Green-Y is the Startup of the Week 47: Affordable, Clean & Efficient Energy Storage System

Energy Efficiency and Environment, Energy Storage, Energy Supply

The issue of green energy poses two major challenges: The storage of energy from green energy and the question of heat/cold generation. In the ideal world, this is achieved with a single device. For some, this may sound like a high cost and energy expenditure. Our Startup of the Week Green-Y uses the well-known compressed air storage technology and solves the above-mentioned problems, in an efficient and sustainable way. Dominik Schnarwiler, co-founder of Green-Y, tells us more about the technology in today’s interview.

Hello Dominik! Great, that you are here today. To get you started, why don’t you tell us what Green-Y does? 

Green-Y combines electricity storage and heating/cooling in one device. This is reducing costs and emissions from buildings.

An important mission. How exactly do you make this possible?

We base Green-Y on patented air reservoir technology. There are two main processes: The charging and discharging of the accumulator. When charging, we compress air, which requires electricity and generates heat. The compressed air is then temporarily stored in compressed air tanks.

When we unload, the air from the compressed air tanks expands again at a later stage, which recovers electricity and generates cold at the same time. Thus, it is combining electricity, heat, and cold in one device.

In principle, one knows this technology for a long time, which allows us to reduce risks, complexity, and costs by using standard components. Yet, the technology has now been decisively developed further and the energy density is increased by a factor of 3, doubling the efficiency of heating and cooling. As a result, Green-Y can be used to heat and cool efficiently in a decentralized manner, i.e. directly in the building, which in turn makes its use as an electricity storage device cheaper.

Green-Y can be used in buildings and industries where there is a need for electricity storage, heating and/or cooling. Typically, Green-Y optimizes the use of electricity from the grid and the internal consumption of e.g. photovoltaic electricity, heats rooms and hot water, and cools rooms and servers.

What is the unique selling point of Green-Y?

Green-Y is environmentally friendly and profitable. The customers benefit as follows:

  • The profit is increased by reducing energy costs, which results in low amortization periods.
  • We can reduce emissions by replacing fossil fuels and integrating renewable energies.
  • Green-Y is environmentally friendly and recyclable, as only air and water are used as working materials.

Compared to competing products, the battery and heat pump, Green-Y is more than 5 times cheaper and does not generate any environmentally harmful waste. The latter is mainly produced by the limited resources of lithium and cobalt in the battery and by the environmentally harmful refrigerants in the heat pump. Thus the combined approach brings the unique selling propositions that clearly set us apart from the competition.

How do you integrate your product into a lucrative business model?

Our business model is initially based on a one-off sales margin, supported by a recurring share of maintenance and repair. In the future, we plan to introduce other business models, such as a contracting model with the end customer, which will cut the high acquisition costs for the customer and result in attractive recurring revenues for us.

Initially, we are approaching the end customer directly with the first installations B2C. In doing so, we take the first step into the market and aim for a product/market fit. After that, the aim is to address the so-called multipliers as quickly as possible. In doing so, the device or a B2B license is sold to e.g. energy suppliers or heat pump manufacturers. This allows us to scale quickly and efficiently.

You have already briefly touched on your target group. Could you elaborate on this topic further?

Of course. The technology is scalable from small applications in the single-family home sector to medium-sized applications in trade and industry and large applications centrally at an energy supplier.

In the beginning, we are clearly focusing on medium-sized applications in the commercial and industrial sectors. The first two customer projects were secured in a Swiss office building. An ideal application was identified there for market entry.

The niche market for office buildings in Switzerland already represents an annual market volume of over CHF 200 million. After the first projects have been realized nationally, we are quickly aiming for the DACH sector before we also want to operate throughout Europe and intercontinental.

This all sounds like very exciting developments. Where do you stand now?

The patented technology is validated on a prototype in a laboratory environment. We were also able to secure our first two customer projects. The next big step is the realization of the pilot project at a customer’s site. Installation in the Swiss office building will start in 2021. After that, we plan to install the first commercial devices in early 2022. For this purpose, we are currently looking for 2-3 further customer projects.

At the same time, we were able to conclude a successful seed investment round in summer 2020. This secures our financing up to and including the pilot project. We plan a Series A financing round for the end of 2021 to enable the commercialization of the product.

We are currently looking for new team members and investors for the next investor round. Also, we want new strategic partners for market entry, and customer projects for early 2022. Are you interested? Contact us and join the journey into a green energy future!


Dominik, thank you very much for the exciting conversation! We wish Green-Y every success for the pilot projects and the search for investors. 

If you would like to learn more about Green-Y, you will find more interesting information on Green-Y’s profile in our innovation network.