You can see the background to the issue here) The answer is just iver 15 weeks. But they don't know how much electricity was wasted or how much it cost.
The FOI response in full...
Can you please tell me when council officers were first made aware that the lights on Streatham Green are turned on throughout the daytime?
Lambeth Parks manage Streatham Green and were made aware that the lights are on during the day on 5th April 2013. A job was raised to rectify this with our repairs contractors on 8th April 2013.
Does Lambeth council have a date when it expects the lights on Streatham Green to be turned off during the day?
Balfour Beatty, the corporate contractor, advised that the repair would be carried out by the 21st July 2013.
Does Lambeth council know how much energy each of the main lights on Streatham Green uses to stay on for an hour?
Lambeth Parks do not hold this information.
Does Lambeth council have an estimate of the additional cost being incurred each week of keeping the lights on Streatham Green on during the day?
Lambeth Parks do not have an estimate of the cost.
What is the annual cost of the electricity used by the lights on Streatham Green in each of the previous three years, by year?
Lambeth Parks do not hold the annual cost of electricity for these lights. It is understood that these lights are powered from the main street supply which is not metered. As these lights are not metered there is no way of accurately identifying costs.