Solar inbetween

Meet the Solar Inbetween: the step between absorbing light and giving off energy. The flexible solar panels in these gorgeous inbetweens soak up sunlight during the day and at night give off the stored energy in the form of heat or light. This elegant, sustainable and self-regulating solution will infuse your home with light and warmth.

The Solar Inbetween represents a new way of using curtains. Traditionally, the primary functions of curtains have always been to provide insulation and to shut out draughts. Neffa now introduces a new function. For the first time, curtains can be actively used to store sustainable solar energy and give it back, by generating heat in the winter and by powering LED lights in the summer. The flexible solar panels, heating yarns and LEDs form a branching application, giving a lovely appearance of light shining through trees. In the winter, the inbetweens offer sustainable heating that is particularly perfect for older homes.

The battery is fully charged after 6.25 hours in full sun which makes the heating work for 3 hours or the LED lighting for 24 hours.

The choice for inbetweens, rather than curtains, was a deliberate one: the purpose of inbetweens is to absorb sufficient sunlight during the day without cutting the room off from the outside world. The colours – a combination of blue and gold – give a sense of warmth. The blue fabric for the application of the branches integrates the solar panels more fully. The inbetween itself consists of two sheer layers in blue and golden hues, giving the entire curtain a glow that emphasizes the warmth that our sun provides. By placing the LEDs in a special shape the lights will shine along these layers.


The idea for the Solar Inbetween was inspired by marine iguanas, which only eat food that comes from the sea. They live off seaweed and algae that they gather from the seabed. Being coldblooded, their bodies need to store warmth before they can swim. If the iguana’s body temperature drops too far, it becomes unable to swim and drowns. This fascinating phenomenon made Neffa think about ways of applying the principle of ‘collecting heat to reuse later’ to the everyday home environment.

The name Solar Inbetween refers both to the step between generating and using solar energy and to the form it takes: a gorgeous inbetween that adds to the appeal of any home.

The Solar inbetween is a working concept that we want to develop into a commercially feasible product with the right partners.
If you are interested in discussing these or other opportunities, please contact us.