Service & Support



Delta and sustainability – Frequently asked questions

What aspects have to be considered to measure high efficiency precisely?
The most precise way is to measure the output power and the power losses by using a calorimeter test method. To perform this calorimeter test method, it requires a very accurate, special test infrastructure.

The less accurate test method is based on traditional output power and input power measurement. With this test method, tolerances in the measurement have significant impact on the accuracy efficiency result. The higher the efficiency, the more sensitive is the accuracy of the test method. Therefore the test setup and measurement points have to be precisely planned. Highly accurate power analyser for the AC side measurement, multimeters and shunts for the DC side measurement has to be selected. The measurement on AC side and DC side has to be synchronized to avoid that any variation effects impact on the efficiency result. Additional side effects to be considered during the test process are the thermal conditions by ambient temperature and warm up effects during the operation of the rectifier.

White Papers TPS

What is the role of information and communication technologies in reducing CO2 emissions?
The ICT sector itself is estimated to create only 2% of global CO2 emissions. However, the ICT sector has a key role in helping to cut emissions in areas that create the 98%. At Delta we are very ambitious about reducing our carbon footprint and helping our customers do the same
What does Delta mean by “Total Energy Efficiency”?
Total Energy Efficiency means that we focus not only on the direct but also the indirect environmental effects of our products. We pay attention to, for example, system-level energy efficiency, material consumption, transportation, the need for maintenance visits, fuel consumption and cooling solutions.
How is the energy of a RenE system produced during the night or in bad weather?
The batteries of a stand-alone solar power system are charged and discharged daily. During the day, the power system recharges the battery. From late afternoon to mid-morning, the system uses the energy from the batteries. As for bad weather, a stand-alone solar power system bridges a sunless period with additional battery capacity and solar recharge power. A hybrid system with a generator uses the generator. Optimized generator use ensures the lowest possible diesel consumption.
What kind of hybrid options does Delta offer?
The energy source of a RenE solution can be any combination of solar power, AC mains, wind turbines, generators and fuel cells. The customer chooses the primary and supporting energy sources. Location, climate conditions and operational costs play an important role in this decision.
When is a hybrid solar power and generator system most feasible?
 A solar power system supported by a generator is a suitable option especially on islands and in remote areas where refuelling trips are nevertheless possible. Usually the reason for using a generator instead of AC mains is that an AC infrastructure is not available or is unreliable.
In what voltage range does Delta’s stand-alone solar power system operate?
The voltage of our standard solar power system is 48V. If an additional 24V backup power supply is required, a modular DC/DC converter can convert 48V to 24V. If further additional backup power supply is needed for AC-powered equipment, a modular or stand-alone inverter will convert 48V to backup the required AC.
In what way does a rectifier’s high power density help reduce a carbon footprint?
High power density in a rectifier means that a great amount of power has been packed into a small space. Therefore, smaller and lighter devices are able to meet more demanding energy needs – and require less materials, packaging, space and transportation. Delta’s DPR 2400 and DPR 2700 series rectifiers have industry-leading power density.
How do the power supply controllers support sustainable development?
A controller is the brains of a power system. A high-quality controller such as Delta’s PSC3 offers direct and indirect benefits in terms of sustainability.

Delta’s PSC3 features a scheduled start-up process for the rectifiers. This means that the diesel generator can be reduced to half its normal size, which in turn means a better fuel-to-electricity conversion efficiency. Optimizing the generator size and operating point can save up to 30% of fuel during operation. This reduces the number of refuelling trips to the site – also an important aspect to total energy efficiency. In addition, the periodical automatic battery tests and remote control possibilities further reduce unnecessary check-up trips to the site.

What does the hybrid cooling of OutD systems mean?
Hybrid cooling means that air ventilation, air conditioning and heat exchanging are combined in a manner ideal for the specific conditions. For example, in an air ventilation + air conditioning configuration, air ventilation is sufficient as long as the temperature remains moderate. Only when the temperature rises does active cooling kick in. For example, if you operate in an area where the temperature rises above +25°C only 4% of the time (e.g. Frankfurt), you can save as much as 83% on energy costs.
In which way has the environment been taken into consideration in developing the Site Monitoring and Control System?
The SMCS promotes sustainability primarily through its impact on diesel generator (genset) operation. For example, the option of using either a full-scale or half-scale genset saves diesel especially during start-up. The SMCS also saves diesel consumption by reducing the need for genset start-ups, as the power system can operate in single phase supply mode using AC utility. Remote monitoring, control and maintenance functions make daily operation easier and also reduce the number of trips to the site, which is especially important in rural areas.
What is a green building?
A green building has been designed so as to take into account energy and water use, ecological considerations, waste and emissions, as well as a safe and pleasant working environment. Green building certification requires the building to meet the official criteria, which vary by country. Delta Rudrapur and Tainan factories are Green buildings, for more information, visit the Indian Green Building Council ( or the Taiwan Green Building Council (
What are Delta EnergE products?
EnergE stands for energy efficiency. We use the EnergE label to help our customers identify the rectifier products that are especially energy efficient. All rectifier products with the label have the world’s leading energy efficiency in their specific power range, and always an efficiency of 95% or higher.
What does a rectifier’s energy efficiency mean?
The energy efficiency of rectifiers refers to how well (that is, without losses) the energy is converted from the AC mains to the DC output. Another dimension of energy efficiency is how well the power system is controlled – to convert energy efficiently, rectifiers should always operate in the optimal way. Thus the best total energy efficiency is achieved by the controller and rectifier working together.
How much energy do EnergE products save?
Currently Delta’s DPR 4000B, DPR 2900 and DPR 2000 rectifier series carry the EnergE label. The actual amount of energy saved by using our EnergE products depends on what you are using currently. Compared to a previous generations, the DPR 2900 is now 4-6 % more energy efficient.

To estimate your DPR 2900 EnergE savings potential, use our energy savings calculator.
How does the energy efficiency of a rectifier contribute to lowering CO2 emissions?
By replacing a rectifier from the 1990s (with an energy efficiency of 90%) with the latest technologies, you can reduce the CO2 emissions by approximately 7%. The older and less efficient the technology to be replaced is, the bigger the CO2 reduction.
You say that Delta is a leader in energy efficiency. What do you mean by that?
Delta focuses on improving the energy efficiency of its whole power range, not just individual flagship models. We see it as our responsibility to provide the latest technology to make sure that no product produces any more CO2 emissions than absolutely necessary.
Does Delta provide more than just energy-efficient rectifiers?
Delta is a leader in power system management, helping customers reduce fuel consumption and CO2 emissions especially in remote areas and emerging markets. “Total energy-efficiency” is build up including the EnergE rectifiers, the ORION controller that, as an example, improves the energy efficiency of usage of generators, the energy-efficient climate management of our OutD outdoor power systems, and our RenE power systems that use renewable energy sources.