• Multiple flat roofs at varying heights
• A building that had listed status
• A plant room with all electrical distribution in the basement
• A very short lead time to meet Government tariff changes
• We chose Perlight 250w all back panels that were mounted on a low profile self ballasted flat roof mounting system from Sunfixings. The inverters needed to be mounted externally on the roof so we chose SMA Tri-Power inverters which offer IP65 protection. 

The multiple roofs were linked together using self ballasted cable tray and the whole electrical connection involved running a 35mm Steel Wire Armoured cable down through the building to the basement as we were not allowed to attach to the external walls as well date cables for remote monitoring as well as a public display in the middle of the ground floor.

Add in the fact the installation is in the centre of Rugby Town Centre we had to carefully manage the crane access for lifting the components onto the roof.

From enquiry to commissioning the system was completed in 3 weeks.

There were many challenges on the site. As the business had developed over a number of years there were multiple roofs with no way to connect the system together. The final design resulted in 4 separate systems each with their own generation meter. This provided benefits in that each was under 50kWp so no G59 relay requirement but we had the added challenge of linking them together for monitoring. Fortunately SMA have their Webbox, so by using multiple units they could all report to the Sunny Portal monitoring platform & be linked as one generation plant providing daily reporting on their installation.

When the project eventually came to fruition we were contracted to work for Borras Construction Ltd. The project was designed to achieve BREEM Code of Excellence, which the Code for Sustainable Built Environment. This provided its own challenges as all aspects of our design and installation has to be analysed before delivery including limiting our journeys to site, removal of all waste and then recycling of waste and all aspects of Carbon reduction associated with the project.

The installation itself was a challenge with the system split over 2 roofs that would eventually be surrounded by Sedum. The mounting system had to fix to the roof with only a minimum number of connections so working with our favoured Solar mounting manufacturer Schueco UK Ltd, who happened to be located less than 2 miles away, we designed, supplied and installed a bespoke raft like design that was suspended above the roof. We then mounted 105 Schueco MPE235 panels on the system which were linked to 2 SMA Tri Power inverters.

The whole design has proved to be a great success for the local community with the project being handed over to Milton Keynes Council on time and within budget. In March 2014 the building was awarded its coveted  BREEM Code of Excellence Certificate.

The landlord’s Solar PV system generates Free, Green electricity which they are able to sell to the tenants.

Pre-installation work involved gaining permission from Western Power Distribution to install the system.

Estimated to generate 42,301kWh per annum the system has actually generated nearly 200,000kWh in 4 years; nearly 15% extra resulting in a payback of less than 5 years.

We were asked to design an array that integrated into the slate roof. Following consultation with our customer Kyocera 215W panels were chosen in conjunction with a Fronius Invertor.

However, there was further consideration to make. A difference here was CEW is made of a group of shareholders who all invest money in community renewable energy systems that provide free or reduced cost electricity to the building owner with the knowledge their investment is rewarded by the Feed-in Tariff income.

With this in mind we also offered a second tender which although more expensive in capital outlay offered a number of added benefits. Firstly we only needed to use two roofs as our design used World leading SunPower E20 327w panels; 49.70kWp from only 152 panels as their efficiency is 20.1%. Secondly the SunPower module has a number of world leading characteristics including the lowest degradation rate, no light induced degradation, market leading temperature coefficients as well as operating well under low lights levels. Finally this is all backed up by a combined 25 year Product & Performance warranty. This all means CEW could be safe in investing in a system that was going to generate energy at the highest rate from day 1 and keep on performing at a rate above any other panel for a guaranteed 25 years.

In 2014 we were awarded the project ahead of four other companies with the most expensive design as CEW could see the benefits from their investment.

The panels and three SMA Tri-Power inverters were installed over 7 days with commissioning on 10th June 2014.

So has the investment paid off? The system is monitored via Sunny Portal and in 22 months the system has generated over 90,000kWh which is more than double the 43,000kWh estimated annual generation.

The main problem was ECC did not have the funds to pay for the supply or installation. We considered a number of options including finance, shareholders but eventually found a private investor who was prepared to fund the costs and provide ECC with the free electricity. The investor would generate his income from the Feed-in Tariff & Fixed Export Income the 30kWp system would provide.

As maximum generation was required we chose to use 78 x SunPower World leading high efficiency E20 327w panels with two SMA TriPower inverters.

However, by using SunPower’s World leading efficiency E20 327w panels we only required 152 to achieve a peak output of 49.70kWp.

We coupled this with two of the latest generation SMA STP25000TL inverters and the system is estimated to generate 43,000kWh per annum. The system has full monitoring via SMA’s WebConnect which requires no extra hardware, just an Internet connection. This enables the client, as well as ourselves, to receive a daily report as well as notifications of any potential problems ensuring maximum return on the investment.