About the sand battery


About us

K-mit AB has been developing sustainable digital technology since 2014. The company's main focus has been the production of apps, websites and digital systems, but now we are expanding the business with an energy project that aims to store energy in the form of heat.


Through a grant from the Swedish Energy Agency, we have had the privilege of constructing a prototype of our innovation "Microgrid with sand battery". We are now developing this innovation by optimising the heating process by using high temperature heat pumps. This project runs from 1 June 2024 - 31 October 2024 in Hässelby, Stockholm.


Meet the team

The project team core consists of the following people:

Pontus Kindblad, an experienced technical project manager in web and system development and the brain behind the innovation


Pontus has 29 years of experience in digital problem-solving and technical project management.


He has held roles such as programmer, CTO, Data Protection Officer, IT architect, Privacy by Design specialist, web strategist, Technical Director, technical project manager, head of the R&D department, teacher, and stuntman.


Pontus has run several companies and is one of the founders of K-mit AB, where the prototype for the sand battery has been developed. He was also one of the founders of Sweden's first digital advertising agency in the early 2000s and has won several awards, including 2 Grand Prix, 2 Gold and Silver Lions at the Cannes Cyber Lions, and a Gold Star for "Most Innovative Technical Solution."

 

Maria Olsson, civil engineer with specialist knowledge in environmental technology 

 

Maria is a civil engineer in ecosystem technology with a focus on energy systems. She has studied courses in solar energy and life cycle analyses.


Her interest in the environment has led to work in research funding within ocean energy technology and solar energy.


Maria now works with investment grants for measures that contribute to cost-effective emission reductions.


Christoffer Möckelind, civil engineer in data and energy technology. The project's data specialist and main programmer


Christoffer has spent the years after KTH working as a developer in various roles at startup companies on Stockholm's tech scene, gaining extensive and diverse experience in development across a range of areas, with a primary focus on AI and data.


Christoffer also has previous experience as a service technician for industrial 3D printers.


Susanne Kindblad, an experienced project manager with many years of experience in running companies and leading development teams


Susanne is educated at Stockholm University in media and communication science, among other fields. Throughout her career, Susanne has held roles as CEO, project manager, web strategist, Data Protection Officer (DPO), and HR manager.


Susanne has founded and managed several companies within digital development and marketing. She is one of the founders of K-mit AB, the company developing the sand battery.


Marcus Nordgren, the project's electrician and specialist in mechanics


Marcus works as a property technician and is trained both as an electrician and chef.


Marcus is a dedicated problem-solver who focuses on driving the project forward with his expertise in mechanics and electrical systems.


We are building a prototype for a sand battery


Follow our work on building the sand battery prototype. We share experiences and lessons learned along the way.

A sand battery is hardware, but this hardware needs surprising amounts of software



This software needs to ensure that the sand battery is efficiently operated and enable the owner to monitor and control its operation. One of the first aspects we had to solve was how to control the temperature in the sand battery radiator array when we have determined that it’s a good time to start heating the sand.


We generally want to put heat down in the sand as quickly as possibly, which means we want the air to be as hot as possible. However, if the air becomes too hot we may damage or destroy components. We considered multiple options, but mainly investigated whether to use a PID controller or a thermostat controller. A thermostat controller is similar to what you have in the radiators in your home, and a PID controller, is one of the most common types of controller algorithms out there, controlling everything from Space ships to RC cars.


Due to its simplicity and because it’s tuning is much more intuitive, we decided to use a thermostat controller to operate the heater array. A PID could potentially have been more accurate in keeping the air in the heater at 650 C, but the complexity of its tuning caused us to settle for the thermostat controller. Future experimentation will determine if we need to revise this decision or not.


For those of you who haven’t worked with thermostat controllers before, you start off with specifying two parameters, an off temperature T_off, and a lower on temperature, T_on. When the T_off is reached, the radiator array is turned off. When the temperature has then dropped to T_on, the heater is turned on again. In our experiments with the sand battery, this controller has provided a sufficient level of control accuracy.


We are developing new environmentally friendly

technology for heat storage in the form of a sand battery. Our goal is to harness solar energy during the summer and store it for heating hot water and buildings during the winter.


Sand battery as part of a plan for crisis management?


We are looking at the possibility of installing sand batteries in connection with schools and other public buildings. Sand batteries would not only save electricity through more efficient heating, but also serve as an important part of emergency preparedness.

