Endorsed by Which?

Tethys Energy Ltd

5.0

60 Reviews

Opening Hours
Today -
  • Monday 08:00–17:00
  • Tuesday 08:00–17:00
  • Wednesday 08:00–17:00
  • Thursday 08:00–17:00
  • Friday 08:00–17:00
  • Saturday - Closed
  • Sunday - Closed

Why you can trust this trader

After undergoing rigorous assessment to become endorsed, every Which? Trusted Trader agrees to our Code of Conduct. This gives consumers the reassurance that they have the best possible protection and adds an extra layer of security to ensure best practices and procedures are followed. Which? fully investigates any breaches and will take any necessary action to ensure consumer protection.

About

Incorporated in 2013, Tethys Energy has been providing solar PV and battery storage solutions to home owners and businesses around Berkshire and the local area for a decade.

With extensive experience in the design and installation of these renewable energy systems and EV charging, we are proud to be members of Which? Trusted Traders and strive to provide a first class customer service through bespoke designs to meet our clients needs.

What we do

  • Renewable energy

    • Solar panels
    • Solar Panel Maintenance
    • Solar water heating
  • Cleaning services

    • Solar panel cleaning
  • Electricians

  • Electric Vehicles

    • Electric Vehicle Charging Points
  • More Services

    • solar pv repair
    • ev installer
    • battery installation

Customer reviews

Why you can trust these reviews

All reviews are verified as being genuine and a true customer of this trader.

How can we be so sure?

100% of the reviews we publish have been through our stringent moderation process.

