Continuing Professional Development Photovoltaic panel installations

How keeping FIT can reduce energy costs

In 2010 the government introduced the feed-in tariff (FIT), a payment per kWh generated for a range of qualifying low and zero carbon (LZC) technologies, including PV arrays. FIT payments are made by the

electricity supplier to the electricity account holder. Payments were originally worth 48.07p/kWh for qualifying domestic and small

commercial arrays of up to 4kW. Early adopters still receive this rate, index linked to the retail price index (RPI) for 25 years, but a 20-year term applies to any PV installation post August 2012. The aim of the FIT was to increase

the take up of LZC technologies and reduce the cost of manufacturing, distributing and installing them. This has been achieved, with the cost of PV arrays dropping by around 40% of their price before the introduction of the FIT. Tariff rates have reduced but the drop in panel prices together with increased effi ciencies achieved more than compensate for this.

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yield. A compromise often has to be made between the panel’s angle of inclination and the amount of PVs installed on the roof space to prevent the panels over shading themselves. For example, reducing the panel angle to 15 degrees can result in a 20% increase in the number of panels on a fl at roof. On the practical side, the structural loadings and waterproofi ng of roofs should be checked prior to the design and installation of PV arrays as they can place signifi cant stress upon a roof through their weight, further exacerbated by wind loading. There are specialist non-ballasted mounting systems that respect the integrity of the weatherproofi ng available to solve this problem. Installing a cheaper, smaller and less

effi cient PV system may not be the best option over time, as usually extra upfront investment will provide a greater return over the lifespan of the system.

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In addition to the FIT, a payment of 4.77p/kWh, increasing to 4.85p/kWh on 1 April, is made for electricity exported to the grid. The quantity of electricity exported is generally metered for larger installations, but only deemed for small ones. Deeming is intended to reduce costs where the cost of a meter and data collection would form a signifi cant proportion of the value of the electricity exported. Owners also benefi t from the

avoided cost of electricity displaced by the PV array, which is typically in excess of 10p/kWh for domestic and small commercial premises. Payback of a PV system is currently around the eight-year mark, giving 12 years of FIT payments as an effective profi t.

Regardless of initial cost, most systems pay back in roughly the same timeframe, but the potential profi t becomes greater with higher quality systems. In addition, many local authorities that

have installed PV arrays on the roofs of primary schools have found them of educational interest to pupils as they raise awareness of environmental issues. As with other low and zero carbon (LZC) technologies, PV arrays can also assist in securing planning permission and meeting energy-saving targets. Solar PV arrays are arguably the simplest to integrate with buildings and their services, compared with other LZC technologies. The help is there, and it’s usually free,

to enable you to give your client the best possible advice. It is not often you can help the environment and make money for your client but with solar PV you can. CM

Rob Jackson is managing director at ICB.

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CPD test paper Photovoltaic panel installations

1. Which angle of inclination would perform best in UK?

● 5 degrees ● 30 degrees ● 45 degrees ● 60 degrees

2. Which scheme regulates the installers of PV systems? ● STA ● MCS

● BRE ● Constructionline

3. What is the current rate for PV energy exported to the grid? ● 4.77p/kWh ● 48.07p/kWh ● 13.5p/kWh ● 4.85p/kWh

4. What year was the feed-in tariff introduced? ● 2009

● 2011

● 2010 ● 2012

5. What is the life expectancy of PV panels? ● 8 years

● 10 years ● 15 years ● 25 years