powerPerfector Voltage Power Optimiser helps The National Archives save energy

(09/06/2010)

The National Archives is the UK government's official archive, containing over 1,000 years of history. The National Archives are based in Kew in in South West London. The buildings were opened in 1977 as an additional home for the public records.

After receiving the annual electricity consumption details for The National Archives, it was possible to give a provisional quote for a powerPerfector unit and to outline the potential for energy savings. Four voltage loggers were then sent on the two buildings for 10 and 14 days respectively, to record the voltage level by connecting them to a regular mains socket. It was found that the average voltage was 246 volts (V) at both sites, 16V higher than the nominal supply in the UK. After a survey of the site by a powerPerfector Approved Contractor, the installations took place on two consecutive Sundays. Analysis following the installation showed that there was an average reduction in kWh consumption of 14.9% attributable to the powerPerfector installations, equating to annual carbon dioxide emissions saving of 958,244 kg.

powerPerfector is the world’s only Voltage Power Optimiser, giving energy, carbon and cost savings by efficiently optimising a site’s supply voltage. By optimising the voltage, electrical equipment runs more efficiently and consumes less energy. The declared electricity supply in the United Kingdom is now, as a result of European Harmonisation, 230V with a tolerance of +10% to -10%. This means that effective voltage can be anywhere between 207V and 253V depending on local conditions.

Most electrical equipment manufactured for Europe and the UK is rated at 220V and operates more efficiently at this level. Forcing appliances to operate at a higher voltage in the UK (242V is the average supply level) leads to significantly higher energy consumption, increased heat losses and a reduced life span. As a result of equipment specification and the range of voltage supply, there is an opportunity to achieve cost savings by optimising voltage at source and at the same time improve the operation and lifespan of a site’s electrical infrastructure. It is estimated that 90% of sites in the UK are operating at too high a voltage and could therefore benefit from installing a powerPerfector.

Savings Summary for The National Archives:
• Predicted reduction in average kWh consumption: 11.5%
• Actual reduction in average kWh consumption: 14.9%
• Projected annual carbon dioxide emissions savings: 958,244 kg
• Projected annual financial savings: £138,276

Four powerPerfector units were installed in two National Archives buildings in September 2009. A 1MVA and a 1.5MVA powerPerfector unit were installed on 6th September 2009. The 1.5MVA unit was installed at a 7% optimisation setting; the 1MVA unit was initially installed at a 0% optimisation setting and therefore was not optimising the voltage until the setting was changed to 7% on 29th November 2009. A further 1MVA and 1.5MVA unit were installed on the 13th September 2009, at a 6% and 7% optimization setting respectively.

Comparing the energy consumption over the period where the whole site is being optimized, to the expected level for temperature at that time, shows that energy consumption has been 17% lower than the expected level for temperature.

The powerPerfectors are also ensuring that the site operates at a higher level of efficiency, as well as benefiting from improved power quality and protection from transients of up to 25,000V.

Related categories:  Electrical installation   Energy efficiency   Surge and lightning protection