With a widely-acknowledged need to become greener and reduce global warming, governments worldwide are using both stick and carrot legislation to push domestic, business and industrial users into lower energy consumption.
The Carbon Trust’s Enhanced Capital Allowance (ECA) is one such carrot. If an organisation buys an energy-efficient product that qualifies for the ECA scheme, the product’s entire cost can be offset against taxable profits. Expenditure on plant and machinery can include not only the actual costs of buying the equipment, but other direct costs such as the transport of the equipment to site, and some of the direct installation expense.
To qualify for the ECA, a product must be listed on the Carbon Trust’s Energy Technology List (ETL). This comprehensive list details energy-efficient products, including plant and machinery that meet certain set criteria. The Carbon Trust manages it on behalf of the UK government.
The ETL has two parts:
- The Energy Technology Criteria List which contains details of the energy-saving criteria that must be met for each of the technology classes.
- The Energy Technology Product List, containing a list of products that have been certified as meeting those standards.
The Energy Technology Product List, published annually, is updated at the beginning of each month on the ECA website. For the most up-to-date copy of the ETL and for further information about the ECA Scheme, refer to the ECA website. General information on ECA Schemes is available at: http://www.hmrc.gov.uk/manuals/camanual/Index.htm.
The Energy Technology Criteria List has sixteen major product categories, of which one is Kohler Uninterruptible Power (Uninterruptible power supplies)1. The list describes UPS power supplies as products that allow electrical equipment to continue operating when the mains supply is interrupted for a period, or the power supply quality deteriorates. They are widely used throughout industry and commerce to maintain safety critical and business critical systems.
The ECA scheme covers both static and rotary UPS systems, but we are only concerned with static types here. To be eligible for the ETL, the uninterruptible power supply must comply with BS EN 62040-3:2011 (or IEC 620403: 2011).
It must also include the following components:
- An electronic control system that controls the operation of the product
- Voltage inverter and rectifier devices
- One or more energy storage devices (for example UPS batteries, flywheels, etc.) specified for use with UPS power supplies
- One or more power supply filters
- A bypass switch (where required)
It must also be designed to be connected to, and provide backup power supply to, three-phase UPS system of nominally fixed frequency and voltage, and be CE Marked. An eligible uninterruptible power supply must have an input power factor greater than or equal to 0.93 at 25%, 50%, 75% and 100% of rated maximum output power. Their input total harmonic distortion (THD) must be less than or equal to 5% at 100% of rated maximum power output.
The UPS power systems must also meet or exceed the minimum efficiencies at full and part load conditions set out in Table 1 below:
% of rated maximum power (i.e. & full load)
|Static uninterruptible power supply units or packages|
Table 1: Performance thresholds for uninterruptible power supplies
1 https://www.gov.uk/ (See pp 183 – 185)