The idea came from a visitor who contacted us via the website because he was interested in the sand battery project. In his work, this visitor is responsible for a school that is part of the municipality's crisis preparedness. He had very interesting thoughts about safe supply of electricity and heat for the municipality's residents for a longer period of time and wanted to discuss whether sand batteries could be a strategic investment for future crisis preparedness. We thank you for the idea and spin further on these thoughts to investigate whether strategically placed sand batteries can be part of a future emergency preparedness package.

Sweden faces challenges when it comes to maintaining the energy supply during crises – from natural disasters and extreme weather events to attacks from foreign powers. The sand battery offers a method for a reliable and sustainable energy storage infrastructure.


By using sand, which is a cheap and environmentally friendly raw material, sand batteries can convert and store excess electricity from the sun and wind from sunny summer days to cold winter months. This technology is versatile enough to adapt to a variety of scenarios. Sand batteries can be used in private homes, condominium associations, schools and public buildings, and even in strategic facilities such as shelters.


The sand battery not only offers an energy storage solution, but also makes a sustainable contribution to reducing the carbon footprint. Its flexibility and efficiency position it as a key component in Sweden's crisis preparedness and as an important part in securing our nation's energy supply in all situations.

Our warmest thanks


We have many people to thank for their voluntary contributions to the project


We would like to highlight the following people in particular for their help, advice and support in the project:


Pontus Kindblad - for the idea of the sand battery, design of the innovation, material selection, and first-class team leadership

Susanne Kindblad - for strong commitment and practical experience that ensures all parts of the work progress smoothly and efficiently

Marcus Nordgren - for muscle power, clever ideas, endless patience and lots of time and commitment

Ingela Andreasson - for support, encouragement, photography and lots of coffee!

Iulian Lobont - for muscle power, energy and smart building solutions

Dan Widegren - for photography, both with drones and with other professional camera equipment

Rodrigo Araya Orostica - for good advice, tangible help and valuable contacts

Jessica Bornkessel - for the loan of a trailer for some of our many transports

Niclas Wickman - for contacts and valuable input as a sounding board

Martin Kemani - for drone footage and engaging conversations

Patrik Heinonen - for muscle power and energy in quantities

Karin Hansson - for diligent work and encouragement when needed

Thomas Fagerström Nyström - for digging jobs and generous sharing of knowledge

Niclas Snellman - for valuable contributions as sounding board

Niclas Bornkessel - for knowledge and commitment, especially in land and construction matters

Stefan Johansson - for good advice, great interest, and valuable knowledge in law

Christoffer Möckelind - for commitment and valuable contributions as a lead programmer in the project

Maria Olsson - for invaluable help with applications regarding funding of the project

Melker Kindblad - for muscle power and very valuable help with transports

Måns Brorsson - for valuable insights into strategy and sales

Tim Lindkvist - for help with 3D-printing


"Decision on grants to implement project: The Swedish Energy Agency decides to grant support in the form of grants to K-mit AB for the implementation of the project "High-Temperature Heat Pumps for Thermal Batteries" during the period June 1, 2024 – October 31, 2024."


The Swedish Energy Agency

The goal of the sand battery

Sustainability focus

  • Consumers' and organizations' increasing awareness of sustainability has driven demand for energy storage solutions that help reduce emissions and support sustainability goals. Our goal is to offer a product that contributes to a positive climate transition while reducing consumers' costs for heating by at least 50%.


Technological development and scalability

  • The technical progress we are making in the pilot project can lower production costs and thus affect the price of sand batteries for consumers.
    The ability to produce sand batteries on a larger scale can help lower unit costs.


Efficiency and performance

In the sand battery, we have the following objectives regarding efficiency and performance:

  • High energy storage capacity
  • Low energy loss
  • Fast and energy-efficient charging
  • Optimized discharge



The end consumer's energy costs will be reduced to the maximum and the sand battery will thereby be worth the investment that the customer makes when installing the sand battery.

Sand batteries to save the public electricity grid


Through our innovation, electricity can be stored in the form of heat in a large buried sand battery. The heat is then used for heating houses and hot water, and in this way the public electricity grid is relieved while the cost for electricity consumers drops. This means that the public electricity grid is relieved at the same time as the cost of electricity drops for consumers in both the short and long term.

Here we are

Store heat to fight global warming?



We are creating a new method for storing energy in the form of heat during the summer. During the winter, the heat is used to heat water and indoor air.

"WE DO THIS

not because it's easy, 


but because we thought it would be easy"


— Pontus och Susanne Kindblad


Get involved in the project!