get the point. The pay back period becomes incredibly fast. So the moral of the story is is that the larger the system and the higher the electricity rate, the faster solar systems pays themselves off. And the more energy savings you will have long term.
So all hypothetical answers but we think decent estimates.
I hope this helps you rest easy.
Greg and Team.
Solar Shop Hua Hin is Hua Hin’s most dependable solar installation and equipment supply company. Highly recommended (see Testimonials from Our Valued Customers) with over 20 years experience in the Hua Hin area. With dozens of installations year-to-year we are motivated by quality of our solar systems and services and deliver on follow-up customer care. Solar Shop Hua Hin energy systems are designed to significantly reduce your electricity bill, increase the re-sale value of your home and allow you to produce your own clean energy. Our expert specialists also perform certified electrical services and roof repairs. Choose a solar solution taylor-made to suit your home or business. We install solar systems with superb quality / yields and exceptional service and long-term customer care, and all this at an affordable price. 5, 12 and 25 year warrantees come standard with finance and installation options available. Talk to our dealer store today! Call us at 089-824-1963 089-614-9234.