Chelveston-cum-Caldecott Parish Council

Serving the people of Chelveston-cum-Caldecott

Clerk: Mr Mark Hunter
Ashbury, Caldecott
Northamptonshire NN9 6AR

Tel: 01933 626039

Street Lighting

70w SON-T lantern glowing

Lamp 34 - a 36w PL-L LIBRA Lantern (PL-L) in Bidwell Lane.

The Parish Council is the Lighting Authority for the 60 street lights in the parish (technically known as a footway lighting system). This equates to one street lamp for every 4 houses in the village, reflecting the spread-out rural nature of the parish.

To report a problem with a street lamp please contact us.

The 60 street lights are made up of -

1x 24w PL-L LIBRA Lantern (PL-L) - this is a newer compact fluorescent lamp, providing better colour rendering, that is being trialled in the Kimbolton Road layby.

2x 36w PL-L LIBRA Lantern (PL-L) - these are a newer compact fluorescent lamp, providing better colour rendering, that are being trialled in Bidwell Lane.

55x 35w Sodium Oxide low pressure lamps (SOX) - these are older lamps, but more energy efficient than the former Mercury Blended Filament Units, which can be found around the parish on different types of posts and columns.

1x 55w Sodium Oxide low pressure lamp (SOX) - which protects the footway crossing by the old School House.

1x 70w Sodium Oxide high pressure lamp (SON-T) - which protects the footway crossing on the Higham hill.

In 2007, the Council resolved to phase out the older 80w Mercury Blended Filament Units (MBFU) and replace them with Sodium lamps, as these are more efficient (200 Lumen/Watt for SOX compared with less than 50 Lumen/Watt for MBFU). The last MBFU lamps were removed in October 2013, ahead of the 2015 obsolescence date.

In 2019, the Council started trialling PL-L LIBRA lanterns, both at 28w and 36w, to assess if the improvement in colour rendering was matched by reduced running costs.

The lamps are connected to what is known as the unmetered supply. This doesn't mean the electricity is free however! The supplier (E-On) calculates the typical load of each type of lamp for dusk to dawn throughout the year (allowing for seasonal variations) and charges the Council on what the lamps should use.

This is another reason why it is important for you to report any lamp that has died, as the power has to paid for whether it is used or not.

The SOX lamps have an optimum operating temperature of about 260 deg C, emitting a warm yellow light at wavelength 589 nanometres. This close to the peak reception wavelength for the human eye. Since they emit a monochromatic light, it is true that they are poorer for colour rendering, but they are safer in fog, rain and falling snow as the light remains sharp (i.e. not diffused as with the older MBFU).