Solar water heating · Heat pumps · Solar cooling
Good systems are managed, not guessed.
We design, install and maintain energy-efficient water heating, heat pump and solar cooling systems, built around your site and your usage, not a catalogue spec.
150+
Clients served
Since 2018
Kenyan-based
German
Engineering standards
End-to-end
Design · Install · Maintain
Why it matters
Energy efficiency isn't about equipment.
Most suppliers sell you a unit. We start with the material and system research: what's available in the Kenyan market, how it holds up against local conditions, and which combination will still be working well down the line. Then we design around how you personally use hot water, not an average estimate. That's the work that happens before installation day, and it's the reason our systems keep performing long after.
Why clients choose Sonnen →What we do
Three ways we keep you efficient
Who we serve
The same engineering, tuned to you
Why Sonnen
The work that makes a system last
We think beyond installation day, and it shows in how long our systems keep delivering.
What sets us apartEvery system design is custom, not off-the-shelf
We size and design from your real hot-water or cooling demand and your site conditions.
Our installation technique is built for longevity
Pipework, electrical termination, mounting, insulation and positioning all affect how long a system lasts. We choose methods for durability first, not for the fastest install.
Honest guidance, not over-specification
We recommend what the job needs. Never a bigger, pricier system than the demand justifies.
Trusted by teams across Kenya
FAQ
Common questions
How much can a solar water heater save on electricity?+
Water heating is often the single largest electricity cost in a Kenyan home or hotel. A correctly sized solar water heater can cut that cost dramatically, with an electric backup only topping up on cloudy days.
Do solar water heaters work on cloudy days?+
Yes. Sonnen's systems include an automatic electric booster, so you have hot water through overcast weather — the sun simply does most of the work whenever it's available.
Do heat pump water heaters work at night?+
Yes. A heat pump pulls warmth from the surrounding air rather than from sunlight, so it heats water day and night, using up to around 70% less electricity than a standard geyser.
What's the difference between a thermosiphon and a split solar water heater?+
A thermosiphon system has the tank and collector both on the roof and uses no pump — simple and cost-effective. A split system keeps the tank indoors with slim collectors on the roof, which suits weak or steep roofs and a cleaner finish.
Will a solar water heater work with borehole or hard water?+
Yes. Sonnen uses indirect systems, so the collector fluid never mixes with your water. That lets them handle borehole, hard or municipal water without scaling up the panels.
Do you repair or service systems installed by another company?+
Yes. Sonnen diagnoses and repairs solar water heaters and heat pumps regardless of brand or original installer, and will advise honestly on repair versus replacement.
Does hybrid solar air conditioning need a battery bank?+
No. It runs directly off solar panels by day and switches between solar and grid automatically — no battery bank and no separate inverter required.
What areas does Sonnen serve?+
Sonnen Energie Technik is based in Nairobi and serves homes, businesses and institutions across Kenya.
How long has Sonnen been operating?+
Sonnen Energie Technik was founded in 2018 and has served 150+ clients across Kenya.
What types of clients does Sonnen work with?+
Homes and apartments, plus hotels, schools, hospitals and property developments — each system sized to real demand rather than a template.
Get in touch
Start with a conversation.
Tell us about your property and how you use hot water, and we'll recommend the right system.