Case Study:

PV Panels On Car Park

Background

In 2018, Wicklow County Council put in place the governance and management support to achieve progress towards 2020 energy reduction obligations applying to all public sector bodies – namely a 33% reduction in energy usage relative to 2009 levels. Multiple energy audits were carried out, including for County Buildings, which identified the possibility of building a 300kW solar PV array to meet the building’s baseload demand. However, the 1970s era flat roof and asbestos-covered pitched roof were deemed impractical to use for rooftop solar power, with possible significant hidden cost implications. The large surface carpark on site, with an open southern exposure, was identified as an ideal location for a solar PV array built as a carportstyle canopy.

Solution

Wicklow County Council is planning to build a 300kW solar car park canopy, covering c.1,600m2 or c.140 parking bays. The canopy will consist of a T-frame, monopitch angled at 10° to the south, approx. 3m high. The canopy will have uninterrupted exposure to the sun, will provide shade from sun and rain to cars and pedestrians underneath, and will significantly reduce light pollution through under-canopy lighting. It will be co-located with EV charging points, which offer the potential of renewably powered EVs and increased comfort for EV drivers while connecting their vehicles to a charger. (Figures 1 and 2).

Figure 1: Flexisolar car park installation example.

Figure 2: Proposed view, car park PV panels.

Benefits of solution

Environmental
The canopy would provide approx. 285,000kWh/year of 100% renewable energy. It is not currently anticipated that any of the electricity will be exported or lost to the grid. With anticipated increased staff and fleet uptake of EVs, the potential for renewably powered transport is significant. The canopy will have guttering that reduces
surface pluvial flooding in the carpark and offers future potential for rainwater collection or attenuation, thereby providing a dual benefit.

Economic
The expected amount of renewable energy is equivalent to the baseload, or 40% of County Buildings’ requirement, saving an estimated €40,000/year in energy costs. The canopy is being considered on a power purchase agreement basis. However, project costings have indicated that the project would have a simple payback of 10 years before grants are considered. The installation comes with a 25-year warranted life expectancy. As a proof of concept, there is significant potential to replicate at virtually any local authority public
surface carpark.

Social
A Part 8 planning application with public display was carried out. The application was approved by Wicklow County Council in September 2019 and comments from the public were positive with no objections received.

Project Details:

Part 8 planning was applied for on 3rd July 2019; Approval granted on 2nd September 2019;

Tender documents to be published: September 2019; Tender award: November 2019;
Construction: Approximately one month.

Further information
Email: raoneill@wicklowcoco.ie

Local authority project contact
Declan Marnane
Chartered Engineer
Senior Engineer
Housing and Corporate Estate, Wicklow County Council
Tel: 040 420 120 Email: dmarnane@wicklowcoco.ie