Our solar installers know that no two roofs are identical; and that’s exactly what we love about our work! Every property brings its own personality, challenges, and opportunities.

When our client approached us to expand the solar setup on their traditional Cornish cottage, they had a clear goal: boost their energy self-sufficiency during the darker months on either side of the summer peak.

Here's how we turned a complex roof space into an energy-generating powerhouse...

The Challenge

Our customer was already running a small 1.4kWp south-facing solar array which was installed back in 2012. While it covered their energy needs during peak summer, the combination of higher energy demands and less sunlight throughout the rest of the year left them relying on grid energy again.

They had an unused flat roof at the rear of the house, which could be used to expand their solar system, but it presented several hurdles:

1. Obstructed Roof Space: An old external hot water header tank sat right in the middle of the flat roof.

2. Severe Weather Exposure: As we all know, Cornish storms can bring some ferocious winter winds! Any mounting system needed to be exceptionally robust without penetrating or compromising the flat roof membrane.

3. Complex Shading: Chimneys on both gables, overhead power lines, and a large deciduous tree to the west cast heavy shadows across the roof throughout the day and year.

4. No Indoor Space for Equipment: In this traditional cottage, there was no suitable indoor space for an extra inverter.

5. An Awkward Roof Profile: The roof featured a physical step where the pitch changed near the middle, meaning standard, uniform solar panels couldn't span the space neatly.

The System Solution

Once the old header tank was removed and the roof made good, we had enough space to add roughly 4,000 watts of solar power (a 4kWp system). To overcome the shade, the harsh Cornish weather and the tight space, we custom-built a clever setup:

• Low-Profile East-West Framing System (K2 Dome): Instead of pointing all the panels south, we angled half to the east for morning sun, and half to the west for evening sun. Resting the panels at a gentle 10-degree tilt meant we could fit far more panels into the small flat space. It also made them more wind-resistant - we secured the whole setup using local paving slabs as heavy counterweights (ballast), meaning we didn't have to drill a single hole into the roof membrane.
• Panel-by-Panel Micro-Inverters (Enphase): Solar panels produce raw direct current (DC) power, but your home uses alternating current (AC). Normally, one large box (a 'string' inverter) sits inside the house and converts power for all the panels at once. Instead, we installed a tiny micro-inverter underneath every single panel. This turned each panel into its own independent mini solar station. All the power feeds directly to the home's main fuse box through a single cable, leaving just a tiny control box to tuck away under the stairs.
• Mix-and-Match Double-Sided Solar Panels (Bifacial Modules): Standard inverter systems force you to use identical panels, but micro-inverters let us mix and match. To fit around the roof dimensions and an awkward step in the roof pitch, we used panels of three different physical sizes and power ratings (575W, 500W, and 450W). Even better, these were double-sided (bifacial) panels that make electricity from light hitting both the front and the back.
• Solar-Reflective Roof Paint: To get the most out of those double-sided panels, we coated the flat roof underneath them with bright, light-reflecting paint. This bounces extra sunlight off the roof surface and straight onto the undersides of the panels for free extra energy!
• Smart Hot Water Diverter (myenergi eddi): Instead of sending unused solar energy straight back into the power grid, we connected the new setup to a smart device that automatically diverts excess power to heat the home's hot water cylinder, turning spare sunshine into free hot showers.

Install in progress, K2 mounting system with ballast and Enphase micro-inverters in place.

The solar array completed.

Weathering Cornish Storms

Cornish weather is known for putting building structures to the test, and this system didn't have to wait long for a trial.

In early 2026, Storm Goretti brought severe winds to the region. A nearby eucalyptus tree fell, dislodging a telegraph pole and dropping live powerlines directly onto part of the array.

Despite the direct impact and extreme gusts, the K2 ballasted mounting system didn't budge, keeping the installation safe and undamaged.

Beating the Shade with Micro-Inverters

On a central "string" inverter system, if one panel gets shaded, the output of the entire row drops down to match the weakest link. Micro-inverters solve this entirely.

During a late-afternoon monitoring test, shading from a western tree dropped one panel's output to just 67W. On a standard string inverter, the 4 panels on that side would have been throttled to 268W total (4 x 67W).

Thanks to the independent Enphase micro-inverters, each panel produced its individual maximum, bringing the West half of the array up to 739W; a massive 67% increase in power output compared to a traditional string inverter!

Smart Export Guarantee (SEG) Optimisation

To make sure our customer squeezed every penny out of both their old and new solar setups, we helped them re-organise how they get paid for their electricity.

Back in 2012, the government offered generous payments called the Feed-in Tariff (FiT) to encourage solar installations. We made sure our customer kept this original, high-paying rate for every single unit of power their old 1.4kWp system generates.

Instead of accepting a estimated default rate for sending spare energy back to the grid, we helped them switch to a Smart Export Guarantee (SEG) with Octopus Energy. Using a smart meter to measure exact output, Octopus pays a top-tier price for all the extra, unused electricity sent to the grid from both solar systems combined.

The Results

The numbers show just how effective this custom setup really is:

• Punching Above Its Weight: Because an East-West roof layout misses the direct noon sun, standard industry estimates predict a flat 10° setup will only produce about 85% of the power generated by a traditional, perfectly angled south-facing roof (35°). In its first full year, this system generated 3,858 kWh of clean electricity - hitting an impressive 90% of that ideal benchmark, even with heavy shade from nearby trees!
• Turning Summer Energy Into Profit: From May through August, the combined power exported to the grid from both systems completely wiped out the home's electricity costs, including daily grid connection fees. Aside from charging their electric vehicle, our customer actually earned a net profit of around £40 a month just from selling spare power.
• Free Hot Water by Breakfast: Thanks to the smart energy diverter, leftover solar power fully heats the 120-litre hot water tank by 9.30am on sunny mornings. Once the water is steaming hot, 100% of the solar generation for the rest of the day goes straight to the grid to boost those export profits.

"On the first anniversary of its installation, the system has generated 3,858kWh... Considering the amount of shading that affects the array, this is a fantastic result. The micro-inverters have definitely been very effective in countering the losses shading would normally incur."

Ready to See What’s Possible for Your Home?

Whether you have awkward shading, limited indoor space, or a complex roof layout, our expert of solar panel installers in Cornwall can design a tailored solar PV and storage solution to make the most of your home's energy independence.

Get in touch with the Natural Generation team today for your free quote