solar panels efficiency and wattage in kenya

Solar companies in Kenya love to tout their high quality and long lasting solar products. It’s one of the primary sales tactics used by sales persons globally. There are 3 primary components in a grid tie solar build:

  • Panels
  • Inverters/microinverters
  • Racking

These 3 primary components have a wide range of quality, and it is important to fit out your home with the right solar products in Kenya. 

In this article, we are going to focus on component #3—the solar panels (or PV module, as they are commonly referred to in the solar industry). 

Differences in Solar Panels in Kenya

Not all panels are created equal. Panels vary in a variety of ways, namely in technology used, aesthetic, build quality, warranty, and probably most notably, in wattage. Let’s briefly touch on each.


There are two main types of solar panels and the technology that powers them—monocrystalline and polycrystalline. In short, monocrystalline panels are more efficient, meaning more energy for a given surface area. However, efficiency is only one part of the equation—we get into this more in the section below.


Beauty is in the eye of the beholder; however, most agree that an all-black panel is the most attractive. Other common panels have a blue tint and some have a white diamond grid. You can have high-efficiency panels with whatever style you prefer.


A good top-tier panel will have a 25-year warranty. The cheapest panels will have shorter warranties, and in our opinion, it’s not worth it. A good 25-year warranty will guarantee at least 80% of originally stated wattage value by year 25, and the actual lifespan of the panels is actually quite a bit longer. This is an area you really want to pay attention to to avoid regrets in future.

Build Quality 

First and foremost, we recommend going with a respected and established brand (Jinko, Amerisolar, Jio, Sunpower, Canadian Solar, etc.). All these manufacturers have high-quality builds rated to IEC 61215, the industry gold standard. Panels with these ratings should be able to withstand wind, snow, and rain without issue. The companies will also be around long enough to live up to their warranties. 

A good 25-year warranty will guarantee at least 80% of originally stated wattage value by year 25, and the actual lifespan of the panels is actually quite a bit longer.


All panels are given a watt rating which tells you how much energy your panel will generate in an hour of direct sunlight. For residential solar, most panels are in the range of 290-400 watts. 


This watt rating can be converted into a metric showing the efficiency of the panel which takes into consideration the total size of the panel and the watt rating. Most panels are somewhere between 15-21% efficient. However, given that the majority of residential roof panels are the same size, the wattage is usually an easier metric to compare.

Wattage and efficiency, because of their connection, are often interchanged when comparing the production output of the panel.

Efficiency/Wattage Comparison

Higher wattage means more energy being generated. So the best system has the highest watt panels, right? Not so fast. 

An important metric in solar is price per watt (PPW). 

Price Per watt is simply the cost of the panel divided by the wattage. This metric is far superior to just analyzing the panel wattage because it factors in price. You use this metric when comparing panels for purchase.

Price per watt is also used to compare TOTAL system cost and is calculated the same way—total system cost divided by the watts, giving you the price per watt of the finished system. You would use this when comparing full-service installation cost among various solar companies in Kenya.

Panels in the 320 W-350 W range cost around Ksh 35/watt. But panels pushing 380-450 watts can be as much as Ksh 55 -80/watt. That means you are paying as much as 2x more for the same energy generated. 

If this isn’t clear, consider this example: 

1.6 kW worth of panels consisting of 5 320 W panels at Ksh 35/watt would cost Ksh 56,000 (this is just the panels and NOT racking, inverters, planning, permits). 

1.6 kW worth of panels consisting of 4 400 W panels at Ksh 75/watt would cost Ksh .120,000

These two examples produce THE SAME amount of power, but one system costs twice as much. The ONLY benefit is that there is 1 fewer panel. This should only be considered when space is extremely limited and when you are REQUIRED to hit a certain kW size that panels with lower wattage can’t hit. 

Doubling the cost lowers your ROI and increases your time to pay off. 


At Jesaton Systems our goal is solar proliferation by means of making solar not just affordable but an economic no-brainer. We achieve this by smart system design, efficient processes, and cutting out the unnecessary costs. 

Don’t get obsessed with pricey, “high-efficiency” panels. Do your research. Find reputable panels with good warranties and a low price per watt

Or, better yet, have us optimize it all for you: we’ll hold your hand through the entire process, and we can help save you money through our long-term relationships and transparent pricing. 

Ready for Solar? Consult a solar expert today.

Interested in our Solar Power installation services in Kenya? Call us today on 0715 020605. Alternatively, you can email us and a member of our team will get back to you as soon as possible. We install solar power systems in Nairobi, Kiambu, Ngong, Kajiado, Kitengela, Athi River, Machakos, Coast Province, Rift Valley, North Eastern, Central, Nyanza and countrywide for domestic and commercial clients.