Project Office Climate Protection & Sustainability Equipment Renewal Program ULTs
Ultra-low-temperature freezers (Ultra-Low-Temperature Freezer), also known as -70°C and -80°C freezers, consume a lot of energy. The equipment renewal program with partial financing for new ULT Freezers provides an incentive to replace outdated and therefore very inefficient ULTs with new, significantly more energy-efficient ULTs, possibly supplemented by optimizing equipment utilization.
For participation, see contact information as well as application form and framework conditions.
Background
Energy consumption in natural and life sciences laboratories contributes significantly to Heidelberg University's greenhouse gas footprint. To reduce this burden and save costs in the long term, it is important to advance energy and resource savings in laboratory operations. The average ultra-low-temperature freezer consumes approximately 16 to 22 kWh of electricity per day, which corresponds to about twice the electricity demand of a 2-person single-family home. Older ULTs (> 10-15 years) consume particularly high amounts of electricity compared to newer models. New energy-efficient models sometimes consume less than 7 kWh of electricity per day. It is estimated that approximately 100 ULTs are currently operated at the university, so widespread implementation holds considerable potential for cost and energy savings.
A case study at the Centre for Organismal Studies (COS) has shown that significant savings would be possible by replacing inefficient equipment. Annually, at COS alone, INF 230, up to 47,000 kWh of electricity and approximately €19,000 could be saved if eight older ultra-low-temperature freezers could be replaced. Additionally, this would correspond to a reduction of approximately 17 tons of CO₂-equivalent emissions. Correspondingly higher savings would be expected if all university research institutions participated in such a measure.
What is the equipment renewal program for ULT freezers?
To promote replacement, the university has launched an equipment renewal program in which up to 75% of the costs for efficient new purchases are covered. The program started at the beginning of 2025 with €100,000 in funding and was restocked in May 2025 with an additional €100,000. All natural and life sciences institutions with relevant needs are encouraged to participate in this exchange program (see contact information as well as application form and framework conditions).
The Medical Faculty Heidelberg offers a similar, complementary funding program. Interested medical institutions should contact the head of the Research Deanery of the Medical Faculty Heidelberg, Ms. Martina Manns, directly.
Initial Results
Initial results from the Centre for Organismal Studies (COS) demonstrate impressive savings through the replacement of one examined ultra-low-temperature freezer. Annually, 4,900 kWh of electricity are saved, which means cost savings of €2,000 and a CO₂-equivalent reduction of 1.8 tons. Overall, energy consumption and costs are reduced by more than 76 percent. With 50 percent funding, the investment pays for itself for the university after just 4.4 years.
Operating temperature ULTs
An ultra-low temperature freezer operating at -80 °C consumes an average of between 16 and 22 kWh of electricity per day. Some older ultra-low temperature freezers can even consume up to 30 kWh of electricity per day. By increasing the operating temperature to -70 °C, electricity consumption can be reduced by approximately 30–40%.
In addition, numerous scientists have proven that -70 °C is a safe storage temperature. In the linked database (first link on the right), researchers can view a detailed list of samples, some of which have been stored at -70 °C for several years at other universities and non-university research institutions. The database was launched in 2011 by the University of Colorado, Boulder, and is now managed by My Green Lab. My Green Lab has also compiled a list of best practices (second link on the right). This provides working groups with detailed recommendations on how to operate their ultra-low temperature freezers in an energy- and resource-efficient manner.
The Climate Protection and Sustainability Project Office calls upon all university departments to check the extent to which their samples can be stored at -70 °C and to reduce the operating temperature of the ultra-low temperature freezers if possible. This could result in significant savings in energy consumption and CO₂ equivalents.