Last month as part of Green Sky Thinking Week we hosted a tour with Islington Council’s award winning Energy Services team to showcase some of the latest energy efficiency innovations at their offices in Highbury.
In the face of huge government funding cuts the council has expanded its energy efficiency programme to reduce energy use, cut costs and generate income. As part of a borough wide invest-to-save scheme bid, over £400,000 has been invested in 3 key energy saving schemes. The tour of the council’s offices at 222 Upper Street included a look at the new LED lighting retrofit throughout the 4 story building, the new cold isle containment system which has been installed to more efficiently deliver A/C to the main server room; and a trip to the roof to see the brand new 30 kW solar PV system.
Juliet Nicholas, Energy Projects & Programmes Officer at the council explained how the site was previously predominantly fitted with T8 flat panel lighting – made up of 4 x 18w fluorescent tubes with an output of 79 watts (ballast).
Through the LED lighting refit these tubes were replaced with a 40 watt LED flat panel throughout. This 50% reduction in output is estimated to result in an annual energy saving of £35,000 per year meaning the project will payback within 7 years and then continue to deliver savings for the rest of the 25 year lifespan. LEDs will save significant maintenance time and cost compared to the T8s which often needed to be replaced.
Some staff were concerned the LED lighting would be too ‘cold’ however the feedback from staff working in the areas where the LED lighting has been installed has been excellent and other offices are now being considered for refit.
|Cost||payback||lifespan||£ saving per year|
Cold Isle Containment (A/C)
Daniel Knight, Energy Conversation Officer at the council took the group down to the basement where the main server units for Islington council are housed in a large open room.
The units were previously cooled using 5 A/C units with an output of over 250 kW. However the system has now been reconfigured for the servers to be cooled in a ‘pod’ unit. This means that only the air within that pod requires cooling. The benefit of this is that the rest of the server room can remain at an ambient temperature, without the need for cooling the larger space. This dramatically reduced the duty on the A/C units and offers savings of over £30,000 per year.
|Cold Isle Containment|
|Cost||payback||lifespan||kWh saving per yr||£ saving per year|
|£ 150,000||4.7 yrs||11 yrs||315,400||£ 31,540|
The final stop on the tour was on the roof where a solar PV system has recently been installed. The 30 kW array compromises 100 panels in an east to west configuration. The panels are installed with a rack system including concrete ballast which requires no penetration to the roof membrane and allows for ease of maintenance should failure occur. The system will provide an estimated annual income of around £5,000, offering an 8 year payback.
|Site Module||System Rating kWp||cost||payback||annual income & savings|
|222 Upper Street||29.58||£41,000||8.5 yrs||£5,200|