5.0
60 reviews
Customer Service
5.0
Quality
5.0
Value
4.9
Sort by
Couldn't be happier with Tethys!
Customer Service
Quality
Value
Tethys provided an excellent service from start to finish. Recommended by a neighbour and WHICH we phoned Jason for a quote. Quickly organising a home visit and very happy to talk through all our options providing multiple quotes for various ideas. We had quotes from many competitors - some cheaper, some more expensive. But we like to support local business as it gives peace of mind that support is close. I am glad we did. Jason quoted a start date which was kept, the works carried out on time, the agreed price never changed and all the workers were willing to work with all our requirements for a neat and tidy install - I felt the installation was done with pride. Slight teething issue with wiring at the start on our first car charge via solar, but very quickly resolved which was zero hassle and good support. We have been recommending to all our friends who might be thinking about solar in the future. I can't comment on aftercare since the initial install as nothing has gone wrong! - and with the unusual sunny spring - we are enjoying the quilt free power generation for our home and car. Also note, all paperwork and communication was completed to the National Grid on our behalf with no hassle so we are now exporting power to other users across the network. Super job all round
Customer in Berkshire Posted on 21/05/2025 , work completed 18/03/2025
Excellent work by Tethys
Customer Service
Quality
Value
Really pleased with our solar and battery installation. From Jason's initial visit, resulting in detailed plans and costings, to the installation led by Chris we found that Tethys were professional and knowledgeable. Our roof is complex, but they were happy to work with us to maximise the number of panels we could install - ending up with 20 where other suppliers said they couldn't even install 2! The installers were careful, neat and tidy and were happy to work with us to minimise the amount of visible cabling. Pricing was transparent, and the cost of modifications agreed up front. They have remained responsive after the installation was completed. We have already recommended them to a couple of neighbours who have expressed an interest.
Customer in Oxfordshire Posted on 21/05/2025 , work completed 13/03/2025
Excellent
Customer Service
Quality
Value
I have no hesitation in recommending Tethys Energy. Jason and his team were very efficient, comms very good, they always explained and kept us informed and their installation of solar panels and a Tesla battery was exemplary. First class!
Customer in Buckinghamshire Posted on 10/12/2024 , work completed 27/11/2024
The trader replied (on 10/12/2024)
I am glad we were able to help you to reduce your energy costs. Thank you! Jason
Excellent
Customer Service
Quality
Value
I can't improve on what a previous customer wrote : "From the moment I contacted Tethys Energy I experienced a polite and courteous team. They always turned up on time, answered phone calls and emails promptly. Once on site the team always kept me informed of progress. The installation looks neat and tidy. They took time to explain how the system and app work. Follow up paperwork came within a matter of days. I would have no hesitation in recommending Tethys Energy. "
Customer in Buckinghamshire Posted on 27/11/2024 , work completed 25/11/2024
The trader replied (on 27/11/2024)
This is great to hear, thank you for your kind words. Jason
Excellent service from start to finish
Customer Service
Quality
Value
From the moment I contacted Tethys Energy I experienced a polite and courteous team. They always turned up on time, answered phone calls and emails promptly. Once on site the team always kept me informed of progress. The installation looks neat and tidy. They took time to explain how the system and app work. Follow up paperwork came within a matter of days. I would have no hesitation in recommending Tethys Energy.
Customer in Berkshire Posted on 17/10/2024 , work completed 10/10/2024
The trader replied (on 19/10/2024)
We are only too happy to have been able to help. Thank you for this wonderful feedback - Jason.
satisfied customer
Customer Service
Quality
Value
Having had my solar panel system for 13 years and believe them to be the best investment I have ever made I decided to use Tethys Energy Ltd to carryout an audit and clean of the system. The team of two led by Chris arrived on time and carried out the work in a most efficient and friendly manner. Further to verbal feedback on the day I duly received the audit report online within the same week. The report identified that the RCD unit on my system although operational was not correctly rated therefore if an earth fault were to occur within the PV inverter it may not trip. Further to contacting Jason Fuller for clarification, I used his team to return and replace the said RCD unit which they did on a day and time that suited me. The service provided by Tethys Energy Ltd was top class and I would certainly recommend them.
Customer in Berkshire Posted on 29/09/2024 , work completed 16/09/2024
The trader replied (on 02/10/2024)
I really appreciate these comments and am glad that we were able to help. Many thanks, Jason
Excellent service
Customer Service
Quality
Value
I contacted Tethys Energy when I discovered a problem with my solar pv eps. They responded promptly and arrived on time. Even though they hadn't installed the system, they demonstrated excellent knowledge and confidence in all aspects of solar pv. After thorough fault finding, Jason fixed the problem and tested everything was working. Everything was left clean and tidy. From start to finish the service they provide is professional, friendly and reliable. I can certainly recommend Jason and his team.
Customer in Berkshire Posted on 13/09/2024 , work completed 12/09/2024
The trader replied (on 16/09/2024)
Thank you for the great review. Many installers won't touch battery back up supply systems but we are able to take on this kind of work to get these systems up and running again. All the best.
Solar iBoost+ fix
Customer Service
Quality
Value
In 2023 we had a solar pv system with battery storage fitted, but not by Tethys. The system works well and subsequently we were recommended to have an iboost+ fitted to heat hot water using excess energy. I thought the fitter (3rd party not part of the install team) was competent, but turned out to be a plumber with no solar experience....the iboost+ didn't work. I called numerous electricians for help, but as soon as solar was mentioned they weren't interested. Having looked a bit more carefully for an electrician I emailed Tethys, simply stating the above and not hoping for much. Jason responded within about 30mins and said they would have a look and it shouldn't be a problem. I was so pleased to get such a prompt and positive reply. Chris duly attended a few days later, tested, found a couple of faults, purchased a replacement part, fitted, tested and working! This was just a small job, but I was really impressed with the can-do attitude and professional way it was handled. I wouldn't hesitate to contact Tethys should we require any maintenance on the array going forward.
Customer in Berkshire Posted on 06/05/2024 , work completed 11/04/2024
The trader replied (on 08/05/2024)
I am glad we were able to help with this and that your system is working as intended. Many thanks, Jason
A most professional experience throughout from every member of the company - Tethys Energy
Customer Service
Quality
Value
From my initial contact with Tethys Energy the administrator was most efficient in keeping me updated with Jason; MD involvement to survey, quote and install 9.5kw battery and associated equipment to my existing PV array of 12 panels. Especially since February 2024 more economic now that 20% VAT no longer applies to just battery installations. The workmanship is first class and working in the cupboard under the stairs without any complaints is to be applauded. I hope copious supplies of coffee helped! Thank you Jason and your team.
Customer in Berkshire Posted on 03/05/2024 , work completed 25/04/2024
The trader replied (on 07/05/2024)
That's great to hear, the guys very much appreciated the coffees. Many thanks, Jason
Excellent service from start to finish
Customer Service
Quality
Value
This was a tricky job with multiple trades involved. Jason and his team worked to make it super easy for me to get all the work done. The work they did on my solar panels was perfect and remedied many faults the original installers had left. An excellent team doing first class work.
Customer in Berkshire Posted on 22/04/2024 , work completed 19/04/2024
The trader replied (on 25/04/2024)
An interesting project with a very unique array set up. A bit of a head scratch putting it back together but we got there in the end. I'm glad we were able to help and thank you for this great review. Jason