Nestegg Solar Panel FAQs

Does solar PV work in the UK (in our famously average weather)

Yes. The technology used in modern solar panels has improved enormously in recent years (we know this because our Chief Techology Officer has a background in cell manufacture) and this means that even in the UK a decent solar system can produce a very significant proportion of a home's electricity usage. Furthermore, the Feed-in tariff is designed to give an average annual return on your investment of 9-10% making it beneficial to you as well as the environment.

How many solar panels do I need?

The average UK household uses 3-4000 kWh of electrical energy per year. A typical 2 kWp solar installation (which uses roughly 12 m2 of roof) will produce around 1700 kWh of energy per year in the UK. So to cover all of your household's energy requirements you'd need approximately 4-5 kWp of solar modules.

This is perfectly feasible on houses with suitable roofs but many houses will have space only for smaller systems, meaning the gap will have to come from energy efficiency improvements or other sources of renewable energy.

How can I get the most out of my installation?

For a given latitude, there is an optimum tilt angle for your solar panels. In the UK, the optimum angle of inclination is between 30 and 35 degrees. As the sun passes from east to west, it is best to have the solar panels facing south or as close to south as possible.

If you have a sloped roof, it makes sense to mount your solar panels at the same angle as the roof for ease and safety. If you have a flat roof we provide specialized racking systems that ensure your solar panels are mounted at the correct angle and secure from wind loads.

How important is shading?

Shading is important. Because the cells in each panel are connected in series, shading even a single cell can affect the whole system. This is one of the main reasons why you should make sure you use an installer with real, proven experience. At Engensa we are really proud to have installed the UK's first micro-converter installation. This is a new technology that allows each panel to operate individually, reducing the effects of shading. It's pretty high-tech but we'd be delighted to explain how it works and see if it might be suitable for your home.

Will a solar system affect the price of my house?

Yes. It should make it more valuable. After all, you'll have a power plant on the roof that will generate a fixed income for 25 years. At the very least, you can add all those subsidies onto the value of your property — after all they are guaranteed by the government.

How do I know how much energy my system will make?

Using state-of-the-art simulation software, we produce a detailed model of the output of the solar energy system. This simulation predicts the average amount of energy produced by the system by month and by year, which enables us to optimize the design to maximise performance. The software, which is based on data provided by the government, is also used to estimate the amount of revenue your PV system will generate over the whole year.

Are prices coming down and if so, why shouldn't I wait before installing solar?

Prices are absolutely coming down — and we're delighted about this. The whole point of the Feed-in tariff is to drive prices down to the point that it's cheaper to make electricity from solar panels than it is from horrible coal. However, for those who think they've spotted a clever way of benefitting from this — I'm afraid it isn't that simple. Once you have installed a system, the Feed-in tariff that you receive is fixed for 25 years and guaranteed by the government however, for new installations, the Tariff is designed to drop every year to reflect lower installation costs. The result is that a system installed in 20 years might be half the price but the Tariff will reflect this and be half of today's level — so the returns will be the same.

What is the Feed-in Tariff?

Feed-in tariffs (commonly abbreviated to FITs) were introduced in April 2010 as a means of stimulating take up of renewable technologies such as solar panels.

Under this scheme, householders and communities who generate their own electricity are guaranteed a minimum amount of money per kW hour, as well as a separate payment for the electricity exported to the grid.

To qualify, the solar panels must be installed by an MCS accredited company (which Engensa is). The current value per kW hour for homeowners is 43p which will be review in April 2012 or sooner if installation rates exceed forecasts.

How long will an installation take?

We typically take two days to install a solar system on someone's home. It can be shorter or longer if the system is bigger or smaller but it's a very quick process. In most cases we arrange to have scaffolding put up the day before the team arrives.

Will I need to re-decorate after my installation?

Absolutely not. In normal circumstances there is no need whatsoever to do any decoration after the installation and if, in the unusual circumstance, we cause any mess then we will put it right at our cost and as soon as humanly possible.

What happens if there is a power cut?

All our systems will turn off automatically during a power cut. This is a safeguard to stop the system exporting current to the grid when someone might be working on repairing it.

How much is an installation likely to cost?

The total cost will depend on how many panels you can fit on your roof, but most private homeowners invest between £7,000 and £14,000.

What if a tile on my roof is broken and needs repairing?

If you need to do some repair work on your roof after the panels have been installed and commissioned and need to remove them to do the work, you will need to contact an accredited MCS installer to remove them. We would, of course, be happy to help.

Do I need planning permission?

You will need planning permission if you want to put solar panels on a flat roof, if you are in a conservation area and your roof can be seen from the road.

Is your property listed?

If your home is listed, full consent is required before we can consider you for a free installation.

Is your property in a conservation area?

If you are in a conservation area and the South facing part of your roof is visible from the road, you will planning permission which must be granted before we can survey your property.