The environmental benefits associated with using Hitec Diesel Rotary UPS modules

Introduction The Hitec Diesel Rotary UPS (DRUPS) module is designed to provide conditioned and secure UPS power to a facility’s Critical Loads and Standby power to a facility’s less critical Essential Loads. In so doing it replaces the battery backed Static UPS equipment required to support the Essential Loads and the Standby Diesel Generating equipment required to support the Essential Loads. By combining these two functions within a single piece of equipment the Hitec DRUPS module provides tangible and measurable environmental benefits over alternative UPS equipment. The environmental benefits of the Hitec DRUPS module are summarised below. The use of Batteries Unlike Static UPS systems the Hitec DRUPS module does not use batteries to support the Critical Load when the there is a failure of the mains supply. Alternatively, the Hitec DRUPS module uses stored mechanical energy to secure the Critical Load. The batteries used in Static UPS systems are normally of the Lead Acid or Nickel Cadmium type, both of which are considered to be environmentally damaging. These batteries contain harmful, hazardous and carcinogenic materials such as Lead Compounds, Cadmium, Mercury and Sulphuric Acid. The quantity of batteries used in the design of a Static UPS system can be enormous. Their number is dependant upon the size of the load to be supported and the amount of time that the batteries are required to support it, the ‘Standby Time’. With large loads and Standby Times in excess of 10 minutes the quantity of individual batteries, or cells, incorporated into a Static UPS system can amount to several thousands. Also, batteries have a limited life span, nominally 5 to 8 years, and due to the materials used in their construction they need to be disposed of correctly. With such large amounts of batteries needing replacement the environmental impact of their disposal needs to be carefully considered. This has not gone unnoticed by the EU, which already classes both Lead Acid and Nickel Cadmium batteries as Hazardous waste. Furthermore, the EU is currently proposing a new ‘Battery Directive’ to ensure the safe and proper disposal of such batteries. The fact that a DRUPS module does not use environmentally damaging and hazardous materials for the support of the Critical Load means that its environmental impact is considerably less than that of Static UPS systems.

No Batteries = Lower Environmental Impact

Diesel Engines The selection of Diesel Engines within the current range of Hitec DRUPS modules is based upon a number of key criteria. In terms of their load handling performance the Diesel Engines must have a high reliability, the necessary total power output and the required speed of starting. However, to address the environmental impact of the diesel engine we also select units that have a high fuel economy, a low emissions level and the ability to run on zero sulphur diesel fuels. In terms of Emissions we have Diesel Engines within our range that meet the requirements of “TA Luft”. The German clean air act “TA Luft” is currently the most restrictive legislation applying to Industrial Diesel Engines. It sets maximum permissible limits for the emission of vapours and gases such as NOx and CO2; “TA Luft” also governs soot and dust emissions. In addition to supplying Diesel Engines that meet the requirements of “TA Luft” we are also able to incorporate Exhaust Gas Cleaning Systems within the design of the flue, these can however reduce the power output of the Diesel Engines. To minimise the number of times the Diesel Engines could start in response to failure of the incoming mains supply we can employ a system called ‘Diesel Start Reduction’. Diesel Start Reduction maintains the DRUPS module output voltage within tolerance while allowing the input mains voltage to fluctuate within prescribed limits. The fluctuation of the input voltage is allowed to occur for a given period of time before it becomes necessary to start the Diesel Engine. The use of Hitec’s Diesel Start Reduction system dramatically reduces the number of Diesel Starts per annum.

Efficient Diesel Engines = Greater Economy and Lower Emissions Operating Efficiency By the very nature of having fewer active components, the Hitec DRUPS is far more efficient than Static UPS systems. While DRUPS modules can achieve efficiency levels greater than 97%, the efficiency level of the best Static UPS equipment will only be around 92%. The efficiency of a UPS system directly relates to its running costs. Therefore, the higher the efficiency the lower the running costs i.e. Based on today’s electricity prices, the 5% difference in efficiency between a 1500kVA Static UPS system and a 1500kVA DRUPS module over a 10year period will equate, to a saving of £263,000 for using the DRUPS module.

High Operating Efficiency = Reduced Running Costs Space A Hitec DRUPS module requires approximately 40% to 60% less space than an equivalently sized Static UPS system plus Standby Diesel Generator arrangement. This high level of space efficiency is achieved through the absence of standby batteries and their air condition equipment, power factor correction panels,

generator paralleling/synchronising panels and an overall simplification of the distribution switchgear.

Smaller Equipment Size = More Efficient Use Of Plant Space Power Conditioning The combination of the Synchronous Alternator and the matched UPS Choke within the Hitec DRUPS module ensures that all load-generated harmonics are prevented from reaching the incoming supply. This combination of components also ensures that all mains born harmonics are prevented from reaching the load. As such a Hitec DRUPS module is fully compliant with the requirements of EA Recommendation G/54 (Guidance on the generation and imposition of harmonics on the Public Utility Network) without the need to employ additional, inefficient and expensive harmonic filtration equipment.

Integral Power Conditioning = Higher Quality Power Power Factor Compensation The combination of the Synchronous Alternator and the matched UPS Choke within the Hitec DRUPS module enables it to provide all of the reactive power demanded by the load. This means that the incoming utility supply is presented with a near unity power factor under all load conditions and that, consequently, there is no need to provide additional power factor correction equipment.

Integral Power Factor Compensation = Fewer Additional Components Flexibility With a Hitec DRUPS module the migration of loads from Critical to Essential and visa versa can be accommodated without the need to procure additional standby generating capacity and/or static UPS modules. Providing that the total load being drawn does not exceed the UPS rating of the DRUPS module the ratio between Critical and Essential loads can be reconfigured.

Increased Flexibility = Future Proof Design

The Future To underline Hitec’s commitment to provide the most environmentally sustainable solution presently available for the support of a facility’s Critical and Essential loads, we are currently investigating the use of Bio-Diesel and other alternative ‘Clean’ fuels. In addition to this we continually assess the environmental impact of our products and how the efficiency, reliability, power and performance of the Hitec DRUPS module can be enhanced. The Hitec Power Protection Environmental Policy Statement is attached.