Store Wind and Solar Power as Heat in Sand
Our novel solution enables the up-scaling of solar or wind energy to up to 100% of your heating and electricity demand. The core of our solution is our patented high-temperature large scale heat storage.
We Use Really, Really Hot Sand as The Storage Medium
We convert electricity to heat, and store it for later use. We use sand as the storage medium, which leads to safe operation and a natural balance in the storage cycle. Additionally, sand is a cheap and abundant material, which can be heated up to 1000 °C and even higher.
Inside the sand we build our heat transfer system that enables effective energy transportation to and from the storage. Proper insulation between the storage and environment ensures long storing period, from hours to months, with minimal heat losses.
The size of our storages varies from tens to thousands of cubic meters. It is possible to locate the storage underground, reserving minimal space from the often highly valued square meters in construction sites.
Clean Energy with Minimum Emissions
CO2 emissions of our heat storage are embedded emissions from construction materials and from the construction phase. As these embedded emissions of the PNE heat storage are minor, the emissions of produced heat result mostly from the source of electricity.
It can be said that the heat taken from our storage is as clean as was the electricity fed into the storage.
energy Systems to Meet Customer Needs
Heat storage is always a part of an energy system, would it be either a heating network of a single building, a large district heating network or a self-contained electricity and heating system of a factory or even an island.
We are currently focusing on two products. At the moment we can offer a heat storage system with 2 MW heating power with a capacity of 300 MWh or 10 MW heating power with a capacity of 1000 MWh. Our heat storage system is scalable for many different purposes and we will expand the product range in the future.
Our storages are designed based on simulations using COMSOL Multiphysics software. We design our systems using 3-D transient heat transport models and with real-life input and output data.
validated technology
We have designed and built our first commercial sand-based thermal energy storage for Vatajankoski, an energy utility based in Western Finland. This innovative system provides heat for Vatajankoski’s district heating network in Kankaanpää, Finland. The Sand Battery has 100 kW heating power and 8 MWh capacity. Full-scale utilization of the storage commenced in 2022.
We also have a 3 MWh running test pilot in Hiedanranta, Tampere. It is connected to a local district heating grid and it provides heat for a couple of buildings. The pilot enables testing, validation and optimization of the heat storage solution. In the pilot, the energy is partly from a 100 square meter solar panel array and partly from the electric grid.
Polar Night Energy’s sand-based heat storages are available for purchase. Don’t hesitate to ask a quote for your heat storage!
The Numbers of Our Energy Storage
Here’s some numbers and facts about our patented thermal energy storage.
Temperature*
Up to 600–1000 °C
Nominal power
Up to 100 MW
Capacity
Up to 20 GWh
Investment cost
< 10 eur/kWh of storage capacity
Safety
No poisonous or hazardous materials, minimal emissions
Running costs
Minimal, no consumables, fully automized
Why We Need Heat Storages in The First Place?
Production of renewable energy sources such as wind and solar power is highly volatile, and only partly overlapping with the consumption in time. As these volatile electricity sources increase rapidly in societies, more and more energy storages are needed. Our technology provides a way to refine cheap and clean surplus electricity to valuable heat in an affordable way to be used when most needed.
PNE's heat storage combines sustainable heat production with storing excess electricity.