Why Now Is The Time To Install A Solar Roof.

So why is now the right time to install a Solar Rooftop on your factory or business?

There are three key points that state the case for installing a Solar Rooftop today;

  1. Cost
  2. Technology
  3. Regulations


During the past five years, we have seen a steady decline in costs relating to Solar PV and Solar Rooftops. Due to advances in new technologies and the surge of new solar manufactures competition has been fierce. Many countries have adopted favourable tax and duties for Solar PV and that has also helped bring costs down. Those factors have contributed to the reduction in costs of equipment, particularly Solar PV Panels and Solar Inverters. Although costs to buy the main components of a Solar Rooftop have come down considerably, other costs related to the installation have seen a steady increase but not enough to impact and deter the development of Solar Rooftops.


The development of Solar PV panels has come a long way, from 170Wp panels a few years ago to 400Wp panels today. There are even 500Wp panels on the market but lead times are long and the costs are relatively high. If you compare a 170Wp solar panel with a footprint of 2sqm (2x1m standard size),  with a 400Wp solar panel with the same footprint then you can see that this has an impact on many fronts. Let’s look at an example;

A 500kW plant using 170Wp solar panels needed 2,940 panels with a footprint of 5,880 sqm.

A 500kW plant using 400Wp solar panels would need 1,250 panels with a footprint of 2,500 sqm.

This alone has a big impact on costs; fewer panels, less racking, less labour, fewer cables and all-round a quicker installation turnaround. Solar Inverters have also come a long way, with regards to functionality, efficiency and reliability. This means that there is a lot less downtime of PV Plants and the overall production is far greater than previous generations of Solar Inverters.


In this article, we discuss regulations in Thailand as that is where we have our business. In the past installing a Solar Rooftop for commercial business was almost unheard of as there were no guidelines in place and just ‘doing-it’ was a big risk for all involved. These days we have pretty clear regulations and guidelines so installing a Solar Roof for ‘self-consumption’ is legal. There are different regulations depending on the size of the Solar Roof but in fact, it’s just that you need to be more compliant and there are a few more hoops to jump through. The process is fairly clear but you need patience. After submitting the application you can start construction and operate the plant whilst waiting for the final inspection and approval. The permits and licences are for 25 years so you only need to go thru the process once. Having a good O&M contract in place and an efficient documentation process in place is sound advice as you never know when you may have some inspector drop by to take a look.


With the improvements in technology, reduction in costs and clear regulations installing a Solar Rooftop makes sense for a facility owner or roof owner as a way to reduce energy costs. The cost of the investment can be paid back within five years, usually, the saving from the utility costs will offset the cost of the investment. The Solar Rooftop will continue to produce energy for 25 years so once your investment is paid off you have free energy…  What to do if the funds are not available?      There are a few options available.

  1. Self-financing through your local bank of finance vehicle
  2. Entering into a PPA agreement with a Solar Services Provider

Self-financing may be an option but most times financial support is required for an investment of this size. Often times this can be difficult and time-consuming. However, if you can secure the funds you have the benefit of free energy after the investment has been paid back.

Another option is to enter into a PPA contract with a Solar Service Provider. This option means you have zero outlay and you get a percentage deduction off of your monthly electricity charge, usually 10-12%. The PPA contract usually runs for 15 years then you get to keep the asset after that time.

For more information about installing a Solar Rooftop for your Business, please email me or send me a message on messenger.

Daniel Parsons

Chief Operating Officer

Kunini EPC Services


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