Here are some answers to frequently asked questions.
Photo by
Ruslan Merzlyakov

What are the specifications?

Capacity: 14 kW/panel.
Panel size: 20 m².
Area: 5000 m²/MW.
DNI (solar irradiation): >850 kWh/m² annually. Find your local DNI from Global Solar Atlas.
Field preparation: None.
Integration with existing fossil-fired process heat systems: Simple.
Show me: Please contact us for a tour of the district heating solar field.

What is the minimum and maximum system size?

Technically, Heliac’s solution is scalable from 14 kW to GWs. However, taking the costs of planning, preparing, and installing into account, Heliac solar fields shouldn’t be less than 200 kW.

How is this technology compared to PV?

PV produces power (electricity). Heliac produces heat. The best commercially available PV panels have a conversion efficiencies below 20%. Heliac’s panels convert 70% of the incoming sunlight to heat. In 2018, PV globally produced 640 TWh of electricity. In comparison, global annual demand for heat below 400⁰C is 30,000 TWh. Storing energy as electricity in Li-Ion batteries costs >€300 per kWh capacity. In comparison, depending on temperature level, storing energy as heat costs €1-25 per kWh capacity.


Concentrated solar power (CSP) has been around since the 1980’s. Just like Heliac’s panels CSP works by generating heat, but where Heliac uses inexpensive, flat lenses that can be produced in very large numbers using standard industrial equipment, CSP uses expensive, curved customized mirrors. Consequently, the cost of CSP solar fields are so high that their heat generation even in the sunniest places cannot compete with heat generated using fossil fuels. From a financial viewpoint the only thing that justifies the use of CSP is that heat is cheaper to store than power. I.e. CSP is mainly used for heating a molten salt heat storage, where the stored heat is used for generating power at nighttime when PV panels can’t produce as this is less costly than storing power in batteries. Still, this is only an advantage in places with plenty of sun and/or attractive financial incentives. Heliac’s panels perform as well as CSP, but at a fraction of the costs. This makes the production of heat cheaper than fossil fuels. Even in areas with limited sunshine and without financial incentives. Which is why Heliac focuses on heat production rather than just power production.

How about other flat solar panels?

Flat solar panels have been around for decades, primarily as rooftop installations producing hot water and heating for private households. In recent years, flat panels have become increasingly integrated into district heating networks. For large scale usage, flat panels are challenged by a number of factors, most prominently that they cannot generate temperatures above 70-80°C. Heliac’s panels generate 40% more energy per area than flat panels – and do so up to 400°C.

Can the panels fit on a rooftop?

The present version of Heliac’s panels is not dimensioned for rooftop installations.

Can the panels be installed at private homes?

No. Heliac’s panels are designed for installation in large-scale solar fields. Each panel is too big to be installed at private homes.

Still have a question? Contact us.