Customer story

Lisbon mall keeps cool and cuts emissions with game-changing thermal batteries

CascaiShopping in Lisbon optimises climate control, cutting costs and emissions with HeatVentors’ smart thermal energy storage system

Discover how CascaiShopping, a Lisbon mall, collaborated with our portfolio company, HeatVentors, to implement their intelligent thermal batteries, enhancing the efficiency of the building’s heating and cooling system and resulting in annual energy savings of 84,200 kWh. HeatVentors’ innovative technology allows for energy storage during off-peak hours, minimising costs and emissions, while delivering a swift return on investment thanks to a 25+ year battery lifespan.

The challenge

CascaiShopping, an indoor shopping mall in Lisbon, Portugal, relies on efficient climate control during opening hours to ensure its customers experience a comfortable temperature throughout the year. The demand for energy to power its heating and cooling (HVAC) system needs to be optimised to avoid unnecessary costs, enabling the shopping mall to offer competitive tenancy rates to shops and businesses, and ultimately a comfortable atmosphere for its visitors, while also reducing its environmental impact through lower emissions.

The solution

HeatVentors’ intelligent thermal batteries are a game changer in thermal energy storage. An intelligent controller optimises the charge and discharge process on the battery by monitoring the availability of cheaper energy and the changes in requested temperatures and outside temperatures.


The battery then charges or releases stored energy as required for optimal economic efficiency. Energy can be stored for hours, days, or even longer, to be used when needed. On-board and central data recording, web and API access ensures the tracking and auditability of energy savings, costs and CO2 emissions, providing effective reporting solutions for the users.

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The impact

Using HeatVentors’ thermal batteries have saved the shopping mall 84,200 kWh energy per year. Energy can be stored overnight during off-peak hours and then released during peak daytime hours when the mall’s existing HVAC system is struggling to meet the interior temperature needs.


Storing cooling energy reduces peak load during summer, extending the system’s lifespan, especially for older machines. This enhances efficiency by generating cooling energy at 60-80% partial load and lower temperatures, and releasing it during less efficient times. Utilising peak/off-peak electricity tariffs results in cost savings and lowers overall electricity demand. Increasing the cooling system’s flexibility offers additional benefits, such as backup security cooling and adjustable electricity consumption. Charging the storage is feasible during periods of lower cooling demand.


Other benefits include up to 90% space and weight savings, 20-50% decrease in emissions, and 2-5 years ROI. Furthermore, the system comes with a battery lifetime of more than 25 years as well as reduced maintenance costs, thanks to a lack of moving parts. It also produces audible energy reports and it boasts a modular, scalable design for added convenience.

84,200 kWh




25+ years