It’s official – Feed-in Tariffs will end in 2019. If you want to invest in renewable electricity generation (such as a solar PV system) and hope to do so through using the FiTs scheme, you need to act quickly.

What is Solar PV?

There are two main types of solar PV cells that are suitable for domestic usage:

  • monocrystalline (made from a single silicon crystal): these are more efficient and more expensive, and often a bit smaller than equivalent polycrystalline systems
  • polycrystalline (made from many silicon crystals): these systems can be up to 20% cheaper. For larger roofs they may, therefore, be more financially attractive, but will produce less electricity than an equivalent rated mono system

How Does it Work?

A PV cell generates electricity by allowing light to pass through a silicon crystal. Because of its atomic structure, an electronic charge moves around inside the crystal in a random manner.

Arsenic and boron are added to the silicon and these impurities cause negative and positive molecules to join and encourage the flow of an electric charge in a single direction.

Bombarding the molecules with sunlight causes electrons to be released, increasing the electric current which can then be harvested.

What do I Need?

A typical domestic solar PV system will be something below 4kW maximum capacity, comprise 12 to 15 panels and cover an area of around 20m².

A solar PV system also includes an inverter. This is the heart of the system as it controls the panels and will determine how well or poorly it works. An inverter converts the variable direct current (DC) output of a PV array to a regulated alternating current (AC) that can be used in the home or exported to the grid.

There are three types of inverter available for domestic installations:

  • string inverter
  • micro inverter
  • battery inverter

Most good quality solar PV systems will offer micro inverters now, and these are generally the ones to go for.

How Much Do Solar PV Systems Cost?

The price of a 3.8kWp array (typical for a domestic installation) will be below £3,000, plus installation. Budget £4,500 to £5,000 for an installed system, connected to the grid.

How Much Can I Expect to Receive from FiTs Payments?

There are two tariffs:

The Feed in Tariff: The current tariff is 3.93p/kWh, and it is paid for each kWh of energy generated, regardless of what happens to that electricity.

The Export Tariff: This is the minimum figure paid for each kWh of electricity generated to the grid. This currently stands at 5.03p/kWh.

Expect a 3.8kWp system to generate £119 in FiTs income per year and £67 in export tariff income per year.

FiTs will end in 2019, so you need to be quick if you want to benefit from the scheme.

How Much Electricity Will a Solar PV System Generate?

A 3.8kWp PV system is likely to produce a little over 3,000kWh of electricity each year. The average UK household uses about 6,000kWh per year.

Do I need Planning Permission?

A change in legislation in 2008 allowed PV panels to be installed under Permitted Development, so planning permission is not needed unless:

  • the building is listed
  • viewed by a listed building
  • in a conservation area. If the house is in a conservation area it may be worth asking the local authority, as permission will sometimes be granted.

How do I Choose a Good Solar PV Supplier?

  • Check the supplier: do they have a good record? Take up references, speak to their former clients and check out the work
  • Use only MCS-accredited suppliers and equipment. The MCS scheme is run by the Government and both the equipment and installer must be accredited for the system to qualify for Feed-in Tariffs
  • Check out the price. Most reputable suppliers are coming in under £3,000/kWp for systems from 2kWp to 4kWp. Much more than that should ring alarm bells
  • Do your homework on Feed-in Tariffs (FiTs) — do not rely on the supplier to explain it all to you. Check that the amount you will get back justifies your investment
  • Use only brand name panels. With manufacturers like Sharp, Schüco, Kyocera, Solar Century and Romag, you know it will be a quality product that will last for decades

A Few Things to Bear in Mind

  • PV arrays are denoted as kWp. That is the peak output in kilowatts. A 4kWp array will produce 4kW output only in ideal conditions — on a bright, cloudless day. For the rest of the year it will produce somewhat less
  • The bigger the system, the lower the unit cost. The reason being that the ‘infrastructure’ such as cabling, scaffolding and the inverter costs pretty much the same whatever the system size (up to 4kWp)
  • Actual production will vary with the site and with the quality of the panels
  • Consider the power demands of various pieces of household equipment, the fluctuating output with passing seasons, and fact that we use most equipment in the evening. We can quickly see that the proportion of production we can actually use in the house is quite small. The figure used is typically 50% but that may not always reflect reality
  • PV panels degrade over time. Actual production can fall by more than 20% over 25 years (the duration of the FiT scheme)
  • PV panels take around 20 years to recover the CO2 emitted during their production. In both financial and CO2 terms, PV is a long-term investment

Beware Rent-a-Panel Options

Some companies offer to mount solar PV to your roof and give you ‘free’ electricity in return. While you might save a small amount of money on your electricity bill, the company will be making a lot more under FiTs.

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