Solasyphon renewable energy system. View of the sea stretching out to the horizon with sun shining on the water
Ashden Award Winners 2010, Find out why we won...
Willis Renewable Energy System Solasyphon tank
Cut you carbon footprint by 40% with the all new Solasyphon from Willis

The Willis Solasyphon not only costs less in general than the alternative conventional twin coil solar cylinder, but it also costs less in labour time to install due to its simplicity.
For the customer, this will cut their installation bill, enabling more home owners to reduce their carbon footprint and provide them with a more economically viable option at an affordable price.

View Solasyphon Animation Pressurised Installation Video Copper Vented Installation Video Seeing is Believing Infrared Video

Customer Benefits

Clever savings for our customers

Delivers solar heated
water in minutes

The unique and innovative feature of the Willis Solasyphon is the way in which it delivers solar heated water directly to the top of the existing water hot water cylinder where it stratifies ready for use at a useable temperature.

Produces hot water even
in marginal conditions

In marginal or intermittent conditions such as are common in the northern hemisphere, particularly in Autumn, Winter and Spring the Willis Solasyphon will produce useable hot water in a way no other renewable energy system can at present. One hours sunshine will produce one hours worth of hot water at a useable temperature.

Installer Benefits

Save more with our quick installation

No replacement cylinder required
The Willis Solasyphon can be connected to the existing hot water cylinder with two simple connections. This is quicker, cheaper and much more environmentally friendly than the alternative.

Easy Installation
Fitting a Willis Solasyphon to an existing system is quick and easy to install and minimises any possibility of upsetting the existing plumbing system that can occur when you are replacing the existing cylinder with a new solar cylinder. Retrofitting a renewable energy system has never been easier.