Voltage reduction system for lighting cuts power consumption by 20% at Lidl

The system has already proved itself with customers in Germany. Energy consumption was reduced by around 20% for indoor lighting at a Lidl supermarket store, and a medium-sized town in Southern Germany has seen the power consumption of its street lighting cut by 25% per year after installing the new system.

Block’s new SAVERGY range of voltage reduction systems is based on the company’s three-phase autotransformer technology, which has an efficiency of more than 97%. The system protects fluorescent lighting, including mercury vapour-based and sodium discharge lamps, from high voltages, smoothing out illumination levels at all times. The basic principle behind the system is to reduce the line voltage to a lower level according to the lighting system’s specification.

The system is suitable for any factory, public building or office that uses a significant amount of lighting for a good proportion of the day and night. Customers of SAVERGY already include supermarkets and underground car parks, as well as installers of street lighting. Other potential applications include multi-storey car parks, industrial companies, oil refineries, airports, public buildings, warehouses, office blocks and logistics companies.

Bob Liddle, Managing Director at Block UK, comments: “Payback time is key for customers of this type of technology. With its robust design, ease of installation and relatively small initial investment, we are confident that SAVERGY will pay for itself within two-and-a-half years.”


SAVERGY is supplied with a cabinet and can be installed indoors or outdoors. The unit includes a special, three-phase autotransformer, a control unit, which is mounted on a back plate for easy installation in the cabinet. There’s also a display for status requests, plus a unique, dual bypass system that includes an automatic and manual bypass. As Liddle explains: “Unlike most competing systems currently on the market, SAVERGY uses a double bypass system for controlling the switches. This system includes an electro-mechanical bypass that most systems offer, but it also has a fully integrated, hard-wired bypass built into the autotransformer.”

Super Solution at Lidl
One customer of SAVERGY is German-based discount supermarket chain LIDL, which has more than 7,000 stores in 17 countries. Block’s German installation partner 4e Energiezentrale GmbH approached Lidl in August 2007. The regional buildings supervisor responsible was about to move to the corporate headquarters at the end of 2007. In November that year, a meeting with the project director took place at 4e’s head office.

The indoor lighting of a typical Lidl supermarket store requires around 55,000kWh of electrical energy each year. It was decided to implement a pilot SAVERGY unit in one store. This system was installed in February 2007. After an initial pilot system was delivered and installed, both parties were not convinced by the savings achieved. Therefore, a new transformer was co-developed by Block and 4e, which could be used for this specific type of electronic ballast. On 11th February, 2008, the new system went online for a four-week testing period at Lidl.

Measurements were taken in BYPASS and SAVING mode. During this test period, an 18.6% reduction in electricity consumption was achieved and has been confirmed by tests undertaken by 4e. Separate tests were carried out by Lidl, which also confirmed these savings.

Sven Holtzhausen, Sales Manager at 4e Energiezentrale GmbH comments: “In total, the consumption will be reduced by around 10,000 kWh per year. This equates to a reduction in CO2 emissions of approximately 5 tonnes per year. The installed SAVERGY units have a payback period of just over two years. Furthermore, if Lidl installs the units in 80 per cent of its stores, annual electricity costs would be cut by around two million euros per year. CO2 emissions would be reduced by 11,000 tonnes per year.”

Town Cuts Street Light Energy Consumption by 25%
Kornwestheim, a medium-sized town in Southern Germany, has reduced electricity consumption for its street lighting by 25%, which equates to around 10,000 euros per year. With overall project costs of 26,000 euros, the SAVERGY solution will pay for itself within 30 months.

The town has 26 supply terminals for the street lighting system. The system is managed by Germany’s fourth largest energy supplier, EnBW. In May 2008, EnBW certified the SAVERGY system.

As Sven Holtzhausen explains: “It was decided to install six pilot SAVERGY units across six streets in the town. The respective streets are a mix of industrial parks, commercial and residential areas. The SAVERGY unit was used with its standard settings, a one step reduction to 207V after a ‘burn-in’ period of 15 minutes.”

Civil engineering was carried out by 4e and electrical installation by EnBW. The installation was completed in September 2007. On October 8th last year, the first measurement results were taken in BYPASS and SAVING mode. “The results of these tests showed a 25 per cent mean reduction in electricity consumption, with all lighting intensity results were within the required range,” adds Holtzhausen.

According to 4e, calculating potential CO2 savings using the official CO2 coefficient of 518g/kWh, around 33 tonnes of CO2 production per year could be saved by these six streets. Overall, savings of approximately 65,000 kWh per year are made. In monetary terms, this equates to around 10,000 euros per year. With overall project costs at 26,000 euros, the town can expect payback in two-and-a-half years.

Block UK is currently looking for a UK-based installation partner for SAVERGY. For more information, please visit www.blockuk.co.uk or telephone Bob Liddle, Managing Director at Block UK on 01621 850 666.